CVE-2026-23383

Technical Description

In the Linux kernel, the following vulnerability has been resolved:

bpf, arm64: Force 8-byte alignment for JIT buffer to prevent atomic tearing

struct bpf_plt contains a u64 target field. Currently, the BPF JIT

allocator requests an alignment of 4 bytes (sizeof(u32)) for the JIT

buffer.

Because the base address of the JIT buffer can be 4-byte aligned (e.g.,

ending in 0x4 or 0xc), the relative padding logic in build_plt() fails

to ensure that target lands on an 8-byte boundary.

This leads to two issues:

1. UBSAN reports misaligned-access warnings when dereferencing the

structure.

2. More critically, target is updated concurrently via WRITE_ONCE() in

bpf_arch_text_poke() while the JIT'd code executes ldr. On arm64,

64-bit loads/stores are only guaranteed to be single-copy atomic if

they are 64-bit aligned. A misaligned target risks a torn read,

causing the JIT to jump to a corrupted address.

Fix this by increasing the allocation alignment requirement to 8 bytes

(sizeo

Remediation

Check the references section for vendor advisories and patches from linux. Update linux_kernel to the latest patched version. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

Affected Products

References