[ 27.259845] general protection fault, probably for non-canonical address 0xdffffc0000000005: 0000 [#1] SMP KASAN PTI [ 27.261043] KASAN: null-ptr-deref in range [0x0000000000000028-0x000000000000002f] [ 27.263730] RIP: 0010:sock_from_file+0x20/0x90 [ 27.272444] Call Trace: [ 27.272736] io_sendmsg+0x98/0x600 [ 27.279216] io_issue_sqe+0x498/0x68d0 [ 27.281142] __io_queue_sqe+0xab/0xb50 [ 27.285830] io_req_task_submit+0xbf/0x1b0 [ 27.286306] tctx_task_work+0x178/0xad0 [ 27.288211] task_work_run+0xe2/0x190 [ 27.288571] exit_to_user_mode_prepare+0x1a1/0x1b0 [ 27.289041] syscall_exit_to_user_mode+0x19/0x50 [ 27.289521] do_syscall_64+0x48/0x90 [ 27.289871] entry_SYSCALL_64_after_hwframe+0x44/0xae io_req_complete_failed() -> io_req_complete_post() -> io_req_task_queue() still would try to enqueue hard linked request, which can be half prepared (e.g. failed init), so we can't allow that to happen. Fixes: a8295b982c46d ("io_uring: fix failed linkchain code logic") Reported-by: syzbot+f9704d1878e290eddf73@xxxxxxxxxxxxxxxxxxxxxxxxx Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx> --- fs/io_uring.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/io_uring.c b/fs/io_uring.c index 473a977c7979..a531c7324ea8 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6717,6 +6717,8 @@ static inline void io_queue_sqe(struct io_kiocb *req) if (likely(!(req->flags & (REQ_F_FORCE_ASYNC | REQ_F_FAIL)))) { __io_queue_sqe(req); } else if (req->flags & REQ_F_FAIL) { + /* fail all, we don't submit */ + req->flags &= ~REQ_F_HARDLINK; io_req_complete_failed(req, req->result); } else { int ret = io_req_prep_async(req); -- 2.33.0