diff options
| author | Al Viro <viro@zeniv.linux.org.uk> | 2016-12-16 13:42:06 -0500 |
|---|---|---|
| committer | Ben Hutchings <ben@decadent.org.uk> | 2017-02-23 03:51:06 +0000 |
| commit | e30250c95b840896da4cb71e84bead5803ee1ff6 (patch) | |
| tree | 82ce305998183031562b102d0b5546ebf8d8d190 | |
| parent | ba43cdd87d0aaed69ef1bb14a91c3e767a4c210f (diff) | |
sg_write()/bsg_write() is not fit to be called under KERNEL_DS
commit a0ac402cfcdc904f9772e1762b3fda112dcc56a0 upstream.
Both damn things interpret userland pointers embedded into the payload;
worse, they are actually traversing those. Leaving aside the bad
API design, this is very much _not_ safe to call with KERNEL_DS.
Bail out early if that happens.
Cc: stable@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
| -rw-r--r-- | block/bsg.c | 3 | ||||
| -rw-r--r-- | drivers/scsi/sg.c | 3 |
2 files changed, 6 insertions, 0 deletions
diff --git a/block/bsg.c b/block/bsg.c index c0ab25c2acf2..2a019402723f 100644 --- a/block/bsg.c +++ b/block/bsg.c @@ -675,6 +675,9 @@ bsg_write(struct file *file, const char __user *buf, size_t count, loff_t *ppos) dprintk("%s: write %Zd bytes\n", bd->name, count); + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) + return -EINVAL; + bsg_set_block(bd, file); bytes_written = 0; diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c index 94b71b4f648e..fb59a49dd01d 100644 --- a/drivers/scsi/sg.c +++ b/drivers/scsi/sg.c @@ -544,6 +544,9 @@ sg_write(struct file *filp, const char __user *buf, size_t count, loff_t * ppos) sg_io_hdr_t *hp; unsigned char cmnd[MAX_COMMAND_SIZE]; + if (unlikely(segment_eq(get_fs(), KERNEL_DS))) + return -EINVAL; + if ((!(sfp = (Sg_fd *) filp->private_data)) || (!(sdp = sfp->parentdp))) return -ENXIO; SCSI_LOG_TIMEOUT(3, printk("sg_write: %s, count=%d\n", |