{"id":"CVE-2026-72105","state":"PUBLISHED","title":"dm-log: fix a bitset_size overflow on 32bit machines","description":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-log: fix a bitset_size overflow on 32bit machines\n\nCommit c20e36b7631d (\"dm log: fix out-of-bounds write due to\nregion_count overflow\") made sure that region_count could fit in an\nunsigned int. But the bitmap memory isn't allocated based on\nregion_count. It uses bitset_size (a size_t variable). The first step of\ncalculating bitset_size is to set it to region_count, rounded up to a\nmultiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG\nsmaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit\narchitecture, this will make bitset_size wrap around to 0 and fail,\ndespite region_count being valid.\n\nSince bitset_size gets divided by 8, it can hold any valid region_count.\nIt just needs a special case to handle the rollover. If it is 0, the\nvalue rolled over, and bitset size should be set to the number of bytes\nneeded to hold 2^32 bits.","publishedAt":"2026-08-15T05:52:48.099Z","updatedAt":"2026-10-19T21:19:28.267Z","severity":{"score":7.8,"label":"High","version":"3.1","vector":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","source":"Linux"},"assigner":"Linux","products":["Linux Linux"],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"44ab8875ae4a2842bde2d756bed195d375e0debb","status":"affected","lessThan":"cdc4ddf9db2cb79f4ab86b1a509b7ac21b0b6cf5","versionType":"git"},{"version":"defe483e47173768c227532694dc78cb65db5f09","status":"affected","lessThan":"4b0de5a3ac1fd42acb0dc1f80ac5747e3287d723","versionType":"git"},{"version":"3ec74da927b4e171a6fc0e77b1188ba4d019af51","status":"affected","lessThan":"567602fa72d57169365cbc589e0b8c3be900636d","versionType":"git"},{"version":"d4ac87567f86a55c3c92e9a5144dcd943a9772a1","status":"affected","lessThan":"d05e0edfecf5260e6dddd28b2f0cce02bfc6ed7a","versionType":"git"},{"version":"12bd5b88e91a02785244ff1d20fb157e96e9cdc8","status":"affected","lessThan":"1c3412b584e1fb6c665ff33ba7259253bc0082cb","versionType":"git"},{"version":"b455903eed4558982be0811f5b7f44f6bbc4ff57","status":"affected","lessThan":"e0b0163a65758ec3a2361ae1cea407898c27f21e","versionType":"git"},{"version":"c20e36b7631d83e7535877f08af8b0af72c44b1a","status":"affected","lessThan":"79feb87ab2396d49b9b65e4bb815d33cc71cba47","versionType":"git"},{"version":"c20e36b7631d83e7535877f08af8b0af72c44b1a","status":"affected","lessThan":"9743132a41f4d9d0e54c5f2adcb821b04796bab1","versionType":"git"},{"version":"4ec8323b9f0764a14d532b1ae9b87f8a9fecb867","status":"affected","versionType":"git"},{"version":"5.10.258","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.15.209","status":"affected","lessThan":"5.15.212","versionType":"semver"},{"version":"6.1.175","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.141","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.12.91","status":"affected","lessThan":"6.12.97","versionType":"semver"},{"version":"6.18.33","status":"affected","lessThan":"6.18.40","versionType":"semver"},{"version":"7.0.10","status":"affected","lessThan":"7.1","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-log.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-log.c"]}],"references":["https://git.kernel.org/stable/c/cdc4ddf9db2cb79f4ab86b1a509b7ac21b0b6cf5","https://git.kernel.org/stable/c/4b0de5a3ac1fd42acb0dc1f80ac5747e3287d723","https://git.kernel.org/stable/c/567602fa72d57169365cbc589e0b8c3be900636d","https://git.kernel.org/stable/c/d05e0edfecf5260e6dddd28b2f0cce02bfc6ed7a","https://git.kernel.org/stable/c/1c3412b584e1fb6c665ff33ba7259253bc0082cb","https://git.kernel.org/stable/c/e0b0163a65758ec3a2361ae1cea407898c27f21e","https://git.kernel.org/stable/c/79feb87ab2396d49b9b65e4bb815d33cc71cba47","https://git.kernel.org/stable/c/9743132a41f4d9d0e54c5f2adcb821b04796bab1"],"weaknesses":["CWE-190"],"ingestedAt":"2026-10-29T20:12:58.252Z","source":{"repository":"CVEProject/cvelistV5","path":"cves/2026/72xxx/CVE-2026-72105.json","commit":"556c9d3a8cd17e218bb8e452ba7cd619a384ff47"},"raw":{"dataType":"CVE_RECORD","dataVersion":"5.2","cveMetadata":{"cveId":"CVE-2026-72105","state":"PUBLISHED","datePublished":"2026-08-15T05:52:48.099Z","dateUpdated":"2026-10-19T21:19:28.267Z","assignerShortName":"Linux","assignerOrgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateReserved":"2026-08-09T03:40:39.906Z"},"containers":{"cna":{"title":"dm-log: fix a bitset_size overflow on 32bit machines","descriptions":[{"lang":"en","value":"In the Linux kernel, the following vulnerability has been resolved:\n\ndm-log: fix a bitset_size overflow on 32bit machines\n\nCommit c20e36b7631d (\"dm log: fix out-of-bounds write due to\nregion_count overflow\") made sure that region_count could fit in an\nunsigned int. But the bitmap memory isn't allocated based on\nregion_count. It uses bitset_size (a size_t variable). The first step of\ncalculating bitset_size is to set it to region_count, rounded up to a\nmultiple of BITS_PER_LONG. If region_size is less than BITS_PER_LONG\nsmaller than UINT_MAX, it will get rounded up to 2^32. On a 32bit\narchitecture, this will make bitset_size wrap around to 0 and fail,\ndespite region_count being valid.\n\nSince bitset_size gets divided by 8, it can hold any valid region_count.\nIt just needs a special case to handle the rollover. If it is 0, the\nvalue rolled over, and bitset size should be set to the number of bytes\nneeded to hold 2^32 bits."}],"affected":[{"vendor":"Linux","product":"Linux","defaultStatus":"unaffected","versions":[{"version":"44ab8875ae4a2842bde2d756bed195d375e0debb","status":"affected","lessThan":"cdc4ddf9db2cb79f4ab86b1a509b7ac21b0b6cf5","versionType":"git"},{"version":"defe483e47173768c227532694dc78cb65db5f09","status":"affected","lessThan":"4b0de5a3ac1fd42acb0dc1f80ac5747e3287d723","versionType":"git"},{"version":"3ec74da927b4e171a6fc0e77b1188ba4d019af51","status":"affected","lessThan":"567602fa72d57169365cbc589e0b8c3be900636d","versionType":"git"},{"version":"d4ac87567f86a55c3c92e9a5144dcd943a9772a1","status":"affected","lessThan":"d05e0edfecf5260e6dddd28b2f0cce02bfc6ed7a","versionType":"git"},{"version":"12bd5b88e91a02785244ff1d20fb157e96e9cdc8","status":"affected","lessThan":"1c3412b584e1fb6c665ff33ba7259253bc0082cb","versionType":"git"},{"version":"b455903eed4558982be0811f5b7f44f6bbc4ff57","status":"affected","lessThan":"e0b0163a65758ec3a2361ae1cea407898c27f21e","versionType":"git"},{"version":"c20e36b7631d83e7535877f08af8b0af72c44b1a","status":"affected","lessThan":"79feb87ab2396d49b9b65e4bb815d33cc71cba47","versionType":"git"},{"version":"c20e36b7631d83e7535877f08af8b0af72c44b1a","status":"affected","lessThan":"9743132a41f4d9d0e54c5f2adcb821b04796bab1","versionType":"git"},{"version":"4ec8323b9f0764a14d532b1ae9b87f8a9fecb867","status":"affected","versionType":"git"},{"version":"5.10.258","status":"affected","lessThan":"5.10.261","versionType":"semver"},{"version":"5.15.209","status":"affected","lessThan":"5.15.212","versionType":"semver"},{"version":"6.1.175","status":"affected","lessThan":"6.1.178","versionType":"semver"},{"version":"6.6.141","status":"affected","lessThan":"6.6.145","versionType":"semver"},{"version":"6.12.91","status":"affected","lessThan":"6.12.97","versionType":"semver"},{"version":"6.18.33","status":"affected","lessThan":"6.18.40","versionType":"semver"},{"version":"7.0.10","status":"affected","lessThan":"7.1","versionType":"semver"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-log.c"]},{"vendor":"Linux","product":"Linux","defaultStatus":"affected","versions":[{"version":"7.1","status":"affected"},{"version":"0","status":"unaffected","lessThan":"7.1","versionType":"semver"},{"version":"5.10.261","status":"unaffected","lessThanOrEqual":"5.10.*","versionType":"semver"},{"version":"5.15.212","status":"unaffected","lessThanOrEqual":"5.15.*","versionType":"semver"},{"version":"6.1.178","status":"unaffected","lessThanOrEqual":"6.1.*","versionType":"semver"},{"version":"6.6.145","status":"unaffected","lessThanOrEqual":"6.6.*","versionType":"semver"},{"version":"6.12.97","status":"unaffected","lessThanOrEqual":"6.12.*","versionType":"semver"},{"version":"6.18.40","status":"unaffected","lessThanOrEqual":"6.18.*","versionType":"semver"},{"version":"7.1.5","status":"unaffected","lessThanOrEqual":"7.1.*","versionType":"semver"},{"version":"7.2","status":"unaffected","lessThanOrEqual":"*","versionType":"original_commit_for_fix"}],"repo":"https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git","programFiles":["drivers/md/dm-log.c"]}],"references":[{"url":"https://git.kernel.org/stable/c/cdc4ddf9db2cb79f4ab86b1a509b7ac21b0b6cf5"},{"url":"https://git.kernel.org/stable/c/4b0de5a3ac1fd42acb0dc1f80ac5747e3287d723"},{"url":"https://git.kernel.org/stable/c/567602fa72d57169365cbc589e0b8c3be900636d"},{"url":"https://git.kernel.org/stable/c/d05e0edfecf5260e6dddd28b2f0cce02bfc6ed7a"},{"url":"https://git.kernel.org/stable/c/1c3412b584e1fb6c665ff33ba7259253bc0082cb"},{"url":"https://git.kernel.org/stable/c/e0b0163a65758ec3a2361ae1cea407898c27f21e"},{"url":"https://git.kernel.org/stable/c/79feb87ab2396d49b9b65e4bb815d33cc71cba47"},{"url":"https://git.kernel.org/stable/c/9743132a41f4d9d0e54c5f2adcb821b04796bab1"}],"metrics":[{"cvssV3_1":{"version":"3.1","vectorString":"CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","baseScore":7.8,"baseSeverity":"HIGH"},"scenarios":[{"lang":"en","value":"AV:L - The flaw is reached only via local Device Mapper ioctls on /dev/mapper/control (dmsetup table load creating a mirror with core/disk log); there is no network, wireless, or physical-bus receive path into create_log_context().\nAC:L - A CAP_SYS_ADMIN attacker fully controls mirror table length and region_size via dmsetup, deterministically forcing region_count into the UINT_MAX-30..UINT_MAX wrap range on 32-bit kernels without races or victim-specific heap layout.\nPR:L - DM control ioctls require CAP_SYS_ADMIN, which is obtainable inside an unprivileged user namespace per kernel CNA guidance; mirror/dm-log setup is not limited to init-namespace root on typical container-capable systems.\nUI:N - Exploitation requires only the attacker issuing dmsetup/ioctl to create or resume a mirror with crafted parameters; no separate victim action such as mounting a filesystem or opening a file is needed.\nS:U - Impact is kernel vmalloc heap corruption and privilege escalation within the host kernel; it does not cross a VM, hypervisor, or IOMMU security boundary.\nC:H - Wrapping bitset_size to zero undersizes clean_bits/sync_bits/recovering_bits versus lc->region_count near UINT_MAX; subsequent log_test_bit/__set_bit_le calls during mirror I/O perform out-of-bounds reads of adjacent vmalloc heap memory.\nI:H - The same undersized bitmap sizing lets log_set_bit and log_clear_bit write far beyond the allocated bitset via region indices derived from dm mirror bios, corrupting adjacent kernel heap objects exploitable for arbitrary write or code execution.\nA:H - Identical dm-log bitset paths (e.g., core_in_sync calling log_test_bit) have been shown to kernel-crash with CR2 faults from out-of-bounds heap access; triggering this overflow causes oops, panic, or hang on affected 32-bit storage nodes."}]}],"providerMetadata":{"shortName":"Linux","orgId":"416baaa9-dc9f-4396-8d5f-8c081fb06d67","dateUpdated":"2026-08-17T05:40:19.004Z"},"cpeApplicability":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.10.258","versionEndExcluding":"5.10.261"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"5.15.209","versionEndExcluding":"5.15.212"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.1.175","versionEndExcluding":"6.1.178"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.6.141","versionEndExcluding":"6.6.145"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.12.91","versionEndExcluding":"6.12.97"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"6.18.33","versionEndExcluding":"6.18.40"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.1.5"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.1","versionEndExcluding":"7.2"},{"vulnerable":true,"criteria":"cpe:2.3:o:linux:linux_kernel:*:*:*:*:*:*:*:*","versionStartIncluding":"7.0.10"}]}]}],"x_generator":{"engine":"bippy-1.2.0"}},"adp":[{"title":"CISA ADP Vulnrichment","metrics":[{"other":{"type":"ssvc","content":{"id":"CVE-2026-72105","role":"CISA Coordinator","options":[{"Exploitation":"none"},{"Automatable":"no"},{"Technical Impact":"total"}],"version":"2.0.3","timestamp":"2026-10-16T15:52:08.599167Z"}}}],"problemTypes":[{"descriptions":[{"cweId":"CWE-190","lang":"en","type":"CWE","description":"CWE-190 Integer Overflow or Wraparound"}]}],"providerMetadata":{"shortName":"CISA-ADP","orgId":"134c704f-9b21-4f2e-91b3-4a467353bcc0","dateUpdated":"2026-10-19T21:19:28.267Z"}}]}}}