{"id":"CVE-2026-53162","summary":"memcg: use round-robin victim selection in refill_stock","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nmemcg: use round-robin victim selection in refill_stock\n\nHarry Yoo reported that get_random_u32_below() is not safe to call in the\nnmi context and memcg charge draining can happen in nmi context.\n\nMore specifically get_random_u32_below() is neither reentrant- nor\nNMI-safe: it acquires a per-cpu local_lock via local_lock_irqsave() on the\nbatched_entropy_u32 state.  An NMI that lands on a CPU mid-update of the\nChaCha batch state and recurses into the random subsystem would corrupt\nthat state.  The memcg_stock local_trylock prevents re-entry on the percpu\nstock itself, but cannot protect an unrelated subsystem's per-cpu lock.\n\nReplace the random pick with a per-cpu round-robin counter stored in\nmemcg_stock_pcp and serialized by the same local_trylock that already\nguards cached[] and nr_pages[].  No atomics, no random calls, no extra\nlocks needed.","modified":"2026-07-08T08:07:23.550617739Z","published":"2026-06-25T08:38:43.453Z","related":["CGA-h4fm-2926-92v4"],"database_specific":{"osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53162.json","cna_assigner":"Linux"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/00731bd7e18f182a32ca54d6b176eaa470b51ed7"},{"type":"WEB","url":"https://git.kernel.org/stable/c/89bd8215e25aa6999cc51696da418e0d422bc5e0"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c0cafe24d3f6534294c4b2bc2d47734ff7cbd313"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/53xxx/CVE-2026-53162.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-53162"},{"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":"f735eebe55f8f61758fe014bd0b02ab50b059e4d"},{"fixed":"89bd8215e25aa6999cc51696da418e0d422bc5e0"},{"fixed":"00731bd7e18f182a32ca54d6b176eaa470b51ed7"},{"fixed":"c0cafe24d3f6534294c4b2bc2d47734ff7cbd313"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53162.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"6.16.0"},{"fixed":"6.18.36"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.0.13"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-53162.json"}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}