From: Andrew Morton <akpm@linux-foundation.org> To: stable@vger.kernel.org,ryabinin.a.a@gmail.com,glider@google.com,dvyukov@google.com,andreyknvl@gmail.com,qiang1.zhang@intel.com,akpm@linux-foundation.org,patches@lists.linux.dev,linux-mm@kvack.org,mm-commits@vger.kernel.org,torvalds@linux-foundation.org,akpm@linux-foundation.org Subject: [patch 1/2] kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time Date: Wed, 27 Apr 2022 12:41:56 -0700 [thread overview] Message-ID: <20220427194157.8F393C385A7@smtp.kernel.org> (raw) In-Reply-To: <20220427124133.cc115bc8acb8de3dda921836@linux-foundation.org> From: Zqiang <qiang1.zhang@intel.com> Subject: 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> --- mm/kasan/quarantine.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/mm/kasan/quarantine.c~kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time +++ a/mm/kasan/quarantine.c @@ -315,6 +315,13 @@ 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); } _
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Morton <akpm@linux-foundation.org> To: stable@vger.kernel.org, ryabinin.a.a@gmail.com, glider@google.com, dvyukov@google.com, andreyknvl@gmail.com, qiang1.zhang@intel.com, akpm@linux-foundation.org, patches@lists.linux.dev, linux-mm@kvack.org, mm-commits@vger.kernel.org, torvalds@linux-foundation.org, akpm@linux-foundation.org Subject: [patch 1/2] kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time Date: Wed, 27 Apr 2022 12:41:56 -0700 [thread overview] Message-ID: <20220427194157.8F393C385A7@smtp.kernel.org> (raw) In-Reply-To: <20220427124133.cc115bc8acb8de3dda921836@linux-foundation.org> From: Zqiang <qiang1.zhang@intel.com> Subject: 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> --- mm/kasan/quarantine.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/mm/kasan/quarantine.c~kasan-prevent-cpu_quarantine-corruption-when-cpu-offline-and-cache-shrink-occur-at-same-time +++ a/mm/kasan/quarantine.c @@ -315,6 +315,13 @@ 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); } _
next prev parent reply other threads:[~2022-04-27 19:41 UTC|newest] Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top 2022-04-27 19:41 incoming Andrew Morton 2022-04-27 19:41 ` Andrew Morton [this message] 2022-04-27 19:41 ` [patch 1/2] kasan: prevent cpu_quarantine corruption when CPU offline and cache shrink occur at same time Andrew Morton 2022-04-27 19:41 ` [patch 2/2] docs: vm/page_owner: use literal blocks for param description Andrew Morton 2022-04-27 19:41 ` Andrew Morton
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