{"id":"CVE-2026-74321","summary":"btrfs: fix invalid pointer dereference in __btrfs_run_delayed_refs()","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nbtrfs: fix invalid pointer dereference in __btrfs_run_delayed_refs()\n\nIn the beginning of the loop, we try to obtain a locked delayed ref head,\nif 'locked_ref' is currently NULL, by calling btrfs_select_ref_head(),\nwhich can return an error pointer. If the error pointer is -EAGAIN we do\na continue and go back to the beginning of the loop, which will not try\nagain to call btrfs_select_ref_head() since 'locked_ref' is no longer\nNULL but it's ERR_PTR(-EAGAIN), and then we do:\n\n   spin_lock(&locked_ref-\u003elock);\n\nagainst a ERR_PTR(-EAGAIN) value, generating an invalid pointer\ndereference.\n\nFix this by ensuring that 'locked_ref' is set to NULL when\nbtrfs_select_ref_head() returns ERR_PTR(-EAGAIN) and incrementing 'count'\nas well, to prevent infinite looping. We do this by doing a goto to the\nbottom of the loop that already sets 'locked_ref' to NULL and does a\ncond_resched(), with an increment to 'count' right before the goto.\nThese measures were in place before the refactoring in commit 0110a4c43451\n(\"btrfs: refactor __btrfs_run_delayed_refs loop\") but were unintentionally\nlost afterwards.","modified":"2026-09-18T10:11:51.357084877Z","published":"2026-08-15T05:58:17.485Z","related":["SUSE-SU-2026:23477-1","SUSE-SU-2026:23481-1","SUSE-SU-2026:23528-1","SUSE-SU-2026:23529-1","SUSE-SU-2026:4120-1","SUSE-SU-2026:4254-1"],"database_specific":{"cna_assigner":"Linux","osv_generated_from":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74321.json"},"references":[{"type":"WEB","url":"https://git.kernel.org/stable/c/015dc4a1e0c2cba551d4620eba13d26d5081dc34"},{"type":"WEB","url":"https://git.kernel.org/stable/c/3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1"},{"type":"WEB","url":"https://git.kernel.org/stable/c/486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae"},{"type":"WEB","url":"https://git.kernel.org/stable/c/65770111a2d47c2b15e20b2ba92bb12198f289d4"},{"type":"WEB","url":"https://git.kernel.org/stable/c/9faa6b69ad73f03c7bde53e07d75a28822dc9a1a"},{"type":"WEB","url":"https://git.kernel.org/stable/c/a71143590ce9764dbcb47617647592ff8b4d48bc"},{"type":"WEB","url":"https://git.kernel.org/stable/c/ba9fa2ff5981589bb49094d3358c339b37c47f53"},{"type":"WEB","url":"https://git.kernel.org/stable/c/c372ca227e16bace86f1df1fa4ae6849e2fcfa28"},{"type":"ADVISORY","url":"https://github.com/CVEProject/cvelistV5/tree/main/cves/2026/74xxx/CVE-2026-74321.json"},{"type":"ADVISORY","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-74321"},{"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":"0110a4c43451533de1ea1bbdc57b5d452f9d8b25"},{"fixed":"c372ca227e16bace86f1df1fa4ae6849e2fcfa28"},{"fixed":"a71143590ce9764dbcb47617647592ff8b4d48bc"},{"fixed":"65770111a2d47c2b15e20b2ba92bb12198f289d4"},{"fixed":"015dc4a1e0c2cba551d4620eba13d26d5081dc34"},{"fixed":"ba9fa2ff5981589bb49094d3358c339b37c47f53"},{"fixed":"3b15d02be05e74321adb1e0ae0cb4ccfba7c6cb1"},{"fixed":"9faa6b69ad73f03c7bde53e07d75a28822dc9a1a"},{"fixed":"486f8298b6188ff11ef1f4be7f1d5d2e4d1b1fae"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-74321.json"}},{"package":{"name":"Kernel","ecosystem":"Linux"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"4.20.0"},{"fixed":"5.10.261"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.11.0"},{"fixed":"5.15.212"}]},{"type":"ECOSYSTEM","events":[{"introduced":"5.16.0"},{"fixed":"6.1.178"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.2.0"},{"fixed":"6.6.145"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.7.0"},{"fixed":"6.12.97"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.13.0"},{"fixed":"6.18.40"}]},{"type":"ECOSYSTEM","events":[{"introduced":"6.19.0"},{"fixed":"7.1.5"}]}],"database_specific":{"source":"https://storage.googleapis.com/osv-test-cve-osv-conversion/osv-output/CVE-2026-74321.json"}}],"schema_version":"1.9.0","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"}]}