{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98503", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.353Z", "datePublished": "2026-10-18T15:17:03.904Z", "dateUpdated": "2026-10-19T09:20:42.115Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:20:42.115Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\npacket: use ubuf_info completion for TX_RING packets\n\ntpacket_snd sends skbs with frags pointing into its ring slots. Slots\nare released when skb->destructor is called.\n\nA call to skb_orphan calls skb->destructor before the skb is freed.\nThis can cause the slot to be reused while still linked into the skb.\n\nSwitch to standard zerocopy completion (ubuf_info) so the slot is only\nreleased once all references to the payload are freed or copied.\nRestore skb->destructor to standard sock_wfree.\n\nThe ubuf_info completion callback can be called with a NULL skb, but\nonly from net_zcopy_put and related API, used by zerocopy implementations\nthat hold their own reference on the uarg, such as MSG_ZEROCOPY. This\nuarg is only ever completed from skb_zcopy_clear, so skb is always set.\n\nTo prevent userspace from aliasing in-flight state on shared ring\nslots, allocate tpacket_uarg per packet, rather than per slot. This\nadds a small allocation to the transmit path. Use standard kmalloc to\nallow backporting to stable kernels.\n\nThe uarg holds an sk_wmem_alloc reference, rather than an sk_refcnt\nreference. packet_free_tx_ring waits on sk_wmem_alloc before freeing\nthe ring pages. Always allocate vec->deferred for tx_ring so page-backed\nrings also wait on sk_wmem_alloc when skb_copy_ubufs drops page refs\nbefore calling tpacket_ubuf_complete.\n\nDrop the tx_ring.pg_vec test that tpacket_destruct_skb performed before\naccessing the slot. The sk_wmem_alloc reference now guarantees that the\nslot is valid. The test is also not sufficient by itself, as it reads\npg_vec without pg_vec_lock, so it can race with packet_set_ring.\n\nAs a result a slot is released when its payload is copied, which can\nbe before transmission (e.g., in skb_orphan_frags_rx). If copied\nbefore skb_tx_timestamp() is called, no slot timestamp is recorded,\nsimilar to when skb_orphan() was called early in the datapath before\nthis patch.\n\nRevert the now unused previous skb_zcopy_.._nouarg infra.\n\nDepends on commit 992cc9f94ca9 (\"net/packet: defer vmalloc TX_RING\nfree until skbs finish\")." } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/skbuff.h", "net/packet/af_packet.c" ], "versions": [ { "version": "5cd8d46ea1562be80063f53c7c6a5f40224de623", "lessThan": "e67c455d79fbf709a94965f09a2be6bf4f4ba5fd", "status": "affected", "versionType": "git" }, { "version": "5cd8d46ea1562be80063f53c7c6a5f40224de623", "lessThan": "eda9bcb721f15a93746a99eabda33d80b86404fd", "status": "affected", "versionType": "git" }, { "version": "5cd8d46ea1562be80063f53c7c6a5f40224de623", "lessThan": "2a0c9afefc0ecea2cc30ccfbbbc98182a0986191", "status": "affected", "versionType": "git" }, { "version": "5cd8d46ea1562be80063f53c7c6a5f40224de623", "lessThan": "9518405613863d0bf0700927a21367f5942cf058", "status": "affected", "versionType": "git" }, { "version": "67f6fba765ef8cb19089d476e3c367212a2fbdfd", "status": "affected", "versionType": "git" }, { "version": "f2a67e68dbaeae7c88e5522873d7b908911f9f77", "status": "affected", "versionType": "git" }, { "version": "4.14.86", "lessThan": "4.15", "status": "affected", "versionType": "semver" }, { "version": "4.19.7", "lessThan": "4.20", "status": "affected", "versionType": "semver" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "include/linux/skbuff.h", "net/packet/af_packet.c" ], "versions": [ { "version": "4.20", "status": "affected" }, { "version": "0", "lessThan": "4.20", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.55", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.9", "lessThanOrEqual": "7.2.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.3", "lessThanOrEqual": "*", "status": "unaffected", "versionType": "original_commit_for_fix" } ] } ], "cpeApplicability": [ { "nodes": [ { "operator": "OR", "negate": false, "cpeMatch": [ { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "6.18.55" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.2.9" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.20", "versionEndExcluding": "7.3" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.14.86" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.19.7" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/e67c455d79fbf709a94965f09a2be6bf4f4ba5fd" }, { "url": "https://git.kernel.org/stable/c/eda9bcb721f15a93746a99eabda33d80b86404fd" }, { "url": "https://git.kernel.org/stable/c/2a0c9afefc0ecea2cc30ccfbbbc98182a0986191" }, { "url": "https://git.kernel.org/stable/c/9518405613863d0bf0700927a21367f5942cf058" } ], "title": "packet: use ubuf_info completion for TX_RING packets", "x_generator": { "engine": "bippy-1.2.0" } } } }