Re: [BUG] ocfs2: possible deadlock in ocfs2_write_begin_nolock on v7.2-rc3

[Joseph Qi]

Seems you posted into a stale mail list.

+cc ocfs2-devel@xxxxxxxxxxxxxxx

On 9/3/26 2:51 PM, CJ wrote:
> 
> 
> Hi,
> 
> I am reporting that possible deadlock in ocfs2_write_begin_nolock remains
> reproducible with a migrated syzkaller reproducer on Linux 7.2-rc3. The
> tested HEAD commit is a13c140cc289c0b7b3770bce5b3ad42ab35074aa.
> 
> The reproducer mounts a crafted OCFS2 image and performs file and xattr
> operations that enter the buffered write path.
> 
> Lockdep reports a circular dependency when ocfs2_write_begin_nolock() starts
> a transaction while the inode allocation semaphore is already held. The
> reverse dependency is established through OCFS2 refcount-tree and xattr
> handling.
> 
> This looks like an inconsistent lock ordering between the inode allocation
> semaphore and the filesystem transaction lock in the OCFS2 write path.
> 
> This issue was previously reported at:
> 
> https://syzkaller.appspot.com/bug?extid=1782a3a587bc53dc10cf
> 
> Reproducer:
> 
> syz reproducer: https://pastebin.com/raw/Ch9E7gAi
> 
> console output: https://pastebin.com/raw/02Zj2gLb
> kernel config: https://pastebin.com/raw/RLSmRk5j
> Kernel:
> 
> HEAD commit: a13c140cc289c0b7b3770bce5b3ad42ab35074aa
> git tree: torvalds/linux
> kernel version: 7.2.0-rc3 #1 PREEMPT(full)
> tested tag: v7.2-rc3
> 
> Let me know if you need more details or testing.
> 
> Best regards,
> Xianying