{"id":"CVE-2026-22979","summary":"net: fix memory leak in skb_segment_list for GRO packets","details":"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-\u003esk = 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().","modified":"2026-04-02T17:29:54.449825Z","published":"2026-01-23T15:24:01.340Z","related":["SUSE-SU-2026:0962-1","SUSE-SU-2026:1081-1","SUSE-SU-2026:20667-1","SUSE-SU-2026:20720-1","SUSE-SU-2026:20838-1","SUSE-SU-2026:20845-1","SUSE-SU-2026:20876-1","SUSE-SU-2026:20931-1","openSUSE-SU-2026:20416-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22979.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/0b27828ebd1ed3107d7929c3737adbe862e99e74"},{"type":"WEB","url":"https://git.kernel.org/stable/c/238e03d0466239410b72294b79494e43d4fabe77"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3264881431e308b9c72cb8a0159d57a56d67dd79"},{"type":"WEB","url":"https://git.kernel.org/stable/c/88bea149db2057112af3aaf63534b24fab5858ab"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c114a32a2e70b82d447f409f7ffcfa3058f9d5bd"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/22xxx/CVE-2026-22979.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-22979"},{"type":"PACKAGE","url":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git"}],"affected":[{"ranges":[{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"2eeab8c47c3c0276e0746bc382f405c9a236a5ad"},{"fixed":"0b27828ebd1ed3107d7929c3737adbe862e99e74"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"fc126c1d51e9552eacd2d717b9ffe9262a8a4cd6"},{"fixed":"88bea149db2057112af3aaf63534b24fab5858ab"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"ed4cccef64c1d0d5b91e69f7a8a6697c3a865486"},{"fixed":"3264881431e308b9c72cb8a0159d57a56d67dd79"},{"fixed":"c114a32a2e70b82d447f409f7ffcfa3058f9d5bd"},{"fixed":"238e03d0466239410b72294b79494e43d4fabe77"}]},{"type":"GIT","repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","events":[{"introduced":"0"},{"last_affected":"d225b0ac96dc40d7e8ae2bc227eb2c56e130975f"},{"last_affected":"5b3b67f731296027cceb3efad881ae281213f86f"}]}],"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2026-22979.json"}}],"schema_version":"1.7.5"}