summaryrefslogtreecommitdiffstats
path: root/mm
diff options
context:
space:
mode:
authorZqiang <qiang1.zhang@intel.com>2022-04-27 21:41:56 +0200
committerLinus Torvalds <torvalds@linux-foundation.org>2022-04-27 22:28:48 +0200
commit31fa985b4196f8a66f027672e9bf2b81fea0417c (patch)
tree38b4498f260c7ffa7bedbcf13242fd21dafb7010 /mm
parentMerge tag 'f2fs-fix-5.18' of git://git.kernel.org/pub/scm/linux/kernel/git/ja... (diff)
downloadlinux-31fa985b4196f8a66f027672e9bf2b81fea0417c.tar.xz
linux-31fa985b4196f8a66f027672e9bf2b81fea0417c.zip
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')
-rw-r--r--mm/kasan/quarantine.c7
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);
}