On 23 Oct 2025, at 2:59, Kairui Song wrote:
From: Kairui Song kasong@tencent.com
The order check and fallback loop is updating the index value on every loop, this will cause the index to be wrongly aligned by a larger value while the loop shrinks the order.
This may result in inserting and returning a folio of the wrong index and cause data corruption with some userspace workloads [1].
Cc: stable@vger.kernel.org Link: https://lore.kernel.org/linux-mm/CAMgjq7DqgAmj25nDUwwu1U2cSGSn8n4-Hqpgottedy... [1] Fixes: e7a2ab7b3bb5d ("mm: shmem: add mTHP support for anonymous shmem") Signed-off-by: Kairui Song kasong@tencent.com
Changes from V2:
- Introduce a temporary variable to improve code, no behavior change, generated code is identical.
- Link to V2: https://lore.kernel.org/linux-mm/20251022105719.18321-1-ryncsn@gmail.com/
Changes from V1:
- Remove unnecessary cleanup and simplify the commit message.
- Link to V1: https://lore.kernel.org/linux-mm/20251021190436.81682-1-ryncsn@gmail.com/
mm/shmem.c | 9 ++++++--- 1 file changed, 6 insertions(+), 3 deletions(-)
Acked-by: Zi Yan ziy@nvidia.com
-- Best Regards, Yan, Zi