diff options
| author | Jens Axboe <axboe@kernel.dk> | 2021-03-05 08:14:08 -0700 |
|---|---|---|
| committer | Jens Axboe <axboe@kernel.dk> | 2021-03-05 08:44:09 -0700 |
| commit | 09ca6c40c2024211657fdb2c50522a355610c3b7 (patch) | |
| tree | 5f7e881811b2efdd4b8ba1240f61caaaea7ee0b1 | |
| parent | b5b0ecb736f1ce1e68eb50613c0cfecff10198eb (diff) | |
io-wq: kill hashed waitqueue before manager exits
If we race with shutting down the io-wq context and someone queueing
a hashed entry, then we can exit the manager with it armed. If it then
triggers after the manager has exited, we can have a use-after-free where
io_wqe_hash_wake() attempts to wake a now gone manager process.
Move the killing of the hashed write queue into the manager itself, so
that we know we've killed it before the task exits.
Fixes: e941894eae31 ("io-wq: make buffered file write hashed work map per-ctx")
Signed-off-by: Jens Axboe <axboe@kernel.dk>
| -rw-r--r-- | fs/io-wq.c | 9 |
1 files changed, 5 insertions, 4 deletions
diff --git a/fs/io-wq.c b/fs/io-wq.c index d7cfe8fd282a..28868eb4cd09 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -726,6 +726,11 @@ static int io_wq_manager(void *data) if (atomic_read(&wq->worker_refs)) wait_for_completion(&wq->worker_done); + spin_lock_irq(&wq->hash->wait.lock); + for_each_node(node) + list_del_init(&wq->wqes[node]->wait.entry); + spin_unlock_irq(&wq->hash->wait.lock); + io_wq_cancel_pending(wq); complete(&wq->exited); do_exit(0); @@ -1051,15 +1056,11 @@ static void io_wq_destroy(struct io_wq *wq) set_bit(IO_WQ_BIT_EXIT, &wq->state); io_wq_destroy_manager(wq); - spin_lock_irq(&wq->hash->wait.lock); for_each_node(node) { struct io_wqe *wqe = wq->wqes[node]; - - list_del_init(&wqe->wait.entry); WARN_ON_ONCE(!wq_list_empty(&wqe->work_list)); kfree(wqe); } - spin_unlock_irq(&wq->hash->wait.lock); io_wq_put_hash(wq->hash); kfree(wq->wqes); kfree(wq); |