The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
From f609cbb8911e40e15f9055e8f945f926ac906924 Mon Sep 17 00:00:00 2001
From: Pavel Begunkov asml.silence@gmail.com Date: Thu, 28 Jan 2021 18:39:24 +0000 Subject: [PATCH] io_uring: fix list corruption for splice file_get
kernel BUG at lib/list_debug.c:29! Call Trace: __list_add include/linux/list.h:67 [inline] list_add include/linux/list.h:86 [inline] io_file_get+0x8cc/0xdb0 fs/io_uring.c:6466 __io_splice_prep+0x1bc/0x530 fs/io_uring.c:3866 io_splice_prep fs/io_uring.c:3920 [inline] io_req_prep+0x3546/0x4e80 fs/io_uring.c:6081 io_queue_sqe+0x609/0x10d0 fs/io_uring.c:6628 io_submit_sqe fs/io_uring.c:6705 [inline] io_submit_sqes+0x1495/0x2720 fs/io_uring.c:6953 __do_sys_io_uring_enter+0x107d/0x1f30 fs/io_uring.c:9353 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9
io_file_get() may be called from splice, and so REQ_F_INFLIGHT may already be set.
Fixes: 02a13674fa0e8 ("io_uring: account io_uring internal files as REQ_F_INFLIGHT") Cc: stable@vger.kernel.org # 5.9+ Reported-by: syzbot+6879187cf57845801267@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov asml.silence@gmail.com Signed-off-by: Jens Axboe axboe@kernel.dk
diff --git a/fs/io_uring.c b/fs/io_uring.c index ae388cc52843..39ae1f821cef 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6460,7 +6460,8 @@ static struct file *io_file_get(struct io_submit_state *state, file = __io_file_get(state, fd); }
- if (file && file->f_op == &io_uring_fops) { + if (file && file->f_op == &io_uring_fops && + !(req->flags & REQ_F_INFLIGHT)) { io_req_init_async(req); req->flags |= REQ_F_INFLIGHT;