Bug 2516927 (CVE-2026-74308) - CVE-2026-74308 kernel: ext4: fix kernel BUG in ext4_write_inline_data_end
Summary: CVE-2026-74308 kernel: ext4: fix kernel BUG in ext4_write_inline_data_end
Keywords:
Status: NEW
Alias: CVE-2026-74308
Product: Security Response
Classification: Other
Component: vulnerability
Version: unspecified
Hardware: All
OS: Linux
low
low
Target Milestone: ---
Assignee: Product Security DevOps Team
QA Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2026-08-15 06:40 UTC by OSIDB Bzimport
Modified: 2026-08-20 16:18 UTC (History)
2 users (show)

Fixed In Version:
Clone Of:
Environment:
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Description OSIDB Bzimport 2026-08-15 06:40:48 UTC
In the Linux kernel, the following vulnerability has been resolved:

ext4: fix kernel BUG in ext4_write_inline_data_end

When the data=journal mount option is used, the ext4_journalled_write_end()
function incorrectly calls ext4_write_inline_data_end() without checking
if the EXT4_STATE_MAY_INLINE_DATA flag is still set on the inode.

If a previous attempt to convert the inline data to an extent failed (e.g.
due to ENOSPC), the EXT4_STATE_MAY_INLINE_DATA flag is cleared, but
the EXT4_INODE_INLINE_DATA flag remains set. In this scenario, the next
call to ext4_write_begin() will not prepare the inline data xattr for
writing, but ext4_journalled_write_end() will incorrectly attempt to write
to it, triggering a BUG_ON(pos + len > EXT4_I(inode)->i_inline_size) in
ext4_write_inline_data() since i_inline_size was not expanded.

Fix this by ensuring that ext4_journalled_write_end() only calls
ext4_write_inline_data_end() if the EXT4_STATE_MAY_INLINE_DATA flag is
set, mirroring the behavior of ext4_write_end() and ext4_da_write_end().


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