diff options
| author | Zqiang <qiang1.zhang@intel.com> | 2022-04-27 12:41:56 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2022-04-27 13:28:48 -0700 |
| commit | 31fa985b4196f8a66f027672e9bf2b81fea0417c (patch) | |
| tree | 38b4498f260c7ffa7bedbcf13242fd21dafb7010 /mm/kasan | |
| parent | d615b5416f8a1afeb82d13b238f8152c572d59c0 (diff) | |
| download | linux-31fa985b4196f8a66f027672e9bf2b81fea0417c.tar.gz | |
kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time
kasan_quarantine_remove_cache() is called in kmem_cache_shrink()/
destroy(). The kasan_quarantine_remove_cache() call is protected by
cpuslock in kmem_cache_destroy() to ensure serialization with
kasan_cpu_offline().
However the kasan_quarantine_remove_cache() call is not protected by
cpuslock in kmem_cache_shrink(). When a CPU is going offline and cache
shrink occurs at same time, the cpu_quarantine may be corrupted by
interrupt (per_cpu_remove_cache operation).
So add a cpu_quarantine offline flags check in per_cpu_remove_cache().
[akpm@linux-foundation.org: add comment, per Zqiang]
Link: https://lkml.kernel.org/r/20220414025925.2423818-1-qiang1.zhang@intel.com
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Reviewed-by: Dmitry Vyukov <dvyukov@google.com>
Cc: Andrey Ryabinin <ryabinin.a.a@gmail.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <andreyknvl@gmail.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/kasan')
| -rw-r--r-- | mm/kasan/quarantine.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/mm/kasan/quarantine.c b/mm/kasan/quarantine.c index 08291ed33e93..0a9def8ce5e8 100644 --- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -315,6 +315,13 @@ static void per_cpu_remove_cache(void *arg) struct qlist_head *q; q = this_cpu_ptr(&cpu_quarantine); + /* + * Ensure the ordering between the writing to q->offline and + * per_cpu_remove_cache. Prevent cpu_quarantine from being corrupted + * by interrupt. + */ + if (READ_ONCE(q->offline)) + return; qlist_move_cache(q, &to_free, cache); qlist_free_all(&to_free, cache); } |