io_uring: do sqo disable on install_fd error
authorPavel Begunkov <asml.silence@gmail.com>
Wed, 13 Jan 2021 12:42:25 +0000 (12:42 +0000)
committerJens Axboe <axboe@kernel.dk>
Wed, 13 Jan 2021 15:29:17 +0000 (08:29 -0700)
commit06585c497b55045ec21aa8128e340f6a6587351c
tree77df895866a57794b4fba4aefff16b116421b617
parentb4411616c26f26c4017b8fa4d3538b1a02028733
io_uring: do sqo disable on install_fd error

WARNING: CPU: 0 PID: 8494 at fs/io_uring.c:8717
io_ring_ctx_wait_and_kill+0x4f2/0x600 fs/io_uring.c:8717
Call Trace:
 io_uring_release+0x3e/0x50 fs/io_uring.c:8759
 __fput+0x283/0x920 fs/file_table.c:280
 task_work_run+0xdd/0x190 kernel/task_work.c:140
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop kernel/entry/common.c:174 [inline]
 exit_to_user_mode_prepare+0x249/0x250 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

failed io_uring_install_fd() is a special case, we don't do
io_ring_ctx_wait_and_kill() directly but defer it to fput, though still
need to io_disable_sqo_submit() before.

note: it doesn't fix any real problem, just a warning. That's because
sqring won't be available to the userspace in this case and so SQPOLL
won't submit anything.

Reported-by: syzbot+9c9c35374c0ecac06516@syzkaller.appspotmail.com
Fixes: d9d05217cb69 ("io_uring: stop SQPOLL submit on creator's death")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
fs/io_uring.c