In the Linux kernel, the following vulnerability has been resolved: arm64: io: Reject non-user protection in ioremap_prot() Mapping a stack-top page via /dev/mem with PROT_NONE and then reading that process's /proc/<pid>/cmdline triggers a spurious WARN in ioremap_prot() through generic_access_phys(): WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys Call trace: generic_access_phys+0x1c8/0x228 (P) __access_remote_vm+0x2b4/0x398 access_remote_vm+0x14/0x30 get_mm_cmdline+0xf8/0x2a0 proc_pid_cmdline_read+0x68/0x120 generic_access_phys() passes the protection derived from the user PTE to ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a present-invalid PTE, so pte_present() still returns true and the protection reaches ioremap_prot(). A PROT_NONE mapping does not have PTE_USER, causing the existing WARN_ON_ONCE() in ioremap_prot() to fire even though this is a valid user mapping. Execute-only mappings have the same issue and must not be readable through this path either. ioremap_prot() should therefore reject protection values without PTE_USER without warning. This makes the access fail cleanly for PROT_NONE and execute-only mappings while retaining the existing user-protection contract.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - arm64: io: Reject non-user protection in ioremap_prot() Mapping a stack-top page via /dev/mem with     PROT_NONE and then reading that process's /proc/<pid>/cmdline triggers a spurious WARN in ioremap_prot()     through generic_access_phys(): WARNING: ./arch/arm64/include/asm/io.h:275 at generic_access_phys Call     trace: generic_access_phys+0x1c8/0x228 (P) __access_remote_vm+0x2b4/0x398 access_remote_vm+0x14/0x30     get_mm_cmdline+0xf8/0x2a0 proc_pid_cmdline_read+0x68/0x120 generic_access_phys() passes the protection     derived from the user PTE to ioremap_prot(). On arm64, a PROT_NONE mapping is represented by a present-     invalid PTE, so pte_present() still returns true and the protection reaches ioremap_prot(). A PROT_NONE     mapping does not have PTE_USER, causing the existing WARN_ON_ONCE() in ioremap_prot() to fire even though     this is a valid user mapping. Execute-only mappings have the same issue and must not be readable through     this path either. ioremap_prot() should therefore reject protection values without PTE_USER without     warning. This makes the access fail cleanly for PROT_NONE and execute-only mappings while retaining the     existing user-protection contract. (CVE-2026-98923)

Note that Nessus relies on the presence of the package as reported by the vendor.

ID	Name	Product	Family	Type	Severity
372333	Linux Distros Unpatched Vulnerability : CVE-2026-98923	Nessus	Misc.	Local	high
371850	Amazon Linux 2023 : bpftool6.18, kernel6.18, kernel6.18-devel (ALAS2023-2026-3251)	Nessus	Amazon Linux Local Security Checks	Local	critical

Detections

Analytics

CVE-2026-98923

high

Tenable Plugins

high

critical