{"id":"CVE-2026-64424","title":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetpoll: fix a use-after-free on shutdown path\n\nThere is a use-after-free error on netpoll, which is clearly detected by\nKASAN.\n\n      BUG: KASAN: slab-use-after-free i…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\nnetpoll: fix a use-after-free on shutdown path\n\nThere is a use-after-free error on netpoll, which is clearly detected by\nKASAN.\n\n      BUG: KASAN: slab-use-after-free i…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-416"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 3.6.1, < 6.12.96","linux_kernel >= 6.13, < 6.18.39","linux_kernel >= 6.19, < 7.1.4","linux_kernel = 3.6","linux_kernel = 7.2"],"patched":["linux_kernel 7.1.4"],"published":"2026-07-25","updated":"2026-09-04","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-64424","references":[{"url":"https://git.kernel.org/stable/c/45f1458a85017a023f138b22ac5c76abd477db42","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/5ed09a108d93a3b002cc79823d9455b50c4a8be7","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/95ecc5b58042f6b6743b589e6588f1cd7ba336aa","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a33f37f8d079da7236ed7b7e2aed2a34ab81e7cf","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd"],"epss":0.00125,"epssPercentile":0.02538,"ingestedAt":"2026-09-05T15:41:15.875Z","slug":"CVE-2026-64424","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\nnetpoll: fix a use-after-free on shutdown path\n\nThere is a use-after-free error on netpoll, which is clearly detected by\nKASAN.\n\n      BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3b/0x80\n      Read of size 1 at addr ... by task kworker/9:1\n      Workqueue: events queue_process\n      Call Trace:\n       skb_dequeue+0x1e/0xb0\n       queue_process+0x2c/0x600\n       process_scheduled_works+0x4b6/0x850\n       worker_thread+0x414/0x5a0\n      Allocated by task 242:\n       __netpoll_setup+0x201/0x4a0\n       netpoll_setup+0x249/0x550\n       enabled_store+0x32f/0x380\n      Freed by task 0:\n       kfree+0x1b7/0x540\n       rcu_core+0x3f8/0x7a0\n\nThe problem happens when there is a pending TX worker running in\nparallel with the cleanup path.\n\nThis is what happens on netpoll shutdown path:\n\n1) __netpoll_cleanup() is called\n2) set dev->npinfo to NULL\n3) call_rcu() with rcu_cleanup_netpoll_info()\n  3.1) rcu_cleanup_netpoll_info() tries to cancel all workers with\n       cancel_delayed_work(), but doesn't wait for the worker to finish\n4) and kfree(npinfo);\n\nBecause 3.1) doesn't really cancel the work, as the comment says \"we\ncan't call cancel_delayed_work_sync here, as we are in softirq\", the TX\nworker can run after 4).\n\nTl;DR: queue_process() is not an RCU reader, it reaches npinfo through\nthe work item via container_of().\n\nUse disable_delayed_work_sync() to ensure the worker is completely\nstopped and prevent any future re-arming attempts. Once npinfo is set\nto NULL, senders will bail out and not queue new work. The disable flag\nensures any in-flight re-arming attempts also fail silently.\n\nIn the future, we can do the cleanup inline here without needing the\nnpinfo->rcu rcu_head, but that is net-next material.\n\n## Affected\n\n- `linux_kernel >= 3.6.1, < 6.12.96`\n- `linux_kernel >= 6.13, < 6.18.39`\n- `linux_kernel >= 6.19, < 7.1.4`\n- `linux_kernel = 3.6`\n- `linux_kernel = 7.2`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 7.1.4`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}