{"id":"CVE-2026-43065","title":"ext4: always drain queued discard work in ext4_mb_release()","summary":"In the Linux kernel, the following vulnerability has been resolved:\n\next4: always drain queued discard work in ext4_mb_release()\n\nWhile reviewing recent ext4 patch[1], Sashiko raised the following\nconcern[2]:\n\n> If the filesystem is init…","severity":"none","vendor":"Linux","product":"Linux","affected":["Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < e96c2354b170aaa53300c8e8fd59e41b133160f7","Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < c360e9d0def4f4ae03254a67c683103908555b75","Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 1c82f863f090ab899085bdfade073313384b514b","Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 9b4d9dda6a71ad3425c8109d27c4c6bfb9da97b8","Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 812b6a7cd3e7f3a3e8a24db85bc6313c26cb1098","Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < b4737e26d4688b8aea88ad6ea4dbfeb6e78b0327","Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 9ee29d20aab228adfb02ca93f87fb53c56c2f3af","Linux 5.15"],"ssvc":{"exploitation":"none","automatable":"no","technicalImpact":"partial","timestamp":"2026-11-06T15:27:46.955616Z"},"published":"2026-05-05","updated":"2026-11-06","sourceUpdated":"2026-11-06T15:32:29.604Z","source":"CVEORG","sourceUrl":"https://www.cve.org/CVERecord?id=CVE-2026-43065","references":[{"url":"https://git.kernel.org/stable/c/e96c2354b170aaa53300c8e8fd59e41b133160f7"},{"url":"https://git.kernel.org/stable/c/c360e9d0def4f4ae03254a67c683103908555b75"},{"url":"https://git.kernel.org/stable/c/1c82f863f090ab899085bdfade073313384b514b"},{"url":"https://git.kernel.org/stable/c/9b4d9dda6a71ad3425c8109d27c4c6bfb9da97b8"},{"url":"https://git.kernel.org/stable/c/812b6a7cd3e7f3a3e8a24db85bc6313c26cb1098"},{"url":"https://git.kernel.org/stable/c/b4737e26d4688b8aea88ad6ea4dbfeb6e78b0327"},{"url":"https://git.kernel.org/stable/c/9ee29d20aab228adfb02ca93f87fb53c56c2f3af"}],"tags":["cve.org"],"epss":0.00117,"epssPercentile":0.01648,"ingestedAt":"2026-11-06T15:54:04.028Z","slug":"CVE-2026-43065","body":"## Overview\n\nIn the Linux kernel, the following vulnerability has been resolved:\n\next4: always drain queued discard work in ext4_mb_release()\n\nWhile reviewing recent ext4 patch[1], Sashiko raised the following\nconcern[2]:\n\n> If the filesystem is initially mounted with the discard option,\n> deleting files will populate sbi->s_discard_list and queue\n> s_discard_work. If it is then remounted with nodiscard, the\n> EXT4_MOUNT_DISCARD flag is cleared, but the pending s_discard_work is\n> neither cancelled nor flushed.\n\n[1] https://lore.kernel.org/r/20260319094545.19291-1-qiang.zhang@linux.dev/\n[2] https://sashiko.dev/#/patchset/20260319094545.19291-1-qiang.zhang%40linux.dev\n\nThe concern was valid, but it had nothing to do with the patch[1].\nOne of the problems with Sashiko in its current (early) form is that\nit will detect pre-existing issues and report it as a problem with the\npatch that it is reviewing.\n\nIn practice, it would be hard to hit deliberately (unless you are a\nmalicious syzkaller fuzzer), since it would involve mounting the file\nsystem with -o discard, and then deleting a large number of files,\nremounting the file system with -o nodiscard, and then immediately\nunmounting the file system before the queued discard work has a change\nto drain on its own.\n\nFix it because it's a real bug, and to avoid Sashiko from raising this\nconcern when analyzing future patches to mballoc.c.\n\n## Affected\n\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < e96c2354b170aaa53300c8e8fd59e41b133160f7`\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < c360e9d0def4f4ae03254a67c683103908555b75`\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 1c82f863f090ab899085bdfade073313384b514b`\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 9b4d9dda6a71ad3425c8109d27c4c6bfb9da97b8`\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 812b6a7cd3e7f3a3e8a24db85bc6313c26cb1098`\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < b4737e26d4688b8aea88ad6ea4dbfeb6e78b0327`\n- `Linux >= 55cdd0af2bc5ffc92a2deb745627755aecd5db33 < 9ee29d20aab228adfb02ca93f87fb53c56c2f3af`\n- `Linux 5.15`\n\n## Remediation\n\nRefer to the linked advisories for vendor-supplied fixes and affected version ranges.","depth":"sunlit","depthScore":3,"depthScoreParts":{"impact":2.8,"likelihood":0,"exploitation":0,"ransomware":0},"changes":[]}