From: Pavel Begunkov asml.silence@gmail.com
[ Upstream commit b2bd1cf99f3e7c8fbf12ea07af2c6998e1209e25 ]
All ->cq_overflow modifications should be under completion_lock, otherwise it can report a wrong number to the userspace. Fix it in io_uring_cancel_files().
Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Sasha Levin sashal@kernel.org --- fs/io_uring.c | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index d732566955d37..1d8761a9f3b88 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7536,10 +7536,9 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx, clear_bit(0, &ctx->cq_check_overflow); ctx->rings->sq_flags &= ~IORING_SQ_CQ_OVERFLOW; } - spin_unlock_irq(&ctx->completion_lock); - WRITE_ONCE(ctx->rings->cq_overflow, atomic_inc_return(&ctx->cached_cq_overflow)); + spin_unlock_irq(&ctx->completion_lock);
/* * Put inflight ref and overflow ref. If that's