ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults

MITRE NVD CVE.ORG JSON API

Summary

CVECVE-2026-90303
StatePUBLISHED
AssignerLinux
Source PriorityCVE Program / NVD first with legacy fallback
Published2026-09-17 17:17:27 UTC
Updated2026-09-17 17:17:27 UTC
DescriptionIn the Linux kernel, the following vulnerability has been resolved: ARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults When CONFIG_DEBUG_USER=y, and cmdline "user_debug=31" is set, a user fault may trigger show_pte() without any lock. If another thread in the same process concurrently calls munmap(), the page table pages may be freed while show_pte() is still traversing them, causing a use-after-free in show_pte(). If CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table of PMD are freed when show_pte() is running. Acquire mmap_write_lock() around show_pte() for user faults to fix the contention. For user faults, additionally restrict that show_pte() is called only when the addr is a user-space address (addr < TASK_SIZE). This is because the lock of tsk->mm only protects the virtual memory of user address space, furthermore, dumping the page tables of a kernel-space address for user faults is unnecessary and may have security implications. Keep everything unchanged for kernel faults, because the kernel is already in the "oops" state, acquiring a lock may risk a deadlock.

Vendor Declared Affected Products

SourceVendorProductVersionPlatforms
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 ab14f07952adfe735d86a53518f8cd576dfd5892 git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 07e4d5380f2a844ab7a1b440dde350caf561cbb0 git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 2a14d7797a49a47bccd1a9327fd69da838dcb0dd git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 63e3c958a602d0896a101a897c2361878c266ca7 git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 59bbf86d0ff9373bfa033ca123c1e924f09f1eba git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 c71f9a56520b419e55d173052629f2324deb5549 git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 720408d98d9fb3c91a12090436734c8c61f04545 git Not specified
CNA Linux Linux affected 6d021b724481fbb908eb29384898deb9f00dfe70 1039bffd6ae9c75b42b7d148d6c1106134107b66 git Not specified
CNA Linux Linux affected 4.0 Not specified
CNA Linux Linux unaffected 4.0 semver Not specified
CNA Linux Linux unaffected 5.10.270 5.10.* semver Not specified
CNA Linux Linux unaffected 5.15.221 5.15.* semver Not specified
CNA Linux Linux unaffected 6.1.188 6.1.* semver Not specified
CNA Linux Linux unaffected 6.6.157 6.6.* semver Not specified
CNA Linux Linux unaffected 6.12.110 6.12.* semver Not specified
CNA Linux Linux unaffected 6.18.52 6.18.* semver Not specified
CNA Linux Linux unaffected 7.2.6 7.2.* semver Not specified
CNA Linux Linux unaffected 7.3-rc1 * original_commit_for_fix Not specified

References

ReferenceSourceLinkTags
git.kernel.org/stable/c/720408d98d9fb3c91a12090436734c8c61f04545 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/c71f9a56520b419e55d173052629f2324deb5549 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/63e3c958a602d0896a101a897c2361878c266ca7 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/2a14d7797a49a47bccd1a9327fd69da838dcb0dd 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/59bbf86d0ff9373bfa033ca123c1e924f09f1eba 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/ab14f07952adfe735d86a53518f8cd576dfd5892 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/1039bffd6ae9c75b42b7d148d6c1106134107b66 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
git.kernel.org/stable/c/07e4d5380f2a844ab7a1b440dde350caf561cbb0 416baaa9-dc9f-4396-8d5f-8c081fb06d67 git.kernel.org
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