CVE-2024-26924: Linux kernel · netfilter: nft_set_pipapo: do not free live element
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 5.15.0-1064.70~20.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 10:59 UTC
- Patch
- Available – fixed in 5.15.0-1064.70~20.04.1, 5.15.0-1067.76~20.04.1, 5.15.0-1065.73~20.04.1 +54
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 25 Apr 2024
Detectable: no evidence on record.
No public nuclei template indexed
Weaponised: 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 26 Oct 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Patches and advisories
- ubuntu.com/security/notices/USN-6869-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6870-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6871-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6872-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6873-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6874-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6863-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6864-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6872-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6864-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6873-2 (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-gcppkg:deb/ubuntu/linux-gcp?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-gkepkg:deb/ubuntu/linux-gke?arch=source&distro=nobleOther threats | Affected
| Fixed in
|
Ubuntu 24.04 LTSlinux-ibmpkg:deb/ubuntu/linux-ibm?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: netfilter: nft_set_pipapo: do not free live element Pablo reports a crash with large batches of elements with a back-to-back add/remove pattern. Quoting Pablo: add_elem("00000000") timeout 100 ms ... add_elem("0000000X") timeout 100 ms del_elem("0000000X") <---------------- delete one that was just added ... add_elem("00005000") timeout 100 ms 1) nft_pipapo_remove() removes element 0000000X Then, KASAN shows a splat. Looking at the remove function there is a chance that we will drop a rule that maps to a non-deactivated element. Removal happens in two steps, first we do a lookup for key k and return the to-be-removed element and mark it as inactive in the next generation. Then, in a second step, the element gets removed from the set/map. The _remove function does not work correctly if we have more than one element that share the same key. This can happen if we insert an element into a set when the set already holds an element with same key, but the element mapping to the existing key has timed out or is not active in the next generation. In such case its possible that removal will unmap the wrong element. If this happens, we will leak the non-deactivated element, it becomes unreachable. The element that got deactivated (and will be freed later) will remain reachable in the set data structure, this can result in a crash when such an element is retrieved during lookup (stale pointer). Add a check that the fully matching key does in fact map to the element that we have marked as inactive in the deactivation step. If not, we need to continue searching. Add a bug/warn trap at the end of the function as well, the remove function must not ever be called with an invisible/unreachable/non-existent element. v2: avoid uneeded temporary variable (Stefano)
References
- ubuntu.com/security/CVE-2024-26924 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-26924 (opens in a new tab)
- git.kernel.org/linus/3cfc9ec039af60dbd8965ae085b2c2ccdcfbe1cc (opens in a new tab)
- git.kernel.org/stable/c/3cfc9ec039af60dbd8965ae085b2c2ccdcfbe1cc (opens in a new tab)
- ubuntu.com/security/notices/USN-6869-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6870-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6871-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6872-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6873-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6874-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6875-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6863-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6864-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6872-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6864-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6873-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6870-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6892-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-6864-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-6900-1 (opens in a new tab)