CVE-2024-26704: Linux kernel · ext4: fix double-free of blocks due to wrong extents moved_len
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 4.4.0-1131.137 : patch Linux kernel soon.
Data as of 12 Nov 2026, 18:50 UTC
- Patch
- Available – fixed in 4.4.0-1131.137, 4.15.0-1177.192~14.04.1, 4.4.0-254.288~14.04.1 +82
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 3 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponized: no evidence on record.
No public exploit code indexed in Metasploit or Exploit-DB
Exploited in the wildExploited: no evidence on record.
Not in CISA KEV and no source reports exploitation
Observed by OffSeq MirageSeen by Mirage: no evidence on record.
No attack traffic recorded by OffSeq Mirage sensors
A missing step is not evidence of safety. Sources: cve.org (opens in a new tab), the Metasploit, Exploit-DB and nuclei-templates index as of 12 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6774-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6778-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-6795-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu Pro Realtime 24.04 LTSlinux-raspi-realtimepkg:deb/ubuntu/linux-raspi-realtime?arch=source&distro=realtime/nobleOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-allwinner-5.19pkg:deb/ubuntu/linux-allwinner-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=jammyOther threats | Affected
| Fixed in
|
Ubuntu 22.04 LTSlinux-aws-5.19pkg:deb/ubuntu/linux-aws-5.19?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Ubuntu 22.04 LTSlinux-aws-6.2pkg:deb/ubuntu/linux-aws-6.2?arch=source&distro=jammyOther threats | Affected
| Fixed in– |
Check your own hosts for these packages with threat-finder (opens in a new tab), our free open-source scanner.
Description
In the Linux kernel, the following vulnerability has been resolved: ext4: fix double-free of blocks due to wrong extents moved_len In ext4_move_extents(), moved_len is only updated when all moves are successfully executed, and only discards orig_inode and donor_inode preallocations when moved_len is not zero. When the loop fails to exit after successfully moving some extents, moved_len is not updated and remains at 0, so it does not discard the preallocations. If the moved extents overlap with the preallocated extents, the overlapped extents are freed twice in ext4_mb_release_inode_pa() and ext4_process_freed_data() (as described in commit 94d7c16cbbbd ("ext4: Fix double-free of blocks with EXT4_IOC_MOVE_EXT")), and bb_free is incremented twice. Hence when trim is executed, a zero-division bug is triggered in mb_update_avg_fragment_size() because bb_free is not zero and bb_fragments is zero. Therefore, update move_len after each extent move to avoid the issue.
References
- ubuntu.com/security/CVE-2024-26704 (opens in a new tab)
- git.kernel.org/linus/55583e899a5357308274601364741a83e78d6ac4 (opens in a new tab)
- git.kernel.org/stable/c/b4fbb89d722cbb16beaaea234b7230faaaf68c71 (opens in a new tab)
- git.kernel.org/stable/c/afbcad9ae7d6d11608399188f03a837451b6b3a1 (opens in a new tab)
- git.kernel.org/stable/c/d033a555d9a1cf53dbf3301af7199cc4a4c8f537 (opens in a new tab)
- git.kernel.org/stable/c/afba9d11320dad5ce222ac8964caf64b7b4bedb1 (opens in a new tab)
- git.kernel.org/stable/c/185eab30486ba3e7bf8b9c2e049c79a06ffd2bc1 (opens in a new tab)
- git.kernel.org/stable/c/2883940b19c38d5884c8626483811acf4d7e148f (opens in a new tab)
- git.kernel.org/stable/c/559ddacb90da1d8786dd8ec4fd76bbfa404eaef6 (opens in a new tab)
- git.kernel.org/stable/c/55583e899a5357308274601364741a83e78d6ac4 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26704 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6767-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6774-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6778-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6766-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6777-2 (opens in a new tab)