linux-stable/io_uring
Hagar Hemdan b17397a0a5 io_uring: fix possible deadlock in io_register_iowq_max_workers()
commit 73254a297c upstream.

The io_register_iowq_max_workers() function calls io_put_sq_data(),
which acquires the sqd->lock without releasing the uring_lock.
Similar to the commit 009ad9f0c6 ("io_uring: drop ctx->uring_lock
before acquiring sqd->lock"), this can lead to a potential deadlock
situation.

To resolve this issue, the uring_lock is released before calling
io_put_sq_data(), and then it is re-acquired after the function call.

This change ensures that the locks are acquired in the correct
order, preventing the possibility of a deadlock.

Suggested-by: Maximilian Heyne <mheyne@amazon.de>
Signed-off-by: Hagar Hemdan <hagarhem@amazon.com>
Link: https://lore.kernel.org/r/20240604130527.3597-1-hagarhem@amazon.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2024-11-17 14:59:39 +01:00
..
io_uring.c io_uring: fix possible deadlock in io_register_iowq_max_workers() 2024-11-17 14:59:39 +01:00
io-wq.c io_uring/io-wq: limit retrying worker initialisation 2024-08-19 05:41:03 +02:00
io-wq.h io_uring: break out of iowq iopoll on teardown 2023-09-19 12:20:23 +02:00
Makefile io_uring: import 5.15-stable io_uring 2023-01-04 11:39:23 +01:00