CVE-2025-39829: Linux kernel · trace/fgraph: Fix the warning caused by missing unregister notifier
Affects Linux kernelSource CVE Database V5
Not known to be exploited · CVSS 5.5 Medium · fixed in edede7a6dcd7435395cf757d053974aaab6ab1c2 : update Linux kernel when convenient.
Data as of 26 Oct 2026, 13:47 UTC
- EPSS
- 0.1% chance of exploitation in 30 days – higher than 8% of CVEsExploit Prediction Scoring System: the likelihood attackers will use this flaw soon.
- 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, 2026-01-14.
- Patch
- Available – fixed in edede7a6dcd7435395cf757d053974aaab6ab1c2, aa977309397fe2438801b1ca1ce7bc4106d8e985, 2a2deb9f8df70480050351ac27041f19bb9e718b +1
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 16 Sep 2025
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 Linux kernel to edede7a6dcd7435395cf757d053974aaab6ab1c2, aa977309397fe2438801b1ca1ce7bc4106d8e985, 2a2deb9f8df70480050351ac27041f19bb9e718b or 000aa47a51233fd38a629b029478e0278e1e9fbe.
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– |
Description
In the Linux kernel, the following vulnerability has been resolved: trace/fgraph: Fix the warning caused by missing unregister notifier This warning was triggered during testing on v6.16: notifier callback ftrace_suspend_notifier_call already registered WARNING: CPU: 2 PID: 86 at kernel/notifier.c:23 notifier_chain_register+0x44/0xb0 ... Call Trace: <TASK> blocking_notifier_chain_register+0x34/0x60 register_ftrace_graph+0x330/0x410 ftrace_profile_write+0x1e9/0x340 vfs_write+0xf8/0x420 ? filp_flush+0x8a/0xa0 ? filp_close+0x1f/0x30 ? do_dup2+0xaf/0x160 ksys_write+0x65/0xe0 do_syscall_64+0xa4/0x260 entry_SYSCALL_64_after_hwframe+0x77/0x7f When writing to the function_profile_enabled interface, the notifier was not unregistered after start_graph_tracing failed, causing a warning the next time function_profile_enabled was written. Fixed by adding unregister_pm_notifier in the exception path.
References
- git.kernel.org/stable/c/aa977309397fe2438801b1ca1ce7bc4106d8e985 (opens in a new tab)
- git.kernel.org/stable/c/2a2deb9f8df70480050351ac27041f19bb9e718b (opens in a new tab)
- git.kernel.org/stable/c/000aa47a51233fd38a629b029478e0278e1e9fbe (opens in a new tab)
- git.kernel.org/stable/c/edede7a6dcd7435395cf757d053974aaab6ab1c2 (opens in a new tab)