CVE-2025-71135: md/raid5: fix possible null-pointer dereferences in raid5_store_group_thread_cnt()
In the Linux kernel, the following vulnerability has been resolved:
md/raid5: fix possible null-pointer dereferences in raid5storegroupthreadcnt()
The variable mddev->private is first assigned to conf and then checked:
conf = mddev->private; if (!conf) ...
If conf is NULL, then mddev->private is also NULL. In this case, null-pointer dereferences can occur when calling raid5quiesce():
raid5quiesce(mddev, true); raid5quiesce(mddev, false);
since mddev->private is assigned to conf again in raid5quiesce(), and conf is dereferenced in several places, for example:
conf->quiesce = 0; wakeup(&conf->waitforquiescent);
To fix this issue, the function should unlock mddev and return before invoking raid5quiesce() when conf is NULL, following the existing pattern in raid5changeconsistencypolicy().
Affected Software
Remediation
Event History
Frequently Asked Questions
What is the severity of CVE-2025-71135?
CVE-2025-71135 has been classified as a moderate severity vulnerability due to the potential for null-pointer dereferences.
How do I fix CVE-2025-71135?
To fix CVE-2025-71135, update the Linux kernel to the latest version that contains the fix for this vulnerability.
What systems are affected by CVE-2025-71135?
CVE-2025-71135 affects versions of the Linux kernel that utilize the md/raid5 functionality and are vulnerable to null-pointer dereferences.
What are the consequences of exploiting CVE-2025-71135?
Exploiting CVE-2025-71135 may lead to system instability or crashes due to null-pointer dereferences in the raid5_store_group_thread_cnt() function.
Is there a workaround for CVE-2025-71135 until a patch is applied?
There are no known workarounds for CVE-2025-71135, so applying the patch is the recommended course of action.