Linux Kernel: AMDXDNA Local Priv Escalation via vmflags_mod
CVE-2026-74716 Published on August 22, 2026
accel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages()
In the Linux kernel, the following vulnerability has been resolved:
accel/amdxdna: Fix locally exploitable BUG_ON in amdxdna_insert_pages()
In amdxdna_insert_pages(), vm_flags_mod() sets VM_MIXEDMAP and clears
VM_PFNMAP. If an unprivileged userspace process mmaps a non-imported GEM
object and then calls madvise(MADV_DONTNEED), the PTEs will be
successfully cleared because VM_MIXEDMAP allows this (unlike VM_PFNMAP).
When userspace subsequently accesses the memory, drm_gem_shmem_fault()
handles the page fault and attempts to map the backing shmem page via
vmf_insert_pfn() which calls vmf_insert_pfn_prot(). Because the backing
shmem page is normal system memory (pfn_valid(pfn) is true) and the VMA
now has VM_MIXEDMAP set, won't this predictably trigger the explicit
assertion BUG_ON((vma->vm_flags & VM_MIXEDMAP) && pfn_valid(pfn))
Fix by removing the vm_flags_mod() call and replacing the vm_insert_pages()
pre-population with the handle_mm_fault() loop that was already used for
the import (dma-buf) path.
Products Associated with CVE-2026-74716
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Affected Versions
Linux:- Version e486147c912f653ef4b60a6c7dbd4168a4c56a9f and below 13339132d89d00b513dff0730bff3a313b9b13b5 is affected.
- Version e486147c912f653ef4b60a6c7dbd4168a4c56a9f and below 4a19f7ab5972ef608b31ae921419bc3e04b3f8ad is affected.
- Version 6.16 is affected.
- Before 6.16 is unaffected.
- Version 7.1.9, <= 7.1.* is unaffected.
- Version 7.2, <= * is unaffected.