CVE-2026-43416
Kernel NULL Pointer Dereference in Linux Kernel perf Subsystem
Publication date: 2026-05-08
Last updated on: 2026-05-08
Assigner: kernel.org
Description
Description
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Meta Information
Affected Vendors & Products
| Vendor | Product | Version / Range |
|---|---|---|
| linux | linux_kernel | * |
Helpful Resources
Exploitability
| CWE ID | Description |
|---|---|
| CWE-UNKNOWN |
Attack-Flow Graph
AI Powered Q&A
Can you explain this vulnerability to me?
This vulnerability exists in the Linux kernel's powerpc perf subsystem. It occurs because the kernel does not properly check if the current process's memory descriptor (current->mm) is still valid before attempting to access the user callchain for profiling.
If current->mm has already been released (i.e., is NULL), the kernel tries to read from an invalid memory area, causing a kernel panic due to a NULL pointer dereference.
The fix involves adding a NULL check for current->mm before accessing the user callchain, preventing the kernel from crashing in this scenario.
How can this vulnerability impact me? :
This vulnerability can cause the Linux kernel to panic and crash when running profiling tools that use the perf subsystem, such as BPF programs.
A kernel panic leads to system instability and downtime, which can disrupt services and applications running on the affected system.
In environments where uptime and reliability are critical, this vulnerability could result in significant operational impact.
How can this vulnerability be detected on my network or system? Can you suggest some commands?
This vulnerability can be detected by monitoring kernel logs for signs of kernel panic or NULL pointer dereference related to perf callchain user events.
Specifically, look for messages similar to the following in your kernel logs:
- Kernel attempted to read user page (exploit attempt?)
- BUG: Kernel NULL pointer dereference on read
- Oops: Kernel access of bad area, sig: 11
You can use the following commands to check for such messages:
- dmesg | grep -i 'NULL pointer dereference'
- journalctl -k | grep -i 'perf_callchain_user'
- grep -i 'Kernel attempted to read user page' /var/log/kern.log
Additionally, if you are running profiling BPF programs (such as profile.py from bcc-tools), monitor their behavior closely as they may trigger this vulnerability.
What immediate steps should I take to mitigate this vulnerability?
The immediate mitigation step is to update the Linux kernel to a version that includes the fix for this vulnerability.
The fix involves adding a NULL check for current->mm before accessing the user callchain in the perf subsystem, preventing kernel panic.
Until the kernel is updated, avoid running profiling BPF programs that trigger this vulnerability, such as profile.py from bcc-tools.
Monitoring kernel logs for early signs of the issue can help in taking timely action.