Linux Kernel up to 6.12.61/6.17.11/6.18.0 ext4 ext4_update_inline_data/ext4_create_inline_data denial of service

Summaryinfo

A vulnerability was found in Linux Kernel up to 6.12.61/6.17.11/6.18.0. It has been classified as critical. Impacted is the function ext4_update_inline_data/ext4_create_inline_data of the component ext4. The manipulation leads to denial of service. This vulnerability is listed as CVE-2025-68264. There is no available exploit. Upgrading the affected component is recommended.

Detailsinfo

A vulnerability was found in Linux Kernel up to 6.12.61/6.17.11/6.18.0 and classified as critical. This issue affects the function ext4_update_inline_data/ext4_create_inline_data of the component ext4. The manipulation with an unknown input leads to a denial of service vulnerability. Using CWE to declare the problem leads to CWE-404. The product does not release or incorrectly releases a resource before it is made available for re-use. Impacted is availability. The summary by CVE is:

In the Linux kernel, the following vulnerability has been resolved: ext4: refresh inline data size before write operations The cached ei->i_inline_size can become stale between the initial size check and when ext4_update_inline_data()/ext4_create_inline_data() use it. Although ext4_get_max_inline_size() reads the correct value at the time of the check, concurrent xattr operations can modify i_inline_size before ext4_write_lock_xattr() is acquired. This causes ext4_update_inline_data() and ext4_create_inline_data() to work with stale capacity values, leading to a BUG_ON() crash in ext4_write_inline_data(): kernel BUG at fs/ext4/inline.c:1331! BUG_ON(pos + len > EXT4_I(inode)->i_inline_size); The race window: 1. ext4_get_max_inline_size() reads i_inline_size = 60 (correct) 2. Size check passes for 50-byte write 3. [Another thread adds xattr, i_inline_size changes to 40] 4. ext4_write_lock_xattr() acquires lock 5. ext4_update_inline_data() uses stale i_inline_size = 60 6. Attempts to write 50 bytes but only 40 bytes actually available 7. BUG_ON() triggers Fix this by recalculating i_inline_size via ext4_find_inline_data_nolock() immediately after acquiring xattr_sem. This ensures ext4_update_inline_data() and ext4_create_inline_data() work with current values that are protected from concurrent modifications. This is similar to commit a54c4613dac1 ("ext4: fix race writing to an inline_data file while its xattrs are changing") which fixed i_inline_off staleness. This patch addresses the related i_inline_size staleness issue.

It is possible to read the advisory at git.kernel.org. The identification of this vulnerability is CVE-2025-68264 since 12/16/2025. The exploitation is known to be difficult. Technical details of the vulnerability are known, but there is no available exploit.

The vulnerability scanner Nessus provides a plugin with the ID 296481 (SUSE SLES15 Security Update : kernel (SUSE-SU-2026:0278-1)), which helps to determine the existence of the flaw in a target environment.

Upgrading to version 6.12.62, 6.17.12, 6.18.1 or 6.19-rc1 eliminates this vulnerability. Applying the patch 210ac60a86a3ad2c76ae60e0dc71c34af6e7ea0b/ca43ea29b4c4d2764aec8a26cffcfb677a871e6e/58df743faf21ceb1880f930aa5dd428e2a5e415d/892e1cf17555735e9d021ab036c36bc7b58b0e3b is able to eliminate this problem. The bugfix is ready for download at git.kernel.org. The best possible mitigation is suggested to be upgrading to the latest version.

The vulnerability is also documented in the databases at Tenable (296481), EUVD (EUVD-2025-203738) and CERT Bund (WID-SEC-2025-2868). Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

Affected

• Debian Linux
• Amazon Linux 2
• Red Hat Enterprise Linux
• Ubuntu Linux
• SUSE Linux
• Oracle Linux
• SUSE openSUSE
• RESF Rocky Linux
• Open Source Linux Kernel

Productinfo

Type

• Operating System

Vendor

• Linux

Name

• Kernel

Version

• 6.0
• 6.1
• 6.2
• 6.3
• 6.4
• 6.5
• 6.6
• 6.7
• 6.8
• 6.9
• 6.10
• 6.11
• 6.12
• 6.12.0
• 6.12.1
• 6.12.2
• 6.12.3
• 6.12.4
• 6.12.5
• 6.12.6
• 6.12.7
• 6.12.8
• 6.12.9
• 6.12.10
• 6.12.11
• 6.12.12
• 6.12.13
• 6.12.14
• 6.12.15
• 6.12.16
• 6.12.17
• 6.12.18
• 6.12.19
• 6.12.20
• 6.12.21
• 6.12.22
• 6.12.23
• 6.12.24
• 6.12.25
• 6.12.26
• 6.12.27
• 6.12.28
• 6.12.29
• 6.12.30
• 6.12.31
• 6.12.32
• 6.12.33
• 6.12.34
• 6.12.35
• 6.12.36
• 6.12.37
• 6.12.38
• 6.12.39
• 6.12.40
• 6.12.41
• 6.12.42
• 6.12.43
• 6.12.44
• 6.12.45
• 6.12.46
• 6.12.47
• 6.12.48
• 6.12.49
• 6.12.50
• 6.12.51
• 6.12.52
• 6.12.53
• 6.12.54
• 6.12.55
• 6.12.56
• 6.12.57
• 6.12.58
• 6.12.59
• 6.12.60
• 6.12.61
• 6.13
• 6.14
• 6.15
• 6.16
• 6.17
• 6.17.0
• 6.17.1
• 6.17.2
• 6.17.3
• 6.17.4
• 6.17.5
• 6.17.6
• 6.17.7
• 6.17.8
• 6.17.9
• 6.17.10
• 6.17.11
• 6.18.0

License

• open-source

Website

• Vendor: https://www.kernel.org/

CPE 2.3info

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CPE 2.2info

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Countermeasuresinfo

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Entryinfo

Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.

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