{"id":"CVE-2026-64579","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-64579","generatedAt":"2026-10-28T03:26:25.254Z","title":"In the Linux kernel, the following vulnerability has been resolved: xfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert xfrm_hash_rebuild()'s first loop preallocates the bins/chains the reinsert loop needs, so the reinsert (after…","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nxfrm: policy: preallocate inexact bins before xfrm_hash_rebuild reinsert\n\nxfrm_hash_rebuild()'s first loop preallocates the bins/chains the reinsert\nloop needs, so the reinsert (after hlist_del_rcu()) cannot allocate or\nfail. But its guard is inverted: it skips policies with prefixlen <\nthreshold and preallocates for the rest.\n\nprefixlen < threshold is exactly when policy_hash_bysel() returns NULL and\nthe reinsert takes the allocating xfrm_policy_inexact_insert() path. So the\nloop preallocates for the exact policies (which never allocate) and skips\nthe inexact ones, whose bin/node is then allocated GFP_ATOMIC during\nreinsert. On failure the error path only WARN_ONCE()s and continues,\nleaving a poisoned bydst node; the next rebuild's hlist_del_rcu()\ndereferences LIST_POISON2 and takes a GPF. Reachable under memory pressure,\ndeterministic via failslab.\n\nInvert the guard so preallocation covers exactly the reinserted policies;\nthe reinsert then allocates nothing and cannot fail.\n\nCrash:\n  Oops: general protection fault, probably for non-canonical address\n  0xfbd59c0000000024: 0000 [#1] SMP KASAN NOPTI\n  KASAN: maybe wild-memory-access in range [0xdead...]\n  ...\n  Workqueue: events xfrm_hash_rebuild\n  RIP: 0010:xfrm_hash_rebuild+0x5b3/0x1190\n  RAX: dead000000000122   (LIST_POISON2 + offset)\n  ...\n  Call Trace:\n   hlist_del_rcu (include/linux/rculist.h:599)\n   xfrm_hash_rebuild (net/xfrm/xfrm_policy.c:1365)\n   process_one_work (kernel/workqueue.c:3322)\n   worker_thread (kernel/workqueue.c:3486)\n   kthread (kernel/kthread.c:436)\n   ret_from_fork (arch/x86/kernel/process.c:158)\n   ret_from_fork_asm (arch/x86/entry/entry_64.S:245)\n   ...\n  Kernel panic - not syncing: Fatal exception in interrupt","published":"2026-08-05T08:16:38.000Z","lastModified":"2026-08-19T17:20:18.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00171,"percentile":0.06427,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"unknown","text":"Not yet scored. NVD analysis is pending; check back once CVSS and EPSS values are published."},"changes":[],"references":[{"url":"https://git.kernel.org/stable/c/1cdeed9df1306f1a277e715600772640d63defa9","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/43a4d510523779891cf8eca7ffb4a086b0b5d8bf","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/6aa3796d18a9fda953ad76a62b57bf6c145cb9ef","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/7acc5ed2f33608a3d83b64f50a5766843b6e2485","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/94c00391a5117530188334f740ce26d3f1256190","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/d9d9cc21cc90014724a14c447e3d587be9447107","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e48f4c3e3df35b34be719d72d737bbeaca77cf0c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/f38f8cce2f7e79775b3db7e8a5eacda04ac908e4","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-64579","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}