ext4: fix timer use-after-free on failed mount
Key facts
- Attack vector
- Local
- Privileges required
- None
- User interaction
- Required
- Attack complexity
- Low
- Impact type
- Code execution
- Confidentiality · integrity · availability
- High · High · High
- Fix status
- Partial Red Hat: 5 fixed, 3 without a fix
Attack profile from CVSS 3.1 · CNA. Fix status from CNA and Red Hat. Impact type from CWE-416 and the CVSS impact.
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix timer use-after-free on failed mount Syzbot has found an ODEBUG bug in ext4_fill_super The del_timer_sync function cancels the s_err_report timer, which reminds about filesystem errors daily. We should guarantee the timer is no longer active before kfree(sbi). When filesystem mounting fails, the flow goes to failed_mount3, where an error occurs when ext4_stop_mmpd is called, causing a read I/O failure. This triggers the ext4_handle_error function that ultimately re-arms the timer, leaving the s_err_report timer active before kfree(sbi) is called. Fix the issue by canceling the s_err_report timer after calling ext4_stop_mmpd.
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 | 5.10.51 to before 5.10.237; 5.12.18 to before 5.13; 5.13.3 to before 5.14 | 5.10.237, 5.13, 5.14 | Patch available | CNA |
| Linux | Linux | 5.14 and later | 5.10.237, 5.15.181, 6.1.118, 6.6.55, 6.10.14, 6.11.3, 6.12 | Patch available | CNA |
- Linux VendorLinux Affected 5.10.51 to before 5.10.237; 5.12.18 to before 5.13; 5.13.3 to before 5.14 Fixed in 5.10.237, 5.13, 5.14 Patch available CNA
- Linux VendorLinux Affected 5.14 and later Fixed in 5.10.237, 5.15.181, 6.1.118, 6.6.55, 6.10.14, 6.11.3, 6.12 Patch available CNA
CPE configurations NVD · 2
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.237, 5.13, 5.14
- Fix · CNA Linux (Linux) Fixed in 5.10.237, 5.15.181, 6.1.118, 6.6.55, 6.10.14, 6.11.3, 6.12
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 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-2024-49960
- 2026-10-03 Alias added: GHSA-xrhf-cccw-cpm8
- 2026-10-29 Affected versions changed · Red Hat
References
Patch 7
- https://git.kernel.org/stable/c/7aac0c17a8cdf4a3236991c1e60435c6a984076c
- https://git.kernel.org/stable/c/22e9b83f0f33bc5a7a3181769d1dccbf021f5b04
- https://git.kernel.org/stable/c/cf3196e5e2f36cd80dab91ffae402e13935724bc
- https://git.kernel.org/stable/c/9203817ba46ebba7c865c8de2aba399537b6e891
- https://git.kernel.org/stable/c/fa78fb51d396f4f2f80f8e96a3b1516f394258be
- https://git.kernel.org/stable/c/b85569585d0154d4db1e4f9e3e6a4731d407feb0
- https://git.kernel.org/stable/c/0ce160c5bdb67081a62293028dc85758a8efb22a
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Sources
- CVE-2024-49960 · CVE Program
- CVE-2024-49960 · NVD
- FIRST EPSS
- GHSA-xrhf-cccw-cpm8 · GitHub Advisory Database · CC BY 4.0
- CVE-2024-49960 · Red Hat security data · CC BY 4.0
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