Vulnerabilities

Vulnerability · CVE-2026-74599

In the Linux kernel, the following vulnerability has been resolved: mm/ptdump: always stabilise against page table freeing using init_mm Previous commits have establis…

Published Aug 22, 2026 · catalog updated Oct 14, 2026 · the affected product

Check if you run it

No confirmed exploitation is on record for CVE-2026-74599. EPSS is 0.17%. Act only if a listed version of the affected product is installed.

Severity

Unknown—

Known exploitation

Not in CISA/VulnCheck KEV

EPSS

0.17%

Remediation

Not established

Affected products

See sources for product scope

In the Linux kernel, the following vulnerability has been resolved: mm/ptdump: always stabilise against page table freeing using init_mm Previous commits have established the invariant that kernel page table freeing is performed while an mmap read lock on init_mm is held, which fixes races between ptdump and kernel page table freeing over init_mm. However, x86 and arm64 can perform a ptdump over an mm other than init_mm via ptdump_walk_pgd() and since kernel memory ranges are shared across non-kernel mm's, this means that the race still exists for these cases. Fix this by acquiring a nested mmap write lock for init_mm in ptdump_walk_pgd(). This is safe as we take this after mmap write locking the mm, and nothing acquires the init_mm lock first before locking an arbitrary mm, so no deadlock is possible. Also update walk_page_range_debug() to assert that init_mm is write locked, add a comment explaining why and remove some redundant code, and eliminate the unnecessary and confusing invocation of walk_kernel_page_table_range(). We can safely remove the non-NULL check for walk.mm, as the mmap lock asserts would NULL pointer deref if it was (and of course no callers do this). The first point at which ptdump can race kernel page table freeing is commit b6bdb7517c3d ("mm/vmalloc: add interfaces to free unmapped page table"), so we target this in the Fixes tag.

No affected version ranges are stored yet. Use the vendor advisory before you decide this record does not apply.