CVE-2026-68245

In the Linux kernel, the following vulnerability has been resolved:

drm/amdgpu: fix lifetime issue of amdgpu_vm_get_task_info_pasid()

The vm pointer returned from amdgpu_vm_get_vm_from_pasid() is only valid while the lock is still being held. Once xa_unlock_irqrestore is called and returned, the pointer is no longer under lock and is subject to modification. Since, the caller still dereferences vm->task_info in amdgpu_vm_get_task_info_vm() after the lock is removed, this causes a use after unlock problem.

Remove the lifetime issue present in amdgpu_vm_get_task_info_pasid() through removing the amdgpu_vm_get_vm_from_pasid() function from amdgpu_vm.c and making the relevant code inline to hold the lock while it is still in use.

(cherry picked from commit 9d01579f3f868b333acc901815972685989092c7)

Weakness

The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.

Affected Software

Extended Description

A race condition occurs within concurrent environments, and it is effectively a property of a code sequence. Depending on the context, a code sequence may be in the form of a function call, a small number of instructions, a series of program invocations, etc. A race condition violates these properties, which are closely related:

A race condition exists when an “interfering code sequence” can still access the shared resource, violating exclusivity. The interfering code sequence could be “trusted” or “untrusted.” A trusted interfering code sequence occurs within the product; it cannot be modified by the attacker, and it can only be invoked indirectly. An untrusted interfering code sequence can be authored directly by the attacker, and typically it is external to the vulnerable product.

Potential Mitigations

• Minimize the usage of shared resources in order to remove as much complexity as possible from the control flow and to reduce the likelihood of unexpected conditions occurring.
• Additionally, this will minimize the amount of synchronization necessary and may even help to reduce the likelihood of a denial of service where an attacker may be able to repeatedly trigger a critical section (CWE-400).

Related Attack Patterns

• https://cwe.mitre.org/data/definitions/26.html
• https://cwe.mitre.org/data/definitions/29.html

References

• https://git.kernel.org/stable/c/04cc4aa3617b0ed67e859f91f09de5d896a46f3a
• https://git.kernel.org/stable/c/1173190412fb9d12e7efce76734118d9712ff970
• https://git.kernel.org/stable/c/5d5fb9124a2bba96a7807086d8fe0f7ce810d546
• https://git.kernel.org/stable/c/fe16a7e5336ae888751984e30c451fbf7cfa5df7