CVE-2025-38696: MIPS: Don't crash in stack_top() for tasks without ABI or vDSO
In the Linux kernel, the following vulnerability has been resolved:
MIPS: Don't crash in stacktop() for tasks without ABI or vDSO
Not all tasks have an ABI associated or vDSO mapped, for example kthreads never do. If such a task ever ends up calling stacktop(), it will derefence the NULL ABI pointer and crash.
This can for example happen when using kunit:
mipsstacktop+0x28/0xc0 archpickmmaplayout+0x190/0x220 kunitvmmmapinit+0xf8/0x138 kunitaddresource+0x40/0xa8 kunitvmmmap+0x88/0xd8 usercopytestinit+0xb8/0x240 kunittryruncase+0x5c/0x1a8 kunitgenericrunthreadfnadapter+0x28/0x50 kthread+0x118/0x240 retfromkernelthread+0x14/0x1c
Only dereference the ABI point if it is set.
The GIC page is also included as it is specific to the vDSO. Also move the randomization adjustment into the same conditional.
Affected Software
Remediation
Recommended actions to resolve this vulnerability, in priority order.
- Upgrade
Upgrade
debian/linuxto a version that resolves this vulnerability.Fixed in 6.1.176-1Fixed in 6.1.190-1Fixed in 6.12.107-1Fixed in 6.12.113-1Fixed in 7.2.12-1Fixed in 7.2.13-1
Event History
Frequently Asked Questions
What is the severity of CVE-2025-38696?
CVE-2025-38696 has been classified with a medium severity level due to its potential impact on kernel tasks.
How do I fix CVE-2025-38696?
To fix CVE-2025-38696, you should update your Linux kernel to a version that includes the patch for this vulnerability.
Which versions of the Linux kernel are affected by CVE-2025-38696?
CVE-2025-38696 affects certain versions of the Linux kernel that allow tasks without an ABI to crash.
What are the consequences of CVE-2025-38696?
The consequence of CVE-2025-38696 is that it can lead to a kernel crash when specific tasks invoke stack_top().
Is there a workaround for CVE-2025-38696?
No specific workaround is recommended for CVE-2025-38696; the best approach is to update the kernel.