ext4: make sure the first directory block is not a hole
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 4 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: make sure the first directory block is not a hole The syzbot constructs a directory that has no dirblock but is non-inline, i.e. the first directory block is a hole. And no errors are reported when creating files in this directory in the following flow. ext4_mknod ... ext4_add_entry // Read block 0 ext4_read_dirblock(dir, block, DIRENT) bh = ext4_bread(NULL, inode, block, 0) if (!bh && (type == INDEX || type == DIRENT_HTREE)) // The first directory block is a hole // But type == DIRENT, so no error is reported. After that, we get a directory block without '.' and '..' but with a valid dentry. This may cause some code that relies on dot or dotdot (such as make_indexed_dir()) to crash. Therefore when ext4_read_dirblock() finds that the first directory block is a hole report that the filesystem is corrupted and return an error to avoid loading corrupted data from disk causing something bad.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- None
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
| Vendor | Product | Affected versions | Fixed in | Status | Source |
|---|---|---|---|---|---|
| Linux | Linux | 4.19.62 to before 4.19.320; 4.9.187 to before 4.10; 4.14.135 to before 4.15; 5.1.21 to before 5.2; 5.2.4 to before 5.3 | 4.19.320, 4.10, 4.15, 5.2, 5.3 | Patch available | CNA |
| Linux | Linux | 5.3 and later | 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.103, 6.6.44, 6.10.3, 6.11 | Patch available | CNA |
- Linux VendorLinux Affected 4.19.62 to before 4.19.320; 4.9.187 to before 4.10; 4.14.135 to before 4.15; 5.1.21 to before 5.2; 5.2.4 to before 5.3 Fixed in 4.19.320, 4.10, 4.15, 5.2, 5.3 Patch available CNA
- Linux VendorLinux Affected 5.3 and later Fixed in 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.103, 6.6.44, 6.10.3, 6.11 Patch available CNA
CPE configurations NVD · 1
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | 4.9.187 to before 4.10; 4.14.135 to before 4.15; 4.19.62 to before 4.19.320; 5.1.21 to before 5.2; 5.2.4 to before 5.4.282; 5.5 to before 5.10.224; 5.11 to before 5.15.165; 5.16 to before 6.1.103; 6.2 to before 6.6.44; 6.7 to before 6.10.3 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions 4.9.187 to before 4.10; 4.14.135 to before 4.15; 4.19.62 to before 4.19.320; 5.1.21 to before 5.2; 5.2.4 to before 5.4.282; 5.5 to before 5.10.224; 5.11 to before 5.15.165; 5.16 to before 6.1.103; 6.2 to before 6.6.44; 6.7 to before 6.10.3 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.19.320, 4.10, 4.15, 5.2, 5.3
- Fix · CNA Linux (Linux) Fixed in 4.19.320, 5.4.282, 5.10.224, 5.15.165, 6.1.103, 6.6.44, 6.10.3, 6.11
Red Hat 1 advisory
- RHSA-2025:6966 Released 2025-05-13 · Red Hat rating Moderatekernel security update
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-570.12.1.el9_6, kernel-64k-debug-devel-matched-5.14.0-570.12.1.el9_6, kernel-64k-devel-5.14.0-570.12.1.el9_6 +12
- Red Hat Enterprise Linux BaseOS (v. 9) kernel-5.14.0-570.12.1.el9_6, kernel-64k-5.14.0-570.12.1.el9_6, kernel-64k-core-5.14.0-570.12.1.el9_6 +28
- Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) kernel-tools-libs-devel-5.14.0-570.12.1.el9_6, libperf-5.14.0-570.12.1.el9_6
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-64k-5.14.0-570.12.1.el9_6, kernel-rt-64k-core-5.14.0-570.12.1.el9_6 +21
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-570.12.1.el9_6, kernel-rt-core-5.14.0-570.12.1.el9_6, kernel-rt-debug-5.14.0-570.12.1.el9_6 +11
Vendor assessments
Red Hat
Red Hat rating: Moderate. Red Hat's page for this CVE →
| Product | Status | Plan or fix |
|---|---|---|
| Red Hat Enterprise Linux 6 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 7 | Affected | No fix planned: Out of support scope |
| Red Hat Enterprise Linux 8 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux 9 | Affected | No fix planned: Will not fix |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux CodeReady Linux Builder (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2025:6966 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2025:6966 |
Timeline
- 2026-10-02 Threatist record created from CVE-2024-42304
- 2026-10-03 Alias added: GHSA-v546-2fcj-rwvx
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 8
- https://git.kernel.org/stable/c/d81d7e347d1f1f48a5634607d39eb90c161c8afe
- https://git.kernel.org/stable/c/e02f9941e8c011aa3eafa799def6a134ce06bcfa
- https://git.kernel.org/stable/c/de2a011a13a46468a6e8259db58b1b62071fe136
- https://git.kernel.org/stable/c/9771e3d8365ae1dd5e8846a204cb9af14e3e656a
- https://git.kernel.org/stable/c/b609753cbbd38f8c0affd4956c0af178348523ac
- https://git.kernel.org/stable/c/c3893d9de8ee153baac56d127d844103488133b5
- https://git.kernel.org/stable/c/299bc6ffa57e04e74c6cce866d6c0741fb4897a1
- https://git.kernel.org/stable/c/f9ca51596bbfd0f9c386dd1c613c394c78d9e5e6
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- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2024-42304 · CVE Program
- CVE-2024-42304 · NVD
- FIRST EPSS
- GHSA-v546-2fcj-rwvx · GitHub Advisory Database · CC BY 4.0
- CVE-2024-42304 · Red Hat security data · CC BY 4.0
This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences