CVE-2024-57952
Huawei Linux Kernel Directory Offset Allocation Vulnerability
Description
In the Linux kernel, the following vulnerability has been resolved: Revert "libfs: fix infinite directory reads for offset dir" The current directory offset allocator (based on mtree_alloc_cyclic) stores the next offset value to return in octx->next_offset. This mechanism typically returns values that increase monotonically over time. Eventually, though, the newly allocated offset value wraps back to a low number (say, 2) which is smaller than other already- allocated offset values. Yu Kuai <[email protected]> reports that, after commit 64a7ce76fb90 ("libfs: fix infinite directory reads for offset dir"), if a directory's offset allocator wraps, existing entries are no longer visible via readdir/getdents because offset_readdir() stops listing entries once an entry's offset is larger than octx->next_offset. These entries vanish persistently -- they can be looked up, but will never again appear in readdir(3) output. The reason for this is that the commit treats directory offsets as monotonically increasing integer values rather than opaque cookies, and introduces this comparison: if (dentry2offset(dentry) >= last_index) { On 64-bit platforms, the directory offset value upper bound is 2^63 - 1. Directory offsets will monotonically increase for millions of years without wrapping. On 32-bit platforms, however, LONG_MAX is 2^31 - 1. The allocator can wrap after only a few weeks (at worst). Revert commit 64a7ce76fb90 ("libfs: fix infinite directory reads for offset dir") to prepare for a fix that can work properly on 32-bit systems and might apply to recent LTS kernels where shmem employs the simple_offset mechanism.
INFO
Published Date :
Feb. 12, 2025, 2:15 p.m.
Last Modified :
Feb. 14, 2025, 3:52 p.m.
Remotely Exploit :
No
Source :
416baaa9-dc9f-4396-8d5f-8c081fb06d67
CVSS Scores
| Score | Version | Severity | Vector | Exploitability Score | Impact Score | Source |
|---|---|---|---|---|---|---|
| CVSS 3.1 | MEDIUM | [email protected] |
Solution
- Revert the commit that introduced the directory offset allocator issue.
- Apply a proper fix for directory offset allocation on 32-bit systems.
- Consider applying the fix to LTS kernels using simple_offset.
References to Advisories, Solutions, and Tools
Here, you will find a curated list of external links that provide in-depth
information, practical solutions, and valuable tools related to
CVE-2024-57952.
CWE - Common Weakness Enumeration
While CVE identifies
specific instances of vulnerabilities, CWE categorizes the common flaws or
weaknesses that can lead to vulnerabilities. CVE-2024-57952 is
associated with the following CWEs:
Common Attack Pattern Enumeration and Classification (CAPEC)
Common Attack Pattern Enumeration and Classification
(CAPEC)
stores attack patterns, which are descriptions of the common attributes and
approaches employed by adversaries to exploit the CVE-2024-57952
weaknesses.
We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).
Results are limited to the first 15 repositories due to potential performance issues.
The following list is the news that have been mention
CVE-2024-57952 vulnerability anywhere in the article.
The following table lists the changes that have been made to the
CVE-2024-57952 vulnerability over time.
Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.
-
Initial Analysis by [email protected]
Feb. 14, 2025
Action Type Old Value New Value Added CVSS V3.1 NIST AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H Added CWE NIST NVD-CWE-noinfo Added CPE Configuration OR *cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:* versions from (including) 6.11 up to (excluding) 6.12.12 *cpe:2.3:o:linux:linux_kernel:6.13:-:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc1:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc2:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc3:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc4:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc5:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc6:*:*:*:*:*:* *cpe:2.3:o:linux:linux_kernel:6.13:rc7:*:*:*:*:*:* Changed Reference Type https://git.kernel.org/stable/c/3f250b82040a72b0059ae00855a74d8570ad2147 No Types Assigned https://git.kernel.org/stable/c/3f250b82040a72b0059ae00855a74d8570ad2147 Patch Changed Reference Type https://git.kernel.org/stable/c/9e9e710f68bac49bd9b587823c077d06363440e0 No Types Assigned https://git.kernel.org/stable/c/9e9e710f68bac49bd9b587823c077d06363440e0 Patch Changed Reference Type https://git.kernel.org/stable/c/b662d858131da9a8a14e68661656989b14dbf113 No Types Assigned https://git.kernel.org/stable/c/b662d858131da9a8a14e68661656989b14dbf113 Patch -
New CVE Received by 416baaa9-dc9f-4396-8d5f-8c081fb06d67
Feb. 12, 2025
Action Type Old Value New Value Added Description In the Linux kernel, the following vulnerability has been resolved: Revert "libfs: fix infinite directory reads for offset dir" The current directory offset allocator (based on mtree_alloc_cyclic) stores the next offset value to return in octx->next_offset. This mechanism typically returns values that increase monotonically over time. Eventually, though, the newly allocated offset value wraps back to a low number (say, 2) which is smaller than other already- allocated offset values. Yu Kuai <[email protected]> reports that, after commit 64a7ce76fb90 ("libfs: fix infinite directory reads for offset dir"), if a directory's offset allocator wraps, existing entries are no longer visible via readdir/getdents because offset_readdir() stops listing entries once an entry's offset is larger than octx->next_offset. These entries vanish persistently -- they can be looked up, but will never again appear in readdir(3) output. The reason for this is that the commit treats directory offsets as monotonically increasing integer values rather than opaque cookies, and introduces this comparison: if (dentry2offset(dentry) >= last_index) { On 64-bit platforms, the directory offset value upper bound is 2^63 - 1. Directory offsets will monotonically increase for millions of years without wrapping. On 32-bit platforms, however, LONG_MAX is 2^31 - 1. The allocator can wrap after only a few weeks (at worst). Revert commit 64a7ce76fb90 ("libfs: fix infinite directory reads for offset dir") to prepare for a fix that can work properly on 32-bit systems and might apply to recent LTS kernels where shmem employs the simple_offset mechanism. Added Reference https://git.kernel.org/stable/c/3f250b82040a72b0059ae00855a74d8570ad2147 Added Reference https://git.kernel.org/stable/c/9e9e710f68bac49bd9b587823c077d06363440e0 Added Reference https://git.kernel.org/stable/c/b662d858131da9a8a14e68661656989b14dbf113