CVE-2024-35797
- Source
- https://nvd.nist.gov/vuln/detail/CVE-2024-35797
- Import Source
- https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-35797.json
- JSON Data
- https://api.osv.dev/v1/vulns/CVE-2024-35797
- Downstream
- Related
- Published
- 2024-05-17T13:23:08Z
- Modified
- 2025-10-21T21:26:09.114585Z
- Severity
-
- 5.3 (Medium) CVSS_V3 - CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L CVSS Calculator
- Summary
- mm: cachestat: fix two shmem bugs
- Details
-
In the Linux kernel, the following vulnerability has been resolved:
mm: cachestat: fix two shmem bugs
When cachestat on shmem races with swapping and invalidation, there are two possible bugs:
1) A swapin error can have resulted in a poisoned swap entry in the shmem inode's xarray. Calling getshadowfromswapcache() on it will result in an out-of-bounds access to swapper_spaces[].
Validate the entry with nonswapentry() before going further.
2) When we find a valid swap entry in the shmem's inode, the shadow entry in the swapcache might not exist yet: swap IO is still in progress and we're before _removemapping; swapin, invalidation, or swapoff have removed the shadow from swapcache after we saw the shmem swap entry.
This will send a NULL to workingsettestrecent(). The latter purely operates on pointer bits, so it won't crash - node 0, memcg ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a bogus test. In theory that could result in a false "recently evicted" count.
Such a false positive wouldn't be the end of the world. But for code clarity and (future) robustness, be explicit about this case.
Bail on getshadowfromswapcache() returning NULL.
- References
-
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- https://git.kernel.org/stable/c/24a0e73d544439bb9329fbbafac44299e548a677
- https://git.kernel.org/stable/c/b79f9e1ff27c994a4c452235ba09e672ec698e23
- https://git.kernel.org/stable/c/d5d39c707a4cf0bcc84680178677b97aa2cb2627
- https://git.kernel.org/stable/c/d962f6c583458037dc7e529659b2b02b9dd3d94b
Affected packages
Git / git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
Affected ranges
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedcf264e1329fb0307e044f7675849f9f38b44c11aFixedb79f9e1ff27c994a4c452235ba09e672ec698e23
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedcf264e1329fb0307e044f7675849f9f38b44c11aFixedd962f6c583458037dc7e529659b2b02b9dd3d94b
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedcf264e1329fb0307e044f7675849f9f38b44c11aFixed24a0e73d544439bb9329fbbafac44299e548a677
- Type
- GIT
- Repo
- https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git
- Events
-
Introducedcf264e1329fb0307e044f7675849f9f38b44c11aFixedd5d39c707a4cf0bcc84680178677b97aa2cb2627