CVE-2026-23346
MediumCVSS 5.5Exploitation Probability (EPSS)
Low risk3th percentile - higher than 3% of all known CVEs
Summary
A vulnerability has been identified in the Linux kernel in the ioremap_prot() function, which may lead to memory read errors from the kernel level on arm64 systems with PAN enabled. The issue lies in returning a new user mapping that is inaccessible to the kernel.
Risk Assessment
This vulnerability may lead to system crashes or unauthorized memory access, posing a serious threat to the stability and security of the operating system.
Recommendation
It is recommended to update the Linux kernel to a version where this vulnerability has been fixed to avoid potential memory access issues.
Original NVD description (English source)
In the Linux kernel, the following vulnerability has been resolved: arm64: io: Extract user memory type in ioremap_prot() The only caller of ioremap_prot() outside of the generic ioremap() implementation is generic_access_phys(), which passes a 'pgprot_t' value determined from the user mapping of the target 'pfn' being accessed by the kernel. On arm64, the 'pgprot_t' contains all of the non-address bits from the pte, including the permission controls, and so we end up returning a new user mapping from ioremap_prot() which faults when accessed from the kernel on systems with PAN: | Unable to handle kernel read from unreadable memory at virtual address ffff80008ea89000 | ... | Call trace: | __memcpy_fromio+0x80/0xf8 | generic_access_phys+0x20c/0x2b8 | __access_remote_vm+0x46c/0x5b8 | access_remote_vm+0x18/0x30 | environ_read+0x238/0x3e8 | vfs_read+0xe4/0x2b0 | ksys_read+0xcc/0x178 | __arm64_sys_read+0x4c/0x68 Extract only the memory type from the user 'pgprot_t' in ioremap_prot() and assert that we're being passed a user mapping, to protect us against any changes in future that may require additional handling. To avoid falsely flagging users of ioremap(), provide our own ioremap() macro which simply wraps __ioremap_prot().