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
This commit is contained in:
Linus Torvalds 2018-03-25 07:34:50 -10:00
commit 9fd64e8ac2
1 changed files with 8 additions and 3 deletions

View File

@ -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))];
}