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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2018-03-25 20:34:50 +0300 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2018-03-25 20:34:50 +0300 |
| commit | 9fd64e8ac2632929fb7f5d1245a15ae45ba21da6 (patch) | |
| tree | fb57c31cac8fa1d6d64d7da6634ab3f7548c8aa9 | |
| parent | bf45bae961d503b4cbf6c78d3ed71fe35e8f168d (diff) | |
| parent | 19b558db12f9f4e45a22012bae7b4783e62224da (diff) | |
| download | linux-9fd64e8ac2632929fb7f5d1245a15ae45ba21da6.tar.xz | |
Merge branch 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull timer fix from Ingo Molnar:
"Make posix clock ID usage Spectre-safe"
* 'timers-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
posix-timers: Protect posix clock array access against speculation
| -rw-r--r-- | kernel/time/posix-timers.c | 11 |
1 files changed, 8 insertions, 3 deletions
diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c index 75043046914e..10b7186d0638 100644 --- a/kernel/time/posix-timers.c +++ b/kernel/time/posix-timers.c @@ -50,6 +50,7 @@ #include <linux/export.h> #include <linux/hashtable.h> #include <linux/compat.h> +#include <linux/nospec.h> #include "timekeeping.h" #include "posix-timers.h" @@ -1346,11 +1347,15 @@ static const struct k_clock * const posix_clocks[] = { static const struct k_clock *clockid_to_kclock(const clockid_t id) { - if (id < 0) + clockid_t idx = id; + + if (id < 0) { return (id & CLOCKFD_MASK) == CLOCKFD ? &clock_posix_dynamic : &clock_posix_cpu; + } - if (id >= ARRAY_SIZE(posix_clocks) || !posix_clocks[id]) + if (id >= ARRAY_SIZE(posix_clocks)) return NULL; - return posix_clocks[id]; + + return posix_clocks[array_index_nospec(idx, ARRAY_SIZE(posix_clocks))]; } |