CVE-2022-49707
ext4: add reserved GDT blocks check
- Published
- Updated
- Reserved
- Assigned by
- Linux
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: add reserved GDT blocks check We capture a NULL pointer issue when resizing a corrupt ext4 image which is freshly clear resize_inode feature (not run e2fsck). It could be simply reproduced by following steps. The problem is because of the resize_inode feature was cleared, and it will convert the filesystem to meta_bg mode in ext4_resize_fs(), but the es->s_reserved_gdt_blocks was not reduced to zero, so could we mistakenly call reserve_backup_gdb() and passing an uninitialized resize_inode to it when adding new group descriptors. mkfs.ext4 /dev/sda 3G tune2fs -O ^resize_inode /dev/sda #forget to run requested e2fsck mount /dev/sda /mnt resize2fs /dev/sda 8G ======== BUG: kernel NULL pointer dereference, address: 0000000000000028 CPU: 19 PID: 3243 Comm: resize2fs Not tainted 5.18.0-rc7-00001-gfde086c5ebfd #748 ... RIP: 0010:ext4_flex_group_add+0xe08/0x2570 ... Call Trace: <TASK> ext4_resize_fs+0xbec/0x1660 __ext4_ioctl+0x1749/0x24e0 ext4_ioctl+0x12/0x20 __x64_sys_ioctl+0xa6/0x110 do_syscall_64+0x3b/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7f2dd739617b ======== The fix is simple, add a check in ext4_resize_begin() to make sure that the es->s_reserved_gdt_blocks is zero when the resize_inode feature is disabled.
Timeline
ID reserved
By Linux
Published
- 15 months later
· 15 months later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| CISA-ADPADP (enrichment) | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
| NVDNVD · Modified | 3.1 | Medium5.5 | CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H |
- EPSS (exploitation in 30 days)
- 0.28% · top 79% of all CVEs (7 Nov 2026)
- CISA SSVC
- Exploitation: none · Automatable: no · Technical impact: partial
The list uses the assigner's score when there is one, then CISA's, then NVD's: Medium 5.5.
Weakness
Affected products
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < 0dc2fca8e4f9ac4a40e8424a10163369cca0cc06
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < 7c921328ac760bba780bdace41f4cd045f7f1405
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < b9747263b13e5290ac4d63bec47e38f701303cad
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < fba54289176702a7caac0b64738406775817f451
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < bfd004a1d3a062aac300523d406ac1f3e5f1a82c
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < 33b1bba31f4c784d33d2c2517964bdccdc9204cd
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < af75c481a2e45e70f62f5942c93695e95bf7bd21
- affected 1c6bd7173d66b3dfdefcedb38cabc1fb03997509 – < b55c3cd102a6f48b90e61c44f7f3dda8c290c694
- affected 3.7
- unaffected < 3.7
- unaffected 4.9.320 – ≤ 4.9.*
- unaffected 4.14.285 – ≤ 4.14.*
- unaffected 4.19.249 – ≤ 4.19.*
- unaffected 5.4.200 – ≤ 5.4.*
- unaffected 5.10.124 – ≤ 5.10.*
- unaffected 5.15.49 – ≤ 5.15.*
- unaffected 5.18.6 – ≤ 5.18.*
- unaffected 5.19 – ≤ *
References (8)
- https://git.kernel.org/stable/c/0dc2fca8e4f9ac4a40e8424a10163369cca0cc06 (opens in a new tab)
- https://git.kernel.org/stable/c/7c921328ac760bba780bdace41f4cd045f7f1405 (opens in a new tab)
- https://git.kernel.org/stable/c/b9747263b13e5290ac4d63bec47e38f701303cad (opens in a new tab)
- https://git.kernel.org/stable/c/fba54289176702a7caac0b64738406775817f451 (opens in a new tab)
- https://git.kernel.org/stable/c/bfd004a1d3a062aac300523d406ac1f3e5f1a82c (opens in a new tab)
- https://git.kernel.org/stable/c/33b1bba31f4c784d33d2c2517964bdccdc9204cd (opens in a new tab)
- https://git.kernel.org/stable/c/af75c481a2e45e70f62f5942c93695e95bf7bd21 (opens in a new tab)
- https://git.kernel.org/stable/c/b55c3cd102a6f48b90e61c44f7f3dda8c290c694 (opens in a new tab)
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisories (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
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[](https://trackcve.app/cve/CVE-2022-49707)Record last updated .