{"id":"CVE-2024-35797","summary":"mm: cachestat: fix two shmem bugs","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmm: cachestat: fix two shmem bugs\n\nWhen cachestat on shmem races with swapping and invalidation, there\nare two possible bugs:\n\n1) A swapin error can have resulted in a poisoned swap entry in the\n   shmem inode's xarray. Calling get_shadow_from_swap_cache() on it\n   will result in an out-of-bounds access to swapper_spaces[].\n\n   Validate the entry with non_swap_entry() before going further.\n\n2) When we find a valid swap entry in the shmem's inode, the shadow\n   entry in the swapcache might not exist yet: swap IO is still in\n   progress and we're before __remove_mapping; swapin, invalidation,\n   or swapoff have removed the shadow from swapcache after we saw the\n   shmem swap entry.\n\n   This will send a NULL to workingset_test_recent(). The latter\n   purely operates on pointer bits, so it won't crash - node 0, memcg\n   ID 0, eviction timestamp 0, etc. are all valid inputs - but it's a\n   bogus test. In theory that could result in a false \"recently\n   evicted\" count.\n\n   Such a false positive wouldn't be the end of the world. But for\n   code clarity and (future) robustness, be explicit about this case.\n\n   Bail on get_shadow_from_swap_cache() returning NULL.","modified":"2026-04-02T11:51:07.857293Z","published":"2024-05-17T13:23:08.204Z","related":["ALSA-2024:6567"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/35xxx/CVE-2024-35797.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/24a0e73d544439bb9329fbbafac44299e548a677"},{"type":"WEB","url":"https://git.kernel.org/stable/c/b79f9e1ff27c994a4c452235ba09e672ec698e23"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d5d39c707a4cf0bcc84680178677b97aa2cb2627"},{"type":"WEB","url":"https://git.kernel.org/stable/c/d962f6c583458037dc7e529659b2b02b9dd3d94b"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2024/35xxx/CVE-2024-35797.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2024-35797"},{"type":"PACKAGE","url":"https://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":[{"introduced":"cf264e1329fb0307e044f7675849f9f38b44c11a"},{"fixed":"b79f9e1ff27c994a4c452235ba09e672ec698e23"},{"fixed":"d962f6c583458037dc7e529659b2b02b9dd3d94b"},{"fixed":"24a0e73d544439bb9329fbbafac44299e548a677"},{"fixed":"d5d39c707a4cf0bcc84680178677b97aa2cb2627"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2024-35797.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:L"}]}