{"id":"CVE-2026-80841","url":"https://www.cyber-defence.io/tools/cve/CVE-2026-80841","generatedAt":"2026-10-28T07:04:08.093Z","title":"In the Linux kernel, the following vulnerability has been resolved: net/packet: defer vmalloc TX_RING free until skbs finish AF_PACKET TX_RING skbs keep a raw pointer to their ring frame.","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet/packet: defer vmalloc TX_RING free until skbs finish\n\nAF_PACKET TX_RING skbs keep a raw pointer to their ring frame. The skb\npage references preserve page-backed ring blocks after pg_vec is freed,\nbut they do not preserve a vmalloc mapping.\n\ntpacket_destruct_skb() currently drops the pending reference before\nwriting the timestamp and TP_STATUS_AVAILABLE to the frame. Move the\ndecrement after those stores. The smp_wmb() in __packet_set_status()\norders the frame stores before the decrement.\n\nAlso recheck pending TX frames under pg_vec_lock before non-closing\nring replacement, so a racing send cannot add a pending skb between\nthe initial check and the ring swap.\n\nRing allocation can produce a mixture of page-backed and vmalloc-backed\nblocks. Allocate deferred-work storage during TX ring setup when the\nfirst vmalloc-backed block is encountered, and keep its pointer in the\npg_vec allocation header. If allocation fails, return -ENOMEM from ring\nsetup. On socket close, a non-NULL pointer identifies a vmalloc-backed\nvector without a scan. If TX skbs remain, defer the whole vector to\nsystem_long_wq.\n\nAfter pg_vec is detached, a late destructor can skip the pending\ndecrement. Use socket write-memory accounting as the deferred lifetime\ngate instead: an skb remains charged through its final sock_wfree(),\nafter all ring-frame accesses. The delayed work retains a socket\nreference and reschedules itself until no TX skbs remain.\n\nMove pending_refcnt release to packet_sock_destruct() so late skb\ndestructors and deferred cleanup can safely use it after\npacket_release(). Page-backed teardown remains synchronous, and no lock\nis added to the TX completion hot path.","published":"2026-09-04T16:18:13.000Z","lastModified":"2026-10-19T09:17:19.000Z","status":"Received","sourceIdentifier":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","cvss":null,"cwe":[],"affected":[],"epss":{"score":0.00173,"percentile":0.06651,"date":"2026-10-27","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/0189dce07db2dc059ae0570e06758ec4233c6e11","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/debf9f50140b3df3949ebcb97d4450f8993fe32d","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b","source":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2026-80841","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."}