ext4: allow ext4_get_group_info() to fail
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- Denial of service
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 10 fixed, 4 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat. Impact type from CWE-476.
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: allow ext4_get_group_info() to fail Previously, ext4_get_group_info() would treat an invalid group number as BUG(), since in theory it should never happen. However, if a malicious attaker (or fuzzer) modifies the superblock via the block device while it is the file system is mounted, it is possible for s_first_data_block to get set to a very large number. In that case, when calculating the block group of some block number (such as the starting block of a preallocation region), could result in an underflow and very large block group number. Then the BUG_ON check in ext4_get_group_info() would fire, resutling in a denial of service attack that can be triggered by root or someone with write access to the block device. For a quality of implementation perspective, it's best that even if the system administrator does something that they shouldn't, that it will not trigger a BUG. So instead of BUG'ing, ext4_get_group_info() will call ext4_error and return NULL. We also add fallback code in all of the callers of ext4_get_group_info() that it might NULL. Also, since ext4_get_group_info() was already borderline to be an inline function, un-inline it. The results in a next reduction of the compiled text size of ext4 by roughly 2k.
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 | 3.11 and later | 5.10.181, 5.15.113, 6.1.30, 6.3.4, 6.4 | Patch available | CNA |
- Linux VendorLinux Affected 3.11 and later Fixed in 5.10.181, 5.15.113, 6.1.30, 6.3.4, 6.4 Patch available CNA
Remediation
- Fix · CNA Linux (Linux) Fixed in 5.10.181, 5.15.113, 6.1.30, 6.3.4, 6.4
Red Hat 2 advisories
- RHSA-2024:10771 Released 2024-12-04 · Red Hat rating Moderatekernel security update
- Red Hat CodeReady Linux Builder EUS (v.9.4) kernel-tools-libs-devel-5.14.0-427.47.1.el9_4, libperf-5.14.0-427.47.1.el9_4
- Red Hat Enterprise Linux AppStream EUS (v.9.4) kernel-64k-debug-devel-5.14.0-427.47.1.el9_4, kernel-64k-debug-devel-matched-5.14.0-427.47.1.el9_4, kernel-64k-devel-5.14.0-427.47.1.el9_4 +11
- Red Hat Enterprise Linux BaseOS EUS (v.9.4) bpftool-7.3.0-427.47.1.el9_4, kernel-5.14.0-427.47.1.el9_4, kernel-64k-5.14.0-427.47.1.el9_4 +29
- Red Hat Enterprise Linux Real Time EUS (v.9.4) kernel-rt-5.14.0-427.47.1.el9_4, kernel-rt-core-5.14.0-427.47.1.el9_4, kernel-rt-debug-5.14.0-427.47.1.el9_4 +9
- Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) kernel-rt-5.14.0-427.47.1.el9_4, kernel-rt-core-5.14.0-427.47.1.el9_4, kernel-rt-debug-5.14.0-427.47.1.el9_4 +11
- RHSA-2024:9315 Released 2024-11-12 · Red Hat rating Moderatekernel security update
- Red Hat CodeReady Linux Builder (v. 9) kernel-cross-headers-5.14.0-503.11.1.el9_5, kernel-tools-libs-devel-5.14.0-503.11.1.el9_5, libperf-5.14.0-503.11.1.el9_5
- Red Hat Enterprise Linux AppStream (v. 9) kernel-64k-debug-devel-5.14.0-503.11.1.el9_5, kernel-64k-debug-devel-matched-5.14.0-503.11.1.el9_5, kernel-64k-devel-5.14.0-503.11.1.el9_5 +12
- Red Hat Enterprise Linux BaseOS (v. 9) bpftool-7.4.0-503.11.1.el9_5, kernel-5.14.0-503.11.1.el9_5, kernel-64k-5.14.0-503.11.1.el9_5 +30
- Red Hat Enterprise Linux Real Time (v. 9) kernel-rt-5.14.0-503.11.1.el9_5, kernel-rt-core-5.14.0-503.11.1.el9_5, kernel-rt-debug-5.14.0-503.11.1.el9_5 +9
- Red Hat Enterprise Linux Real Time for NFV (v. 9) kernel-rt-5.14.0-503.11.1.el9_5, kernel-rt-core-5.14.0-503.11.1.el9_5, kernel-rt-debug-5.14.0-503.11.1.el9_5 +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 yet: Fix deferred |
| Red Hat Enterprise Linux 8 | Affected | No fix yet: Fix deferred |
| Red Hat Enterprise Linux 9 | Affected | No fix yet: Fix deferred |
| Red Hat CodeReady Linux Builder (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat CodeReady Linux Builder EUS (v.9.4) | Fixed | RHSA-2024:10771 |
| Red Hat Enterprise Linux AppStream (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux AppStream EUS (v.9.4) | Fixed | RHSA-2024:10771 |
| Red Hat Enterprise Linux BaseOS (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux BaseOS EUS (v.9.4) | Fixed | RHSA-2024:10771 |
| Red Hat Enterprise Linux Real Time (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux Real Time EUS (v.9.4) | Fixed | RHSA-2024:10771 |
| Red Hat Enterprise Linux Real Time for NFV (v. 9) | Fixed | RHSA-2024:9315 |
| Red Hat Enterprise Linux Real Time for NFV EUS (v.9.4) | Fixed | RHSA-2024:10771 |
Not affected: 3 products
- Red Hat CodeReady Linux Builder (v. 9)
- Red Hat Enterprise Linux 10
- Red Hat Enterprise Linux AppStream (v. 9)
Timeline
- 2026-10-02 Threatist record created from CVE-2023-53503
- 2026-10-03 Alias added: GHSA-794g-3p8m-5jpc
- 2026-11-05 CISA SSVC decision points changed
References
Patch 5
- https://git.kernel.org/stable/c/100c0ad6c04597fefeaaba2bb1827cc015d95067
- https://git.kernel.org/stable/c/620a3c28221bb219b81bc0bffd065cc187494302
- https://git.kernel.org/stable/c/b4319e457d6e3fb33e443efeaf4634fc36e8a9ed
- https://git.kernel.org/stable/c/31668cebf45adfb6283e465e641c4f5a21b07afa
- https://git.kernel.org/stable/c/5354b2af34064a4579be8bc0e2f15a7b70f14b5f
More Linux Kernel vulnerabilities
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- TI-2026-38352 netfilter: bridge: make ebt_snat ARP rewrite writable KEVCVSS 3.1HIGH 8.8
- TI-2013-05264 The (1) get_user and (2) put_user API functions in the Linux kernel before 3.5.5 on the… KEVCVSS 3.1HIGH 8.8
- TI-2022-00125 Integer overflow in kernel KEVCVSS 3.1HIGH 8.4
- TI-2013-01864 The perf_swevent_init function in kernel/events/core.c in the Linux kernel before 3.8.9… KEVCVSS 3.1HIGH 8.4
- TI-2021-05514 Heap Out-Of-Bounds Write in Netfilter IP6T_SO_SET_REPLACE KEVCVSS 3.1HIGH 8.3
Sources
- CVE-2023-53503 · CVE Program
- CVE-2023-53503 · NVD
- FIRST EPSS
- GHSA-794g-3p8m-5jpc · GitHub Advisory Database · CC BY 4.0
- CVE-2023-53503 · 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