Answer in brief
CVE-2023-53503 records a Medium severity (CVSS 5.5) vulnerability in ext4: allow ext4_get_group_info() to fail. The current sources do not mark it as known exploited. The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
Analysis pending evidence review
HOL Guard separates source facts from reviewed analysis. See the methodology.
CVSS is 5.5. The current sources do not mark it as known exploited. Treat this as a source-backed prioritization signal, not a statement about your environment.
Analysis status
Analysis pending evidence review
Factual feed record only; HOL analysis is not approved for indexing. Read the methodology.
The current feed maps Linux/Linux (generic), Linux/Linux (generic). Check affected ranges and fixed versions before updating.
| Product | Affected versions | Fixed versions |
|---|---|---|
| cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* | Not reported | Not reported |
| cpe:2.3:o:linux:linux_kernel:6.4:rc1:*:*:*:*:*:* | Not reported | Not reported |
| Package | Affected range | Fixed version |
|---|---|---|
| Linux/Linuxgeneric | >=2f2e09eb15849562aede80ed007658e4504ded26 <100c0ad6c04597fefeaaba2bb1827cc015d95067 || >=2f2e09eb15849562aede80ed007658e4504ded26 <620a3c28221bb219b81bc0bffd065cc187494302 || >=2f2e09eb15849562aede80ed007658e4504ded26 <b4319e457d6e3fb33e443efeaf4634fc36e8a9ed || >=2f2e09eb15849562aede80ed007658e4504ded26 <31668cebf45adfb6283e465e641c4f5a21b07afa || >=2f2e09eb15849562aede80ed007658e4504ded26 <5354b2af34064a4579be8bc0e2f15a7b70f14b5f | 100c0ad6c04597fefeaaba2bb1827cc015d95067, 620a3c28221bb219b81bc0bffd065cc187494302, b4319e457d6e3fb33e443efeaf4634fc36e8a9ed, 31668cebf45adfb6283e465e641c4f5a21b07afa, 5354b2af34064a4579be8bc0e2f15a7b70f14b5f |
| Linux/Linuxgeneric | 3.11 | Not reported |
Published upstream
Oct 1, 2025
Evidence: source:cvelist:source_dates:source-dates:recordSource modified
Nov 5, 2026
Evidence: source:cvelist:source_dates:source-dates:recordFirst seen by HOL
Nov 5, 2026
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.
Quoted source text, attributed separately from HOL analysis.