{"id":"CVE-2024-45021","state":"PUBLISHED","title":"memcg_write_event_control(): fix a user-triggerable oops","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nmemcg_write_event_control(): fix a user-triggerable oops\n\nwe are *not* guaranteed that anything past the terminating NUL\nis mapped (let alone initialized with anything sane).","publishedAt":"2024-09-11T15:13:55.211Z","updatedAt":"2026-08-05T11:37:45.912Z","severity":{"score":7.1,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"fa5bfdf6cb5846a00e712d630a43e3cf55ccb411","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"1b37ec85ad95b612307627758c6018cd9d92cca8","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"ad149f5585345e383baa65f1539d816cd715fd3b","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"0fbe2a72e853a1052abe9bc2b7df8ddb102da227","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"43768fa80fd192558737e24ed6548f74554611d7","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"f1aa7c509aa766080db7ab3aec2e31b1df09e57c","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"21b578f1d599edb87462f11113c5b0fc7a04ac61","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"046667c4d3196938e992fba0dfcde570aa85cd0e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memcontrol-v1.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.34","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.34","versionType":"semver"},{"version":"4.19.321","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.283","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.225","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.166","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.107","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.48","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.7","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memcontrol-v1.c"]}],"references":["https://git.kernel.org/stable/c/fa5bfdf6cb5846a00e712d630a43e3cf55ccb411","https://git.kernel.org/stable/c/1b37ec85ad95b612307627758c6018cd9d92cca8","https://git.kernel.org/stable/c/ad149f5585345e383baa65f1539d816cd715fd3b","https://git.kernel.org/stable/c/0fbe2a72e853a1052abe9bc2b7df8ddb102da227","https://git.kernel.org/stable/c/43768fa80fd192558737e24ed6548f74554611d7","https://git.kernel.org/stable/c/f1aa7c509aa766080db7ab3aec2e31b1df09e57c","https://git.kernel.org/stable/c/21b578f1d599edb87462f11113c5b0fc7a04ac61","https://git.kernel.org/stable/c/046667c4d3196938e992fba0dfcde570aa85cd0e","https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html","https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:07:47.831Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2024/45xxx/CVE-2024-45021.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2024-45021","state":"PUBLISHED","datePublished":"2024-09-11T15:13:55.211Z","dateUpdated":"2026-08-05T11:37:45.912Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2024-08-21T05:34:56.684Z"},"containers":{"cna":{"title":"memcg_write_event_control(): fix a user-triggerable oops","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nmemcg_write_event_control(): fix a user-triggerable oops\n\nwe are *not* guaranteed that anything past the terminating NUL\nis mapped (let alone initialized with anything sane)."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"fa5bfdf6cb5846a00e712d630a43e3cf55ccb411","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"1b37ec85ad95b612307627758c6018cd9d92cca8","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"ad149f5585345e383baa65f1539d816cd715fd3b","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"0fbe2a72e853a1052abe9bc2b7df8ddb102da227","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"43768fa80fd192558737e24ed6548f74554611d7","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"f1aa7c509aa766080db7ab3aec2e31b1df09e57c","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"21b578f1d599edb87462f11113c5b0fc7a04ac61","versionType":"git"},{"version":"0dea116876eefc9c7ca9c5d74fe665481e499fa3","status":"affected","lessThan":"046667c4d3196938e992fba0dfcde570aa85cd0e","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memcontrol-v1.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.34","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.34","versionType":"semver"},{"version":"4.19.321","status":"unaffected","lessThanOrEqual":"4.19.*","versionType":"semver"},{"version":"5.4.283","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.225","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.166","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.107","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.48","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.10.7","status":"unaffected","lessThanOrEqual":"6.10.*","versionType":"semver"},{"version":"6.11","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["mm/memcontrol-v1.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/fa5bfdf6cb5846a00e712d630a43e3cf55ccb411"},{"url":"https://git.kernel.org/stable/c/1b37ec85ad95b612307627758c6018cd9d92cca8"},{"url":"https://git.kernel.org/stable/c/ad149f5585345e383baa65f1539d816cd715fd3b"},{"url":"https://git.kernel.org/stable/c/0fbe2a72e853a1052abe9bc2b7df8ddb102da227"},{"url":"https://git.kernel.org/stable/c/43768fa80fd192558737e24ed6548f74554611d7"},{"url":"https://git.kernel.org/stable/c/f1aa7c509aa766080db7ab3aec2e31b1df09e57c"},{"url":"https://git.kernel.org/stable/c/21b578f1d599edb87462f11113c5b0fc7a04ac61"},{"url":"https://git.kernel.org/stable/c/046667c4d3196938e992fba0dfcde570aa85cd0e"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:H","baseScore":7.1,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The vulnerability is triggered by a write(2) to the cgroup v1 file `cgroup.event_control` on a locally mounted cgroupfs hierarchy. There is no network-reachable path to `memcg_write_event_control()`.\nAC:L - The attacker fully controls the write length and content, so the out-of-bounds read past the end of the `kmalloc(len+1)` buffer is 100% deterministic; sizing the write to exactly 4095 bytes places the buffer at a page boundary, and heap/page grooming lets the attacker steer the unbounded `memparse()` walk into an unmapped page. cgroup v1 with the memory controller is a widely deployed default (Android, legacy/hybrid systemd, embedded), not a rare config.\nPR:L - `cgroup.event_control` was flagged `CFTYPE_WORLD_WRITABLE` (mode 0666), so any unprivileged local user can write it wherever a cgroup v1 memory hierarchy is mounted; additionally `cgroup_fs_type` has `FS_USERNS_MOUNT` and `cgroup1_get_tree()` only requires `ns_capable(user_ns, CAP_SYS_ADMIN)`, obtainable via `unshare -Urmc`.\nUI:N - A single write() syscall from the attacker's own process triggers the bug; no victim action, mount by an administrator, or other user involvement is required.\nS:U - The out-of-bounds read and the resulting oops occur entirely within the kernel's own security authority, with no crossing of a VM, IOMMU, or sandbox boundary.\nC:H - The read runs off the end of the slab object and, via `memparse()`/`simple_strtoull()`, continues unbounded until a non-digit byte (and up to 19 bytes via `kstrndup()` on the vmpressure path), so it is not strictly bounded to a few bytes. The parsed adjacent-heap value is installed as a memcg usage threshold that the attacker can read back by driving cgroup memory usage and observing eventfd notifications, giving a genuine kernel-memory disclosure channel.\nI:N - The defect is purely an out-of-bounds read; no memory is written out of bounds and no attacker-controlled write primitive is created. The only state change is a threshold value inside the attacker's own cgroup, which they could already set directly by supplying an explicit args field.\nA:H - The unbounded read past a page-aligned kmalloc-4k object can reach an unmapped page and produce a kernel oops, exactly as described by the fix (\"user-triggerable oops\"); on KASAN or DEBUG_PAGEALLOC kernels the fault is deterministic and repeatable."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-05T11:37:45.912Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"4.19.321"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"5.4.283"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"5.10.225"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"5.15.166"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"6.1.107"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"6.6.48"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"6.10.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.34","versionEndExcluding":"6.11"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"timestamp":"2024-09-29T15:47:59.119087Z","id":"CVE-2024-45021","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"partial"}],"role":"CISA Coordinator","version":"2.0.3"}}}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2024-09-29T15:48:13.491Z"}},{"title":"CVE Program Container","references":[{"url":"https://lists.debian.org/debian-lts-announce/2025/01/msg00001.html"},{"url":"https://lists.debian.org/debian-lts-announce/2024/10/msg00003.html"}],"providerMetadata":{"shortName":"CVE","orgId":"af854a3a-2127-422b-91ae-364da2661108","dateUpdated":"2025-11-03T22:15:30.579Z"}}]}}}