CVE-2026-46196: Linux kernel · tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func()
Affects Linux kernelSource CVE Database V5
Not known to be exploited · fixed in fad217e16fded7f3c09f8637b0f6a224d58b5f2e : update Linux kernel when convenient.
Data as of 6 Nov 2026, 16:34 UTC
Rated by Threat Radar · No CVSS score from NVD or the CNA
Thin evidence
One scorer or none- CISA SSVC
- Exploitation
- No evidence of active exploitation and no public proof of concept
- Automatable
- Attackers cannot reliably automate steps 1–4 of the kill chain
- Technical impact
- Limited control over the software or limited information exposure
CISA SSVC assessment, 2026-11-06.
- Patch
- Available – fixed in fad217e16fded7f3c09f8637b0f6a224d58b5f2e, 5787052e5f69beb649f3d6a80a8aa37d9e683e4e, 342829e042ac00f3d68d442ea92873fb6683f494 +5
Exploitation evidence
Disclosed: evidence found.
CVE published 28 May 2026
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 6 Nov 2026.
What to do
Upgrade to a fixed release listed under Affected software.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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| LinuxLinux | Affected
| Fixed in
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Description
In the Linux kernel, the following vulnerability has been resolved: tracepoint: balance regfunc() on func_add() failure in tracepoint_add_func() When a tracepoint goes through the 0 -> 1 transition, tracepoint_add_func() invokes the subsystem's ext->regfunc() before attempting to install the new probe via func_add(). If func_add() then fails (for example, when allocate_probes() cannot allocate a new probe array under memory pressure and returns -ENOMEM), the function returns the error without calling the matching ext->unregfunc(), leaving the side effects of regfunc() behind with no installed probe to justify them. For syscall tracepoints this is particularly unpleasant: syscall_regfunc() bumps sys_tracepoint_refcount and sets SYSCALL_TRACEPOINT on every task. After a leaked failure, the refcount is stuck at a non-zero value with no consumer, and every task continues paying the syscall trace entry/exit overhead until reboot. Other subsystems providing regfunc()/unregfunc() pairs exhibit similarly scoped persistent state. Mirror the existing 1 -> 0 cleanup and call ext->unregfunc() in the func_add() error path, gated on the same condition used there so the unwind is symmetric with the registration.
References
- git.kernel.org/stable/c/5787052e5f69beb649f3d6a80a8aa37d9e683e4e (opens in a new tab)
- git.kernel.org/stable/c/4f1756d043e56ea2e9a6c858fb290a0cf6fc2251 (opens in a new tab)
- git.kernel.org/stable/c/36ff362235307af95152d510b53c2d9b8773a342 (opens in a new tab)
- git.kernel.org/stable/c/247ed8a969f981bfba3112fd4bb441eaa6cef59c (opens in a new tab)
- git.kernel.org/stable/c/7bcadb3c2bc1cf60690e931aadd35fb7bd646a49 (opens in a new tab)
- git.kernel.org/stable/c/2c5b8eeea006eb694c81631cd5713d494b80be90 (opens in a new tab)
- git.kernel.org/stable/c/342829e042ac00f3d68d442ea92873fb6683f494 (opens in a new tab)
- git.kernel.org/stable/c/fad217e16fded7f3c09f8637b0f6a224d58b5f2e (opens in a new tab)
- cert-portal.siemens.com/productcert/html/ssa-784472.html (opens in a new tab)