CVE-2026-23316

CVE-2026-23316CVE-2026-23316

linux / linux_kernel

Description

In the Linux kernel, the following vulnerability has been resolved: net: ipv4: fix ARM64 alignment fault in multipath hash seed `struct sysctl_fib_multipath_hash_seed` contains two u32 fields (user_seed and mp_seed), making it an 8-byte structure with a 4-byte alignment requirement. In `fib_multipath_hash_from_keys()`, the code evaluates the entire struct atomically via `READ_ONCE()`: mp_seed = READ_ONCE(net->ipv4.sysctl_fib_multipath_hash_seed).mp_seed; While this silently works on GCC by falling back to unaligned regular loads which the ARM64 kernel tolerates, it causes a fatal kernel panic when compiled with Clang and LTO enabled. Commit e35123d83ee3 ("arm64: lto: Strengthen READ_ONCE() to acquire when CONFIG_LTO=y") strengthens `READ_ONCE()` to use Load-Acquire instructions (`ldar` / `ldapr`) to prevent compiler reordering bugs under Clang LTO. Since the macro evaluates the full 8-byte struct, Clang emits a 64-bit `ldar` instruction. ARM64 architecture strictly requires `

Scoring

CVSS 5.5 ()
VectorCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:H
Last modified2026-11-05
Sourced from NVD. Curated for EU compliance use cases by Adam Lundqvist, Founder at SQUR.