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CVE-2026-53059

dm log: fix out-of-bounds write due to region_count overflow PUBLISHED

Description (CNA)

In the Linux kernel, the following vulnerability has been resolved: dm log: fix out-of-bounds write due to region_count overflow The local variable region_count in create_log_context() is declared as unsigned int (32-bit), but dm_sector_div_up() returns sector_t (64-bit). When a device-mapper target has a sufficiently large ti->len with a small region_size, the division result can exceed UINT_MAX. The truncated value is then used to calculate bitset_size, causing clean_bits, sync_bits, and recovering_bits to be allocated far smaller than needed for the actual number of regions. Subsequent log operations (log_set_bit, log_clear_bit, log_test_bit) use region indices derived from the full untruncated region space, causing out-of-bounds writes to kernel heap memory allocated by vmalloc. This can be reproduced by creating a mirror target whose region_count overflows 32 bits: dmsetup create bigzero --table '0 8589934594 zero' dmsetup create mymirror --table '0 8589934594 mirror \ core 2 2 nosync 2 /dev/mapper/bigzero 0 \ /dev/mapper/bigzero 0' The status output confirms the truncation (sync_count=1 instead of 4294967297, because 0x100000001 was truncated to 1): $ dmsetup status mymirror 0 8589934594 mirror 2 254:1 254:1 1/4294967297 ... This leads to a kernel crash in core_in_sync: BUG: scheduling while atomic: (udev-worker)/9150/0x00000000 RIP: 0010:core_in_sync+0x14/0x30 [dm_log] CR2: 0000000000000008 Fixing recursive fault but reboot is needed! Fix by widening the local region_count to sector_t and adding an explicit overflow check before the value is assigned to lc->region_count.

Affected (CNA)

Vendor / productVersions
Linux / Linuxaffected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 44ab8875ae4a2842bde2d756bed195d375e0debb; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before defe483e47173768c227532694dc78cb65db5f09; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 3ec74da927b4e171a6fc0e77b1188ba4d019af51; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before d4ac87567f86a55c3c92e9a5144dcd943a9772a1; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 12bd5b88e91a02785244ff1d20fb157e96e9cdc8; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before b455903eed4558982be0811f5b7f44f6bbc4ff57; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before 4ec8323b9f0764a14d532b1ae9b87f8a9fecb867; affected 1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 before c20e36b7631d83e7535877f08af8b0af72c44b1a
Linux / Linuxaffected 2.6.12; unaffected 0 before 2.6.12; unaffected 5.10.258 through 5.10.*; unaffected 5.15.209 through 5.15.*; unaffected 6.1.175 through 6.1.*; unaffected 6.6.141 through 6.6.*; unaffected 6.12.91 through 6.12.*; unaffected 6.18.33 through 6.18.*; unaffected 7.0.10 through 7.0.*; unaffected 7.1 through *

CWE

No CWE identifiers supplied.

References

ADP enrichment

redhat-SADP

A flaw was found in the Linux kernel's device-mapper log (dm log) component. A local attacker could exploit an integer overflow vulnerability where a 64-bit value is truncated to 32 bits, leading to undersized memory allocations. This allows for out-of-bounds writes to kernel memory during log operations. Successful exploitation of this flaw can cause a kernel crash, resulting in a Denial of Service (DoS) for the affected system.