CVE-2024-50273: Linux kernel · btrfs: reinitialize delayed ref list after deleting it from the list
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.4.0-1142.152~18.04.1 : patch Linux kernel soon.
Data as of 29 Oct 2026, 22:34 UTC
- Patch
- Available – fixed in 5.4.0-1142.152~18.04.1, 5.4.0-1145.152~18.04.1, 5.4.0-1143.152~18.04.1 +84
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 19 Nov 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 29 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7291-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7293-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7294-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7295-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7305-1 (opens in a new tab)
Affected software
| Product | Affected | Fixed in |
|---|---|---|
Ubuntu 24.04 LTSlinuxpkg:deb/ubuntu/linux?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-awspkg:deb/ubuntu/linux-aws?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azurepkg:deb/ubuntu/linux-azure?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-6.11pkg:deb/ubuntu/linux-azure-6.11?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-azure-nvidiapkg:deb/ubuntu/linux-azure-nvidia?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther 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: btrfs: reinitialize delayed ref list after deleting it from the list At insert_delayed_ref() if we need to update the action of an existing ref to BTRFS_DROP_DELAYED_REF, we delete the ref from its ref head's ref_add_list using list_del(), which leaves the ref's add_list member not reinitialized, as list_del() sets the next and prev members of the list to LIST_POISON1 and LIST_POISON2, respectively. If later we end up calling drop_delayed_ref() against the ref, which can happen during merging or when destroying delayed refs due to a transaction abort, we can trigger a crash since at drop_delayed_ref() we call list_empty() against the ref's add_list, which returns false since the list was not reinitialized after the list_del() and as a consequence we call list_del() again at drop_delayed_ref(). This results in an invalid list access since the next and prev members are set to poison pointers, resulting in a splat if CONFIG_LIST_HARDENED and CONFIG_DEBUG_LIST are set or invalid poison pointer dereferences otherwise. So fix this by deleting from the list with list_del_init() instead.
References
- ubuntu.com/security/CVE-2024-50273 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-50273 (opens in a new tab)
- git.kernel.org/linus/c9a75ec45f1111ef530ab186c2a7684d0a0c9245 (opens in a new tab)
- git.kernel.org/stable/c/2fd0948a483e9cb2d669c7199bc620a21c97673d (opens in a new tab)
- git.kernel.org/stable/c/93c5b8decc0ef39ba84f4211d2db6da0a4aefbeb (opens in a new tab)
- git.kernel.org/stable/c/bf0b0c6d159767c0d1c21f793950d78486690ee0 (opens in a new tab)
- git.kernel.org/stable/c/c24fa427fc0ae827b2a3a07f13738cbf82c3f851 (opens in a new tab)
- git.kernel.org/stable/c/2cb1a73d1d44a1c11b0ee5eeced765dd80ec48e6 (opens in a new tab)
- git.kernel.org/stable/c/f04be6d68f715c1473a8422fc0460f57b5e99931 (opens in a new tab)
- git.kernel.org/stable/c/50a3933760b427759afdd23156a7280a19357a92 (opens in a new tab)
- git.kernel.org/stable/c/c9a75ec45f1111ef530ab186c2a7684d0a0c9245 (opens in a new tab)
- ubuntu.com/security/notices/USN-7276-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7277-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7291-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7288-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7289-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7293-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7294-1 (opens in a new tab)