CVE-2024-40947: Linux kernel · ima: Avoid blocking in RCU read-side critical section
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 7.8 High · fixed in 6.8.0-1015.16~22.04.1 : patch Linux kernel soon.
Data as of 28 Oct 2026, 11:00 UTC
- Patch
- Available – fixed in 6.8.0-1015.16~22.04.1, 6.8.0-1014.16~22.04.1, 6.8.0-45.45~22.04.1 +16
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 12 Jul 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-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7029-1 (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-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.
AI-suggested
A patch is available and has been released in Linux kernel versions 6.8.0-1015.16~22.04.1 and later. Users should update to these fixed kernel versions or later to remediate this vulnerability. No additional mitigation is required as the fix addresses the root cause by avoiding blocking calls in RCU read-side critical sections.
Description
CVE-2024-40947 is a vulnerability in the Linux kernel's Integrity Measurement Architecture (IMA) subsystem where blocking operations occur within an RCU read-side critical section. This can lead to a use-after-free (UAF) condition causing kernel panic due to NULL pointer dereference. The issue arises from kmalloc calls with GFP_KERNEL inside RCU read-side critical sections, violating RCU constraints. The flaw has been fixed by converting these kmalloc calls to use GFP_ATOMIC to avoid sleeping in critical sections.
References
- ubuntu.com/security/CVE-2024-40947 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-40947 (opens in a new tab)
- git.kernel.org/linus/9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 (opens in a new tab)
- git.kernel.org/stable/c/9c3906c3738562b1fedc6f1cfc81756a7cfefff0 (opens in a new tab)
- git.kernel.org/stable/c/28d0ecc52f6c927d0e9ba70a4f2c1ea15453ee88 (opens in a new tab)
- git.kernel.org/stable/c/58275455893066149e9f4df2223ab2fdbdc59f9c (opens in a new tab)
- git.kernel.org/stable/c/9a95c5bfbf02a0a7f5983280fe284a0ff0836c34 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7004-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7008-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7005-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-6999-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7029-1 (opens in a new tab)