A flaw in the Linux kernel’s AMD XDNA acceleration module causes a BUG_ON assertion when an unprivileged userspace process maps a non-imported GEM object, overwrites its page entries via madvise(MADV_DONTNEED), and then accesses the resulting memory. The kernel then attempts to map a backing shmem page with VM_MIXEDMAP set and a valid PFN, which triggers an explicit assertion and causes the kernel to die. The vulnerability is locally exploitable from user‑space and results in a kernel panic, effectively taking the system offline.

All Linux kernel builds that include the accel/amdxdna driver and have not yet applied the patch that removes the vm_flags_mod call are affected. Versions prior to the commit that introduced the fix are vulnerable; current stable kernels awaiting the merge are also at risk until the update is deployed.

The EPSS score of <1% indicates a very low probability of exploitation, but the vulnerability remains locally exploitable from user space. Because it triggers a BUG_ON that causes the kernel to crash, the impact is a denial of service. The CVSS score of 5.5 reflects that no escalation or data disclosure is achievable, and the primary effect is an unstable kernel. The vulnerability is not listed in the CISA KEV catalog.