CVE-2026-23383
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.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.17%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
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 (sizeof(u64)) in bpf_jit_binary_pack_alloc(). This anchors the base of the JIT buffer to an 8-byte boundary, allowing the relative padding math in build_plt() to correctly align the target field.
- CVSS 3.1
- 7.8 HIGHCVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
- EPSS
- 0.17% probability · 7th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Affected
- linux/linux kernel
- Source
- 416baaa9-dc9f-4396-8d5f-8c081fb06d67
EPSS 0.2% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://git.kernel.org/stable/c/519b1ad91de5bf7a496f2b858e9212db6328e1dePatch
- https://git.kernel.org/stable/c/66959ed481a474eaae278c7f6860a2a9b188a4d6Patch
- https://git.kernel.org/stable/c/80ad264da02cc4aee718e799c2b79f0f834673dcPatch
- https://git.kernel.org/stable/c/ef06fd16d48704eac868441d98d4ef083d8f3d07Patch
- https://git.kernel.org/stable/c/f5a41b61b5faae1965a5a2cb55322fe8f17e3b2d
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.