{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2025-38572", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2025-04-16T04:51:24.025Z", "datePublished": "2025-08-19T17:02:52.340Z", "dateUpdated": "2026-08-05T12:03:00.703Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-08-05T12:03:00.703Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nipv6: reject malicious packets in ipv6_gso_segment()\n\nsyzbot was able to craft a packet with very long IPv6 extension headers\nleading to an overflow of skb->transport_header.\n\nThis 16bit field has a limited range.\n\nAdd skb_reset_transport_header_careful() helper and use it\nfrom ipv6_gso_segment()\n\nWARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 skb_reset_transport_header include/linux/skbuff.h:3032 [inline]\nWARNING: CPU: 0 PID: 5871 at ./include/linux/skbuff.h:3032 ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151\nModules linked in:\nCPU: 0 UID: 0 PID: 5871 Comm: syz-executor211 Not tainted 6.16.0-rc6-syzkaller-g7abc678e3084 #0 PREEMPT(full)\nHardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025\n RIP: 0010:skb_reset_transport_header include/linux/skbuff.h:3032 [inline]\n RIP: 0010:ipv6_gso_segment+0x15e2/0x21e0 net/ipv6/ip6_offload.c:151\nCall Trace:\n \n skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53\n nsh_gso_segment+0x54a/0xe10 net/nsh/nsh.c:110\n skb_mac_gso_segment+0x31c/0x640 net/core/gso.c:53\n __skb_gso_segment+0x342/0x510 net/core/gso.c:124\n skb_gso_segment include/net/gso.h:83 [inline]\n validate_xmit_skb+0x857/0x11b0 net/core/dev.c:3950\n validate_xmit_skb_list+0x84/0x120 net/core/dev.c:4000\n sch_direct_xmit+0xd3/0x4b0 net/sched/sch_generic.c:329\n __dev_xmit_skb net/core/dev.c:4102 [inline]\n __dev_queue_xmit+0x17b6/0x3a70 net/core/dev.c:4679" } ], "metrics": [ { "cvssV3_1": { "version": "3.1", "vectorString": "CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H", "baseScore": 7.8, "baseSeverity": "HIGH" }, "scenarios": [ { "lang": "en", "value": "AV:L - The overflow is in the transmit-side GSO segmentation path (`validate_xmit_skb` → `__skb_gso_segment` → `ipv6_gso_segment`), reached by locally injecting a crafted GSO skb via an `AF_PACKET`/`PACKET_VNET_HDR` socket or a tun/tap device. A >64KB extension-header chain cannot be delivered in a single frame over any real link and GRO does not grow the header chain, so a purely remote packet cannot reach it.\nAC:L - The attacker fully controls the number and size of IPv6 extension headers, the linear-area size (`vnet_hdr.hdr_len`), the gso_type/gso_size and `csum_start`, so `skb->data - skb->head` can be driven deterministically past 65535 and made to satisfy the `skb_checksum_start() != skb_transport_header()` guard in `tcp_gso_segment()`. No race, timing window, or memory grooming is involved.\nPR:L - A local socket is required, but `unshare -Urn` gives any unprivileged user CAP_NET_RAW and CAP_NET_ADMIN inside a fresh user+net namespace — enough to open an `AF_PACKET` socket, disable GSO offload on a veth/dummy, and transmit; the `IPV6_2292PKTOPTIONS` (64KB) plus `UDP_SEGMENT` route needs no capability at all.\nUI:N - The attacking process triggers the flaw entirely on its own by sending a packet; no victim action such as mounting, opening a file, or connecting is required.\nS:U - The truncated header offset and all resulting bad accesses stay inside the kernel's own security authority — no hypervisor, IOMMU, or sandbox boundary is crossed.\nC:H - `skb_transport_header()` is left pointing at an attacker-chosen wrong location and `skb_network_header_len()` wraps to a ~64K u16, so segmentation reads header fields and copies data from out-of-bounds/unintended offsets into the emitted segments, which are then transmitted on the wire — an unbounded disclosure primitive rather than a few strictly bounded bytes.\nI:H - The corrupted offset is propagated into every segment by `__copy_skb_header()`/`skb_headers_offset_update()` (u16 arithmetic that itself wraps), and the callbacks then write `th->seq`, `th->check`, `th->fin/psh/cwr`, `uh->len`, `uh->check` and `*prevhdr` through it, giving attacker-directed writes at offsets the kernel never validated.\nA:H - The negative `skb_transport_offset()` flows into `skb_push()`/length computations in `skb_segment()`/`skb_segment_list()` where it can trip `skb_under_panic()`, each segment forces a >64KB allocation, and on `CONFIG_DEBUG_NET`/`panic_on_warn` kernels the `WARN` in `skb_reset_transport_header()` panics outright — all repeatable at will from an unprivileged process." } ] } ], "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/ipv6/ip6_offload.c" ], "versions": [ { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "5dc60b2a00ed7629214ac0c48e43f40af2078703", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "3f638e0b28bde7c3354a0df938ab3a96739455d1", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "09ff062b89d8e48165247d677d1ca23d6d607e9b", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "de322cdf600fc9433845a9e944d1ca6b31cfb67e", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "ef05007b403dcc21e701cb1f30d4572ac0a9da20", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "5489e7fc6f8be3062f8cb7e49406de4bfd94db67", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "573b8250fc2554761db3bc2bbdbab23789d52d4e", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "ee851768e4b8371ce151fd446d24bf3ae2d18789", "status": "affected", "versionType": "git" }, { "version": "d1da932ed4ecad2a14cbcc01ed589d617d0f0f09", "lessThan": "d45cf1e7d7180256e17c9ce88e32e8061a7887fe", "status": "affected", "versionType": "git" } ] }, { "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/ipv6/ip6_offload.c" ], "versions": [ { "version": "3.8", "status": "affected" }, { "version": "0", "lessThan": "3.8", "status": "unaffected", "versionType": "semver" }, { "version": "5.4.297", "lessThanOrEqual": "5.4.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.10.241", "lessThanOrEqual": "5.10.*", "status": "unaffected", "versionType": "semver" }, { "version": "5.15.190", "lessThanOrEqual": "5.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.1.148", "lessThanOrEqual": "6.1.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.6.102", "lessThanOrEqual": "6.6.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.42", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.15.10", "lessThanOrEqual": "6.15.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.16.1", "lessThanOrEqual": "6.16.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.17", "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": "3.8", "versionEndExcluding": "5.4.297" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "5.10.241" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "5.15.190" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.1.148" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.6.102" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.12.42" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.15.10" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.16.1" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "3.8", "versionEndExcluding": "6.17" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/5dc60b2a00ed7629214ac0c48e43f40af2078703" }, { "url": "https://git.kernel.org/stable/c/3f638e0b28bde7c3354a0df938ab3a96739455d1" }, { "url": "https://git.kernel.org/stable/c/09ff062b89d8e48165247d677d1ca23d6d607e9b" }, { "url": "https://git.kernel.org/stable/c/de322cdf600fc9433845a9e944d1ca6b31cfb67e" }, { "url": "https://git.kernel.org/stable/c/ef05007b403dcc21e701cb1f30d4572ac0a9da20" }, { "url": "https://git.kernel.org/stable/c/5489e7fc6f8be3062f8cb7e49406de4bfd94db67" }, { "url": "https://git.kernel.org/stable/c/573b8250fc2554761db3bc2bbdbab23789d52d4e" }, { "url": "https://git.kernel.org/stable/c/ee851768e4b8371ce151fd446d24bf3ae2d18789" }, { "url": "https://git.kernel.org/stable/c/d45cf1e7d7180256e17c9ce88e32e8061a7887fe" } ], "title": "ipv6: reject malicious packets in ipv6_gso_segment()", "x_generator": { "engine": "bippy-1.2.0" } }, "adp": [ { "title": "CVE Program Container", "references": [ { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html" }, { "url": "https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html" } ], "providerMetadata": { "orgId": "af854a3a-2127-422b-91ae-364da2661108", "shortName": "CVE", "dateUpdated": "2025-11-03T17:39:59.107Z" } } ] } }