CVE-2026-53343

ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow

MEDIUM
5.5
CVSS Score
Published: July 1, 2026 at 01:32 PM UTC
Updated: July 23, 2026 at 09:51 PM UTC
1 product affected across 1 vendorLinux Kernel

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Severity
MEDIUM5.5
Exploit prediction
EPSS 0.1%

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.

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

6.1.120 ≤ v < 6.1.1766.12.4 ≤ v < 6.12.946.13 ≤ v < 6.18.366.13 ≤ v < 7.0.136.13 ≤ v < 7.16.19 ≤ v < 7.0.136.6.64 ≤ v < 6.6.14344e9a3bb76e5f2eecd374c8176b2c5163c8bb2e26.1.1206.12.46.6.647.1 rc17.1 rc27.1 rc37.1 rc47.1 rc57.1 rc67.1 rc78fe148d39c127de3fb78dfa6da95a3608dfda454c86d26b4b089ca294b3b7d915a7da61edb77935fef21187c0672a2b2cbec44f33bab9ec47d5c277c
Vendor states this is fixed in 2a4dc9a0ac3326e79fb58fdaae724b92127709a9 (fixed)
Vendor states this is fixed in 517720913bd3c17a52cd55a740064f68455ab88e (fixed)
Vendor states this is fixed in 77a1f6883dc6e837bb2cb30b9b02e2f94338e2c6 (fixed)
Vendor states this is fixed in c0b8c148a7754826156993ed6442d31536ec86b4 (fixed)
Vendor states this is fixed in c2e3aadc8fef7da068490597fc5582f8f362aeb2 (fixed)
Vendor states this is fixed in c74990828d3c486ee44aaa68240eb3abff289d1c (fixed)
Vendor states this is fixed in 6.1.176 (unaffected)
Vendor states this is fixed in 6.12.94 (unaffected)
Vendor states this is fixed in 6.13 (unaffected)
Vendor states this is fixed in 6.18.36 (unaffected)
Vendor states this is fixed in 6.6.143 (unaffected)
Vendor states this is fixed in 7.0.13 (unaffected)
Vendor states this is fixed in 7.1 (unaffected)

CVSS

Attack Vector
LOCAL
Complexity
LOW
Privileges
LOW
User Interaction
NONE
Scope
UNCHANGED
Confidentiality
NONE
Integrity
NONE
Availability
HIGH
Vector?

Quick Info

StatusANALYZED
CWE
NVD-CWE-noinfo

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