mm/huge_memory: preserve pmd_swp_uffd_wp on device-private PMD downgrade
3Vexday Risk Score
No sign of exploitation. No public exploitation artifact known so far.
ssvc Trackepss 0.2%
exploitation probability
0.2%top 90% of all CVEs
observed exploitation
nono source reports it
In the Linux kernel, the following vulnerability has been resolved:
mm/huge_memory: preserve pmd_swp_uffd_wp on device-private PMD downgrade
change_non_present_huge_pmd() rewrites a writable device-private PMD swap
entry into a readable one without carrying pmd_swp_uffd_wp() across. The
PTE-level change_softleaf_pte() does this correctly; mirror that here,
matching what copy_huge_pmd() does for the fork path. Without the carry,
a plain mprotect() over a UFFD_WP-marked device-private THP strips the bit
and the trap is bypassed on swap-in.
Affected products
Linux · Linux