CVE-2026-74308: ext4: fix kernel BUG in ext4_write_inline_data_end

Severity: unknown
Exploited in the wild: not listed in CISA KEV
EPSS: 0.2% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2026-08-15 · updated 2026-10-30

Description

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().

Affected products

Linux: 3.8 — fixed in 7.2

How to fix

Upgrade to a fixed version: Linux 7.2. Check the vendor advisory for mitigations.

References

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