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CVE-2026-43065

Full vulnerability record from the local CVENow database.

Description

In the Linux kernel, the following vulnerability has been resolved: ext4: always drain queued discard work in ext4_mb_release() While reviewing recent ext4 patch[1], Sashiko raised the following concern[2]: > If the filesystem is initially mounted with the discard option, > deleting files will populate sbi->s_discard_list and queue > s_discard_work. If it is then remounted with nodiscard, the > EXT4_MOUNT_DISCARD flag is cleared, but the pending s_discard_work is > neither cancelled nor flushed. [1] https://lore.kernel.org/r/[email protected]/ [2] https://sashiko.dev/#/patchset/20260319094545.19291-1-qiang.zhang%40linux.dev The concern was valid, but it had nothing to do with the patch[1]. One of the problems with Sashiko in its current (early) form is that it will detect pre-existing issues and report it as a problem with the patch that it is reviewing. In practice, it would be hard to hit deliberately (unless you are a malicious syzkaller fuzzer), since it would involve mounting the file system with -o discard, and then deleting a large number of files, remounting the file system with -o nodiscard, and then immediately unmounting the file system before the queued discard work has a change to drain on its own. Fix it because it's a real bug, and to avoid Sashiko from raising this concern when analyzing future patches to mballoc.c.

Severity
MEDIUM
CVSS score
5.5 (v3.1)
Vulnerability status
Analyzed
Source identifier
416baaa9-dc9f-4396-8d5f-8c081fb06d67
Published
2026-05-05 16:16:15.683000
Last modified
2026-11-06 16:18:20.567000
View original CVE JSON 
{
  "id": "CVE-2026-43065",
  "sourceIdentifier": "416baaa9-dc9f-4396-8d5f-8c081fb06d67",
  "published": "2026-05-05T16:16:15.683",
  "lastModified": "2026-11-06T16:18:20.567",
  "vulnStatus": "Analyzed",
  "cveTags": [],
  "descriptions": [
    {
      "lang": "en",
      "value": "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 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/[email protected]/\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."
    }
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