CVE-2024-42096: Linux kernel · x86: stop playing stack games in profile_pc()
Affects Linux kernelSource GCVE Database
Not known to be exploited · CVSS 5.5 Medium · fixed in 5.4.0-1132.142~18.04.1 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 23:28 UTC
- Patch
- Available – fixed in 5.4.0-1132.142~18.04.1, 5.4.0-1137.144~18.04.1, 5.4.0-1136.145~18.04.1 +77
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HExploitation evidence
Disclosed: evidence found.
CVE published 29 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-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-4 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-5 (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-gkeoppkg:deb/ubuntu/linux-gkeop?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: x86: stop playing stack games in profile_pc() The 'profile_pc()' function is used for timer-based profiling, which isn't really all that relevant any more to begin with, but it also ends up making assumptions based on the stack layout that aren't necessarily valid. Basically, the code tries to account the time spent in spinlocks to the caller rather than the spinlock, and while I support that as a concept, it's not worth the code complexity or the KASAN warnings when no serious profiling is done using timers anyway these days. And the code really does depend on stack layout that is only true in the simplest of cases. We've lost the comment at some point (I think when the 32-bit and 64-bit code was unified), but it used to say: Assume the lock function has either no stack frame or a copy of eflags from PUSHF. which explains why it just blindly loads a word or two straight off the stack pointer and then takes a minimal look at the values to just check if they might be eflags or the return pc: Eflags always has bits 22 and up cleared unlike kernel addresses but that basic stack layout assumption assumes that there isn't any lock debugging etc going on that would complicate the code and cause a stack frame. It causes KASAN unhappiness reported for years by syzkaller [1] and others [2]. With no real practical reason for this any more, just remove the code. Just for historical interest, here's some background commits relating to this code from 2006: 0cb91a229364 ("i386: Account spinlocks to the caller during profiling for !FP kernels") 31679f38d886 ("Simplify profile_pc on x86-64") and a code unification from 2009: ef4512882dbe ("x86: time_32/64.c unify profile_pc") but the basics of this thing actually goes back to before the git tree.
References
- ubuntu.com/security/CVE-2024-42096 (opens in a new tab)
- cve.org/CVERecord?id=CVE-2024-42096 (opens in a new tab)
- git.kernel.org/linus/093d9603b60093a9aaae942db56107f6432a5dca (opens in a new tab)
- git.kernel.org/stable/c/65ebdde16e7f5da99dbf8a548fb635837d78384e (opens in a new tab)
- git.kernel.org/stable/c/27c3be840911b15a3f24ed623f86153c825b6b29 (opens in a new tab)
- git.kernel.org/stable/c/49c09ca35a5f521d7fa18caf62fdf378f15e8aa4 (opens in a new tab)
- git.kernel.org/stable/c/2d07fea561d64357fb7b3f3751e653bf20306d77 (opens in a new tab)
- git.kernel.org/stable/c/161cef818545ecf980f0e2ebaf8ba7326ce53c2b (opens in a new tab)
- git.kernel.org/stable/c/16222beb9f8e5ceb0beeb5cbe54bef16df501a92 (opens in a new tab)
- git.kernel.org/stable/c/a3b65c8cbc139bfce9541bc81c1bb766e5ba3f68 (opens in a new tab)
- git.kernel.org/stable/c/093d9603b60093a9aaae942db56107f6432a5dca (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7006-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7003-3 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7009-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7019-1 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-2 (opens in a new tab)
- ubuntu.com/security/notices/USN-7007-3 (opens in a new tab)