{"id":"CVE-2026-80841","title":"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","summary":"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 ri…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= b013840810c221f2b0cf641d01531526052dc1fb < 4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c","Linux >= b013840810c221f2b0cf641d01531526052dc1fb < ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b","Linux >= b013840810c221f2b0cf641d01531526052dc1fb < 0189dce07db2dc059ae0570e06758ec4233c6e11","Linux >= b013840810c221f2b0cf641d01531526052dc1fb < 550d00aa58193fb649a09a9c9e338c685adad784","Linux >= b013840810c221f2b0cf641d01531526052dc1fb < 992cc9f94ca924089a506ba9b327caa9af797529","Linux 3.14"],"published":"2026-09-04","updated":"2026-09-21","sourceUpdated":"2026-09-21T14:17:20.800","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2026-80841","references":[{"url":"https://git.kernel.org/stable/c/0189dce07db2dc059ae0570e06758ec4233c6e11","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"}],"tags":["nvd","cve.org"],"epss":0.00168,"epssPercentile":0.06487,"ingestedAt":"2026-09-11T16:45:47.925Z","slug":"CVE-2026-80841","body":"## Overview\n\nIn 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.\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}