{"id":"CVE-2026-22979","state":"PUBLISHED","title":"net: fix memory leak in skb_segment_list for GRO packets","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fix memory leak in skb_segment_list for GRO packets\n\nWhen skb_segment_list() is called during packet forwarding, it handles\npackets that were aggregated by the GRO engine.\n\nHistorically, the segmentation logic in skb_segment_list assumes that\nindividual segments are split from a parent SKB and may need to carry\ntheir own socket memory accounting. Accordingly, the code transfers\ntruesize from the parent to the newly created segments.\n\nPrior to commit ed4cccef64c1 (\"gro: fix ownership transfer\"), this\ntruesize subtraction in skb_segment_list() was valid because fragments\nstill carry a reference to the original socket.\n\nHowever, commit ed4cccef64c1 (\"gro: fix ownership transfer\") changed\nthis behavior by ensuring that fraglist entries are explicitly\norphaned (skb->sk = NULL) to prevent illegal orphaning later in the\nstack. This change meant that the entire socket memory charge remained\nwith the head SKB, but the corresponding accounting logic in\nskb_segment_list() was never updated.\n\nAs a result, the current code unconditionally adds each fragment's\ntruesize to delta_truesize and subtracts it from the parent SKB. Since\nthe fragments are no longer charged to the socket, this subtraction\nresults in an effective under-count of memory when the head is freed.\nThis causes sk_wmem_alloc to remain non-zero, preventing socket\ndestruction and leading to a persistent memory leak.\n\nThe leak can be observed via KMEMLEAK when tearing down the networking\nenvironment:\n\nunreferenced object 0xffff8881e6eb9100 (size 2048):\n  comm \"ping\", pid 6720, jiffies 4295492526\n  backtrace:\n    kmem_cache_alloc_noprof+0x5c6/0x800\n    sk_prot_alloc+0x5b/0x220\n    sk_alloc+0x35/0xa00\n    inet6_create.part.0+0x303/0x10d0\n    __sock_create+0x248/0x640\n    __sys_socket+0x11b/0x1d0\n\nSince skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST\npackets constructed by GRO, the truesize adjustment is removed.\n\nThe call to skb_release_head_state() must be preserved. As documented in\ncommit cf673ed0e057 (\"net: fix fraglist segmentation reference count\nleak\"), it is still required to correctly drop references to SKB\nextensions that may be overwritten during __copy_skb_header().","publishedAt":"2026-01-23T15:24:01.340Z","updatedAt":"2026-10-15T01:12:24.721Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2eeab8c47c3c0276e0746bc382f405c9a236a5ad","status":"affected","lessThan":"0b27828ebd1ed3107d7929c3737adbe862e99e74","versionType":"git"},{"version":"fc126c1d51e9552eacd2d717b9ffe9262a8a4cd6","status":"affected","lessThan":"88bea149db2057112af3aaf63534b24fab5858ab","versionType":"git"},{"version":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486","status":"affected","lessThan":"3264881431e308b9c72cb8a0159d57a56d67dd79","versionType":"git"},{"version":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486","status":"affected","lessThan":"c114a32a2e70b82d447f409f7ffcfa3058f9d5bd","versionType":"git"},{"version":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486","status":"affected","lessThan":"238e03d0466239410b72294b79494e43d4fabe77","versionType":"git"},{"version":"d225b0ac96dc40d7e8ae2bc227eb2c56e130975f","status":"affected","versionType":"git"},{"version":"5b3b67f731296027cceb3efad881ae281213f86f","status":"affected","versionType":"git"},{"version":"6.1.85","status":"affected","lessThan":"6.1.161","versionType":"semver"},{"version":"6.6.26","status":"affected","lessThan":"6.6.121","versionType":"semver"},{"version":"5.15.154","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"6.8.5","status":"affected","lessThan":"6.9","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.1.161","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.121","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.66","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.6","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"]}],"references":["https://git.kernel.org/stable/c/0b27828ebd1ed3107d7929c3737adbe862e99e74","https://git.kernel.org/stable/c/88bea149db2057112af3aaf63534b24fab5858ab","https://git.kernel.org/stable/c/3264881431e308b9c72cb8a0159d57a56d67dd79","https://git.kernel.org/stable/c/c114a32a2e70b82d447f409f7ffcfa3058f9d5bd","https://git.kernel.org/stable/c/238e03d0466239410b72294b79494e43d4fabe77","https://cert-portal.siemens.com/productcert/html/ssa-019113.html","https://cert-portal.siemens.com/productcert/html/ssa-457936.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:21.040Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/22xxx/CVE-2026-22979.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-22979","state":"PUBLISHED","datePublished":"2026-01-23T15:24:01.340Z","dateUpdated":"2026-10-15T01:12:24.721Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-01-13T15:37:45.936Z"},"containers":{"cna":{"title":"net: fix memory leak in skb_segment_list for GRO packets","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nnet: fix memory leak in skb_segment_list for GRO packets\n\nWhen skb_segment_list() is called during packet forwarding, it handles\npackets that were aggregated by the GRO engine.\n\nHistorically, the segmentation logic in skb_segment_list assumes that\nindividual segments are split from a parent SKB and may need to carry\ntheir own socket memory accounting. Accordingly, the code transfers\ntruesize from the parent to the newly created segments.\n\nPrior to commit ed4cccef64c1 (\"gro: fix ownership transfer\"), this\ntruesize subtraction in skb_segment_list() was valid because fragments\nstill carry a reference to the original socket.\n\nHowever, commit ed4cccef64c1 (\"gro: fix ownership transfer\") changed\nthis behavior by ensuring that fraglist entries are explicitly\norphaned (skb->sk = NULL) to prevent illegal orphaning later in the\nstack. This change meant that the entire socket memory charge remained\nwith the head SKB, but the corresponding accounting logic in\nskb_segment_list() was never updated.\n\nAs a result, the current code unconditionally adds each fragment's\ntruesize to delta_truesize and subtracts it from the parent SKB. Since\nthe fragments are no longer charged to the socket, this subtraction\nresults in an effective under-count of memory when the head is freed.\nThis causes sk_wmem_alloc to remain non-zero, preventing socket\ndestruction and leading to a persistent memory leak.\n\nThe leak can be observed via KMEMLEAK when tearing down the networking\nenvironment:\n\nunreferenced object 0xffff8881e6eb9100 (size 2048):\n  comm \"ping\", pid 6720, jiffies 4295492526\n  backtrace:\n    kmem_cache_alloc_noprof+0x5c6/0x800\n    sk_prot_alloc+0x5b/0x220\n    sk_alloc+0x35/0xa00\n    inet6_create.part.0+0x303/0x10d0\n    __sock_create+0x248/0x640\n    __sys_socket+0x11b/0x1d0\n\nSince skb_segment_list() is exclusively used for SKB_GSO_FRAGLIST\npackets constructed by GRO, the truesize adjustment is removed.\n\nThe call to skb_release_head_state() must be preserved. As documented in\ncommit cf673ed0e057 (\"net: fix fraglist segmentation reference count\nleak\"), it is still required to correctly drop references to SKB\nextensions that may be overwritten during __copy_skb_header()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"2eeab8c47c3c0276e0746bc382f405c9a236a5ad","status":"affected","lessThan":"0b27828ebd1ed3107d7929c3737adbe862e99e74","versionType":"git"},{"version":"fc126c1d51e9552eacd2d717b9ffe9262a8a4cd6","status":"affected","lessThan":"88bea149db2057112af3aaf63534b24fab5858ab","versionType":"git"},{"version":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486","status":"affected","lessThan":"3264881431e308b9c72cb8a0159d57a56d67dd79","versionType":"git"},{"version":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486","status":"affected","lessThan":"c114a32a2e70b82d447f409f7ffcfa3058f9d5bd","versionType":"git"},{"version":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486","status":"affected","lessThan":"238e03d0466239410b72294b79494e43d4fabe77","versionType":"git"},{"version":"d225b0ac96dc40d7e8ae2bc227eb2c56e130975f","status":"affected","versionType":"git"},{"version":"5b3b67f731296027cceb3efad881ae281213f86f","status":"affected","versionType":"git"},{"version":"6.1.85","status":"affected","lessThan":"6.1.161","versionType":"semver"},{"version":"6.6.26","status":"affected","lessThan":"6.6.121","versionType":"semver"},{"version":"5.15.154","status":"affected","lessThan":"5.16","versionType":"semver"},{"version":"6.8.5","status":"affected","lessThan":"6.9","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.9","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.9","versionType":"semver"},{"version":"6.1.161","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.121","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.66","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.6","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["net/core/skbuff.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/0b27828ebd1ed3107d7929c3737adbe862e99e74"},{"url":"https://git.kernel.org/stable/c/88bea149db2057112af3aaf63534b24fab5858ab"},{"url":"https://git.kernel.org/stable/c/3264881431e308b9c72cb8a0159d57a56d67dd79"},{"url":"https://git.kernel.org/stable/c/c114a32a2e70b82d447f409f7ffcfa3058f9d5bd"},{"url":"https://git.kernel.org/stable/c/238e03d0466239410b72294b79494e43d4fabe77"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-23T16:03:37.832Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.85","versionEndExcluding":"6.1.161"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.26","versionEndExcluding":"6.6.121"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.12.66"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.18.6"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.9","versionEndExcluding":"6.19"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.154"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.8.5"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"affected":[{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIMATIC S7-1500 CPU 1518F-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.6","status":"affected","lessThan":"*","versionType":"custom"}]},{"vendor":"Siemens","product":"SIPLUS S7-1500 CPU 1518-4 PN/DP MFP","defaultStatus":"unknown","versions":[{"version":"V3.1.7","status":"affected","lessThan":"*","versionType":"custom"}]}],"references":[{"url":"https://cert-portal.siemens.com/productcert/html/ssa-019113.html"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-457936.html"}],"providerMetadata":{"shortName":"siemens-SADP","orgId":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e","dateUpdated":"2026-10-15T01:12:24.721Z"},"x_adpType":"supplier"}]}}}