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CVE-2026-90303

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

Published
Last modified
published
Not listed in CISA KEV
Fix
Fixed in 5.10.270, 5.15.221, 6.1.188, 6.6.157, 6.12.110, and 2 more
None on Exploit-DB, Metasploit or GitHub

Summary

In 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.

Timeline

  1. CVE published
  2. Record last updated

Affected versions

  • Linux Linux

    From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in ab14f07952adfe735d86a53518f8cd576dfd5892; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in 07e4d5380f2a844ab7a1b440dde350caf561cbb0; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in 2a14d7797a49a47bccd1a9327fd69da838dcb0dd; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in 63e3c958a602d0896a101a897c2361878c266ca7; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in 59bbf86d0ff9373bfa033ca123c1e924f09f1eba; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in c71f9a56520b419e55d173052629f2324deb5549; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in 720408d98d9fb3c91a12090436734c8c61f04545; From 6d021b724481fbb908eb29384898deb9f00dfe70 · fixed in 1039bffd6ae9c75b42b7d148d6c1106134107b66

  • Linux Linux

    4.0

  • KernelLinux

    From 4.0.0 · fixed in 5.10.270; From 5.11.0 · fixed in 5.15.221; From 5.16.0 · fixed in 6.1.188; From 6.2.0 · fixed in 6.6.157; From 6.7.0 · fixed in 6.12.110; From 6.13.0 · fixed in 6.18.52; From 6.19.0 · fixed in 7.2.6

References 8

git.kernel.org