{"id":"CVE-2026-97906","state":"PUBLISHED","title":"bootconfig: Fix integer overflow in initrd size check","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nbootconfig: Fix integer overflow in initrd size check\n\nSashiko reported that in get_boot_config_from_initrd(), a crafted initrd\nwith a huge bootconfig size (such as 0xFFFFFFFF) can cause the pointer\narithmetic:\n\n    data = ((void *)hdr) - size;\n\nto wrap around on 32-bit systems (or when pointer subtraction overflows).\nBecause data wraps around, the subsequent bounds check:\n\n    if ((unsigned long)data < initrd_start)\n\nevaluates to false, bypassing the check. The kernel then calls\nxbc_calc_checksum(data, size), which attempts to read 4GB of memory,\nhitting unmapped pages and triggering a fatal kernel page fault during\nearly boot. Furthermore, on 64-bit systems with an initrd > 4.29 GB, an\nunbounded 32-bit size can similarly bypass the initrd_start check.\n\nFix this by:\n1. Ensuring the initrd is at least large enough to contain the bootconfig\n   footer and verifying hdr is within the initrd bounds.\n2. Checking that size does not exceed XBC_DATA_MAX and does not exceed\n   the available space between initrd_start and hdr before performing\n   pointer subtraction.","publishedAt":"2026-09-25T10:22:31.640Z","updatedAt":"2026-10-21T12:53:32.335Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"97be05f33f79342ea65d9b99c9ad07a93b8eef5a","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"4d45bc0f8cdf606d5409b5f64a8a6609f6520c03","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"8d4343a411eaa182d323ab5b149496416015f27d","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"7812d6dab0698001e50e8c2f901e17da3eb6f429","versionType":"git"},{"version":"32394df25d8e46935b442b429d74b37885c4f092","status":"affected","versionType":"git"},{"version":"5.6.14","status":"affected","lessThan":"5.7","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["init/main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["init/main.c"]}],"references":["https://git.kernel.org/stable/c/97be05f33f79342ea65d9b99c9ad07a93b8eef5a","https://git.kernel.org/stable/c/4d45bc0f8cdf606d5409b5f64a8a6609f6520c03","https://git.kernel.org/stable/c/8d4343a411eaa182d323ab5b149496416015f27d","https://git.kernel.org/stable/c/bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6","https://git.kernel.org/stable/c/7812d6dab0698001e50e8c2f901e17da3eb6f429"],"weaknesses":[],"ingestedAt":"2026-10-29T20:13:43.249Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/97xxx/CVE-2026-97906.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-97906","state":"PUBLISHED","datePublished":"2026-09-25T10:22:31.640Z","dateUpdated":"2026-10-21T12:53:32.335Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-09-25T10:18:58.200Z"},"containers":{"cna":{"title":"bootconfig: Fix integer overflow in initrd size check","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nbootconfig: Fix integer overflow in initrd size check\n\nSashiko reported that in get_boot_config_from_initrd(), a crafted initrd\nwith a huge bootconfig size (such as 0xFFFFFFFF) can cause the pointer\narithmetic:\n\n    data = ((void *)hdr) - size;\n\nto wrap around on 32-bit systems (or when pointer subtraction overflows).\nBecause data wraps around, the subsequent bounds check:\n\n    if ((unsigned long)data < initrd_start)\n\nevaluates to false, bypassing the check. The kernel then calls\nxbc_calc_checksum(data, size), which attempts to read 4GB of memory,\nhitting unmapped pages and triggering a fatal kernel page fault during\nearly boot. Furthermore, on 64-bit systems with an initrd > 4.29 GB, an\nunbounded 32-bit size can similarly bypass the initrd_start check.\n\nFix this by:\n1. Ensuring the initrd is at least large enough to contain the bootconfig\n   footer and verifying hdr is within the initrd bounds.\n2. Checking that size does not exceed XBC_DATA_MAX and does not exceed\n   the available space between initrd_start and hdr before performing\n   pointer subtraction."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"97be05f33f79342ea65d9b99c9ad07a93b8eef5a","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"4d45bc0f8cdf606d5409b5f64a8a6609f6520c03","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"8d4343a411eaa182d323ab5b149496416015f27d","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6","versionType":"git"},{"version":"de462e5f10718517bacf2f84c8aa2804567ef7df","status":"affected","lessThan":"7812d6dab0698001e50e8c2f901e17da3eb6f429","versionType":"git"},{"version":"32394df25d8e46935b442b429d74b37885c4f092","status":"affected","versionType":"git"},{"version":"5.6.14","status":"affected","lessThan":"5.7","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["init/main.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"5.7","status":"affected"},{"version":"0","status":"unaffected","lessThan":"5.7","versionType":"semver"},{"version":"6.6.160","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.112","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.53","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.2.7","status":"unaffected","lessThanOrEqual":"7.2.*","versionType":"semver"},{"version":"7.3","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["init/main.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/97be05f33f79342ea65d9b99c9ad07a93b8eef5a"},{"url":"https://git.kernel.org/stable/c/4d45bc0f8cdf606d5409b5f64a8a6609f6520c03"},{"url":"https://git.kernel.org/stable/c/8d4343a411eaa182d323ab5b149496416015f27d"},{"url":"https://git.kernel.org/stable/c/bff9a1579e2c9b2a59fdf3793becc9d7bf5ff1a6"},{"url":"https://git.kernel.org/stable/c/7812d6dab0698001e50e8c2f901e17da3eb6f429"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-10-21T12:53:32.335Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.6.160"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.12.112"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"6.18.53"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"7.2.7"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.7","versionEndExcluding":"7.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.6.14"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}