diff options
| author | Peter Zijlstra <peterz@infradead.org> | 2018-04-20 14:29:51 +0200 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2018-05-16 10:12:35 +0200 |
| commit | 5d728a4ecab107668f241c6d2a10cc9380830c25 (patch) | |
| tree | 7dfab1d231881ae1b765b31cd6a574c5eec6bc9c /kernel | |
| parent | 62e16d89b4cf9b64436c33c6383df321eca91bec (diff) | |
sched/core: Fix possible Spectre-v1 indexing for sched_prio_to_weight[]
commit 7281c8dec8a87685cb54d503d8cceef5a0fc2fdd upstream.
> kernel/sched/core.c:6921 cpu_weight_nice_write_s64() warn: potential spectre issue 'sched_prio_to_weight'
Userspace controls @nice, so sanitize the value before using it to
index an array.
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: <stable@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/sched/core.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/kernel/sched/core.c b/kernel/sched/core.c index c94895bc5a2c..5f37ef9f6cd5 100644 --- a/kernel/sched/core.c +++ b/kernel/sched/core.c @@ -23,6 +23,7 @@ #include <linux/mmu_context.h> #include <linux/module.h> #include <linux/nmi.h> +#include <linux/nospec.h> #include <linux/prefetch.h> #include <linux/profile.h> #include <linux/security.h> @@ -6873,11 +6874,15 @@ static int cpu_weight_nice_write_s64(struct cgroup_subsys_state *css, struct cftype *cft, s64 nice) { unsigned long weight; + int idx; if (nice < MIN_NICE || nice > MAX_NICE) return -ERANGE; - weight = sched_prio_to_weight[NICE_TO_PRIO(nice) - MAX_RT_PRIO]; + idx = NICE_TO_PRIO(nice) - MAX_RT_PRIO; + idx = array_index_nospec(idx, 40); + weight = sched_prio_to_weight[idx]; + return sched_group_set_shares(css_tg(css), scale_load(weight)); } #endif |