CVE-2026-74721

High

Description

In the Linux kernel, the following vulnerability has been resolved: accel/amxdna: Fix page-insertion errors in amdxdna_insert_pages() Two error paths in amdxdna_insert_pages() called vma->vm_ops->close(vma) before returning an error code to the caller. This is incorrect: amdxdna_gem_obj_mmap() registers an HMM interval notifier before calling amdxdna_insert_pages(), and on a hard error it jumps to hmm_unreg to undo that registration. Calling vm_ops->close() manually — which drops the shmem pages_pin_count and the GEM object reference that backs the VMA — before the mmap syscall has even returned causes those resources to be released while the VMA is still alive. The kernel VMA teardown will call vm_ops->close() a second time when the process later unmaps the range, producing a reference count underflow. Replace both hard-error returns with a deferred-fault approach that keeps the VMA alive and retries page insertion through the HMM range-fault path.

SeverityHigh
CVSS7.8
Exploit probability—
ProductLinux
PublishedAug 22, 2026
First seenAug 22, 2026

How to fix

Update
  • Linux Linuxb3d05a335cbd3d89538e9dde1621dccf33ae945a, 1501e4d07c6fee0d50531a0d1cb2be01a63e6e75, 8d51e0fd3e698919d2adeff71936377f0c0d4aa0 or later

Affected products

ProductAffected versionsFixed in
Linux Linuxe486147c912f653ef4b60a6c7dbd4168a4c56a9f ≤ v < b3d05a335cbd3d89538e9dde1621dccf33ae945a, e486147c912f653ef4b60a6c7dbd4168a4c56a9f ≤ v < 1501e4d07c6fee0d50531a0d1cb2be01a63e6e75, e486147c912f653ef4b60a6c7dbd4168a4c56a9f ≤ v < 8d51e0fd3e698919d2adeff71936377f0c0d4aa0, 6.16b3d05a335cbd3d89538e9dde1621dccf33ae945a, 1501e4d07c6fee0d50531a0d1cb2be01a63e6e75, 8d51e0fd3e698919d2adeff71936377f0c0d4aa0

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CVE-2026-74721 · Linux · Dark Radar