diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2020-06-25 12:37:11 +0300 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2020-06-25 07:20:43 -0600 |
| commit | d60b5fbc1ce8210759b568da49d149b868e7c6d3 (patch) | |
| tree | 9c4a309153309826cacc804999a38b4ca47c40ba | |
| parent | cd664b0e35cb1202f40c259a1a5ea791d18c879d (diff) | |
| download | linux-d60b5fbc1ce8210759b568da49d149b868e7c6d3.tar.gz | |
io_uring: fix current->mm NULL dereference on exit
Don't reissue requests from io_iopoll_reap_events(), the task may not
have mm, which ends up with NULL. It's better to kill everything off on
exit anyway.
[ 677.734670] RIP: 0010:io_iopoll_complete+0x27e/0x630
...
[ 677.734679] Call Trace:
[ 677.734695] ? __send_signal+0x1f2/0x420
[ 677.734698] ? _raw_spin_unlock_irqrestore+0x24/0x40
[ 677.734699] ? send_signal+0xf5/0x140
[ 677.734700] io_iopoll_getevents+0x12f/0x1a0
[ 677.734702] io_iopoll_reap_events.part.0+0x5e/0xa0
[ 677.734703] io_ring_ctx_wait_and_kill+0x132/0x1c0
[ 677.734704] io_uring_release+0x20/0x30
[ 677.734706] __fput+0xcd/0x230
[ 677.734707] ____fput+0xe/0x10
[ 677.734709] task_work_run+0x67/0xa0
[ 677.734710] do_exit+0x35d/0xb70
[ 677.734712] do_group_exit+0x43/0xa0
[ 677.734713] get_signal+0x140/0x900
[ 677.734715] do_signal+0x37/0x780
[ 677.734717] ? enqueue_hrtimer+0x41/0xb0
[ 677.734718] ? recalibrate_cpu_khz+0x10/0x10
[ 677.734720] ? ktime_get+0x3e/0xa0
[ 677.734721] ? lapic_next_deadline+0x26/0x30
[ 677.734723] ? tick_program_event+0x4d/0x90
[ 677.734724] ? __hrtimer_get_next_event+0x4d/0x80
[ 677.734726] __prepare_exit_to_usermode+0x126/0x1c0
[ 677.734741] prepare_exit_to_usermode+0x9/0x40
[ 677.734742] idtentry_exit_cond_rcu+0x4c/0x60
[ 677.734743] sysvec_reschedule_ipi+0x92/0x160
[ 677.734744] ? asm_sysvec_reschedule_ipi+0xa/0x20
[ 677.734745] asm_sysvec_reschedule_ipi+0x12/0x20
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io_uring.c | 9 |
1 files changed, 9 insertions, 0 deletions
diff --git a/fs/io_uring.c b/fs/io_uring.c index c3e5c1346cfe9e..e507737f044e08 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -890,6 +890,7 @@ static int __io_sqe_files_update(struct io_ring_ctx *ctx, struct io_uring_files_update *ip, unsigned nr_args); static int io_grab_files(struct io_kiocb *req); +static void io_complete_rw_common(struct kiocb *kiocb, long res); static void io_cleanup_req(struct io_kiocb *req); static int io_file_get(struct io_submit_state *state, struct io_kiocb *req, int fd, struct file **out_file, bool fixed); @@ -1749,6 +1750,14 @@ static void io_iopoll_queue(struct list_head *again) do { req = list_first_entry(again, struct io_kiocb, list); list_del(&req->list); + + /* shouldn't happen unless io_uring is dying, cancel reqs */ + if (unlikely(!current->mm)) { + io_complete_rw_common(&req->rw.kiocb, -EAGAIN); + io_put_req(req); + continue; + } + refcount_inc(&req->refs); io_queue_async_work(req); } while (!list_empty(again)); |