{"id":"CVE-2025-38415","state":"PUBLISHED","title":"Squashfs: check return result of sb_min_blocksize","description":"In the Linux kernel, the following vulnerability has been resolved:\n\nSquashfs: check return result of sb_min_blocksize\n\nSyzkaller reports an \"UBSAN: shift-out-of-bounds in squashfs_bio_read\" bug.\n\nSyzkaller forks multiple processes which after mounting the Squashfs\nfilesystem, issues an ioctl(\"/dev/loop0\", LOOP_SET_BLOCK_SIZE, 0x8000). \nNow if this ioctl occurs at the same time another process is in the\nprocess of mounting a Squashfs filesystem on /dev/loop0, the failure\noccurs.  When this happens the following code in squashfs_fill_super()\nfails.\n\n----\nmsblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);\nmsblk->devblksize_log2 = ffz(~msblk->devblksize);\n----\n\nsb_min_blocksize() returns 0, which means msblk->devblksize is set to 0.\n\nAs a result, ffz(~msblk->devblksize) returns 64, and msblk->devblksize_log2\nis set to 64.\n\nThis subsequently causes the\n\nUBSAN: shift-out-of-bounds in fs/squashfs/block.c:195:36\nshift exponent 64 is too large for 64-bit type 'u64' (aka\n'unsigned long long')\n\nThis commit adds a check for a 0 return by sb_min_blocksize().","publishedAt":"2025-07-25T13:32:09.711Z","updatedAt":"2026-06-18T20:55:27.614Z","severity":null,"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"db7096ea160e40d78c67fce52e7cc51bde049497","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"549f9e3d7b60d53808c98b9fde49b4f46d0524a5","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"5c51aa862cbeed2f3887f0382a2708956710bd68","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"6abf6b78c6fb112eee495f5636ffcc350dd2ce25","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"4f99357dadbf9c979ad737156ad4c37fadf7c56b","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"0aff95d9bc7fb5400ca8af507429c4b067bdb425","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"295ab18c2dbce8d0ac6ecf7c5187e16e1ac8b282","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"734aa85390ea693bb7eaf2240623d41b03705c84","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.29","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.29","versionType":"semver"},{"version":"5.4.295","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.239","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.186","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.142","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.94","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.34","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.3","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/super.c"]}],"references":["https://git.kernel.org/stable/c/db7096ea160e40d78c67fce52e7cc51bde049497","https://git.kernel.org/stable/c/549f9e3d7b60d53808c98b9fde49b4f46d0524a5","https://git.kernel.org/stable/c/5c51aa862cbeed2f3887f0382a2708956710bd68","https://git.kernel.org/stable/c/6abf6b78c6fb112eee495f5636ffcc350dd2ce25","https://git.kernel.org/stable/c/4f99357dadbf9c979ad737156ad4c37fadf7c56b","https://git.kernel.org/stable/c/0aff95d9bc7fb5400ca8af507429c4b067bdb425","https://git.kernel.org/stable/c/295ab18c2dbce8d0ac6ecf7c5187e16e1ac8b282","https://git.kernel.org/stable/c/734aa85390ea693bb7eaf2240623d41b03705c84","https://lists.debian.org/debian-lts-announce/2025/10/msg00008.html","https://lists.debian.org/debian-lts-announce/2025/10/msg00007.html"],"weaknesses":[],"ingestedAt":"2026-10-29T20:09:09.358Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2025/38xxx/CVE-2025-38415.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2025-38415","state":"PUBLISHED","datePublished":"2025-07-25T13:32:09.711Z","dateUpdated":"2026-06-18T20:55:27.614Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2025-04-16T04:51:24.013Z"},"containers":{"cna":{"title":"Squashfs: check return result of sb_min_blocksize","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\nSquashfs: check return result of sb_min_blocksize\n\nSyzkaller reports an \"UBSAN: shift-out-of-bounds in squashfs_bio_read\" bug.\n\nSyzkaller forks multiple processes which after mounting the Squashfs\nfilesystem, issues an ioctl(\"/dev/loop0\", LOOP_SET_BLOCK_SIZE, 0x8000). \nNow if this ioctl occurs at the same time another process is in the\nprocess of mounting a Squashfs filesystem on /dev/loop0, the failure\noccurs.  When this happens the following code in squashfs_fill_super()\nfails.\n\n----\nmsblk->devblksize = sb_min_blocksize(sb, SQUASHFS_DEVBLK_SIZE);\nmsblk->devblksize_log2 = ffz(~msblk->devblksize);\n----\n\nsb_min_blocksize() returns 0, which means msblk->devblksize is set to 0.\n\nAs a result, ffz(~msblk->devblksize) returns 64, and msblk->devblksize_log2\nis set to 64.\n\nThis subsequently causes the\n\nUBSAN: shift-out-of-bounds in fs/squashfs/block.c:195:36\nshift exponent 64 is too large for 64-bit type 'u64' (aka\n'unsigned long long')\n\nThis commit adds a check for a 0 return by sb_min_blocksize()."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"db7096ea160e40d78c67fce52e7cc51bde049497","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"549f9e3d7b60d53808c98b9fde49b4f46d0524a5","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"5c51aa862cbeed2f3887f0382a2708956710bd68","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"6abf6b78c6fb112eee495f5636ffcc350dd2ce25","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"4f99357dadbf9c979ad737156ad4c37fadf7c56b","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"0aff95d9bc7fb5400ca8af507429c4b067bdb425","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"295ab18c2dbce8d0ac6ecf7c5187e16e1ac8b282","versionType":"git"},{"version":"0aa666190509ffab81c202c5095a166be23961ac","status":"affected","lessThan":"734aa85390ea693bb7eaf2240623d41b03705c84","versionType":"git"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/super.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"2.6.29","status":"affected"},{"version":"0","status":"unaffected","lessThan":"2.6.29","versionType":"semver"},{"version":"5.4.295","status":"unaffected","lessThanOrEqual":"5.4.*","versionType":"semver"},{"version":"5.10.239","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.186","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.142","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.94","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.34","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.15.3","status":"unaffected","lessThanOrEqual":"6.15.*","versionType":"semver"},{"version":"6.16","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["fs/squashfs/super.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/db7096ea160e40d78c67fce52e7cc51bde049497"},{"url":"https://git.kernel.org/stable/c/549f9e3d7b60d53808c98b9fde49b4f46d0524a5"},{"url":"https://git.kernel.org/stable/c/5c51aa862cbeed2f3887f0382a2708956710bd68"},{"url":"https://git.kernel.org/stable/c/6abf6b78c6fb112eee495f5636ffcc350dd2ce25"},{"url":"https://git.kernel.org/stable/c/4f99357dadbf9c979ad737156ad4c37fadf7c56b"},{"url":"https://git.kernel.org/stable/c/0aff95d9bc7fb5400ca8af507429c4b067bdb425"},{"url":"https://git.kernel.org/stable/c/295ab18c2dbce8d0ac6ecf7c5187e16e1ac8b282"},{"url":"https://git.kernel.org/stable/c/734aa85390ea693bb7eaf2240623d41b03705c84"}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-05-11T21:27:32.721Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"5.4.295"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"5.10.239"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"5.15.186"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"6.1.142"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"6.6.94"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"6.12.34"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"6.15.3"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"2.6.29","versionEndExcluding":"6.16"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CVE 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