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| author | Jens Axboe <axboe@kernel.dk> | 2022-12-21 07:11:33 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2022-12-21 13:31:40 -0700 |
| commit | 23fffb2f09ce1145cbd751801d45ba74acaa6542 (patch) | |
| tree | e671424b224afc2f9a8500e87fdfd0f3cefe42c6 /io_uring | |
| parent | 52ea806ad983490b3132a9e526e11a10dc2fd10c (diff) | |
| download | lwn-23fffb2f09ce1145cbd751801d45ba74acaa6542.tar.gz lwn-23fffb2f09ce1145cbd751801d45ba74acaa6542.zip | |
io_uring/cancel: re-grab ctx mutex after finishing wait
If we have a signal pending during cancelations, it'll cause the
task_work run to return an error. Since we didn't run task_work, the
current task is left in TASK_INTERRUPTIBLE state when we need to
re-grab the ctx mutex, and the kernel will rightfully complain about
that.
Move the lock grabbing for the error cases outside the loop to avoid
that issue.
Reported-by: syzbot+7df055631cd1be4586fd@syzkaller.appspotmail.com
Link: https://lore.kernel.org/io-uring/0000000000003a14a905f05050b0@google.com/
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Diffstat (limited to 'io_uring')
| -rw-r--r-- | io_uring/cancel.c | 9 |
1 files changed, 4 insertions, 5 deletions
diff --git a/io_uring/cancel.c b/io_uring/cancel.c index 2291a53cdabd..b4f5dfacc0c3 100644 --- a/io_uring/cancel.c +++ b/io_uring/cancel.c @@ -288,24 +288,23 @@ int io_sync_cancel(struct io_ring_ctx *ctx, void __user *arg) ret = __io_sync_cancel(current->io_uring, &cd, sc.fd); + mutex_unlock(&ctx->uring_lock); if (ret != -EALREADY) break; - mutex_unlock(&ctx->uring_lock); ret = io_run_task_work_sig(ctx); - if (ret < 0) { - mutex_lock(&ctx->uring_lock); + if (ret < 0) break; - } ret = schedule_hrtimeout(&timeout, HRTIMER_MODE_ABS); - mutex_lock(&ctx->uring_lock); if (!ret) { ret = -ETIME; break; } + mutex_lock(&ctx->uring_lock); } while (1); finish_wait(&ctx->cq_wait, &wait); + mutex_lock(&ctx->uring_lock); if (ret == -ENOENT || ret > 0) ret = 0; |