In the Linux kernel, the following vulnerability has been resolved:
ext4: handle wraparound when searching for blocks for indirect mapped blocks
Commit 4865c768b563 ("ext4: always allocate blocks only from groups
inode can use") restricts what blocks will be allocated for indirect
block based files to block numbers that fit within 32-bit block
numbers.
However, when using a review bot running on the latest Gemini LLM to
check this commit when backporting into an LTS based kernel, it raised
this concern:
If ac->ac_g_ex.fe_group is >= ngroups (for instance, if the goal
group was populated via stream allocation from s_mb_last_groups),
then start will be >= ngroups.
Does this allow allocating blocks beyond the 32-bit limit for
indirect block mapped files? The commit message mentions that
ext4_mb_scan_groups_linear() takes care to not select unsupported
groups. However, its loop uses group = *start, and the very first
iteration will call ext4_mb_scan_group() with this unsupported
group because next_linear_group() is only called at the end of the
iteration.
After reviewing the code paths involved and considering the LLM
review, I determined that this can happen when there is a file system
where some files/directories are extent-mapped and others are
indirect-block mapped. To address this, add a safety clamp in
ext4_mb_scan_groups().
References
Configurations
Configuration 1 (hide)
|
History
20 May 2026, 23:16
| Type | Values Removed | Values Added |
|---|---|---|
| References | () https://git.kernel.org/stable/c/12624c5b724a81e14e532972b40d863b0de3b7d1 - Patch | |
| References | () https://git.kernel.org/stable/c/2a368ccddfc492a0aa951e2caef2985f20e96503 - Patch | |
| References | () https://git.kernel.org/stable/c/4bec4a498ce86314d470ae6144120461f2138c29 - Patch | |
| References | () https://git.kernel.org/stable/c/83170a05908b6cf2fb3235d3065bf613ff866f3c - Patch | |
| References | () https://git.kernel.org/stable/c/bb81702370fad22c06ca12b6e1648754dbc37e0f - Patch | |
| References | () https://git.kernel.org/stable/c/f89bba144938921a2249237ad04a0183ff3f8930 - Patch | |
| First Time |
Linux linux Kernel
Linux |
|
| CPE | cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* cpe:2.3:o:linux:linux_kernel:6.1.167:*:*:*:*:*:*:* |
|
| CWE | NVD-CWE-noinfo |
08 May 2026, 13:16
| Type | Values Removed | Values Added |
|---|---|---|
| CVSS |
v2 : v3 : |
v2 : unknown
v3 : 9.8 |
05 May 2026, 16:16
| Type | Values Removed | Values Added |
|---|---|---|
| New CVE |
Information
Published : 2026-05-05 16:16
Updated : 2026-05-20 23:16
NVD link : CVE-2026-43067
Mitre link : CVE-2026-43067
CVE.ORG link : CVE-2026-43067
JSON object : View
Products Affected
linux
- linux_kernel
CWE