{ "dataType": "CVE_RECORD", "dataVersion": "5.2", "cveMetadata": { "cveId": "CVE-2026-98271", "assignerOrgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "state": "PUBLISHED", "assignerShortName": "Linux", "dateReserved": "2026-09-25T10:25:14.333Z", "datePublished": "2026-10-06T08:45:33.298Z", "dateUpdated": "2026-10-19T09:16:41.976Z" }, "containers": { "cna": { "providerMetadata": { "orgId": "416baaa9-dc9f-4396-8d5f-8c081fb06d67", "shortName": "Linux", "dateUpdated": "2026-10-19T09:16:41.976Z" }, "descriptions": [ { "lang": "en", "value": "In the Linux kernel, the following vulnerability has been resolved:\n\nnet: skbuff: do not leave stale header offsets after pskb_carve()\n\npskb_carve_inside_header() and pskb_carve_inside_nonlinear() remove\nthe first bytes of a packet and reallocate skb->head.\n\nAll the headers that were present before the operation are gone,\nbut both functions call skb_headers_offset_update(skb, 0), which\nis a no-op : skb->mac_header, skb->network_header,\nskb->transport_header and skb->csum_start keep their old values and\nnow describe bytes which are no longer there.\n\nBoth helpers size the new head from the old skb_end_offset(), so the\nstale offsets still land inside the new allocation. They point past\nskb_tail_pointer() though, to bytes that were never initialized.\n\npskb_carve_inside_nonlinear() is the worst case, because it leaves a\nzombie skb with an empty linear part (skb->data ==\nskb_tail_pointer(skb), skb_headlen(skb) == 0), while\nskb_mac_header_was_set() is still true and skb->mac_header is way\nahead of skb->data.\n\nThe only user of pskb_extract() is rds_tcp_data_recv(), and the\ncarved skb is queued on tinc->ti_skb_list. When the RDS incoming\nmessage is released, rds_tcp_inc_free() calls skb_queue_purge(),\nwhich frees the skbs with SKB_DROP_REASON_QUEUE_PURGE. This is\nvisible from drop_monitor, which then tries to pull back to the\n(bogus) mac header :\n\nskbuff: __skb_pull(len=234)\nskb len=6968 data_len=6968 headroom=0 headlen=0 tailroom=0\nend-tail=384 mac=(234,14) mac_len=14 net=(248,40) trans=288\nshinfo(txflags=0 nr_frags=1 gso(size=1428 type=16 segs=5))\ncsum(0x100120 start=288 offset=16 ip_summed=3 complete_sw=0 valid=1 level=0)\nhash(0x7b446c6c sw=0 l4=1) proto=0x86dd pkttype=0 iif=60\nkernel BUG at ./include/linux/skbuff.h:2847!\n\nAdd skb_carve_reset_headers() to mark the mac and transport headers\nas not set, reset the network header, clear skb->mac_len, and drop\na now meaningless CHECKSUM_PARTIAL (csum_start no longer describes\nanything).\n\nInvalidate the inner offsets as well. Unlike mac_header and\ntransport_header they have no \"unset\" sentinel, so a leftover\nnon-zero value still looks like a real header. Zero\nskb->inner_mac_header, skb->inner_network_header,\nskb->inner_transport_header, skb->inner_protocol and\nskb->encapsulation, so that all the header state is invalidated in\none place.\n\nv2: fixed an inaccurate changelog. The stale offsets stay inside the\n new skb->head, which is never smaller than the old one, they\n simply point past skb_tail_pointer() to bytes that are gone.\n Thanks to Xuanqiang Luo for insisting on this.\n Also invalidate the inner header state, as suggested by the\n netdev AI review :\n https://netdev-ai.bots.linux.dev/sashiko/#/patchset/20260911114922.621937-1-edumazet%40google.com" } ], "affected": [ { "product": "Linux", "vendor": "Linux", "defaultStatus": "unaffected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/skbuff.c" ], "versions": [ { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "lessThan": "75e4a3e62531738c124c8555a626426fca29d392", "status": "affected", "versionType": "git" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "lessThan": "bff8a8e53a6d290bc2777bde36d3cb6317b8463d", "status": "affected", "versionType": "git" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "lessThan": "12929ed66a5166177ef5f06d3da81e4f99993e90", "status": "affected", "versionType": "git" }, { "version": "6fa01ccd883021105e9f8af7d04b9f156fa3494a", "lessThan": "a5117e1eccac6ee3bd4aed7cacf8ebcb6b3eb309", "status": "affected", "versionType": "git" } ] }, { "product": "Linux", "vendor": "Linux", "defaultStatus": "affected", "repo": "https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git", "programFiles": [ "net/core/skbuff.c" ], "versions": [ { "version": "4.7", "status": "affected" }, { "version": "0", "lessThan": "4.7", "status": "unaffected", "versionType": "semver" }, { "version": "6.12.112", "lessThanOrEqual": "6.12.*", "status": "unaffected", "versionType": "semver" }, { "version": "6.18.54", "lessThanOrEqual": "6.18.*", "status": "unaffected", "versionType": "semver" }, { "version": "7.2.8", "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": "4.7", "versionEndExcluding": "6.12.112" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "6.18.54" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "7.2.8" }, { "vulnerable": true, "criteria": "cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*", "versionStartIncluding": "4.7", "versionEndExcluding": "7.3" } ] } ] } ], "references": [ { "url": "https://git.kernel.org/stable/c/75e4a3e62531738c124c8555a626426fca29d392" }, { "url": "https://git.kernel.org/stable/c/bff8a8e53a6d290bc2777bde36d3cb6317b8463d" }, { "url": "https://git.kernel.org/stable/c/12929ed66a5166177ef5f06d3da81e4f99993e90" }, { "url": "https://git.kernel.org/stable/c/a5117e1eccac6ee3bd4aed7cacf8ebcb6b3eb309" } ], "title": "net: skbuff: do not leave stale header offsets after pskb_carve()", "x_generator": { "engine": "bippy-1.2.0" } } } }