{"id":"CVE-2026-53343","state":"PUBLISHED","title":"ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow\n\nCommit 44e9a3bb76e5 (\"ARM: 9430/1: entry: Do a dummy read from\nVMAP shadow\") added a dummy read from the KASAN VMAP stack shadow in\n__switch_to(). The read uses ldr, but the KASAN shadow address is\nbyte-granular and is not guaranteed to be word aligned.\n\nARMv5 faults unaligned word loads. With CONFIG_KASAN_VMALLOC and\nCONFIG_VMAP_STACK enabled, ARM926/VersatilePB crashes in __switch_to()\nwith an alignment exception before reaching init.\n\nUse ldrb for the dummy shadow access. The code only needs to fault in the\nshadow mapping if the stack shadow is missing, so a byte load is sufficient\nand matches the granularity of KASAN shadow memory.","publishedAt":"2026-07-01T13:32:23.979Z","updatedAt":"2026-07-01T13:32:23.979Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8fe148d39c127de3fb78dfa6da95a3608dfda454","status":"affected","lessThan":"c0b8c148a7754826156993ed6442d31536ec86b4","versionType":"git"},{"version":"ef21187c0672a2b2cbec44f33bab9ec47d5c277c","status":"affected","lessThan":"c2e3aadc8fef7da068490597fc5582f8f362aeb2","versionType":"git"},{"version":"c86d26b4b089ca294b3b7d915a7da61edb77935f","status":"affected","lessThan":"c74990828d3c486ee44aaa68240eb3abff289d1c","versionType":"git"},{"version":"44e9a3bb76e5f2eecd374c8176b2c5163c8bb2e2","status":"affected","lessThan":"517720913bd3c17a52cd55a740064f68455ab88e","versionType":"git"},{"version":"44e9a3bb76e5f2eecd374c8176b2c5163c8bb2e2","status":"affected","lessThan":"2a4dc9a0ac3326e79fb58fdaae724b92127709a9","versionType":"git"},{"version":"44e9a3bb76e5f2eecd374c8176b2c5163c8bb2e2","status":"affected","lessThan":"77a1f6883dc6e837bb2cb30b9b02e2f94338e2c6","versionType":"git"},{"version":"6.1.120","status":"affected","lessThan":"6.1.176","versionType":"semver"},{"version":"6.6.64","status":"affected","lessThan":"6.6.143","versionType":"semver"},{"version":"6.12.4","status":"affected","lessThan":"6.12.94","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm/kernel/entry-armv.S"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm/kernel/entry-armv.S"]}],"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"],"weaknesses":[],"ingestedAt":"2026-10-29T20:12:16.098Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/53xxx/CVE-2026-53343.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-53343","state":"PUBLISHED","datePublished":"2026-07-01T13:32:23.979Z","dateUpdated":"2026-07-01T13:32:23.979Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-06-09T07:44:35.399Z"},"containers":{"cna":{"title":"ARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nARM: 9475/1: entry: use byte load for KASAN VMAP stack shadow\n\nCommit 44e9a3bb76e5 (\"ARM: 9430/1: entry: Do a dummy read from\nVMAP shadow\") added a dummy read from the KASAN VMAP stack shadow in\n__switch_to(). The read uses ldr, but the KASAN shadow address is\nbyte-granular and is not guaranteed to be word aligned.\n\nARMv5 faults unaligned word loads. With CONFIG_KASAN_VMALLOC and\nCONFIG_VMAP_STACK enabled, ARM926/VersatilePB crashes in __switch_to()\nwith an alignment exception before reaching init.\n\nUse ldrb for the dummy shadow access. The code only needs to fault in the\nshadow mapping if the stack shadow is missing, so a byte load is sufficient\nand matches the granularity of KASAN shadow memory."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"8fe148d39c127de3fb78dfa6da95a3608dfda454","status":"affected","lessThan":"c0b8c148a7754826156993ed6442d31536ec86b4","versionType":"git"},{"version":"ef21187c0672a2b2cbec44f33bab9ec47d5c277c","status":"affected","lessThan":"c2e3aadc8fef7da068490597fc5582f8f362aeb2","versionType":"git"},{"version":"c86d26b4b089ca294b3b7d915a7da61edb77935f","status":"affected","lessThan":"c74990828d3c486ee44aaa68240eb3abff289d1c","versionType":"git"},{"version":"44e9a3bb76e5f2eecd374c8176b2c5163c8bb2e2","status":"affected","lessThan":"517720913bd3c17a52cd55a740064f68455ab88e","versionType":"git"},{"version":"44e9a3bb76e5f2eecd374c8176b2c5163c8bb2e2","status":"affected","lessThan":"2a4dc9a0ac3326e79fb58fdaae724b92127709a9","versionType":"git"},{"version":"44e9a3bb76e5f2eecd374c8176b2c5163c8bb2e2","status":"affected","lessThan":"77a1f6883dc6e837bb2cb30b9b02e2f94338e2c6","versionType":"git"},{"version":"6.1.120","status":"affected","lessThan":"6.1.176","versionType":"semver"},{"version":"6.6.64","status":"affected","lessThan":"6.6.143","versionType":"semver"},{"version":"6.12.4","status":"affected","lessThan":"6.12.94","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm/kernel/entry-armv.S"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"6.13","status":"affected"},{"version":"0","status":"unaffected","lessThan":"6.13","versionType":"semver"},{"version":"6.1.176","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.143","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.94","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.36","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.0.13","status":"unaffected","lessThanOrEqual":"7.0.*","versionType":"semver"},{"version":"7.1","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["arch/arm/kernel/entry-armv.S"]}],"references":[{"url":"https://git.kernel.org/stable/c/c0b8c148a7754826156993ed6442d31536ec86b4"},{"url":"https://git.kernel.org/stable/c/c2e3aadc8fef7da068490597fc5582f8f362aeb2"},{"url":"https://git.kernel.org/stable/c/c74990828d3c486ee44aaa68240eb3abff289d1c"},{"url":"https://git.kernel.org/stable/c/517720913bd3c17a52cd55a740064f68455ab88e"},{"url":"https://git.kernel.org/stable/c/2a4dc9a0ac3326e79fb58fdaae724b92127709a9"},{"url":"https://git.kernel.org/stable/c/77a1f6883dc6e837bb2cb30b9b02e2f94338e2c6"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-07-01T13:32:23.979Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.120","versionEndExcluding":"6.1.176"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.64","versionEndExcluding":"6.6.143"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.4","versionEndExcluding":"6.12.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"6.18.36"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.0.13"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.13","versionEndExcluding":"7.1"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}