{"id":"CVE-2024-26923","title":"In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Fix garbage collector racing against connect()\n\nGarbage collector does not take into account the risk of embryo getting\nenqueued during the garbage collection.…","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Fix garbage collector racing against connect()\n\nGarbage collector does not take into account the risk of embryo getting\nenqueued during the garbage collection.…","severity":"high","cvss":7.8,"cvssVector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","cwe":["CWE-362"],"vendor":"linux","product":"linux_kernel","affected":["linux_kernel >= 2.6.23, < 4.19.314","linux_kernel >= 4.20, < 5.4.275","linux_kernel >= 5.5, < 5.10.216","linux_kernel >= 5.11, < 5.15.156","linux_kernel >= 5.16, < 6.1.87","linux_kernel >= 6.2, < 6.6.28","linux_kernel >= 6.7, < 6.8.7","linux_kernel = 6.9","debian_linux = 10.0"],"patched":["linux_kernel 6.8.7"],"published":"2024-04-25","updated":"2026-10-15","sourceUpdated":"2026-10-15T01:17:31.997","source":"NVD","sourceUrl":"https://nvd.nist.gov/vuln/detail/CVE-2024-26923","references":[{"url":"https://git.kernel.org/stable/c/2e2a03787f4f0abc0072350654ab0ef3324d9db3","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/343c5372d5e17b306db5f8f3c895539b06e3177f","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/47d8ac011fe1c9251070e1bd64cb10b48193ec51","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/507cc232ffe53a352847893f8177d276c3b532a9","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/a36ae0ec2353015f0f6762e59f4c2dbc0c906423","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/b75722be422c276b699200de90527d01c602ea7c","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/dbdf7bec5c920200077d693193f989cb1513f009","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/e76c2678228f6aec74b305ae30c9374cc2f28a51","label":"416baaa9-dc9f-4396-8d5f-8c081fb06d67"},{"url":"https://git.kernel.org/stable/c/2e2a03787f4f0abc0072350654ab0ef3324d9db3","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/343c5372d5e17b306db5f8f3c895539b06e3177f","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/47d8ac011fe1c9251070e1bd64cb10b48193ec51","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/507cc232ffe53a352847893f8177d276c3b532a9","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/a36ae0ec2353015f0f6762e59f4c2dbc0c906423","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/b75722be422c276b699200de90527d01c602ea7c","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/dbdf7bec5c920200077d693193f989cb1513f009","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://git.kernel.org/stable/c/e76c2678228f6aec74b305ae30c9374cc2f28a51","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00017.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://lists.debian.org/debian-lts-announce/2024/06/msg00020.html","label":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-265688.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-398330.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"},{"url":"https://cert-portal.siemens.com/productcert/html/ssa-613116.html","label":"0b142b55-0307-4c5a-b3c9-f314f3fb7c5e"}],"tags":["nvd","cve.org"],"epss":0.00207,"epssPercentile":0.10089,"ingestedAt":"2026-10-15T03:30:12.661Z","ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"total","timestamp":"2024-07-02T00:00:00+00:00"},"slug":"CVE-2024-26923","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\naf_unix: Fix garbage collector racing against connect()\n\nGarbage collector does not take into account the risk of embryo getting\nenqueued during the garbage collection. If such embryo has a peer that\ncarries SCM_RIGHTS, two consecutive passes of scan_children() may see a\ndifferent set of children. Leading to an incorrectly elevated inflight\ncount, and then a dangling pointer within the gc_inflight_list.\n\nsockets are AF_UNIX/SOCK_STREAM\nS is an unconnected socket\nL is a listening in-flight socket bound to addr, not in fdtable\nV's fd will be passed via sendmsg(), gets inflight count bumped\n\nconnect(S, addr)\tsendmsg(S, [V]); close(V)\t__unix_gc()\n----------------\t-------------------------\t-----------\n\nNS = unix_create1()\nskb1 = sock_wmalloc(NS)\nL = unix_find_other(addr)\nunix_state_lock(L)\nunix_peer(S) = NS\n\t\t\t// V count=1 inflight=0\n\n \t\t\tNS = unix_peer(S)\n \t\t\tskb2 = sock_alloc()\n\t\t\tskb_queue_tail(NS, skb2[V])\n\n\t\t\t// V became in-flight\n\t\t\t// V count=2 inflight=1\n\n\t\t\tclose(V)\n\n\t\t\t// V count=1 inflight=1\n\t\t\t// GC candidate condition met\n\n\t\t\t\t\t\tfor u in gc_inflight_list:\n\t\t\t\t\t\t  if (total_refs == inflight_refs)\n\t\t\t\t\t\t    add u to gc_candidates\n\n\t\t\t\t\t\t// gc_candidates={L, V}\n\n\t\t\t\t\t\tfor u in gc_candidates:\n\t\t\t\t\t\t  scan_children(u, dec_inflight)\n\n\t\t\t\t\t\t// embryo (skb1) was not\n\t\t\t\t\t\t// reachable from L yet, so V's\n\t\t\t\t\t\t// inflight remains unchanged\n__skb_queue_tail(L, skb1)\nunix_state_unlock(L)\n\t\t\t\t\t\tfor u in gc_candidates:\n\t\t\t\t\t\t  if (u.inflight)\n\t\t\t\t\t\t    scan_children(u, inc_inflight_move_tail)\n\n\t\t\t\t\t\t// V count=1 inflight=2 (!)\n\nIf there is a GC-candidate listening socket, lock/unlock its state. This\nmakes GC wait until the end of any ongoing connect() to that socket. After\nflipping the lock, a possibly SCM-laden embryo is already enqueued. And if\nthere is another embryo coming, it can not possibly carry SCM_RIGHTS. At\nthis point, unix_inflight() can not happen because unix_gc_lock is already\ntaken. Inflight graph remains unaffected.\n\n## Affected\n\n- `linux_kernel >= 2.6.23, < 4.19.314`\n- `linux_kernel >= 4.20, < 5.4.275`\n- `linux_kernel >= 5.5, < 5.10.216`\n- `linux_kernel >= 5.11, < 5.15.156`\n- `linux_kernel >= 5.16, < 6.1.87`\n- `linux_kernel >= 6.2, < 6.6.28`\n- `linux_kernel >= 6.7, < 6.8.7`\n- `linux_kernel = 6.9`\n- `debian_linux = 10.0`\n\n## Remediation\n\nUpgrade past the affected range:\n\n- `linux_kernel 6.8.7`","depth":"twilight","depthScore":43,"depthScoreParts":{"impact":42.9,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}