{"id":"CVE-2026-68127","state":"PUBLISHED","title":"ila: reload IPv6 header after pskb_may_pull in checksum adjust","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nila: reload IPv6 header after pskb_may_pull in checksum adjust\n\nila_csum_adjust_transport() caches ip6h = ipv6_hdr(skb) before calling\npskb_may_pull(). On a non-linear skb whose transport header sits in a page\nfragment, pskb_may_pull() can call __pskb_pull_tail() / pskb_expand_head()\nand free the old skb head, leaving ip6h dangling; the following\nget_csum_diff(ip6h, p) then reads freed memory. ila_update_ipv6_locator()\nuses ip6h (and the iaddr derived from it) again after the csum-adjust\ncall and additionally writes the new locator through that pointer.\n\nImpact: a remote IPv6 packet routed through a configured ILA\ncsum-adjust-transport route or receive-side mapping triggers a\nslab-use-after-free in ila_update_ipv6_locator() (KASAN). The route or\nmapping requires CAP_NET_ADMIN to configure, but trigger packets are\nunauthenticated once it exists.\n\nReload ip6h after each pskb_may_pull() in ila_csum_adjust_transport()\nbefore the csum-diff read. In ila_update_ipv6_locator() only the\nILA_CSUM_ADJUST_TRANSPORT case pulls the skb, so reload ip6h and iaddr in\nthat case alone before the destination-address write; the neutral-map\nmodes never pull and keep their cached pointers.","publishedAt":"2026-08-10T11:58:48.489Z","updatedAt":"2026-10-19T20:58:52.243Z","severity":{"score":9.8,"label":"Critical","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"e451a904606c571f731ef7a06b3398619dce5300","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"1eadcb43893b897ade85ac5bf5c618054bc3c655","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"ba353caafb06ccee57b78d3254e3cebf1dea4a93","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"896a9512d0d83c2a4b357e5585b7b62a8e3f95c1","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"7097a0280b178237265681be66d1bef11d15894b","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"472aba2603ca74c4f7722cb0c0296942b0776b8d","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"c6a13ae00dab3a1a8c7cf2f843f0fc9e8d4b0ccc","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"92d3817649df2b0b6a008a686c8275c88d7ef594","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ila/ila_common.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.5","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ila/ila_common.c"]}],"references":["https://git.kernel.org/stable/c/e451a904606c571f731ef7a06b3398619dce5300","https://git.kernel.org/stable/c/1eadcb43893b897ade85ac5bf5c618054bc3c655","https://git.kernel.org/stable/c/ba353caafb06ccee57b78d3254e3cebf1dea4a93","https://git.kernel.org/stable/c/896a9512d0d83c2a4b357e5585b7b62a8e3f95c1","https://git.kernel.org/stable/c/7097a0280b178237265681be66d1bef11d15894b","https://git.kernel.org/stable/c/472aba2603ca74c4f7722cb0c0296942b0776b8d","https://git.kernel.org/stable/c/c6a13ae00dab3a1a8c7cf2f843f0fc9e8d4b0ccc","https://git.kernel.org/stable/c/92d3817649df2b0b6a008a686c8275c88d7ef594"],"weaknesses":["CWE-416"],"ingestedAt":"2026-10-29T20:12:49.727Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/68xxx/CVE-2026-68127.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-68127","state":"PUBLISHED","datePublished":"2026-08-10T11:58:48.489Z","dateUpdated":"2026-10-19T20:58:52.243Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-07-30T09:28:09.369Z"},"containers":{"cna":{"title":"ila: reload IPv6 header after pskb_may_pull in checksum adjust","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nila: reload IPv6 header after pskb_may_pull in checksum adjust\n\nila_csum_adjust_transport() caches ip6h = ipv6_hdr(skb) before calling\npskb_may_pull(). On a non-linear skb whose transport header sits in a page\nfragment, pskb_may_pull() can call __pskb_pull_tail() / pskb_expand_head()\nand free the old skb head, leaving ip6h dangling; the following\nget_csum_diff(ip6h, p) then reads freed memory. ila_update_ipv6_locator()\nuses ip6h (and the iaddr derived from it) again after the csum-adjust\ncall and additionally writes the new locator through that pointer.\n\nImpact: a remote IPv6 packet routed through a configured ILA\ncsum-adjust-transport route or receive-side mapping triggers a\nslab-use-after-free in ila_update_ipv6_locator() (KASAN). The route or\nmapping requires CAP_NET_ADMIN to configure, but trigger packets are\nunauthenticated once it exists.\n\nReload ip6h after each pskb_may_pull() in ila_csum_adjust_transport()\nbefore the csum-diff read. In ila_update_ipv6_locator() only the\nILA_CSUM_ADJUST_TRANSPORT case pulls the skb, so reload ip6h and iaddr in\nthat case alone before the destination-address write; the neutral-map\nmodes never pull and keep their cached pointers."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"e451a904606c571f731ef7a06b3398619dce5300","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"1eadcb43893b897ade85ac5bf5c618054bc3c655","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"ba353caafb06ccee57b78d3254e3cebf1dea4a93","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"896a9512d0d83c2a4b357e5585b7b62a8e3f95c1","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"7097a0280b178237265681be66d1bef11d15894b","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"472aba2603ca74c4f7722cb0c0296942b0776b8d","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"c6a13ae00dab3a1a8c7cf2f843f0fc9e8d4b0ccc","versionType":"git"},{"version":"33f11d16142b06588eedfc1dd8cf93790979a712","status":"affected","lessThan":"92d3817649df2b0b6a008a686c8275c88d7ef594","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ila/ila_common.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"4.5","status":"affected"},{"version":"0","status":"unaffected","lessThan":"4.5","versionType":"semver"},{"version":"5.10.265","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.216","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.183","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.148","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.101","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.42","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.6","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/ipv6/ila/ila_common.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/e451a904606c571f731ef7a06b3398619dce5300"},{"url":"https://git.kernel.org/stable/c/1eadcb43893b897ade85ac5bf5c618054bc3c655"},{"url":"https://git.kernel.org/stable/c/ba353caafb06ccee57b78d3254e3cebf1dea4a93"},{"url":"https://git.kernel.org/stable/c/896a9512d0d83c2a4b357e5585b7b62a8e3f95c1"},{"url":"https://git.kernel.org/stable/c/7097a0280b178237265681be66d1bef11d15894b"},{"url":"https://git.kernel.org/stable/c/472aba2603ca74c4f7722cb0c0296942b0776b8d"},{"url":"https://git.kernel.org/stable/c/c6a13ae00dab3a1a8c7cf2f843f0fc9e8d4b0ccc"},{"url":"https://git.kernel.org/stable/c/92d3817649df2b0b6a008a686c8275c88d7ef594"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","baseScore":9.8,"baseSeverity":"CRITICAL"},"scenarios":[{"lang":"en","value":"AV:N - The bug is reached from ipv6_rcv() through NF_INET_PRE_ROUTING (ila_nf_input) or IPv6 routing/LWT input/output when remote IPv6 packets matching a configured ILA csum-adjust-transport mapping or route are processed; no local syscall is required on internet-facing routers, gateways, or NVO3/overlay hosts.\nAC:L - Once ILA csum-adjust-transport is configured, a remote attacker can reliably send IPv6 TCP/UDP/ICMPv6 packets whose transport headers live in skb page fragments so pskb_may_pull() reallocates the head; they control packet layout and can retry without races or uncontrollable memory layout.\nPR:N - Trigger packets are processed unauthenticated on the network datapath; although ILA routes/mappings require CAP_NET_ADMIN to install, that is operator infrastructure (also obtainable in a user netns), not a privilege the remote attacker needs to send the malformed IPv6 packets that hit ila_update_ipv6_locator().\nUI:N - No victim user action is required beyond normal IPv6 packet delivery; exploitation is fully automated once the affected ILA configuration exists and the attacker sends crafted packets to the host.\nS:U - The slab use-after-free corrupts kernel packet-processing memory within the host kernel security authority; it is not a VM escape, container breakout, or IOMMU/DMA boundary bypass.\nC:H - ila_csum_adjust_transport() reads the cached IPv6 header via get_csum_diff(ip6h, p) after pskb_may_pull() frees the old skb head, causing a slab use-after-free read of freed memory that can disclose kernel heap contents.\nI:H - ila_update_ipv6_locator() then writes iaddr->loc = p->locator through the same stale iaddr pointer derived from the freed header, giving a slab use-after-free write primitive that can be leveraged for arbitrary memory corruption and control-flow hijacking.\nA:H - The freed skb-head slab use-after-free was reproduced under KASAN and can cause kernel oops/panic during IPv6 receive/forwarding; even unsuccessful exploitation typically crashes or destabilizes the host."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-19T16:29:41.771Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"5.10.265"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"5.15.216"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.1.183"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.6.148"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.12.101"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"6.18.42"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"7.1.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"4.5","versionEndExcluding":"7.2"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-68127","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"yes"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:44:18.440814Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-416","lang":"en","type":"CWE","description":"CWE-416 Use After Free"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T20:58:52.243Z"}}]}}}