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authorLinus Torvalds <torvalds@linux-foundation.org>2018-03-25 07:34:50 -1000
committerLinus Torvalds <torvalds@linux-foundation.org>2018-03-25 07:34:50 -1000
commit9fd64e8ac2632929fb7f5d1245a15ae45ba21da6 (patch)
treefb57c31cac8fa1d6d64d7da6634ab3f7548c8aa9
parentbf45bae961d503b4cbf6c78d3ed71fe35e8f168d (diff)
parent19b558db12f9f4e45a22012bae7b4783e62224da (diff)
downloadlinux-stericsson-9fd64e8ac2632929fb7f5d1245a15ae45ba21da6.tar.gz
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.c11
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))];
}