CVE-2024-56645: Linux kernel · can: j1939: j1939_session_new(): fix skb reference counting
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 9.8 Critical · fixed in 5.4.0-1142.152~18.04.1 : patch Linux kernel as a priority.
Data as of 29 Oct 2026, 22:35 UTC
- Patch
- Available – fixed in 5.4.0-1142.152~18.04.1, 5.4.0-1147.154~18.04.1, 5.4.0-1145.154~18.04.1 +83
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:HExploitation evidence
Disclosed: evidence found.
CVE published 27 Dec 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-7379-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7380-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7381-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7382-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7391-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7392-1 (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: can: j1939: j1939_session_new(): fix skb reference counting Since j1939_session_skb_queue() does an extra skb_get() for each new skb, do the same for the initial one in j1939_session_new() to avoid refcount underflow. [mkl: clean up commit message]
References
- ubuntu.com/security/CVE-2024-56645 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-56645 (opens in a new tab)
- git.kernel.org/linus/a8c695005bfe6569acd73d777ca298ddddd66105 (opens in a new tab)
- git.kernel.org/stable/c/224e606a8d8e8c7db94036272c47a37455667313 (opens in a new tab)
- git.kernel.org/stable/c/4199dd78a59896e091d3a7a05a77451aa7fd724d (opens in a new tab)
- git.kernel.org/stable/c/426d94815e12b6bdb9a75af294fbbafb9301601d (opens in a new tab)
- git.kernel.org/stable/c/68fceb143b635cdc59fed3896d5910aff38f345e (opens in a new tab)
- git.kernel.org/stable/c/a8c695005bfe6569acd73d777ca298ddddd66105 (opens in a new tab)
- git.kernel.org/stable/c/b3282c2bebeeb82ceec492ee4972f51ee7a4a132 (opens in a new tab)
- git.kernel.org/stable/c/f117cba69cbbd496babb3defcdf440df4fd6fe14 (opens in a new tab)
- ubuntu.com/security/notices/USN-7379-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7380-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7381-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7382-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7388-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7389-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7390-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7387-3 (opens in a new tab)