{"id":"CVE-2026-31778","state":"PUBLISHED","title":"ALSA: caiaq: fix stack out-of-bounds read in init_card","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: caiaq: fix stack out-of-bounds read in init_card\n\nThe loop creates a whitespace-stripped copy of the card shortname\nwhere `len < sizeof(card->id)` is used for the bounds check. Since\nsizeof(card->id) is 16 and the local id buffer is also 16 bytes,\nwriting 16 non-space characters fills the entire buffer,\noverwriting the terminating nullbyte.\n\nWhen this non-null-terminated string is later passed to\nsnd_card_set_id() -> copy_valid_id_string(), the function scans\nforward with `while (*nid && ...)` and reads past the end of the\nstack buffer, reading the contents of the stack.\n\nA USB device with a product name containing many non-ASCII, non-space\ncharacters (e.g. multibyte UTF-8) will reliably trigger this as follows:\n\n  BUG: KASAN: stack-out-of-bounds in copy_valid_id_string\n       sound/core/init.c:696 [inline]\n  BUG: KASAN: stack-out-of-bounds in snd_card_set_id_no_lock+0x698/0x74c\n       sound/core/init.c:718\n\nThe off-by-one has been present since commit bafeee5b1f8d (\"ALSA:\nsnd_usb_caiaq: give better shortname\") from June 2009 (v2.6.31-rc1),\nwhich first introduced this whitespace-stripping loop. The original\ncode never accounted for the null terminator when bounding the copy.\n\nFix this by changing the loop bound to `sizeof(card->id) - 1`,\nensuring at least one byte remains as the null terminator.","publishedAt":"2026-05-01T14:15:05.804Z","updatedAt":"2026-05-11T22:15:37.687Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"02d9c5b0b5553a391448b6d655262bd829f90234","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"66194c2575a4f567577ae70b1d7561163ce791a6","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"a82c1bce2d1299dd3c686a8fe48cf75b79a403c7","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"3178b62e2e31bab39f63d4c8e54bf4ee0a425627","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"3afa2e67f3523a980a2f90fd63c22322ac2b9ce0","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"7594a6464873d90fd229e5b94cdd3b92c9feabed","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"45424e871abf2a152e247a9cff78359f18dd95c0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/caiaq/device.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.31","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.31","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/caiaq/device.c"]}],"references":["https://git.kernel.org/stable/c/02d9c5b0b5553a391448b6d655262bd829f90234","https://git.kernel.org/stable/c/3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6","https://git.kernel.org/stable/c/66194c2575a4f567577ae70b1d7561163ce791a6","https://git.kernel.org/stable/c/a82c1bce2d1299dd3c686a8fe48cf75b79a403c7","https://git.kernel.org/stable/c/3178b62e2e31bab39f63d4c8e54bf4ee0a425627","https://git.kernel.org/stable/c/3afa2e67f3523a980a2f90fd63c22322ac2b9ce0","https://git.kernel.org/stable/c/7594a6464873d90fd229e5b94cdd3b92c9feabed","https://git.kernel.org/stable/c/45424e871abf2a152e247a9cff78359f18dd95c0"],"weaknesses":[],"ingestedAt":"2026-10-29T20:11:40.391Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/31xxx/CVE-2026-31778.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-31778","state":"PUBLISHED","datePublished":"2026-05-01T14:15:05.804Z","dateUpdated":"2026-05-11T22:15:37.687Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-03-09T15:48:24.140Z"},"containers":{"cna":{"title":"ALSA: caiaq: fix stack out-of-bounds read in init_card","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nALSA: caiaq: fix stack out-of-bounds read in init_card\n\nThe loop creates a whitespace-stripped copy of the card shortname\nwhere `len < sizeof(card->id)` is used for the bounds check. Since\nsizeof(card->id) is 16 and the local id buffer is also 16 bytes,\nwriting 16 non-space characters fills the entire buffer,\noverwriting the terminating nullbyte.\n\nWhen this non-null-terminated string is later passed to\nsnd_card_set_id() -> copy_valid_id_string(), the function scans\nforward with `while (*nid && ...)` and reads past the end of the\nstack buffer, reading the contents of the stack.\n\nA USB device with a product name containing many non-ASCII, non-space\ncharacters (e.g. multibyte UTF-8) will reliably trigger this as follows:\n\n  BUG: KASAN: stack-out-of-bounds in copy_valid_id_string\n       sound/core/init.c:696 [inline]\n  BUG: KASAN: stack-out-of-bounds in snd_card_set_id_no_lock+0x698/0x74c\n       sound/core/init.c:718\n\nThe off-by-one has been present since commit bafeee5b1f8d (\"ALSA:\nsnd_usb_caiaq: give better shortname\") from June 2009 (v2.6.31-rc1),\nwhich first introduced this whitespace-stripping loop. The original\ncode never accounted for the null terminator when bounding the copy.\n\nFix this by changing the loop bound to `sizeof(card->id) - 1`,\nensuring at least one byte remains as the null terminator."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"02d9c5b0b5553a391448b6d655262bd829f90234","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"66194c2575a4f567577ae70b1d7561163ce791a6","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"a82c1bce2d1299dd3c686a8fe48cf75b79a403c7","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"3178b62e2e31bab39f63d4c8e54bf4ee0a425627","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"3afa2e67f3523a980a2f90fd63c22322ac2b9ce0","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"7594a6464873d90fd229e5b94cdd3b92c9feabed","versionType":"git"},{"version":"bafeee5b1f8d32cbf791c322b40a6fa91d8ccf7a","status":"affected","lessThan":"45424e871abf2a152e247a9cff78359f18dd95c0","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/caiaq/device.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.31","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.31","versionType":"semver"},{"version":"5.10.253","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.203","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.168","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.134","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.81","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.22","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"6.19.12","status":"unaffected","lessThanOrEqual":"6.19.*","versionType":"semver"},{"version":"7.0","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["sound/usb/caiaq/device.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/02d9c5b0b5553a391448b6d655262bd829f90234"},{"url":"https://git.kernel.org/stable/c/3f7f8bae0d52cbd07ab04b76b6aac89ef98ee9f6"},{"url":"https://git.kernel.org/stable/c/66194c2575a4f567577ae70b1d7561163ce791a6"},{"url":"https://git.kernel.org/stable/c/a82c1bce2d1299dd3c686a8fe48cf75b79a403c7"},{"url":"https://git.kernel.org/stable/c/3178b62e2e31bab39f63d4c8e54bf4ee0a425627"},{"url":"https://git.kernel.org/stable/c/3afa2e67f3523a980a2f90fd63c22322ac2b9ce0"},{"url":"https://git.kernel.org/stable/c/7594a6464873d90fd229e5b94cdd3b92c9feabed"},{"url":"https://git.kernel.org/stable/c/45424e871abf2a152e247a9cff78359f18dd95c0"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T22:15:37.687Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"5.10.253"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"5.15.203"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"6.1.168"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"6.6.134"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"6.12.81"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"6.18.22"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"6.19.12"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.31","versionEndExcluding":"7.0"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}}}}}