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2018-12-19Merge 4.4.168 into android-4.4Greg Kroah-Hartman
Changes in 4.4.168 ipv6: Check available headroom in ip6_xmit() even without options net: 8139cp: fix a BUG triggered by changing mtu with network traffic net: phy: don't allow __set_phy_supported to add unsupported modes net: Prevent invalid access to skb->prev in __qdisc_drop_all rtnetlink: ndo_dflt_fdb_dump() only work for ARPHRD_ETHER devices tcp: fix NULL ref in tail loss probe tun: forbid iface creation with rtnl ops neighbour: Avoid writing before skb->head in neigh_hh_output() ARM: OMAP2+: prm44xx: Fix section annotation on omap44xx_prm_enable_io_wakeup ARM: OMAP1: ams-delta: Fix possible use of uninitialized field sysv: return 'err' instead of 0 in __sysv_write_inode s390/cpum_cf: Reject request for sampling in event initialization hwmon: (ina2xx) Fix current value calculation ASoC: dapm: Recalculate audio map forcely when card instantiated hwmon: (w83795) temp4_type has writable permission Btrfs: send, fix infinite loop due to directory rename dependencies ASoC: omap-mcpdm: Add pm_qos handling to avoid under/overruns with CPU_IDLE ASoC: omap-dmic: Add pm_qos handling to avoid overruns with CPU_IDLE exportfs: do not read dentry after free bpf: fix check of allowed specifiers in bpf_trace_printk USB: omap_udc: use devm_request_irq() USB: omap_udc: fix crashes on probe error and module removal USB: omap_udc: fix omap_udc_start() on 15xx machines USB: omap_udc: fix USB gadget functionality on Palm Tungsten E KVM: x86: fix empty-body warnings net: thunderx: fix NULL pointer dereference in nic_remove ixgbe: recognize 1000BaseLX SFP modules as 1Gbps net: hisilicon: remove unexpected free_netdev drm/ast: fixed reading monitor EDID not stable issue xen: xlate_mmu: add missing header to fix 'W=1' warning fscache: fix race between enablement and dropping of object fscache, cachefiles: remove redundant variable 'cache' ocfs2: fix deadlock caused by ocfs2_defrag_extent() hfs: do not free node before using hfsplus: do not free node before using debugobjects: avoid recursive calls with kmemleak ocfs2: fix potential use after free pstore: Convert console write to use ->write_buf ALSA: pcm: remove SNDRV_PCM_IOCTL1_INFO internal command KVM: nVMX: fix msr bitmaps to prevent L2 from accessing L0 x2APIC KVM: nVMX: mark vmcs12 pages dirty on L2 exit KVM: nVMX: Eliminate vmcs02 pool KVM: VMX: introduce alloc_loaded_vmcs KVM: VMX: make MSR bitmaps per-VCPU KVM/x86: Add IBPB support KVM/VMX: Emulate MSR_IA32_ARCH_CAPABILITIES KVM/VMX: Allow direct access to MSR_IA32_SPEC_CTRL KVM/SVM: Allow direct access to MSR_IA32_SPEC_CTRL KVM/x86: Remove indirect MSR op calls from SPEC_CTRL x86: reorganize SMAP handling in user space accesses x86: fix SMAP in 32-bit environments x86: Introduce __uaccess_begin_nospec() and uaccess_try_nospec x86/usercopy: Replace open coded stac/clac with __uaccess_{begin, end} x86/uaccess: Use __uaccess_begin_nospec() and uaccess_try_nospec x86/bugs, KVM: Support the combination of guest and host IBRS x86/KVM/VMX: Expose SPEC_CTRL Bit(2) to the guest KVM: SVM: Move spec control call after restore of GS x86/bugs, KVM: Extend speculation control for VIRT_SPEC_CTRL x86/speculation: Use synthetic bits for IBRS/IBPB/STIBP KVM: SVM: Implement VIRT_SPEC_CTRL support for SSBD bpf: support 8-byte metafield access bpf/verifier: Add spi variable to check_stack_write() bpf/verifier: Pass instruction index to check_mem_access() and check_xadd() bpf: Prevent memory disambiguation attack wil6210: missing length check in wmi_set_ie posix-timers: Sanitize overrun handling mm/hugetlb.c: don't call region_abort if region_chg fails hugetlbfs: fix offset overflow in hugetlbfs mmap hugetlbfs: check for pgoff value overflow hugetlbfs: fix bug in pgoff overflow checking swiotlb: clean up reporting sr: pass down correctly sized SCSI sense buffer mm: remove write/force parameters from __get_user_pages_locked() mm: remove write/force parameters from __get_user_pages_unlocked() mm/nommu.c: Switch __get_user_pages_unlocked() to use __get_user_pages() mm: replace get_user_pages_unlocked() write/force parameters with gup_flags mm: replace get_user_pages_locked() write/force parameters with gup_flags mm: replace get_vaddr_frames() write/force parameters with gup_flags mm: replace get_user_pages() write/force parameters with gup_flags mm: replace __access_remote_vm() write parameter with gup_flags mm: replace access_remote_vm() write parameter with gup_flags proc: don't use FOLL_FORCE for reading cmdline and environment proc: do not access cmdline nor environ from file-backed areas media: dvb-frontends: fix i2c access helpers for KASAN matroxfb: fix size of memcpy staging: speakup: Replace strncpy with memcpy rocker: fix rocker_tlv_put_* functions for KASAN selftests: Move networking/timestamping from Documentation Linux 4.4.168 Change-Id: I71a633f645fada4b473abcff660a9ada3103592b Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-12-17mm: replace get_user_pages() write/force parameters with gup_flagsLorenzo Stoakes
commit 768ae309a96103ed02eb1e111e838c87854d8b51 upstream. This removes the 'write' and 'force' from get_user_pages() and replaces them with 'gup_flags' to make the use of FOLL_FORCE explicit in callers as use of this flag can result in surprising behaviour (and hence bugs) within the mm subsystem. Signed-off-by: Lorenzo Stoakes <lstoakes@gmail.com> Acked-by: Christian König <christian.koenig@amd.com> Acked-by: Jesper Nilsson <jesper.nilsson@axis.com> Acked-by: Michal Hocko <mhocko@suse.com> Reviewed-by: Jan Kara <jack@suse.cz> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [bwh: Backported to 4.4: - Drop changes in rapidio, vchiq, goldfish - Keep the "write" variable in amdgpu_ttm_tt_pin_userptr() as it's still needed - Also update calls from various other places that now use get_user_pages_remote() upstream, which were updated there by commit 9beae1ea8930 "mm: replace get_user_pages_remote() write/force ..." - Also update calls from hfi1 and ipath - Adjust context] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-12-13Merge 4.4.167 into android-4.4Greg Kroah-Hartman
Changes in 4.4.167 media: em28xx: Fix use-after-free when disconnecting Revert "wlcore: Add missing PM call for wlcore_cmd_wait_for_event_or_timeout()" rapidio/rionet: do not free skb before reading its length s390/qeth: fix length check in SNMP processing usbnet: ipheth: fix potential recvmsg bug and recvmsg bug 2 kvm: mmu: Fix race in emulated page table writes xtensa: enable coprocessors that are being flushed xtensa: fix coprocessor context offset definitions Btrfs: ensure path name is null terminated at btrfs_control_ioctl ALSA: wss: Fix invalid snd_free_pages() at error path ALSA: ac97: Fix incorrect bit shift at AC97-SPSA control write ALSA: control: Fix race between adding and removing a user element ALSA: sparc: Fix invalid snd_free_pages() at error path ext2: fix potential use after free dmaengine: at_hdmac: fix memory leak in at_dma_xlate() dmaengine: at_hdmac: fix module unloading btrfs: release metadata before running delayed refs USB: usb-storage: Add new IDs to ums-realtek usb: core: quirks: add RESET_RESUME quirk for Cherry G230 Stream series misc: mic/scif: fix copy-paste error in scif_create_remote_lookup Kbuild: suppress packed-not-aligned warning for default setting only exec: avoid gcc-8 warning for get_task_comm disable stringop truncation warnings for now kobject: Replace strncpy with memcpy unifdef: use memcpy instead of strncpy kernfs: Replace strncpy with memcpy ip_tunnel: Fix name string concatenate in __ip_tunnel_create() drm: gma500: fix logic error scsi: bfa: convert to strlcpy/strlcat staging: rts5208: fix gcc-8 logic error warning kdb: use memmove instead of overlapping memcpy iser: set sector for ambiguous mr status errors uprobes: Fix handle_swbp() vs. unregister() + register() race once more MIPS: ralink: Fix mt7620 nd_sd pinmux mips: fix mips_get_syscall_arg o32 check drm/ast: Fix incorrect free on ioregs scsi: scsi_devinfo: cleanly zero-pad devinfo strings ALSA: trident: Suppress gcc string warning scsi: csiostor: Avoid content leaks and casts kgdboc: Fix restrict error kgdboc: Fix warning with module build leds: call led_pwm_set() in leds-pwm to enforce default LED_OFF leds: turn off the LED and wait for completion on unregistering LED class device leds: leds-gpio: Fix return value check in create_gpio_led() Input: xpad - quirk all PDP Xbox One gamepads Input: matrix_keypad - check for errors from of_get_named_gpio() Input: elan_i2c - add ELAN0620 to the ACPI table Input: elan_i2c - add ACPI ID for Lenovo IdeaPad 330-15ARR Input: elan_i2c - add support for ELAN0621 touchpad btrfs: Always try all copies when reading extent buffers Btrfs: fix use-after-free when dumping free space ARC: change defconfig defaults to ARCv2 arc: [devboards] Add support of NFSv3 ACL mm: cleancache: fix corruption on missed inode invalidation mm: mlock: avoid increase mm->locked_vm on mlock() when already mlock2(,MLOCK_ONFAULT) usb: gadget: dummy: fix nonsensical comparisons iommu/vt-d: Fix NULL pointer dereference in prq_event_thread() iommu/ipmmu-vmsa: Fix crash on early domain free can: rcar_can: Fix erroneous registration batman-adv: Expand merged fragment buffer for full packet bnx2x: Assign unique DMAE channel number for FW DMAE transactions. qed: Fix PTT leak in qed_drain() qed: Fix reading wrong value in loop condition net/mlx4_core: Zero out lkey field in SW2HW_MPT fw command net/mlx4_core: Fix uninitialized variable compilation warning net/mlx4: Fix UBSAN warning of signed integer overflow net: faraday: ftmac100: remove netif_running(netdev) check before disabling interrupts iommu/vt-d: Use memunmap to free memremap net: amd: add missing of_node_put() usb: quirk: add no-LPM quirk on SanDisk Ultra Flair device usb: appledisplay: Add 27" Apple Cinema Display USB: check usb_get_extra_descriptor for proper size ALSA: usb-audio: Fix UAF decrement if card has no live interfaces in card.c ALSA: hda: Add support for AMD Stoney Ridge ALSA: pcm: Fix starvation on down_write_nonblock() ALSA: pcm: Call snd_pcm_unlink() conditionally at closing ALSA: pcm: Fix interval evaluation with openmin/max virtio/s390: avoid race on vcdev->config virtio/s390: fix race in ccw_io_helper() SUNRPC: Fix leak of krb5p encode pages xhci: Prevent U1/U2 link pm states if exit latency is too long Staging: lustre: remove two build warnings cifs: Fix separator when building path from dentry tty: serial: 8250_mtk: always resume the device in probe. kgdboc: fix KASAN global-out-of-bounds bug in param_set_kgdboc_var() mac80211_hwsim: Timer should be initialized before device registered mac80211: Clear beacon_int in ieee80211_do_stop mac80211: ignore tx status for PS stations in ieee80211_tx_status_ext mac80211: fix reordering of buffered broadcast packets mac80211: ignore NullFunc frames in the duplicate detection Linux 4.4.167 Change-Id: Ib893e2bb7e739960eed0710447033f7ab65dab4f Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2018-12-13exec: avoid gcc-8 warning for get_task_commArnd Bergmann
commit 3756f6401c302617c5e091081ca4d26ab604bec5 upstream. gcc-8 warns about using strncpy() with the source size as the limit: fs/exec.c:1223:32: error: argument to 'sizeof' in 'strncpy' call is the same expression as the source; did you mean to use the size of the destination? [-Werror=sizeof-pointer-memaccess] This is indeed slightly suspicious, as it protects us from source arguments without NUL-termination, but does not guarantee that the destination is terminated. This keeps the strncpy() to ensure we have properly padded target buffer, but ensures that we use the correct length, by passing the actual length of the destination buffer as well as adding a build-time check to ensure it is exactly TASK_COMM_LEN. There are only 23 callsites which I all reviewed to ensure this is currently the case. We could get away with doing only the check or passing the right length, but it doesn't hurt to do both. Link: http://lkml.kernel.org/r/20171205151724.1764896-1-arnd@arndb.de Signed-off-by: Arnd Bergmann <arnd@arndb.de> Suggested-by: Kees Cook <keescook@chromium.org> Acked-by: Kees Cook <keescook@chromium.org> Acked-by: Ingo Molnar <mingo@kernel.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Serge Hallyn <serge@hallyn.com> Cc: James Morris <james.l.morris@oracle.com> Cc: Aleksa Sarai <asarai@suse.de> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Frederic Weisbecker <frederic@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-07-21Merge 4.4.78 into android-4.4Greg Kroah-Hartman
Changes in 4.4.78 net_sched: fix error recovery at qdisc creation net: sched: Fix one possible panic when no destroy callback net/phy: micrel: configure intterupts after autoneg workaround ipv6: avoid unregistering inet6_dev for loopback net: dp83640: Avoid NULL pointer dereference. tcp: reset sk_rx_dst in tcp_disconnect() net: prevent sign extension in dev_get_stats() bpf: prevent leaking pointer via xadd on unpriviledged net: handle NAPI_GRO_FREE_STOLEN_HEAD case also in napi_frags_finish() ipv6: dad: don't remove dynamic addresses if link is down net: ipv6: Compare lwstate in detecting duplicate nexthops vrf: fix bug_on triggered by rx when destroying a vrf rds: tcp: use sock_create_lite() to create the accept socket brcmfmac: fix possible buffer overflow in brcmf_cfg80211_mgmt_tx() cfg80211: Define nla_policy for NL80211_ATTR_LOCAL_MESH_POWER_MODE cfg80211: Validate frequencies nested in NL80211_ATTR_SCAN_FREQUENCIES cfg80211: Check if PMKID attribute is of expected size irqchip/gic-v3: Fix out-of-bound access in gic_set_affinity parisc: Report SIGSEGV instead of SIGBUS when running out of stack parisc: use compat_sys_keyctl() parisc: DMA API: return error instead of BUG_ON for dma ops on non dma devs parisc/mm: Ensure IRQs are off in switch_mm() tools/lib/lockdep: Reduce MAX_LOCK_DEPTH to avoid overflowing lock_chain/: Depth kernel/extable.c: mark core_kernel_text notrace mm/list_lru.c: fix list_lru_count_node() to be race free fs/dcache.c: fix spin lockup issue on nlru->lock checkpatch: silence perl 5.26.0 unescaped left brace warnings binfmt_elf: use ELF_ET_DYN_BASE only for PIE arm: move ELF_ET_DYN_BASE to 4MB arm64: move ELF_ET_DYN_BASE to 4GB / 4MB powerpc: move ELF_ET_DYN_BASE to 4GB / 4MB s390: reduce ELF_ET_DYN_BASE exec: Limit arg stack to at most 75% of _STK_LIM vt: fix unchecked __put_user() in tioclinux ioctls mnt: In umount propagation reparent in a separate pass mnt: In propgate_umount handle visiting mounts in any order mnt: Make propagate_umount less slow for overlapping mount propagation trees selftests/capabilities: Fix the test_execve test tpm: Get rid of chip->pdev tpm: Provide strong locking for device removal Add "shutdown" to "struct class". tpm: Issue a TPM2_Shutdown for TPM2 devices. mm: fix overflow check in expand_upwards() crypto: talitos - Extend max key length for SHA384/512-HMAC and AEAD crypto: atmel - only treat EBUSY as transient if backlog crypto: sha1-ssse3 - Disable avx2 crypto: caam - fix signals handling sched/topology: Fix overlapping sched_group_mask sched/topology: Optimize build_group_mask() PM / wakeirq: Convert to SRCU PM / QoS: return -EINVAL for bogus strings tracing: Use SOFTIRQ_OFFSET for softirq dectection for more accurate results KVM: x86: disable MPX if host did not enable MPX XSAVE features kvm: vmx: Do not disable intercepts for BNDCFGS kvm: x86: Guest BNDCFGS requires guest MPX support kvm: vmx: Check value written to IA32_BNDCFGS kvm: vmx: allow host to access guest MSR_IA32_BNDCFGS Linux 4.4.78 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-07-21exec: Limit arg stack to at most 75% of _STK_LIMKees Cook
commit da029c11e6b12f321f36dac8771e833b65cec962 upstream. To avoid pathological stack usage or the need to special-case setuid execs, just limit all arg stack usage to at most 75% of _STK_LIM (6MB). Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-06-29Merge 4.4.75 into android-4.4Greg Kroah-Hartman
Changes in 4.4.75 fs/exec.c: account for argv/envp pointers autofs: sanity check status reported with AUTOFS_DEV_IOCTL_FAIL lib/cmdline.c: fix get_options() overflow while parsing ranges KVM: PPC: Book3S HV: Preserve userspace HTM state properly CIFS: Improve readdir verbosity HID: Add quirk for Dell PIXART OEM mouse signal: Only reschedule timers on signals timers have sent powerpc/kprobes: Pause function_graph tracing during jprobes handling Input: i8042 - add Fujitsu Lifebook AH544 to notimeout list time: Fix clock->read(clock) race around clocksource changes target: Fix kref->refcount underflow in transport_cmd_finish_abort iscsi-target: Reject immediate data underflow larger than SCSI transfer length drm/radeon: add a PX quirk for another K53TK variant drm/radeon: add a quirk for Toshiba Satellite L20-183 drm/amdgpu/atom: fix ps allocation size for EnableDispPowerGating drm/amdgpu: adjust default display clock USB: usbip: fix nonconforming hub descriptor rxrpc: Fix several cases where a padded len isn't checked in ticket decode of: Add check to of_scan_flat_dt() before accessing initial_boot_params mtd: spi-nor: fix spansion quad enable powerpc/slb: Force a full SLB flush when we insert for a bad EA usb: gadget: f_fs: avoid out of bounds access on comp_desc net: phy: Initialize mdio clock at probe function net: phy: fix marvell phy status reading nvme/quirk: Add a delay before checking for adapter readiness nvme: apply DELAY_BEFORE_CHK_RDY quirk at probe time too Linux 4.4.75 Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>
2017-06-29fs/exec.c: account for argv/envp pointersKees Cook
commit 98da7d08850fb8bdeb395d6368ed15753304aa0c upstream. When limiting the argv/envp strings during exec to 1/4 of the stack limit, the storage of the pointers to the strings was not included. This means that an exec with huge numbers of tiny strings could eat 1/4 of the stack limit in strings and then additional space would be later used by the pointers to the strings. For example, on 32-bit with a 8MB stack rlimit, an exec with 1677721 single-byte strings would consume less than 2MB of stack, the max (8MB / 4) amount allowed, but the pointers to the strings would consume the remaining additional stack space (1677721 * 4 == 6710884). The result (1677721 + 6710884 == 8388605) would exhaust stack space entirely. Controlling this stack exhaustion could result in pathological behavior in setuid binaries (CVE-2017-1000365). [akpm@linux-foundation.org: additional commenting from Kees] Fixes: b6a2fea39318 ("mm: variable length argument support") Link: http://lkml.kernel.org/r/20170622001720.GA32173@beast Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Rik van Riel <riel@redhat.com> Acked-by: Michal Hocko <mhocko@suse.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Qualys Security Advisory <qsa@qualys.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-02-15Merge remote-tracking branch 'common/android-4.4' into android-4.4.yDmitry Shmidt
Change-Id: Icf907f5067fb6da5935ab0d3271df54b8d5df405
2017-01-26ANDROID: vfs: Add permission2 for filesystems with per mount permissionsDaniel Rosenberg
This allows filesystems to use their mount private data to influence the permssions they return in permission2. It has been separated into a new call to avoid disrupting current permission users. Change-Id: I9d416e3b8b6eca84ef3e336bd2af89ddd51df6ca Signed-off-by: Daniel Rosenberg <drosen@google.com>
2017-01-06exec: Ensure mm->user_ns contains the execed filesEric W. Biederman
commit f84df2a6f268de584a201e8911384a2d244876e3 upstream. When the user namespace support was merged the need to prevent ptrace from revealing the contents of an unreadable executable was overlooked. Correct this oversight by ensuring that the executed file or files are in mm->user_ns, by adjusting mm->user_ns. Use the new function privileged_wrt_inode_uidgid to see if the executable is a member of the user namespace, and as such if having CAP_SYS_PTRACE in the user namespace should allow tracing the executable. If not update mm->user_ns to the parent user namespace until an appropriate parent is found. Reported-by: Jann Horn <jann@thejh.net> Fixes: 9e4a36ece652 ("userns: Fail exec for suid and sgid binaries with ids outside our user namespace.") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06fs: exec: apply CLOEXEC before changing dumpable task flagsAleksa Sarai
commit 613cc2b6f272c1a8ad33aefa21cad77af23139f7 upstream. If you have a process that has set itself to be non-dumpable, and it then undergoes exec(2), any CLOEXEC file descriptors it has open are "exposed" during a race window between the dumpable flags of the process being reset for exec(2) and CLOEXEC being applied to the file descriptors. This can be exploited by a process by attempting to access /proc/<pid>/fd/... during this window, without requiring CAP_SYS_PTRACE. The race in question is after set_dumpable has been (for get_link, though the trace is basically the same for readlink): [vfs] -> proc_pid_link_inode_operations.get_link -> proc_pid_get_link -> proc_fd_access_allowed -> ptrace_may_access(task, PTRACE_MODE_READ_FSCREDS); Which will return 0, during the race window and CLOEXEC file descriptors will still be open during this window because do_close_on_exec has not been called yet. As a result, the ordering of these calls should be reversed to avoid this race window. This is of particular concern to container runtimes, where joining a PID namespace with file descriptors referring to the host filesystem can result in security issues (since PRCTL_SET_DUMPABLE doesn't protect against access of CLOEXEC file descriptors -- file descriptors which may reference filesystem objects the container shouldn't have access to). Cc: dev@opencontainers.org Cc: <stable@vger.kernel.org> # v3.2+ Reported-by: Michael Crosby <crosbymichael@gmail.com> Signed-off-by: Aleksa Sarai <asarai@suse.de> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2017-01-06ptrace: Capture the ptracer's creds not PT_PTRACE_CAPEric W. Biederman
commit 64b875f7ac8a5d60a4e191479299e931ee949b67 upstream. When the flag PT_PTRACE_CAP was added the PTRACE_TRACEME path was overlooked. This can result in incorrect behavior when an application like strace traces an exec of a setuid executable. Further PT_PTRACE_CAP does not have enough information for making good security decisions as it does not report which user namespace the capability is in. This has already allowed one mistake through insufficient granulariy. I found this issue when I was testing another corner case of exec and discovered that I could not get strace to set PT_PTRACE_CAP even when running strace as root with a full set of caps. This change fixes the above issue with strace allowing stracing as root a setuid executable without disabling setuid. More fundamentaly this change allows what is allowable at all times, by using the correct information in it's decision. Fixes: 4214e42f96d4 ("v2.4.9.11 -> v2.4.9.12") Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2015-07-10vfs: Commit to never having exectuables on proc and sysfs.Eric W. Biederman
Today proc and sysfs do not contain any executable files. Several applications today mount proc or sysfs without noexec and nosuid and then depend on there being no exectuables files on proc or sysfs. Having any executable files show on proc or sysfs would cause a user space visible regression, and most likely security problems. Therefore commit to never allowing executables on proc and sysfs by adding a new flag to mark them as filesystems without executables and enforce that flag. Test the flag where MNT_NOEXEC is tested today, so that the only user visible effect will be that exectuables will be treated as if the execute bit is cleared. The filesystems proc and sysfs do not currently incoporate any executable files so this does not result in any user visible effects. This makes it unnecessary to vet changes to proc and sysfs tightly for adding exectuable files or changes to chattr that would modify existing files, as no matter what the individual file say they will not be treated as exectuable files by the vfs. Not having to vet changes to closely is important as without this we are only one proc_create call (or another goof up in the implementation of notify_change) from having problematic executables on proc. Those mistakes are all too easy to make and would create a situation where there are security issues or the assumptions of some program having to be broken (and cause userspace regressions). Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2015-05-12parisc,metag: Fix crashes due to stack randomization on stack-grows-upwards ↵Helge Deller
architectures On architectures where the stack grows upwards (CONFIG_STACK_GROWSUP=y, currently parisc and metag only) stack randomization sometimes leads to crashes when the stack ulimit is set to lower values than STACK_RND_MASK (which is 8 MB by default if not defined in arch-specific headers). The problem is, that when the stack vm_area_struct is set up in fs/exec.c, the additional space needed for the stack randomization (as defined by the value of STACK_RND_MASK) was not taken into account yet and as such, when the stack randomization code added a random offset to the stack start, the stack effectively got smaller than what the user defined via rlimit_max(RLIMIT_STACK) which then sometimes leads to out-of-stack situations and crashes. This patch fixes it by adding the maximum possible amount of memory (based on STACK_RND_MASK) which theoretically could be added by the stack randomization code to the initial stack size. That way, the user-defined stack size is always guaranteed to be at minimum what is defined via rlimit_max(RLIMIT_STACK). This bug is currently not visible on the metag architecture, because on metag STACK_RND_MASK is defined to 0 which effectively disables stack randomization. The changes to fs/exec.c are inside an "#ifdef CONFIG_STACK_GROWSUP" section, so it does not affect other platformws beside those where the stack grows upwards (parisc and metag). Signed-off-by: Helge Deller <deller@gmx.de> Cc: linux-parisc@vger.kernel.org Cc: James Hogan <james.hogan@imgtec.com> Cc: linux-metag@vger.kernel.org Cc: stable@vger.kernel.org # v3.16+
2015-04-19fs: take i_mutex during prepare_binprm for set[ug]id executablesJann Horn
This prevents a race between chown() and execve(), where chowning a setuid-user binary to root would momentarily make the binary setuid root. This patch was mostly written by Linus Torvalds. Signed-off-by: Jann Horn <jann@thejh.net> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17fs/exec.c:de_thread: move notify_count write under lockKirill Tkhai
We set sig->notify_count = -1 between RELEASE and ACQUIRE operations: spin_unlock_irq(lock); ... if (!thread_group_leader(tsk)) { ... for (;;) { sig->notify_count = -1; write_lock_irq(&tasklist_lock); There are no restriction on it so other processors may see this STORE mixed with other STOREs in both areas limited by the spinlocks. Probably, it may be reordered with the above sig->group_exit_task = tsk; sig->notify_count = zap_other_threads(tsk); in some way. Set it under tasklist_lock locked to be sure nothing will be reordered. Signed-off-by: Kirill Tkhai <ktkhai@parallels.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-04-17prctl: avoid using mmap_sem for exe_file serializationDavidlohr Bueso
Oleg cleverly suggested using xchg() to set the new mm->exe_file instead of calling set_mm_exe_file() which requires some form of serialization -- mmap_sem in this case. For archs that do not have atomic rmw instructions we still fallback to a spinlock alternative, so this should always be safe. As such, we only need the mmap_sem for looking up the backing vm_file, which can be done sharing the lock. Naturally, this means we need to manually deal with both the new and old file reference counting, and we need not worry about the MMF_EXE_FILE_CHANGED bits, which can probably be deleted in the future anyway. Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Suggested-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-01-23fs: create proper filename objects using getname_kernel()Paul Moore
There are several areas in the kernel that create temporary filename objects using the following pattern: int func(const char *name) { struct filename *file = { .name = name }; ... return 0; } ... which for the most part works okay, but it causes havoc within the audit subsystem as the filename object does not persist beyond the lifetime of the function. This patch converts all of these temporary filename objects into proper filename objects using getname_kernel() and putname() which ensure that the filename object persists until the audit subsystem is finished with it. Also, a special thanks to Al Viro, Guenter Roeck, and Sabrina Dubroca for helping resolve a difficult kernel panic on boot related to a use-after-free problem in kern_path_create(); the thread can be seen at the link below: * https://lkml.org/lkml/2015/1/20/710 This patch includes code that was either based on, or directly written by Al in the above thread. CC: viro@zeniv.linux.org.uk CC: linux@roeck-us.net CC: sd@queasysnail.net CC: linux-fsdevel@vger.kernel.org Signed-off-by: Paul Moore <pmoore@redhat.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-12-13syscalls: implement execveat() system callDavid Drysdale
This patchset adds execveat(2) for x86, and is derived from Meredydd Luff's patch from Sept 2012 (https://lkml.org/lkml/2012/9/11/528). The primary aim of adding an execveat syscall is to allow an implementation of fexecve(3) that does not rely on the /proc filesystem, at least for executables (rather than scripts). The current glibc version of fexecve(3) is implemented via /proc, which causes problems in sandboxed or otherwise restricted environments. Given the desire for a /proc-free fexecve() implementation, HPA suggested (https://lkml.org/lkml/2006/7/11/556) that an execveat(2) syscall would be an appropriate generalization. Also, having a new syscall means that it can take a flags argument without back-compatibility concerns. The current implementation just defines the AT_EMPTY_PATH and AT_SYMLINK_NOFOLLOW flags, but other flags could be added in future -- for example, flags for new namespaces (as suggested at https://lkml.org/lkml/2006/7/11/474). Related history: - https://lkml.org/lkml/2006/12/27/123 is an example of someone realizing that fexecve() is likely to fail in a chroot environment. - http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=514043 covered documenting the /proc requirement of fexecve(3) in its manpage, to "prevent other people from wasting their time". - https://bugzilla.redhat.com/show_bug.cgi?id=241609 described a problem where a process that did setuid() could not fexecve() because it no longer had access to /proc/self/fd; this has since been fixed. This patch (of 4): Add a new execveat(2) system call. execveat() is to execve() as openat() is to open(): it takes a file descriptor that refers to a directory, and resolves the filename relative to that. In addition, if the filename is empty and AT_EMPTY_PATH is specified, execveat() executes the file to which the file descriptor refers. This replicates the functionality of fexecve(), which is a system call in other UNIXen, but in Linux glibc it depends on opening "/proc/self/fd/<fd>" (and so relies on /proc being mounted). The filename fed to the executed program as argv[0] (or the name of the script fed to a script interpreter) will be of the form "/dev/fd/<fd>" (for an empty filename) or "/dev/fd/<fd>/<filename>", effectively reflecting how the executable was found. This does however mean that execution of a script in a /proc-less environment won't work; also, script execution via an O_CLOEXEC file descriptor fails (as the file will not be accessible after exec). Based on patches by Meredydd Luff. Signed-off-by: David Drysdale <drysdale@google.com> Cc: Meredydd Luff <meredydd@senatehouse.org> Cc: Shuah Khan <shuah.kh@samsung.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Ingo Molnar <mingo@redhat.com> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Kees Cook <keescook@chromium.org> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Rich Felker <dalias@aerifal.cx> Cc: Christoph Hellwig <hch@infradead.org> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-11-18fs: Do not include mpx.h in exec.cDave Hansen
We no longer need mpx.h in exec.c. This will obviously also break the build for non-x86 builds. We get the MPX includes that we need from mmu_context.h now. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20141118003608.837015B3@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-11-18x86, mpx: On-demand kernel allocation of bounds tablesDave Hansen
This is really the meat of the MPX patch set. If there is one patch to review in the entire series, this is the one. There is a new ABI here and this kernel code also interacts with userspace memory in a relatively unusual manner. (small FAQ below). Long Description: This patch adds two prctl() commands to provide enable or disable the management of bounds tables in kernel, including on-demand kernel allocation (See the patch "on-demand kernel allocation of bounds tables") and cleanup (See the patch "cleanup unused bound tables"). Applications do not strictly need the kernel to manage bounds tables and we expect some applications to use MPX without taking advantage of this kernel support. This means the kernel can not simply infer whether an application needs bounds table management from the MPX registers. The prctl() is an explicit signal from userspace. PR_MPX_ENABLE_MANAGEMENT is meant to be a signal from userspace to require kernel's help in managing bounds tables. PR_MPX_DISABLE_MANAGEMENT is the opposite, meaning that userspace don't want kernel's help any more. With PR_MPX_DISABLE_MANAGEMENT, the kernel won't allocate and free bounds tables even if the CPU supports MPX. PR_MPX_ENABLE_MANAGEMENT will fetch the base address of the bounds directory out of a userspace register (bndcfgu) and then cache it into a new field (->bd_addr) in the 'mm_struct'. PR_MPX_DISABLE_MANAGEMENT will set "bd_addr" to an invalid address. Using this scheme, we can use "bd_addr" to determine whether the management of bounds tables in kernel is enabled. Also, the only way to access that bndcfgu register is via an xsaves, which can be expensive. Caching "bd_addr" like this also helps reduce the cost of those xsaves when doing table cleanup at munmap() time. Unfortunately, we can not apply this optimization to #BR fault time because we need an xsave to get the value of BNDSTATUS. ==== Why does the hardware even have these Bounds Tables? ==== MPX only has 4 hardware registers for storing bounds information. If MPX-enabled code needs more than these 4 registers, it needs to spill them somewhere. It has two special instructions for this which allow the bounds to be moved between the bounds registers and some new "bounds tables". They are similar conceptually to a page fault and will be raised by the MPX hardware during both bounds violations or when the tables are not present. This patch handles those #BR exceptions for not-present tables by carving the space out of the normal processes address space (essentially calling the new mmap() interface indroduced earlier in this patch set.) and then pointing the bounds-directory over to it. The tables *need* to be accessed and controlled by userspace because the instructions for moving bounds in and out of them are extremely frequent. They potentially happen every time a register pointing to memory is dereferenced. Any direct kernel involvement (like a syscall) to access the tables would obviously destroy performance. ==== Why not do this in userspace? ==== This patch is obviously doing this allocation in the kernel. However, MPX does not strictly *require* anything in the kernel. It can theoretically be done completely from userspace. Here are a few ways this *could* be done. I don't think any of them are practical in the real-world, but here they are. Q: Can virtual space simply be reserved for the bounds tables so that we never have to allocate them? A: As noted earlier, these tables are *HUGE*. An X-GB virtual area needs 4*X GB of virtual space, plus 2GB for the bounds directory. If we were to preallocate them for the 128TB of user virtual address space, we would need to reserve 512TB+2GB, which is larger than the entire virtual address space today. This means they can not be reserved ahead of time. Also, a single process's pre-popualated bounds directory consumes 2GB of virtual *AND* physical memory. IOW, it's completely infeasible to prepopulate bounds directories. Q: Can we preallocate bounds table space at the same time memory is allocated which might contain pointers that might eventually need bounds tables? A: This would work if we could hook the site of each and every memory allocation syscall. This can be done for small, constrained applications. But, it isn't practical at a larger scale since a given app has no way of controlling how all the parts of the app might allocate memory (think libraries). The kernel is really the only place to intercept these calls. Q: Could a bounds fault be handed to userspace and the tables allocated there in a signal handler instead of in the kernel? A: (thanks to tglx) mmap() is not on the list of safe async handler functions and even if mmap() would work it still requires locking or nasty tricks to keep track of the allocation state there. Having ruled out all of the userspace-only approaches for managing bounds tables that we could think of, we create them on demand in the kernel. Based-on-patch-by: Qiaowei Ren <qiaowei.ren@intel.com> Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Cc: linux-mm@kvack.org Cc: linux-mips@linux-mips.org Cc: Dave Hansen <dave@sr71.net> Link: http://lkml.kernel.org/r/20141114151829.AD4310DE@viggo.jf.intel.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
2014-10-09handle suicide on late failure exits in execve() in search_binary_handler()Al Viro
... rather than doing that in the guts of ->load_binary(). [updated to fix the bug spotted by Shentino - for SIGSEGV we really need something stronger than send_sig_info(); again, better do that in one place] Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-08-08fork/exec: cleanup mm initializationVladimir Davydov
mm initialization on fork/exec is spread all over the place, which makes the code look inconsistent. We have mm_init(), which is supposed to init/nullify mm's internals, but it doesn't init all the fields it should: - on fork ->mmap,mm_rb,vmacache_seqnum,map_count,mm_cpumask,locked_vm are zeroed in dup_mmap(); - on fork ->pmd_huge_pte is zeroed in dup_mm(), immediately before calling mm_init(); - ->cpu_vm_mask_var ptr is initialized by mm_init_cpumask(), which is called before mm_init() on both fork and exec; - ->context is initialized by init_new_context(), which is called after mm_init() on both fork and exec; Let's consolidate all the initializations in mm_init() to make the code look cleaner. Signed-off-by: Vladimir Davydov <vdavydov@parallels.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: David Rientjes <rientjes@google.com> Cc: Christoph Lameter <cl@linux.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-07-18seccomp: implement SECCOMP_FILTER_FLAG_TSYNCKees Cook
Applying restrictive seccomp filter programs to large or diverse codebases often requires handling threads which may be started early in the process lifetime (e.g., by code that is linked in). While it is possible to apply permissive programs prior to process start up, it is difficult to further restrict the kernel ABI to those threads after that point. This change adds a new seccomp syscall flag to SECCOMP_SET_MODE_FILTER for synchronizing thread group seccomp filters at filter installation time. When calling seccomp(SECCOMP_SET_MODE_FILTER, SECCOMP_FILTER_FLAG_TSYNC, filter) an attempt will be made to synchronize all threads in current's threadgroup to its new seccomp filter program. This is possible iff all threads are using a filter that is an ancestor to the filter current is attempting to synchronize to. NULL filters (where the task is running as SECCOMP_MODE_NONE) are also treated as ancestors allowing threads to be transitioned into SECCOMP_MODE_FILTER. If prctrl(PR_SET_NO_NEW_PRIVS, ...) has been set on the calling thread, no_new_privs will be set for all synchronized threads too. On success, 0 is returned. On failure, the pid of one of the failing threads will be returned and no filters will have been applied. The race conditions against another thread are: - requesting TSYNC (already handled by sighand lock) - performing a clone (already handled by sighand lock) - changing its filter (already handled by sighand lock) - calling exec (handled by cred_guard_mutex) The clone case is assisted by the fact that new threads will have their seccomp state duplicated from their parent before appearing on the tasklist. Holding cred_guard_mutex means that seccomp filters cannot be assigned while in the middle of another thread's exec (potentially bypassing no_new_privs or similar). The call to de_thread() may kill threads waiting for the mutex. Changes across threads to the filter pointer includes a barrier. Based on patches by Will Drewry. Suggested-by: Julien Tinnes <jln@chromium.org> Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net>
2014-07-18sched: move no_new_privs into new atomic flagsKees Cook
Since seccomp transitions between threads requires updates to the no_new_privs flag to be atomic, the flag must be part of an atomic flag set. This moves the nnp flag into a separate task field, and introduces accessors. Signed-off-by: Kees Cook <keescook@chromium.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Reviewed-by: Andy Lutomirski <luto@amacapital.net>
2014-06-06perf: Differentiate exec() and non-exec() comm eventsAdrian Hunter
perf tools like 'perf report' can aggregate samples by comm strings, which generally works. However, there are other potential use-cases. For example, to pair up 'calls' with 'returns' accurately (from branch events like Intel BTS) it is necessary to identify whether the process has exec'd. Although a comm event is generated when an 'exec' happens it is also generated whenever the comm string is changed on a whim (e.g. by prctl PR_SET_NAME). This patch adds a flag to the comm event to differentiate one case from the other. In order to determine whether the kernel supports the new flag, a selection bit named 'exec' is added to struct perf_event_attr. The bit does nothing but will cause perf_event_open() to fail if the bit is set on kernels that do not have it defined. Signed-off-by: Adrian Hunter <adrian.hunter@intel.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Link: http://lkml.kernel.org/r/537D9EBE.7030806@intel.com Cc: Paul Mackerras <paulus@samba.org> Cc: Dave Jones <davej@redhat.com> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-06-06perf: Fix perf_event_comm() vs. exec() assumptionPeter Zijlstra
perf_event_comm() assumes that set_task_comm() is only called on exec(), and in particular that its only called on current. Neither are true, as Dave reported a WARN triggered by set_task_comm() being called on !current. Separate the exec() hook from the comm hook. Reported-by: Dave Jones <davej@redhat.com> Signed-off-by: Peter Zijlstra <peterz@infradead.org> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Arnaldo Carvalho de Melo <acme@kernel.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: linux-fsdevel@vger.kernel.org Cc: linux-kernel@vger.kernel.org Link: http://lkml.kernel.org/r/20140521153219.GH5226@laptop.programming.kicks-ass.net [ Build fix. ] Signed-off-by: Ingo Molnar <mingo@kernel.org>
2014-05-15metag: Reduce maximum stack size to 256MBJames Hogan
Specify the maximum stack size for arches where the stack grows upward (parisc and metag) in asm/processor.h rather than hard coding in fs/exec.c so that metag can specify a smaller value of 256MB rather than 1GB. This fixes a BUG on metag if the RLIMIT_STACK hard limit is increased beyond a safe value by root. E.g. when starting a process after running "ulimit -H -s unlimited" it will then attempt to use a stack size of the maximum 1GB which is far too big for metag's limited user virtual address space (stack_top is usually 0x3ffff000): BUG: failure at fs/exec.c:589/shift_arg_pages()! Signed-off-by: James Hogan <james.hogan@imgtec.com> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <jejb@parisc-linux.org> Cc: linux-parisc@vger.kernel.org Cc: linux-metag@vger.kernel.org Cc: John David Anglin <dave.anglin@bell.net> Cc: stable@vger.kernel.org # only needed for >= v3.9 (arch/metag)
2014-04-12Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "The first vfs pile, with deep apologies for being very late in this window. Assorted cleanups and fixes, plus a large preparatory part of iov_iter work. There's a lot more of that, but it'll probably go into the next merge window - it *does* shape up nicely, removes a lot of boilerplate, gets rid of locking inconsistencie between aio_write and splice_write and I hope to get Kent's direct-io rewrite merged into the same queue, but some of the stuff after this point is having (mostly trivial) conflicts with the things already merged into mainline and with some I want more testing. This one passes LTP and xfstests without regressions, in addition to usual beating. BTW, readahead02 in ltp syscalls testsuite has started giving failures since "mm/readahead.c: fix readahead failure for memoryless NUMA nodes and limit readahead pages" - might be a false positive, might be a real regression..." * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits) missing bits of "splice: fix racy pipe->buffers uses" cifs: fix the race in cifs_writev() ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure kill generic_file_buffered_write() ocfs2_file_aio_write(): switch to generic_perform_write() ceph_aio_write(): switch to generic_perform_write() xfs_file_buffered_aio_write(): switch to generic_perform_write() export generic_perform_write(), start getting rid of generic_file_buffer_write() generic_file_direct_write(): get rid of ppos argument btrfs_file_aio_write(): get rid of ppos kill the 5th argument of generic_file_buffered_write() kill the 4th argument of __generic_file_aio_write() lustre: don't open-code kernel_recvmsg() ocfs2: don't open-code kernel_recvmsg() drbd: don't open-code kernel_recvmsg() constify blk_rq_map_user_iov() and friends lustre: switch to kernel_sendmsg() ocfs2: don't open-code kernel_sendmsg() take iov_iter stuff to mm/iov_iter.c process_vm_access: tidy up a bit ...
2014-04-07exec: kill bprm->tcomm[], simplify the "basename" logicOleg Nesterov
Starting from commit c4ad8f98bef7 ("execve: use 'struct filename *' for executable name passing") bprm->filename can not go away after flush_old_exec(), so we do not need to save the binary name in bprm->tcomm[] added by 96e02d158678 ("exec: fix use-after-free bug in setup_new_exec()"). And there was never need for filename_to_taskname-like code, we can simply do set_task_comm(kbasename(filename). This patch has to change set_task_comm() and trace_task_rename() to accept "const char *", but I think this change is also good. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Cc: Heiko Carstens <heiko.carstens@de.ibm.com> Cc: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-07mm: per-thread vma cachingDavidlohr Bueso
This patch is a continuation of efforts trying to optimize find_vma(), avoiding potentially expensive rbtree walks to locate a vma upon faults. The original approach (https://lkml.org/lkml/2013/11/1/410), where the largest vma was also cached, ended up being too specific and random, thus further comparison with other approaches were needed. There are two things to consider when dealing with this, the cache hit rate and the latency of find_vma(). Improving the hit-rate does not necessarily translate in finding the vma any faster, as the overhead of any fancy caching schemes can be too high to consider. We currently cache the last used vma for the whole address space, which provides a nice optimization, reducing the total cycles in find_vma() by up to 250%, for workloads with good locality. On the other hand, this simple scheme is pretty much useless for workloads with poor locality. Analyzing ebizzy runs shows that, no matter how many threads are running, the mmap_cache hit rate is less than 2%, and in many situations below 1%. The proposed approach is to replace this scheme with a small per-thread cache, maximizing hit rates at a very low maintenance cost. Invalidations are performed by simply bumping up a 32-bit sequence number. The only expensive operation is in the rare case of a seq number overflow, where all caches that share the same address space are flushed. Upon a miss, the proposed replacement policy is based on the page number that contains the virtual address in question. Concretely, the following results are seen on an 80 core, 8 socket x86-64 box: 1) System bootup: Most programs are single threaded, so the per-thread scheme does improve ~50% hit rate by just adding a few more slots to the cache. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 50.61% | 19.90 | | patched | 73.45% | 13.58 | +----------------+----------+------------------+ 2) Kernel build: This one is already pretty good with the current approach as we're dealing with good locality. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 75.28% | 11.03 | | patched | 88.09% | 9.31 | +----------------+----------+------------------+ 3) Oracle 11g Data Mining (4k pages): Similar to the kernel build workload. +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 70.66% | 17.14 | | patched | 91.15% | 12.57 | +----------------+----------+------------------+ 4) Ebizzy: There's a fair amount of variation from run to run, but this approach always shows nearly perfect hit rates, while baseline is just about non-existent. The amounts of cycles can fluctuate between anywhere from ~60 to ~116 for the baseline scheme, but this approach reduces it considerably. For instance, with 80 threads: +----------------+----------+------------------+ | caching scheme | hit-rate | cycles (billion) | +----------------+----------+------------------+ | baseline | 1.06% | 91.54 | | patched | 99.97% | 14.18 | +----------------+----------+------------------+ [akpm@linux-foundation.org: fix nommu build, per Davidlohr] [akpm@linux-foundation.org: document vmacache_valid() logic] [akpm@linux-foundation.org: attempt to untangle header files] [akpm@linux-foundation.org: add vmacache_find() BUG_ON] [hughd@google.com: add vmacache_valid_mm() (from Oleg)] [akpm@linux-foundation.org: coding-style fixes] [akpm@linux-foundation.org: adjust and enhance comments] Signed-off-by: Davidlohr Bueso <davidlohr@hp.com> Reviewed-by: Rik van Riel <riel@redhat.com> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Michel Lespinasse <walken@google.com> Cc: Oleg Nesterov <oleg@redhat.com> Tested-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-03fs, kernel: permit disabling the uselib syscallJosh Triplett
uselib hasn't been used since libc5; glibc does not use it. Support turning it off. When disabled, also omit the load_elf_library implementation from binfmt_elf.c, which only uselib invokes. bloat-o-meter: add/remove: 0/4 grow/shrink: 0/1 up/down: 0/-785 (-785) function old new delta padzero 39 36 -3 uselib_flags 20 - -20 sys_uselib 168 - -168 SyS_uselib 168 - -168 load_elf_library 426 - -426 The new CONFIG_USELIB defaults to `y'. Signed-off-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-04-01read_code(): go through vfs_read() instead of calling the method directlyAl Viro
... and don't skip on sanity checks. It's *not* a hot path, TYVM (a couple of calls per a.out execve(), for pity sake) and headers of random a.out binary are not to be trusted. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2014-03-06fs/compat: convert to COMPAT_SYSCALL_DEFINEHeiko Carstens
Convert all compat system call functions where all parameter types have a size of four or less than four bytes, or are pointer types to COMPAT_SYSCALL_DEFINE. The implicit casts within COMPAT_SYSCALL_DEFINE will perform proper zero and sign extension to 64 bit of all parameters if needed. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
2014-02-05execve: use 'struct filename *' for executable name passingLinus Torvalds
This changes 'do_execve()' to get the executable name as a 'struct filename', and to free it when it is done. This is what the normal users want, and it simplifies and streamlines their error handling. The controlled lifetime of the executable name also fixes a use-after-free problem with the trace_sched_process_exec tracepoint: the lifetime of the passed-in string for kernel users was not at all obvious, and the user-mode helper code used UMH_WAIT_EXEC to serialize the pathname allocation lifetime with the execve() having finished, which in turn meant that the trace point that happened after mm_release() of the old process VM ended up using already free'd memory. To solve the kernel string lifetime issue, this simply introduces "getname_kernel()" that works like the normal user-space getname() function, except with the source coming from kernel memory. As Oleg points out, this also means that we could drop the tcomm[] array from 'struct linux_binprm', since the pathname lifetime now covers setup_new_exec(). That would be a separate cleanup. Reported-by: Igor Zhbanov <i.zhbanov@samsung.com> Tested-by: Steven Rostedt <rostedt@goodmis.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23fs/exec.c: call arch_pick_mmap_layout() only onceRichard Weinberger
Currently both setup_new_exec() and flush_old_exec() issue a call to arch_pick_mmap_layout(). As setup_new_exec() and flush_old_exec() are always called pairwise arch_pick_mmap_layout() is called twice. This patch removes one call from setup_new_exec() to have it only called once. Signed-off-by: Richard Weinberger <richard@nod.at> Tested-by: Pat Erley <pat-lkml@erley.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23exec: avoid propagating PF_NO_SETAFFINITY into userspace childZhang Yi
Userspace process doesn't want the PF_NO_SETAFFINITY, but its parent may be a kernel worker thread which has PF_NO_SETAFFINITY set, and this worker thread can do kernel_thread() to create the child. Clearing this flag in usersapce child to enable its migrating capability. Signed-off-by: Zhang Yi <zhang.yi20@zte.com.cn> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23exec: kill task_struct->did_execOleg Nesterov
We can kill either task->did_exec or PF_FORKNOEXEC, they are mutually exclusive. The patch kills ->did_exec because it has a single user. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23exec: move the final allow_write_access/fput into free_bprm()Oleg Nesterov
Both success/failure paths cleanup bprm->file, we can move this code into free_bprm() to simlify and cleanup this logic. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23exec:check_unsafe_exec: kill the dead -EAGAIN and clear_in_exec logicOleg Nesterov
fs_struct->in_exec == T means that this ->fs is used by a single process (thread group), and one of the treads does do_execve(). To avoid the mt-exec races this code has the following complications: 1. check_unsafe_exec() returns -EBUSY if ->in_exec was already set by another thread. 2. do_execve_common() records "clear_in_exec" to ensure that the error path can only clear ->in_exec if it was set by current. However, after 9b1bf12d5d51 "signals: move cred_guard_mutex from task_struct to signal_struct" we do not need these complications: 1. We can't race with our sub-thread, this is called under per-process ->cred_guard_mutex. And we can't race with another CLONE_FS task, we already checked that this fs is not shared. We can remove the dead -EAGAIN logic. 2. "out_unmark:" in do_execve_common() is either called under ->cred_guard_mutex, or after de_thread() which kills other threads, so we can't race with sub-thread which could set ->in_exec. And if ->fs is shared with another process ->in_exec should be false anyway. We can clear in_exec unconditionally. This also means that check_unsafe_exec() can be void. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23exec:check_unsafe_exec: use while_each_thread() rather than next_thread()Oleg Nesterov
next_thread() should be avoided, change check_unsafe_exec() to use while_each_thread(). Nobody except signal->curr_target actually needs next_thread-like code, and we need to change (fix) this interface. This particular code is fine, p == current. But in general the code like this can loop forever if p exits and next_thread(t) can't reach the unhashed thread. This also saves 32 bytes. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23coredump: make __get_dumpable/get_dumpable inline, kill fs/coredump.hOleg Nesterov
1. Remove fs/coredump.h. It is not clear why do we need it, it only declares __get_dumpable(), signal.c includes it for no reason. 2. Now that get_dumpable() and __get_dumpable() are really trivial make them inline in linux/sched.h. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alex Kelly <alex.page.kelly@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23coredump: kill MMF_DUMPABLE and MMF_DUMP_SECURELYOleg Nesterov
Nobody actually needs MMF_DUMPABLE/MMF_DUMP_SECURELY, they are only used to enforce the encoding of SUID_DUMP_* enum in mm->flags & MMF_DUMPABLE_MASK. Now that set_dumpable() updates both bits atomically we can kill them and simply store the value "as is" in 2 lower bits. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alex Kelly <alex.page.kelly@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2014-01-23coredump: set_dumpable: fix the theoretical race with itselfOleg Nesterov
set_dumpable() updates MMF_DUMPABLE_MASK in a non-trivial way to ensure that get_dumpable() can't observe the intermediate state, but this all can't help if multiple threads call set_dumpable() at the same time. And in theory commit_creds()->set_dumpable(SUID_DUMP_ROOT) racing with sys_prctl()->set_dumpable(SUID_DUMP_DISABLE) can result in SUID_DUMP_USER. Change this code to update both bits atomically via cmpxchg(). Note: this assumes that it is safe to mix bitops and cmpxchg. IOW, if, say, an architecture implements cmpxchg() using the locking (like arch/parisc/lib/bitops.c does), then it should use the same locks for set_bit/etc. Signed-off-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Kees Cook <keescook@chromium.org> Cc: Alex Kelly <alex.page.kelly@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Josh Triplett <josh@joshtriplett.org> Cc: Petr Matousek <pmatouse@redhat.com> Cc: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-21Merge git://git.infradead.org/users/eparis/auditLinus Torvalds
Pull audit updates from Eric Paris: "Nothing amazing. Formatting, small bug fixes, couple of fixes where we didn't get records due to some old VFS changes, and a change to how we collect execve info..." Fixed conflict in fs/exec.c as per Eric and linux-next. * git://git.infradead.org/users/eparis/audit: (28 commits) audit: fix type of sessionid in audit_set_loginuid() audit: call audit_bprm() only once to add AUDIT_EXECVE information audit: move audit_aux_data_execve contents into audit_context union audit: remove unused envc member of audit_aux_data_execve audit: Kill the unused struct audit_aux_data_capset audit: do not reject all AUDIT_INODE filter types audit: suppress stock memalloc failure warnings since already managed audit: log the audit_names record type audit: add child record before the create to handle case where create fails audit: use given values in tty_audit enable api audit: use nlmsg_len() to get message payload length audit: use memset instead of trying to initialize field by field audit: fix info leak in AUDIT_GET requests audit: update AUDIT_INODE filter rule to comparator function audit: audit feature to set loginuid immutable audit: audit feature to only allow unsetting the loginuid audit: allow unsetting the loginuid (with priv) audit: remove CONFIG_AUDIT_LOGINUID_IMMUTABLE audit: loginuid functions coding style selinux: apply selinux checks on new audit message types ...
2013-11-13Merge branch 'akpm' (patches from Andrew Morton)Linus Torvalds
Merge first patch-bomb from Andrew Morton: "Quite a lot of other stuff is banked up awaiting further next->mainline merging, but this batch contains: - Lots of random misc patches - OCFS2 - Most of MM - backlight updates - lib/ updates - printk updates - checkpatch updates - epoll tweaking - rtc updates - hfs - hfsplus - documentation - procfs - update gcov to gcc-4.7 format - IPC" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (269 commits) ipc, msg: fix message length check for negative values ipc/util.c: remove unnecessary work pending test devpts: plug the memory leak in kill_sb ./Makefile: export initial ramdisk compression config option init/Kconfig: add option to disable kernel compression drivers: w1: make w1_slave::flags long to avoid memory corruption drivers/w1/masters/ds1wm.cuse dev_get_platdata() drivers/memstick/core/ms_block.c: fix unreachable state in h_msb_read_page() drivers/memstick/core/mspro_block.c: fix attributes array allocation drivers/pps/clients/pps-gpio.c: remove redundant of_match_ptr kernel/panic.c: reduce 1 byte usage for print tainted buffer gcov: reuse kbasename helper kernel/gcov/fs.c: use pr_warn() kernel/module.c: use pr_foo() gcov: compile specific gcov implementation based on gcc version gcov: add support for gcc 4.7 gcov format gcov: move gcov structs definitions to a gcc version specific file kernel/taskstats.c: return -ENOMEM when alloc memory fails in add_del_listener() kernel/taskstats.c: add nla_nest_cancel() for failure processing between nla_nest_start() and nla_nest_end() kernel/sysctl_binary.c: use scnprintf() instead of snprintf() ...
2013-11-13Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull vfs updates from Al Viro: "All kinds of stuff this time around; some more notable parts: - RCU'd vfsmounts handling - new primitives for coredump handling - files_lock is gone - Bruce's delegations handling series - exportfs fixes plus misc stuff all over the place" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (101 commits) ecryptfs: ->f_op is never NULL locks: break delegations on any attribute modification locks: break delegations on link locks: break delegations on rename locks: helper functions for delegation breaking locks: break delegations on unlink namei: minor vfs_unlink cleanup locks: implement delegations locks: introduce new FL_DELEG lock flag vfs: take i_mutex on renamed file vfs: rename I_MUTEX_QUOTA now that it's not used for quotas vfs: don't use PARENT/CHILD lock classes for non-directories vfs: pull ext4's double-i_mutex-locking into common code exportfs: fix quadratic behavior in filehandle lookup exportfs: better variable name exportfs: move most of reconnect_path to helper function exportfs: eliminate unused "noprogress" counter exportfs: stop retrying once we race with rename/remove exportfs: clear DISCONNECTED on all parents sooner exportfs: more detailed comment for path_reconnect ...
2013-11-13exec/ptrace: fix get_dumpable() incorrect testsKees Cook
The get_dumpable() return value is not boolean. Most users of the function actually want to be testing for non-SUID_DUMP_USER(1) rather than SUID_DUMP_DISABLE(0). The SUID_DUMP_ROOT(2) is also considered a protected state. Almost all places did this correctly, excepting the two places fixed in this patch. Wrong logic: if (dumpable == SUID_DUMP_DISABLE) { /* be protective */ } or if (dumpable == 0) { /* be protective */ } or if (!dumpable) { /* be protective */ } Correct logic: if (dumpable != SUID_DUMP_USER) { /* be protective */ } or if (dumpable != 1) { /* be protective */ } Without this patch, if the system had set the sysctl fs/suid_dumpable=2, a user was able to ptrace attach to processes that had dropped privileges to that user. (This may have been partially mitigated if Yama was enabled.) The macros have been moved into the file that declares get/set_dumpable(), which means things like the ia64 code can see them too. CVE-2013-2929 Reported-by: Vasily Kulikov <segoon@openwall.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: "Luck, Tony" <tony.luck@intel.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2013-11-05audit: call audit_bprm() only once to add AUDIT_EXECVE informationRichard Guy Briggs
Move the audit_bprm() call from search_binary_handler() to exec_binprm(). This allows us to get rid of the mm member of struct audit_aux_data_execve since bprm->mm will equal current->mm. This also mitigates the issue that ->argc could be modified by the load_binary() call in search_binary_handler(). audit_bprm() was being called to add an AUDIT_EXECVE record to the audit context every time search_binary_handler() was recursively called. Only one reference is necessary. Reported-by: Oleg Nesterov <onestero@redhat.com> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Richard Guy Briggs <rgb@redhat.com> Signed-off-by: Eric Paris <eparis@redhat.com> --- This patch is against 3.11, but was developed on Oleg's post-3.11 patches that introduce exec_binprm().
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