From: Zqiang qiang1.zhang@intel.com
commit 31fa985b4196f8a66f027672e9bf2b81fea0417c upstream.
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 Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- mm/kasan/quarantine.c | 7 +++++++ 1 file changed, 7 insertions(+)
--- a/mm/kasan/quarantine.c +++ b/mm/kasan/quarantine.c @@ -299,6 +299,13 @@ static void per_cpu_remove_cache(void *a 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); }