Re: [PATCH v2] Fix: ext4: guard against EA inode refcount underflow in xattr update

From: Theodore Ts'o

Date: Fri Sep 26 2025 - 17:48:03 EST



On Sat, 20 Sep 2025 05:13:43 +0300, Ahmet Eray Karadag wrote:
> syzkaller found a path where ext4_xattr_inode_update_ref() reads an EA
> inode refcount that is already <= 0 and then applies ref_change (often
> -1). That lets the refcount underflow and we proceed with a bogus value,
> triggering errors like:
>
> EXT4-fs error: EA inode <n> ref underflow: ref_count=-1 ref_change=-1
> EXT4-fs warning: ea_inode dec ref err=-117
>
> [...]

Applied, thanks!

[1/1] Fix: ext4: guard against EA inode refcount underflow in xattr update
commit: 57295e835408d8d425bef58da5253465db3d6888

Best regards,
--
Theodore Ts'o <tytso@xxxxxxx>