CVE-2026-74612

{"dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": {"cveId": "CVE-2026-74612", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-08-15T05:44:03.920Z", "datePublished": "2026-08-22T15:31:58.295Z", "dateUpdated": "2026-10-16T19:06:01.379Z"}, "containers": {"cna": {"providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:38.488Z"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nveth: fix skb length accounting after XDP frag adjustment\n\nveth exposes non-linear skb fragments through an xdp_buff. If an XDP\nprogram adjusts the fragment area, veth_xdp_rcv_skb() copies\nxdp_frags_size back to skb->data_len but leaves skb->len containing the\nold fragment contribution.\n\nAfter a fragment shrink, this makes skb_headlen() larger than the actual\nlinear area. In the reproduced UDP receive path, __skb_datagram_iter()\ncopied 1024 bytes past the actual linear tail to userspace, starting at\nstruct skb_shared_info. The copied bytes included the affected skb's\nnr_frags, xdp_frags_size, and a kernel pointer from\nskb_shinfo(skb)->frags[0]. Real packet data was displaced by the same\namount and truncated at the end.\n\nSubtract the old data_len before replacing it and add the new data_len\nafterwards, keeping skb->len and skb->data_len synchronized.\n\nAdditionally, bpf_xdp_pull_data() can advance data_end while leaving\nfrags present. The skb is then still non-linear, so the old\n__skb_put(skb, off) triggers SKB_LINEAR_ASSERT().\n\nUse skb_set_tail_pointer() and update skb->len explicitly instead,\nfollowing bpf_prog_run_generic_xdp(). Unlike __skb_put(),\nskb_set_tail_pointer() does not require a linear skb.\n\nA 60000-byte UDP datagram on a veth pair with MTU 64000 was shortened by\n1024 bytes from its fragment area. Before the fix, all 10 runs produced\ncorrupted payloads. After the fix, all 10 runs matched the expected\npayload exactly. A forced-tailroom reproducer also exercises\nbpf_xdp_pull_data() with frags still present; the old code triggers\nSKB_LINEAR_ASSERT(), while this fix passes 10/10 runs."}], "metrics": [{"cvssV3_1": {"version": "3.1", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "baseScore": 10, "baseSeverity": "CRITICAL"}, "scenarios": [{"lang": "en", "value": "AV:N - Remote packets routed through container/host veth pairs reach veth_xdp_rcv_skb() after veth_xmit on the peer; cloud and edge nodes routinely forward Internet traffic across veth links with XDP attached, matching the reproduced UDP receive path.\nAC:L - The fix commit shows 10/10 reliable reproduction with a 60000-byte UDP datagram and XDP bpf_xdp_adjust_tail()/bpf_xdp_pull_data() fragment shrink; the attacker controls packet size, timing, and both veth ends without races or uncontrollable kernel state.\nPR:N - Exploitation only requires an XDP program using bpf_xdp_adjust_tail or bpf_xdp_pull_data to already be attached on a reachable veth peer; the remote packet sender needs no local account, capabilities, or authentication to trigger the bad skb length accounting.\nUI:N - No victim interaction is needed beyond normal always-on packet reception and socket delivery; corrupted payloads and leaked kernel metadata are produced automatically when a userspace process reads the affected datagram.\nS:C - veth links intentionally cross container/host network namespaces on multi-tenant servers, and skb_shared_info metadata plus kernel pointers leaked into a tenant userspace recv buffer exceed that tenant's authorized security boundary.\nC:H - Desynchronized skb->len makes skb_headlen() exceed the real linear tail, so __skb_datagram_iter() copies up to 1024 bytes past the skb into userspace, exposing nr_frags, xdp_frags_size, and a kernel pointer from skb_shinfo(skb)->frags[0].\nI:H - The same length mismatch inflates the linear region, displacing and truncating real datagram bytes in the delivered UDP buffer and corrupting application-visible data beyond intended packet bounds while compounding misuse of leaked kernel metadata.\nA:H - bpf_xdp_pull_data() can leave frags present while the old __skb_put() path hits SKB_LINEAR_ASSERT()/BUG_ON on nonlinear skbs; the commit reports deterministic kernel asserts and crashes in addition to datagram corruption."}]}], "affected": [{"product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/veth.c"], "versions": [{"version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "0c3024afabb8064b141f3cedcb1ddd6ab05ad9d5", "status": "affected", "versionType": "git"}, {"version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139", "status": "affected", "versionType": "git"}, {"version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "41b96667d42b74bb4b137f1bb78b611a953c5943", "status": "affected", "versionType": "git"}, {"version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "cdf745b7a777f87f51666e5d8f4c6fc279bcf54d", "status": "affected", "versionType": "git"}, {"version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "3205b0652a37255dbb7ca8f3d942c8d8aa677c21", "status": "affected", "versionType": "git"}, {"version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "cb6379feaaff11c4e1e79c26c745ffa23182768a", "status": "affected", "versionType": "git"}]}, {"product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": ["drivers/net/veth.c"], "versions": [{"version": "5.18", "status": "affected"}, {"version": "0", "lessThan": "5.18", "status": "unaffected", "versionType": "semver"}, {"version": "6.1.184", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.6.152", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.12.104", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver"}, {"version": "6.18.45", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.1.9", "lessThanOrEqual": "7.1.*", "status": "unaffected", "versionType": "semver"}, {"version": "7.2", "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": "5.18", "versionEndExcluding": "6.1.184"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.6.152"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.12.104"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "6.18.45"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.1.9"}, {"vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "5.18", "versionEndExcluding": "7.2"}]}]}], "references": [{"url": "https://git.kernel.org/stable/c/0c3024afabb8064b141f3cedcb1ddd6ab05ad9d5"}, {"url": "https://git.kernel.org/stable/c/2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139"}, {"url": "https://git.kernel.org/stable/c/41b96667d42b74bb4b137f1bb78b611a953c5943"}, {"url": "https://git.kernel.org/stable/c/cdf745b7a777f87f51666e5d8f4c6fc279bcf54d"}, {"url": "https://git.kernel.org/stable/c/3205b0652a37255dbb7ca8f3d942c8d8aa677c21"}, {"url": "https://git.kernel.org/stable/c/cb6379feaaff11c4e1e79c26c745ffa23182768a"}], "title": "veth: fix skb length accounting after XDP frag adjustment", "x_generator": {"engine": "bippy-1.2.0"}}, "adp": [{"metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74612", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:02:22.074793Z"}}}], "title": "CISA ADP Vulnrichment", "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:06:01.379Z"}}]}}

{"dataType": "CVE_RECORD", "containers": {"adp": [{"title": "CISA ADP Vulnrichment", "metrics": [{"other": {"type": "ssvc", "content": {"id": "CVE-2026-74612", "role": "CISA Coordinator", "options": [{"Exploitation": "none"}, {"Automatable": "yes"}, {"Technical Impact": "total"}], "version": "2.0.3", "timestamp": "2026-10-16T19:02:22.074793Z"}}}], "providerMetadata": {"orgId": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "shortName": "CISA-ADP", "dateUpdated": "2026-10-16T19:02:23.031Z"}}], "cna": {"title": "veth: fix skb length accounting after XDP frag adjustment", "metrics": [{"cvssV3_1": {"version": "3.1", "baseScore": 10, "baseSeverity": "CRITICAL", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H"}, "scenarios": [{"lang": "en", "value": "AV:N - Remote packets routed through container/host veth pairs reach veth_xdp_rcv_skb() after veth_xmit on the peer; cloud and edge nodes routinely forward Internet traffic across veth links with XDP attached, matching the reproduced UDP receive path.\nAC:L - The fix commit shows 10/10 reliable reproduction with a 60000-byte UDP datagram and XDP bpf_xdp_adjust_tail()/bpf_xdp_pull_data() fragment shrink; the attacker controls packet size, timing, and both veth ends without races or uncontrollable kernel state.\nPR:N - Exploitation only requires an XDP program using bpf_xdp_adjust_tail or bpf_xdp_pull_data to already be attached on a reachable veth peer; the remote packet sender needs no local account, capabilities, or authentication to trigger the bad skb length accounting.\nUI:N - No victim interaction is needed beyond normal always-on packet reception and socket delivery; corrupted payloads and leaked kernel metadata are produced automatically when a userspace process reads the affected datagram.\nS:C - veth links intentionally cross container/host network namespaces on multi-tenant servers, and skb_shared_info metadata plus kernel pointers leaked into a tenant userspace recv buffer exceed that tenant's authorized security boundary.\nC:H - Desynchronized skb->len makes skb_headlen() exceed the real linear tail, so __skb_datagram_iter() copies up to 1024 bytes past the skb into userspace, exposing nr_frags, xdp_frags_size, and a kernel pointer from skb_shinfo(skb)->frags[0].\nI:H - The same length mismatch inflates the linear region, displacing and truncating real datagram bytes in the delivered UDP buffer and corrupting application-visible data beyond intended packet bounds while compounding misuse of leaked kernel metadata.\nA:H - bpf_xdp_pull_data() can leave frags present while the old __skb_put() path hits SKB_LINEAR_ASSERT()/BUG_ON on nonlinear skbs; the commit reports deterministic kernel asserts and crashes in addition to datagram corruption."}]}], "affected": [{"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "0c3024afabb8064b141f3cedcb1ddd6ab05ad9d5", "versionType": "git"}, {"status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139", "versionType": "git"}, {"status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "41b96667d42b74bb4b137f1bb78b611a953c5943", "versionType": "git"}, {"status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "cdf745b7a777f87f51666e5d8f4c6fc279bcf54d", "versionType": "git"}, {"status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "3205b0652a37255dbb7ca8f3d942c8d8aa677c21", "versionType": "git"}, {"status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "lessThan": "cb6379feaaff11c4e1e79c26c745ffa23182768a", "versionType": "git"}], "programFiles": ["drivers/net/veth.c"], "defaultStatus": "unaffected"}, {"repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "product": "Linux", "versions": [{"status": "affected", "version": "5.18"}, {"status": "unaffected", "version": "0", "lessThan": "5.18", "versionType": "semver"}, {"status": "unaffected", "version": "6.1.184", "versionType": "semver", "lessThanOrEqual": "6.1.*"}, {"status": "unaffected", "version": "6.6.152", "versionType": "semver", "lessThanOrEqual": "6.6.*"}, {"status": "unaffected", "version": "6.12.104", "versionType": "semver", "lessThanOrEqual": "6.12.*"}, {"status": "unaffected", "version": "6.18.45", "versionType": "semver", "lessThanOrEqual": "6.18.*"}, {"status": "unaffected", "version": "7.1.9", "versionType": "semver", "lessThanOrEqual": "7.1.*"}, {"status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix", "lessThanOrEqual": "*"}], "programFiles": ["drivers/net/veth.c"], "defaultStatus": "affected"}], "references": [{"url": "https://git.kernel.org/stable/c/0c3024afabb8064b141f3cedcb1ddd6ab05ad9d5"}, {"url": "https://git.kernel.org/stable/c/2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139"}, {"url": "https://git.kernel.org/stable/c/41b96667d42b74bb4b137f1bb78b611a953c5943"}, {"url": "https://git.kernel.org/stable/c/cdf745b7a777f87f51666e5d8f4c6fc279bcf54d"}, {"url": "https://git.kernel.org/stable/c/3205b0652a37255dbb7ca8f3d942c8d8aa677c21"}, {"url": "https://git.kernel.org/stable/c/cb6379feaaff11c4e1e79c26c745ffa23182768a"}], "x_generator": {"engine": "bippy-1.2.0"}, "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nveth: fix skb length accounting after XDP frag adjustment\n\nveth exposes non-linear skb fragments through an xdp_buff. If an XDP\nprogram adjusts the fragment area, veth_xdp_rcv_skb() copies\nxdp_frags_size back to skb->data_len but leaves skb->len containing the\nold fragment contribution.\n\nAfter a fragment shrink, this makes skb_headlen() larger than the actual\nlinear area. In the reproduced UDP receive path, __skb_datagram_iter()\ncopied 1024 bytes past the actual linear tail to userspace, starting at\nstruct skb_shared_info. The copied bytes included the affected skb's\nnr_frags, xdp_frags_size, and a kernel pointer from\nskb_shinfo(skb)->frags[0]. Real packet data was displaced by the same\namount and truncated at the end.\n\nSubtract the old data_len before replacing it and add the new data_len\nafterwards, keeping skb->len and skb->data_len synchronized.\n\nAdditionally, bpf_xdp_pull_data() can advance data_end while leaving\nfrags present. The skb is then still non-linear, so the old\n__skb_put(skb, off) triggers SKB_LINEAR_ASSERT().\n\nUse skb_set_tail_pointer() and update skb->len explicitly instead,\nfollowing bpf_prog_run_generic_xdp(). Unlike __skb_put(),\nskb_set_tail_pointer() does not require a linear skb.\n\nA 60000-byte UDP datagram on a veth pair with MTU 64000 was shortened by\n1024 bytes from its fragment area. Before the fix, all 10 runs produced\ncorrupted payloads. After the fix, all 10 runs matched the expected\npayload exactly. A forced-tailroom reproducer also exercises\nbpf_xdp_pull_data() with frags still present; the old code triggers\nSKB_LINEAR_ASSERT(), while this fix passes 10/10 runs."}], "cpeApplicability": [{"nodes": [{"negate": false, "cpeMatch": [{"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.1.184", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.6.152", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.12.104", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "6.18.45", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.1.9", "versionStartIncluding": "5.18"}, {"criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "vulnerable": true, "versionEndExcluding": "7.2", "versionStartIncluding": "5.18"}], "operator": "OR"}]}], "providerMetadata": {"orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-25T05:40:38.488Z"}}}, "cveMetadata": {"cveId": "CVE-2026-74612", "state": "PUBLISHED", "dateUpdated": "2026-10-16T19:06:01.379Z", "dateReserved": "2026-08-15T05:44:03.920Z", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "datePublished": "2026-08-22T15:31:58.295Z", "assignerShortName": "Linux"}, "dataVersion": "5.2"}

{"affected": [{"affectedData": [{"defaultStatus": "unaffected", "product": "Linux", "programFiles": ["drivers/net/veth.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"lessThan": "0c3024afabb8064b141f3cedcb1ddd6ab05ad9d5", "status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "versionType": "git"}, {"lessThan": "2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139", "status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "versionType": "git"}, {"lessThan": "41b96667d42b74bb4b137f1bb78b611a953c5943", "status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "versionType": "git"}, {"lessThan": "cdf745b7a777f87f51666e5d8f4c6fc279bcf54d", "status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "versionType": "git"}, {"lessThan": "3205b0652a37255dbb7ca8f3d942c8d8aa677c21", "status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "versionType": "git"}, {"lessThan": "cb6379feaaff11c4e1e79c26c745ffa23182768a", "status": "affected", "version": "718a18a0c8a67f97781e40bdef7cdd055c430996", "versionType": "git"}]}, {"defaultStatus": "affected", "product": "Linux", "programFiles": ["drivers/net/veth.c"], "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "vendor": "Linux", "versions": [{"status": "affected", "version": "5.18"}, {"lessThan": "5.18", "status": "unaffected", "version": "0", "versionType": "semver"}, {"lessThanOrEqual": "6.1.*", "status": "unaffected", "version": "6.1.184", "versionType": "semver"}, {"lessThanOrEqual": "6.6.*", "status": "unaffected", "version": "6.6.152", "versionType": "semver"}, {"lessThanOrEqual": "6.12.*", "status": "unaffected", "version": "6.12.104", "versionType": "semver"}, {"lessThanOrEqual": "6.18.*", "status": "unaffected", "version": "6.18.45", "versionType": "semver"}, {"lessThanOrEqual": "7.1.*", "status": "unaffected", "version": "7.1.9", "versionType": "semver"}, {"lessThanOrEqual": "*", "status": "unaffected", "version": "7.2", "versionType": "original_commit_for_fix"}]}], "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67"}], "cveTags": [], "descriptions": [{"lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nveth: fix skb length accounting after XDP frag adjustment\n\nveth exposes non-linear skb fragments through an xdp_buff. If an XDP\nprogram adjusts the fragment area, veth_xdp_rcv_skb() copies\nxdp_frags_size back to skb->data_len but leaves skb->len containing the\nold fragment contribution.\n\nAfter a fragment shrink, this makes skb_headlen() larger than the actual\nlinear area. In the reproduced UDP receive path, __skb_datagram_iter()\ncopied 1024 bytes past the actual linear tail to userspace, starting at\nstruct skb_shared_info. The copied bytes included the affected skb's\nnr_frags, xdp_frags_size, and a kernel pointer from\nskb_shinfo(skb)->frags[0]. Real packet data was displaced by the same\namount and truncated at the end.\n\nSubtract the old data_len before replacing it and add the new data_len\nafterwards, keeping skb->len and skb->data_len synchronized.\n\nAdditionally, bpf_xdp_pull_data() can advance data_end while leaving\nfrags present. The skb is then still non-linear, so the old\n__skb_put(skb, off) triggers SKB_LINEAR_ASSERT().\n\nUse skb_set_tail_pointer() and update skb->len explicitly instead,\nfollowing bpf_prog_run_generic_xdp(). Unlike __skb_put(),\nskb_set_tail_pointer() does not require a linear skb.\n\nA 60000-byte UDP datagram on a veth pair with MTU 64000 was shortened by\n1024 bytes from its fragment area. Before the fix, all 10 runs produced\ncorrupted payloads. After the fix, all 10 runs matched the expected\npayload exactly. A forced-tailroom reproducer also exercises\nbpf_xdp_pull_data() with frags still present; the old code triggers\nSKB_LINEAR_ASSERT(), while this fix passes 10/10 runs."}, {"lang": "es", "value": "En el kernel de Linux, la siguiente vulnerabilidad ha sido resuelta:\n\nveth: correcci\u00f3n de la contabilidad de la longitud del skb despu\u00e9s del ajuste de fragmentos XDP\n\nveth expone fragmentos skb no lineales a trav\u00e9s de un xdp_buff. Si un programa XDP ajusta el \u00e1rea de fragmentos, veth_xdp_rcv_skb() copia xdp_frags_size de vuelta a skb -> data_len pero deja skb -> len conteniendo la antigua contribuci\u00f3n del fragmento.\n\nDespu\u00e9s de una reducci\u00f3n de fragmento, esto hace que skb_headlen() sea mayor que el \u00e1rea lineal real. En la ruta de recepci\u00f3n UDP reproducida, __skb_datagram_iter() copi\u00f3 1024 bytes m\u00e1s all\u00e1 de la cola lineal real al espacio de usuario, comenzando en struct skb_shared_info. Los bytes copiados inclu\u00edan nr_frags, xdp_frags_size del skb afectado, y un puntero del kernel de skb_shinfo(skb) -> frags[0]. Los datos de paquete reales fueron desplazados por la misma cantidad y truncados al final.\n\nRestar el antiguo data_len antes de reemplazarlo y a\u00f1adir el nuevo data_len despu\u00e9s, manteniendo skb -> len y skb -> data_len sincronizados.\n\nAdem\u00e1s, bpf_xdp_pull_data() puede avanzar data_end mientras deja los frags presentes. El skb sigue siendo no lineal, por lo que el antiguo __skb_put(skb, off) activa SKB_LINEAR_ASSERT().\n\nUsar skb_set_tail_pointer() y actualizar skb -> len expl\u00edcitamente en su lugar, siguiendo a bpf_prog_run_generic_xdp(). A diferencia de __skb_put(), skb_set_tail_pointer() no requiere un skb lineal.\n\nUn datagrama UDP de 60000 bytes en un par veth con MTU 64000 fue acortado en 1024 bytes de su \u00e1rea de fragmentos. Antes de la correcci\u00f3n, las 10 ejecuciones produjeron cargas \u00fatiles corruptas. Despu\u00e9s de la correcci\u00f3n, las 10 ejecuciones coincidieron exactamente con la carga \u00fatil esperada. Un reproductor de 'tailroom' forzado tambi\u00e9n ejercita bpf_xdp_pull_data() con los frags a\u00fan presentes; el c\u00f3digo antiguo activa SKB_LINEAR_ASSERT(), mientras que esta correcci\u00f3n pasa 10/10 ejecuciones."}], "id": "CVE-2026-74612", "lastModified": "2026-10-16T20:17:46.373", "metrics": {"cvssMetricV31": [{"cvssData": {"attackComplexity": "LOW", "attackVector": "NETWORK", "availabilityImpact": "HIGH", "baseScore": 10.0, "baseSeverity": "CRITICAL", "confidentialityImpact": "HIGH", "integrityImpact": "HIGH", "privilegesRequired": "NONE", "scope": "CHANGED", "userInteraction": "NONE", "vectorString": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H", "version": "3.1"}, "exploitabilityScore": 3.9, "impactScore": 6.0, "source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "type": "Secondary"}], "ssvcV203": [{"source": "134c704f-9b21-4f2e-91b3-4a467353bcc0", "ssvcData": {"id": "CVE-2026-74612", "options": [{"exploitation": "none"}, {"automatable": "yes"}, {"technicalImpact": "total"}], "role": "CISA Coordinator", "timestamp": "2026-10-16T19:02:22.074793Z", "version": "2.0.3"}}]}, "published": "2026-08-22T16:16:33.770", "references": [{"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/0c3024afabb8064b141f3cedcb1ddd6ab05ad9d5"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/3205b0652a37255dbb7ca8f3d942c8d8aa677c21"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/41b96667d42b74bb4b137f1bb78b611a953c5943"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cb6379feaaff11c4e1e79c26c745ffa23182768a"}, {"source": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "url": "https://git.kernel.org/stable/c/cdf745b7a777f87f51666e5d8f4c6fc279bcf54d"}], "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "vulnStatus": "Received"}

{"bugzilla": {"description": "kernel: veth: fix skb length accounting after XDP frag adjustment", "id": "2521483", "url": "https://bugzilla.redhat.com/show_bug.cgi?id=2521483"}, "csaw": false, "cvss3": {"cvss3_base_score": "7.0", "cvss3_scoring_vector": "CVSS:3.1/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H", "status": "draft"}, "cwe": "CWE-125", "details": ["In the Linux kernel, the following vulnerability has been resolved:\nveth: fix skb length accounting after XDP frag adjustment\nveth exposes non-linear skb fragments through an xdp_buff. If an XDP\nprogram adjusts the fragment area, veth_xdp_rcv_skb() copies\nxdp_frags_size back to skb->data_len but leaves skb->len containing the\nold fragment contribution.\nAfter a fragment shrink, this makes skb_headlen() larger than the actual\nlinear area. In the reproduced UDP receive path, __skb_datagram_iter()\ncopied 1024 bytes past the actual linear tail to userspace, starting at\nstruct skb_shared_info. The copied bytes included the affected skb's\nnr_frags, xdp_frags_size, and a kernel pointer from\nskb_shinfo(skb)->frags[0]. Real packet data was displaced by the same\namount and truncated at the end.\nSubtract the old data_len before replacing it and add the new data_len\nafterwards, keeping skb->len and skb->data_len synchronized.\nAdditionally, bpf_xdp_pull_data() can advance data_end while leaving\nfrags present. The skb is then still non-linear, so the old\n__skb_put(skb, off) triggers SKB_LINEAR_ASSERT().\nUse skb_set_tail_pointer() and update skb->len explicitly instead,\nfollowing bpf_prog_run_generic_xdp(). Unlike __skb_put(),\nskb_set_tail_pointer() does not require a linear skb.\nA 60000-byte UDP datagram on a veth pair with MTU 64000 was shortened by\n1024 bytes from its fragment area. Before the fix, all 10 runs produced\ncorrupted payloads. After the fix, all 10 runs matched the expected\npayload exactly. A forced-tailroom reproducer also exercises\nbpf_xdp_pull_data() with frags still present; the old code triggers\nSKB_LINEAR_ASSERT(), while this fix passes 10/10 runs.", "A flaw was found in the Linux kernel's veth component. A remote attacker could exploit incorrect packet buffer (skb) length accounting after an eXpress Data Path (XDP) fragment adjustment. This could lead to the disclosure of sensitive kernel memory information to userspace and corruption or truncation of network packet data, potentially resulting in a denial of service."], "name": "CVE-2026-74612", "package_state": [{"cpe": "cpe:/o:redhat:enterprise_linux:10", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 10"}, {"cpe": "cpe:/o:redhat:enterprise_linux:6", "fix_state": "Out of support scope", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 6"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:7", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 7"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:8", "fix_state": "Not affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 8"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel", "product_name": "Red Hat Enterprise Linux 9"}, {"cpe": "cpe:/o:redhat:enterprise_linux:9", "fix_state": "Affected", "package_name": "kernel-rt", "product_name": "Red Hat Enterprise Linux 9"}], "public_date": "2026-08-22T00:00:00Z", "references": ["https://www.cve.org/CVERecord?id=CVE-2026-74612\nhttps://nvd.nist.gov/vuln/detail/CVE-2026-74612\nhttps://lore.kernel.org/linux-cve-announce/2026082217-CVE-2026-74612-c760@gregkh/T"], "threat_severity": "Moderate"}

{"affected": [{"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[718a18a0c8a67f97781e40bdef7cdd055c430996,2f2a7f3f8b9f1bffc9b0488aa02b6951b2aec139)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[718a18a0c8a67f97781e40bdef7cdd055c430996,41b96667d42b74bb4b137f1bb78b611a953c5943)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[718a18a0c8a67f97781e40bdef7cdd055c430996,cdf745b7a777f87f51666e5d8f4c6fc279bcf54d)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[718a18a0c8a67f97781e40bdef7cdd055c430996,3205b0652a37255dbb7ca8f3d942c8d8aa677c21)"}}, {"platform": null, "status": "affected", "versions": {"scheme": "code_commit", "value": "[718a18a0c8a67f97781e40bdef7cdd055c430996,cb6379feaaff11c4e1e79c26c745ffa23182768a)"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}, {"configurations": [{"platform": null, "status": "affected", "versions": {"scheme": "generic", "value": "5.18"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[0,5.18)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.6.152,6.7.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.12.104,6.13.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[6.18.45,6.19.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "semver", "value": "[7.1.9,7.2.0)"}}, {"platform": null, "status": "unaffected", "versions": {"scheme": "generic", "value": "[7.2,*]"}}], "enrichment": {"confidence": 99.0, "confidence_source": "inferred", "scores": [{"score": 99.0, "source": "inferred"}, {"score": 100.0, "source": "matching"}]}, "original": {"product": "Linux", "source": "cna", "vendor": "Linux"}, "product": "linux_kernel", "vendor": "linux"}], "created": "2026-08-22T18:15:03.351832+00:00", "updated": "2026-08-25T10:15:04.113121+00:00", "vendors": ["linux", "linux$PRODUCT$linux_kernel"], "weaknesses": ["CWE-125", "CWE-200"]}