ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed
Key facts
- Attack vector
- Local
- Privileges required
- Low
- User interaction
- None
- Attack complexity
- Low
- Impact type
- —
- Confidentiality · integrity · availability
- None · None · High
- Fix status
- Partial Red Hat: 2 without a fix
Attack profile from CVSS 3.1 · NVD. Fix status from CNA and Red Hat.
Summary
In the Linux kernel, the following vulnerability has been resolved: ext4: fix bug on in ext4_es_cache_extent as ext4_split_extent_at failed We got follow bug_on when run fsstress with injecting IO fault: [130747.323114] kernel BUG at fs/ext4/extents_status.c:762! [130747.323117] Internal error: Oops - BUG: 0 [#1] SMP ...... [130747.334329] Call trace: [130747.334553] ext4_es_cache_extent+0x150/0x168 [ext4] [130747.334975] ext4_cache_extents+0x64/0xe8 [ext4] [130747.335368] ext4_find_extent+0x300/0x330 [ext4] [130747.335759] ext4_ext_map_blocks+0x74/0x1178 [ext4] [130747.336179] ext4_map_blocks+0x2f4/0x5f0 [ext4] [130747.336567] ext4_mpage_readpages+0x4a8/0x7a8 [ext4] [130747.336995] ext4_readpage+0x54/0x100 [ext4] [130747.337359] generic_file_buffered_read+0x410/0xae8 [130747.337767] generic_file_read_iter+0x114/0x190 [130747.338152] ext4_file_read_iter+0x5c/0x140 [ext4] [130747.338556] __vfs_read+0x11c/0x188 [130747.338851] vfs_read+0x94/0x150 [130747.339110] ksys_read+0x74/0xf0 This patch's modification is according to Jan Kara's suggestion in: https://patchwork.ozlabs.org/project/linux-ext4/patch/[email protected]/ "I see. Now I understand your patch. Honestly, seeing how fragile is trying to fix extent tree after split has failed in the middle, I would probably go even further and make sure we fix the tree properly in case of ENOSPC and EDQUOT (those are easily user triggerable). Anything else indicates a HW problem or fs corruption so I'd rather leave the extent tree as is and don't try to fix it (which also means we will not create overlapping extents)."
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 | 3.9 and later | 4.4.272, 4.9.272, 4.14.236, 4.19.194, 5.4.125, 5.10.43, 5.12.10, 5.13 | Patch available | CNA |
- Linux VendorLinux Affected 3.9 and later Fixed in 4.4.272, 4.9.272, 4.14.236, 4.19.194, 5.4.125, 5.10.43, 5.12.10, 5.13 Patch available CNA
CPE configurations NVD · 5
| CPE | Versions | Role | Vendor |
|---|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | before 4.4.272; 4.5 to before 4.9.272; 4.10 to before 4.14.236; 4.15 to before 4.19.194; 4.20 to before 5.4.125; 5.5 to before 5.10.43; 5.11 to before 5.12.10 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* | 5.13 rc1 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* | 5.13 rc2 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* | 5.13 rc3 | Vulnerable | Linux |
| cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* | 5.13 rc4 | Vulnerable | Linux |
- cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* Versions before 4.4.272; 4.5 to before 4.9.272; 4.10 to before 4.14.236; 4.15 to before 4.19.194; 4.20 to before 5.4.125; 5.5 to before 5.10.43; 5.11 to before 5.12.10 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc1:*:*:*:*:*:* Versions 5.13 rc1 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc2:*:*:*:*:*:* Versions 5.13 rc2 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc3:*:*:*:*:*:* Versions 5.13 rc3 Vulnerable ·Linux
- cpe:2.3:o:linux:linux_kernel:5.13:rc4:*:*:*:*:*:* Versions 5.13 rc4 Vulnerable ·Linux
Remediation
- Fix · CNA Linux (Linux) Fixed in 4.4.272, 4.9.272, 4.14.236, 4.19.194, 5.4.125, 5.10.43, 5.12.10, 5.13
Vendor assessments
Red Hat
Red Hat rating: Low. 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 |
Not affected: 2 products
- Red Hat Enterprise Linux 8
- Red Hat Enterprise Linux 9
Timeline
- 2026-10-02 Threatist record created from CVE-2021-47117
- 2026-10-03 Alias added: GHSA-2cqh-cfpq-83ph
References
Patch 8
- https://git.kernel.org/stable/c/e33bafad30d34cfa5e9787cb099cab05e2677fcb
- https://git.kernel.org/stable/c/5b3a9a2be59478b013a430ac57b0f3d65471b071
- https://git.kernel.org/stable/c/d8116743ef5432336289256b2f7c117299213eb9
- https://git.kernel.org/stable/c/569496aa3776eea1ff0d49d0174ac1b7e861e107
- https://git.kernel.org/stable/c/920697b004e49cb026e2e15fe91be065bf0741b7
- https://git.kernel.org/stable/c/d3b668b96ad3192c0581a248ae2f596cd054792a
- https://git.kernel.org/stable/c/48105dc98c9ca35af418746277b087cb2bc6df7c
- https://git.kernel.org/stable/c/082cd4ec240b8734a82a89ffb890216ac98fec68
More Linux Kernel vulnerabilities
- TI-2025-26358 tls: fix handling of zero-length records on the rx_list KEVCVSS 3.1CRITICAL 9.8
- 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-2021-47117 · CVE Program
- CVE-2021-47117 · NVD
- FIRST EPSS
- GHSA-2cqh-cfpq-83ph · GitHub Advisory Database · CC BY 4.0
- CVE-2021-47117 · 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