From: Jens Axboe axboe@kernel.dk
mainline inclusion from mainline-5.4-rc1 commit 6cc47d1d2a9b631f62405f56df651975c7587a97 category: feature bugzilla: https://bugzilla.openeuler.org/show_bug.cgi?id=27 CVE: NA ---------------------------
If we end up getting woken in poll (due to a signal), then we may need to punt the poll request to an async worker. When we do that, we look up the list to queue at, deferefencing req->submit.sqe, however that is only set for requests we initially decided to queue async.
This fixes a crash with poll command usage and wakeups that need to punt to async context.
Fixes: 54a91f3bb9b9 ("io_uring: limit parallelism of buffered writes") Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Zhihao Cheng chengzhihao1@huawei.com Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: zhangyi (F) yi.zhang@huawei.com Signed-off-by: Cheng Jian cj.chengjian@huawei.com --- fs/io_uring.c | 18 +++++++++--------- 1 file changed, 9 insertions(+), 9 deletions(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 55db30a9ebed..6b2295fcb355 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -445,16 +445,15 @@ static void __io_commit_cqring(struct io_ring_ctx *ctx) static inline void io_queue_async_work(struct io_ring_ctx *ctx, struct io_kiocb *req) { - int rw; + int rw = 0;
- switch (req->submit.sqe->opcode) { - case IORING_OP_WRITEV: - case IORING_OP_WRITE_FIXED: - rw = !(req->rw.ki_flags & IOCB_DIRECT); - break; - default: - rw = 0; - break; + if (req->submit.sqe) { + switch (req->submit.sqe->opcode) { + case IORING_OP_WRITEV: + case IORING_OP_WRITE_FIXED: + rw = !(req->rw.ki_flags & IOCB_DIRECT); + break; + } }
queue_work(ctx->sqo_wq[rw], &req->work); @@ -1713,6 +1712,7 @@ static int io_poll_add(struct io_kiocb *req, const struct io_uring_sqe *sqe) if (!poll->file) return -EBADF;
+ req->submit.sqe = NULL; INIT_WORK(&req->work, io_poll_complete_work); events = READ_ONCE(sqe->poll_events); poll->events = demangle_poll(events) | EPOLLERR | EPOLLHUP;