--- cve: "CVE-2026-90303" severity: "LOW" cvss: 3.1 epss: "3.2%" vendor: "Linux" kev: false exploited: false published: "2026-09-17 17:17:27" tags: [cve, security, low] source: tsecurity.de CVE-Dossier exported: "2026-09-21T14:48:04+02:00" --- # CVE-2026-90303 > 3.1 LOW ## Beschreibung 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. ## Patch verfügbar (OSV) - Kernel ≥ 5.10.270 - Kernel ≥ 5.15.221 - Kernel ≥ 6.1.188 - Kernel ≥ 6.6.157 - Kernel ≥ 6.12.110 - Kernel ≥ 6.18.52 - Kernel ≥ 7.2.6 ## Referenzen - - - - - - - - --- _Exportiert aus dem [tsecurity.de CVE-Dossier](https://tsecurity.de/cve?cve=CVE-2026-90303) · Datenquellen: EUVD (ENISA), NVD, OSV, CISA KEV, FIRST EPSS, Exploit-DB, BSI BITS_