Re: [PATCH] nbd: Reclassify sockets to avoid lockdep circular dependency
- To: Josef Bacik <josef@toxicpanda.com>, Eric Dumazet <edumazet@google.com>
- Cc: linux-kernel <linux-kernel@vger.kernel.org>, linux-block@vger.kernel.org, nbd@other.debian.org, Eric Dumazet <eric.dumazet@gmail.com>, Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>, Kuniyuki Iwashima <kuniyu@google.com>, netdev@vger.kernel.org, syzbot+607cdcf978b3e79da878@syzkaller.appspotmail.com
- Subject: Re: [PATCH] nbd: Reclassify sockets to avoid lockdep circular dependency
- From: Jens Axboe <axboe@kernel.dk>
- Date: Sat, 13 Jun 2026 06:34:49 -0600
- Message-id: <[🔎] 178135408918.1902132.15354673921815927532.b4-ty@b4>
- In-reply-to: <[🔎] 20260613042619.1108126-1-edumazet@google.com>
- References: <[🔎] 20260613042619.1108126-1-edumazet@google.com>
On Sat, 13 Jun 2026 04:26:19 +0000, Eric Dumazet wrote:
> syzbot reported a possible circular locking dependency in udp_sendmsg()
> where fs_reclaim can be triggered while holding sk_lock, and fs_reclaim
> can eventually depend on another sk_lock (e.g., if NBD is used for swap
> or writeback and NBD uses TLS/TCP which acquires sk_lock).
>
> Since the UDP socket and the NBD TCP/TLS socket are different, this is a
> false positive. Fix this by reclassifying NBD sockets to a separate lock
> class when they are added to the NBD device.
>
> [...]
Applied, thanks!
[1/1] nbd: Reclassify sockets to avoid lockdep circular dependency
commit: d532cddb6c6049ced414d64d83c6ce7149a6421a
Best regards,
--
Jens Axboe
Reply to: