{"id":"CVE-2021-47646","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nRevert \"Revert \"block, bfq: honor already-setup queue merges\"\"\n\nA crash [1] happened to be triggered in conjunction with commit\n2d52c58b9c9b (\"block, bfq: honor already-setup queue merges\"). The\nlatter was then reverted by commit ebc69e897e17 (\"Revert \"block, bfq:\nhonor already-setup queue merges\"\"). Yet, the reverted commit was not\nthe one introducing the bug. In fact, it actually triggered a UAF\nintroduced by a different commit, and now fixed by commit d29bd41428cf\n(\"block, bfq: reset last_bfqq_created on group change\").\n\nSo, there is no point in keeping commit 2d52c58b9c9b (\"block, bfq:\nhonor already-setup queue merges\") out. This commit restores it.\n\n[1] https://bugzilla.kernel.org/show_bug.cgi?id=214503","modified":"2026-03-15T21:45:14.005017Z","published":"2025-02-26T06:37:06.390Z","related":["SUSE-SU-2025:1027-1","SUSE-SU-2025:1176-1","SUSE-SU-2025:1183-1","SUSE-SU-2025:1241-1"],"references":[{"type":"FIX","url":"https://git.kernel.org/stable/c/cc051f497eac9d8a0d816cd4bffa3415f2724871"},{"type":"FIX","url":"https://git.kernel.org/stable/c/f990f0985eda59d4f29fc83fcf300c92b1225d39"},{"type":"FIX","url":"https://git.kernel.org/stable/c/15729ff8143f8135b03988a100a19e66d7cb7ecd"},{"type":"FIX","url":"https://git.kernel.org/stable/c/4083925bd6dc89216d156474a8076feec904e607"},{"type":"FIX","url":"https://git.kernel.org/stable/c/65d8a737452e88f251fe5d925371de6d606df613"},{"type":"FIX","url":"https://git.kernel.org/stable/c/931aff627469a75c77b9fd3823146d0575afffd6"},{"type":"FIX","url":"https://git.kernel.org/stable/c/abc2129e646af7b43025d90a071f83043f1ae76c"}],"affected":[{"database_specific":{"source":"https://storage.googleapis.com/cve-osv-conversion/osv-output/CVE-2021-47646.json","unresolved_ranges":[{"events":[{"introduced":"0"},{"fixed":"4.19.238"}]},{"events":[{"introduced":"4.20"},{"fixed":"5.4.189"}]},{"events":[{"introduced":"5.5"},{"fixed":"5.10.110"}]},{"events":[{"introduced":"5.11"},{"fixed":"5.15.33"}]},{"events":[{"introduced":"5.16"},{"fixed":"5.16.19"}]},{"events":[{"introduced":"5.17"},{"fixed":"5.17.2"}]}]}}],"schema_version":"1.7.5","severity":[{"type":"CVSS_V3","score":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H"}]}