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| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-11-26 17:38:14 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2021-12-01 11:04:42 +0300 |
| commit | 3d2a1e68fd9904fdc1b02f2e7d40ca47df7ba39f (patch) | |
| tree | 1da1894bb35a866fde25a3c0d330e4b0f81baaf2 /fs/io_uring.c | |
| parent | 09eb40f6776c8b50c2e46a504bf5483440ca607d (diff) | |
| download | linux-3d2a1e68fd9904fdc1b02f2e7d40ca47df7ba39f.tar.xz | |
io_uring: fail cancellation for EXITING tasks
commit 617a89484debcd4e7999796d693cf0b77d2519de upstream.
WARNING: CPU: 1 PID: 20 at fs/io_uring.c:6269 io_try_cancel_userdata+0x3c5/0x640 fs/io_uring.c:6269
CPU: 1 PID: 20 Comm: kworker/1:0 Not tainted 5.16.0-rc1-syzkaller #0
Workqueue: events io_fallback_req_func
RIP: 0010:io_try_cancel_userdata+0x3c5/0x640 fs/io_uring.c:6269
Call Trace:
<TASK>
io_req_task_link_timeout+0x6b/0x1e0 fs/io_uring.c:6886
io_fallback_req_func+0xf9/0x1ae fs/io_uring.c:1334
process_one_work+0x9b2/0x1690 kernel/workqueue.c:2298
worker_thread+0x658/0x11f0 kernel/workqueue.c:2445
kthread+0x405/0x4f0 kernel/kthread.c:327
ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
</TASK>
We need original task's context to do cancellations, so if it's dying
and the callback is executed in a fallback mode, fail the cancellation
attempt.
Fixes: 89b263f6d56e6 ("io_uring: run linked timeouts from task_work")
Cc: stable@kernel.org # 5.15+
Reported-by: syzbot+ab0cfe96c2b3cd1c1153@syzkaller.appspotmail.com
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/4c41c5f379c6941ad5a07cd48cb66ed62199cf7e.1637937097.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs/io_uring.c')
| -rw-r--r-- | fs/io_uring.c | 5 |
1 files changed, 3 insertions, 2 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index f230ae730a53..edd30baa568d 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6886,10 +6886,11 @@ static inline struct file *io_file_get(struct io_ring_ctx *ctx, static void io_req_task_link_timeout(struct io_kiocb *req, bool *locked) { struct io_kiocb *prev = req->timeout.prev; - int ret; + int ret = -ENOENT; if (prev) { - ret = io_try_cancel_userdata(req, prev->user_data); + if (!(req->task->flags & PF_EXITING)) + ret = io_try_cancel_userdata(req, prev->user_data); io_req_complete_post(req, ret ?: -ETIME, 0); io_put_req(prev); } else { |