{"id":"CVE-2026-80841","state":"PUBLISHED","title":"net/packet: defer vmalloc TX_RING free until skbs finish","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.","publishedAt":"2026-09-04T15:54:51.459Z","updatedAt":"2026-10-30T12:31:11.820Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"ed126ca71d4d949ad99f40b974a8f7685e808f8b","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"debf9f50140b3df3949ebcb97d4450f8993fe32d","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"0189dce07db2dc059ae0570e06758ec4233c6e11","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"550d00aa58193fb649a09a9c9e338c685adad784","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"992cc9f94ca924089a506ba9b327caa9af797529","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/packet/af_packet.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.14","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/packet/af_packet.c"]}],"references":["https://git.kernel.org/stable/c/ed126ca71d4d949ad99f40b974a8f7685e808f8b","https://git.kernel.org/stable/c/debf9f50140b3df3949ebcb97d4450f8993fe32d","https://git.kernel.org/stable/c/4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c","https://git.kernel.org/stable/c/ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b","https://git.kernel.org/stable/c/0189dce07db2dc059ae0570e06758ec4233c6e11","https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784","https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529"],"weaknesses":[],"ingestedAt":"2026-10-30T12:50:04.827Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/80xxx/CVE-2026-80841.json","commit":"1f312381e38164a43607eebab851b151dd16861e","baselineCommit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-80841","state":"PUBLISHED","datePublished":"2026-09-04T15:54:51.459Z","dateUpdated":"2026-10-30T12:31:11.820Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-26T14:34:25.796Z"},"containers":{"cna":{"title":"net/packet: defer vmalloc TX_RING free until skbs finish","descriptions":[{"lang":"en","value":"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."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"ed126ca71d4d949ad99f40b974a8f7685e808f8b","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"debf9f50140b3df3949ebcb97d4450f8993fe32d","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"0189dce07db2dc059ae0570e06758ec4233c6e11","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"550d00aa58193fb649a09a9c9e338c685adad784","versionType":"git"},{"version":"b013840810c221f2b0cf641d01531526052dc1fb","status":"affected","lessThan":"992cc9f94ca924089a506ba9b327caa9af797529","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/packet/af_packet.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"3.14","status":"affected"},{"version":"0","status":"unaffected","lessThan":"3.14","versionType":"semver"},{"version":"6.1.191","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.158","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.111","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.51","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.13","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2.3","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/packet/af_packet.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/ed126ca71d4d949ad99f40b974a8f7685e808f8b"},{"url":"https://git.kernel.org/stable/c/debf9f50140b3df3949ebcb97d4450f8993fe32d"},{"url":"https://git.kernel.org/stable/c/4ce6e2d2e38055b2012bd5fdb0c8a8183c8a1b0c"},{"url":"https://git.kernel.org/stable/c/ed25ed29034ddc3dbe451ccbaa58ab9932f99d8b"},{"url":"https://git.kernel.org/stable/c/0189dce07db2dc059ae0570e06758ec4233c6e11"},{"url":"https://git.kernel.org/stable/c/550d00aa58193fb649a09a9c9e338c685adad784"},{"url":"https://git.kernel.org/stable/c/992cc9f94ca924089a506ba9b327caa9af797529"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-30T12:31:11.820Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.1.191"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.6.158"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.12.111"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"6.18.51"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"7.1.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"7.2.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"3.14","versionEndExcluding":"7.3"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}