diff options
| author | Pavel Begunkov <asml.silence@gmail.com> | 2021-10-12 15:02:14 +0100 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-10-19 05:49:55 -0600 |
| commit | def77acf4396a850544b41623d7720ea3a2674a9 (patch) | |
| tree | 3f7f348a44010aec96304377270a42cfd2f69c1f /fs/io_uring.c | |
| parent | 0cd3e3ddb4f60062c401929b2005eb7ff6399a4d (diff) | |
io_uring: fix io_free_batch_list races
[ 158.514382] WARNING: CPU: 5 PID: 15251 at fs/io_uring.c:1141 io_free_batch_list+0x269/0x360
[ 158.514426] RIP: 0010:io_free_batch_list+0x269/0x360
[ 158.514437] Call Trace:
[ 158.514440] __io_submit_flush_completions+0xde/0x180
[ 158.514444] tctx_task_work+0x14a/0x220
[ 158.514447] task_work_run+0x64/0xa0
[ 158.514448] __do_sys_io_uring_enter+0x7c/0x970
[ 158.514450] __x64_sys_io_uring_enter+0x22/0x30
[ 158.514451] do_syscall_64+0x43/0x90
[ 158.514453] entry_SYSCALL_64_after_hwframe+0x44/0xae
We should not touch request internals including req->comp_list.next
after putting our ref if it's not final, e.g. we can start freeing
requests from the free cache.
Fixed: 62ca9cb93e7f8 ("io_uring: optimise io_free_batch_list()")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/b1f4df38fbb8f111f52911a02fd418d0283a4e6f.1634047298.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
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 383b8f61359d..141bfe720ce2 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -2266,9 +2266,10 @@ static void io_free_batch_list(struct io_ring_ctx *ctx, struct io_kiocb *req = container_of(node, struct io_kiocb, comp_list); - if (!req_ref_put_and_test(req)) { + if (unlikely(req->flags & REQ_F_REFCOUNT)) { node = req->comp_list.next; - continue; + if (!req_ref_put_and_test(req)) + continue; } io_queue_next(req); |