[ Upstream commit 4325cb498cb743dacaa3edbec398c5255f476ef6 ]
WARNING: CPU: 1 PID: 11100 at fs/io_uring.c:9096
io_uring_flush+0x326/0x3a0 fs/io_uring.c:9096
RIP: 0010:io_uring_flush+0x326/0x3a0 fs/io_uring.c:9096
Call Trace:
filp_close+0xb4/0x170 fs/open.c:1280
close_files fs/file.c:401 [inline]
put_files_struct fs/file.c:416 [inline]
put_files_struct+0x1cc/0x350 fs/file.c:413
exit_files+0x7e/0xa0 fs/file.c:433
do_exit+0xc22/0x2ae0 kernel/exit.c:820
do_group_exit+0x125/0x310 kernel/exit.c:922
get_signal+0x3e9/0x20a0 kernel/signal.c:2770
arch_do_signal_or_restart+0x2a8/0x1eb0 arch/x86/kernel/signal.c:811
handle_signal_work kernel/entry/common.c:147 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x148/0x250 kernel/entry/common.c:201
__syscall_exit_to_user_mode_work kernel/entry/common.c:291 [inline]
syscall_exit_to_user_mode+0x19/0x50 kernel/entry/common.c:302
entry_SYSCALL_64_after_hwframe+0x44/0xa9
An SQPOLL ring creator task may have gotten rid of its file note during
exit and called io_disable_sqo_submit(), but the io_uring is still left
referenced through fdtable, which will be put during close_files() and
cause a false positive warning.
First split the warning into two for more clarity when is hit, and the
add sqo_dead check to handle the described case.
Cc: stable@xxxxxxxxxxxxxxx # 5.5+
Reported-by: syzbot+a32b546d58dde07875a1@xxxxxxxxxxxxxxxxxxxxxxxxx
Signed-off-by: Pavel Begunkov <asml.silence@xxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
---
fs/io_uring.c | 5 ++++-
1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/io_uring.c b/fs/io_uring.c
index e8d0bea702a3..12fa5e09cefa 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -8931,7 +8931,10 @@ static int io_uring_flush(struct file *file, void *data)
if (ctx->flags & IORING_SETUP_SQPOLL) {
/* there is only one file note, which is owned by sqo_task */
- WARN_ON_ONCE((ctx->sqo_task == current) ==
+ WARN_ON_ONCE(ctx->sqo_task != current &&
+ xa_load(&tctx->xa, (unsigned long)file));
+ /* sqo_dead check is for when this happens after cancellation */
+ WARN_ON_ONCE(ctx->sqo_task == current && !ctx->sqo_dead &&
!xa_load(&tctx->xa, (unsigned long)file));
io_disable_sqo_submit(ctx);
--
2.24.0
