{"id":"AZL-101873","summary":"CVE-2026-90303 affecting package kernel 6.6.150.1-1","details":"In the Linux kernel, the following vulnerability has been resolved:\n\nARM: 9485/1: mm: acquire mmap write lock around show_pte() for user faults\n\nWhen CONFIG_DEBUG_USER=y, and cmdline \"user_debug=31\" is set,\na user fault may trigger show_pte() without any lock.\nIf another thread in the same process concurrently calls munmap(),\nthe page table pages may be freed while show_pte() is still traversing\nthem, causing a use-after-free in show_pte().\n\nIf CONFIG_ARM_LPAE=y, this may cause a kernel panic if the pages table\nof PMD are freed when show_pte() is running.\n\nAcquire mmap_write_lock() around show_pte() for user faults to fix the\ncontention.\n\nFor user faults, additionally restrict that show_pte() is called only\nwhen the addr is a user-space address (addr \u003c TASK_SIZE). This is because\nthe lock of tsk-\u003emm only protects the virtual memory of user address space,\nfurthermore, dumping the page tables of a kernel-space address for user\nfaults is unnecessary and may have security implications.\n\nKeep everything unchanged for kernel faults, because the kernel is\nalready in the \"oops\" state, acquiring a lock may risk a deadlock.","modified":"2026-09-18T14:16:29.135348897Z","published":"2026-09-17T17:17:27Z","upstream":["CVE-2026-90303"],"references":[{"type":"WEB","url":"https://nvd.nist.gov/vuln/detail/CVE-2026-90303"}],"affected":[{"package":{"name":"kernel","ecosystem":"Azure Linux:3","purl":"pkg:rpm/azure-linux/kernel"},"ranges":[{"type":"ECOSYSTEM","events":[{"introduced":"0"},{"last_affected":"6.6.150.1-1"}]}],"database_specific":{"source":"https://github.com/microsoft/AzureLinuxVulnerabilityData/blob/main/osv/AZL-101873.json"}}],"schema_version":"1.9.0"}