Medium 5.5Published May 5, 2026

CVE-2026-43068ext4: avoid allocate block from corrupted group in ext4_mb_find_by_goal()

Updated under an hour ago (Oct 27, 2026, 9:40 AM ET)

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Exploited in the last 30 days

In the Linux kernel, the following vulnerability has been resolved: ext4: avoid allocate block from corrupted group in ext4_mb_find_by_goal() There's issue as follows: ... EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 206 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 2243 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): Delayed block allocation failed for inode 2239 at logical offset 0 with max blocks 1 with error 117 EXT4-fs (mmcblk0p1): This should not happen!! Data will be lost EXT4-fs (mmcblk0p1): error count since last fsck: 1 EXT4-fs (mmcblk0p1): initial error at time 1765597433: ext4_mb_generate_buddy:760 EXT4-fs (mmcblk0p1): last error at time 1765597433: ext4_mb_generate_buddy:760 ... According to the log analysis, blocks are always requested from the corrupted block group. This may happen as follows: ext4_mb_find_by_goal ext4_mb_load_buddy ext4_mb_load_buddy_gfp ext4_mb_init_cache ext4_read_block_bitmap_nowait ext4_wait_block_bitmap ext4_validate_block_bitmap if (!grp || EXT4_MB_GRP_BBITMAP_CORRUPT(grp)) return -EFSCORRUPTED; // There's no logs. if (err) return err; // Will return error ext4_lock_group(ac->ac_sb, group); if (unlikely(EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info))) // Unreachable goto out; After commit 9008a58e5dce ("ext4: make the bitmap read routines return real error codes") merged, Commit 163a203ddb36 ("ext4: mark block group as corrupt on block bitmap error") is no real solution for allocating blocks from corrupted block groups. This is because if 'EXT4_MB_GRP_BBITMAP_CORRUPT(e4b->bd_info)' is true, then 'ext4_mb_load_buddy()' may return an error. This means that the block allocation will fail. Therefore, check block group if corrupted when ext4_mb_load_buddy() returns error.

CVSS: 5.5 MEDIUM (v3.1, NVD)CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Weakness (CWE): Not given
Known exploited: Not in CISA's KEV catalog
EPSS (exploitation in the next 30 days): Not loaded for this CVE
Assigned by: Linux
NVD analysis: Analyzed
Record last updated: May 11, 2026
First seen by InfoSec Signals: Oct 9, 2026

Affected products

Affected products

Linux Linux linux:linux (from the name)	from 163a203ddb36c36d4a1c942aececda0cc8d06aa7 before fea6b2e250ff48f10d166011b57a8516ae5438c9; 163a203ddb36c36d4a1c942aececda0cc8d06aa7 builds before 0b84571c886719823d537f05f4f07cad6357c4b7; from 163a203ddb36c36d4a1c942aececda0cc8d06aa7 before ffc0a282462d45fee5957621be5afa29752f3b6d; 163a203ddb36c36d4a1c942aececda0cc8d06aa7 builds before 2d31a5073f86a177edf44015e0dedb0c47cfd6d8; from 163a203ddb36c36d4a1c942aececda0cc8d06aa7 before 9370207b36d26e45a8c8ef0500706d37036edd6b; from 163a203ddb36c36d4a1c942aececda0cc8d06aa7 before 1895f7904be71c48f1e6f338b28f24dabd6b8aeb; 163a203ddb36c36d4a1c942aececda0cc8d06aa7 builds before 1c0d7c4cde38a887c6d74e0c89ddb25226943c78; from 163a203ddb36c36d4a1c942aececda0cc8d06aa7 before 46066e3a06647c5b186cc6334409722622d05c44	CNA record
linux linux_kernel linux:linux_kernel	from 3.12 before 5.10.253; from 5.11 before 5.15.203; from 5.16 before 6.1.168; from 6.2 before 6.6.131; from 6.7 before 6.12.80; from 6.13 before 6.18.21; from 6.19 before 6.19.11; 7.0; and 6 more ranges	NVD

References

References

https://git.kernel.org/stable/c/fea6b2e250ff48f10d166011b57a8516ae5438c9	patch
https://git.kernel.org/stable/c/0b84571c886719823d537f05f4f07cad6357c4b7	patch
https://git.kernel.org/stable/c/ffc0a282462d45fee5957621be5afa29752f3b6d	patch
https://git.kernel.org/stable/c/2d31a5073f86a177edf44015e0dedb0c47cfd6d8	patch
https://git.kernel.org/stable/c/9370207b36d26e45a8c8ef0500706d37036edd6b	patch
https://git.kernel.org/stable/c/1895f7904be71c48f1e6f338b28f24dabd6b8aeb	patch
https://git.kernel.org/stable/c/1c0d7c4cde38a887c6d74e0c89ddb25226943c78	patch
https://git.kernel.org/stable/c/46066e3a06647c5b186cc6334409722622d05c44	patch

The CVE record on cve.org NVD's entry

The CVE record is authoritative. Products marked “from the name” were identified from the CNA's free-text names, not a CPE, and are matched less certainly. This product uses the NVD API but is not endorsed or certified by the NVD.