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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.
Upstream advisory: https://lore.kernel.org/linux-cve-announce/2026062401-CVE-2026-53059-f32e@gregkh/T
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:45115 https://access.redhat.com/errata/RHSA-2026:45115
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2026:45116 https://access.redhat.com/errata/RHSA-2026:45116
This issue has been addressed in the following products: Red Hat Enterprise Linux 10 Via RHSA-2026:45114 https://access.redhat.com/errata/RHSA-2026:45114
This issue has been addressed in the following products: Red Hat Enterprise Linux 9 Via RHSA-2026:45192 https://access.redhat.com/errata/RHSA-2026:45192
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.4 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.4 Extended Update Support Long-Life Add-On Via RHSA-2026:47248 https://access.redhat.com/errata/RHSA-2026:47248
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.8 Update Services for SAP Solutions Red Hat Enterprise Linux 8.8 Telecommunications Update Service Via RHSA-2026:52649 https://access.redhat.com/errata/RHSA-2026:52649
This issue has been addressed in the following products: Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support Red Hat Enterprise Linux 8.6 Extended Update Support Long-Life Add-On Via RHSA-2026:53989 https://access.redhat.com/errata/RHSA-2026:53989
This issue has been addressed in the following products: Red Hat Enterprise Linux 10.0 Extended Update Support Via RHSA-2026:55445 https://access.redhat.com/errata/RHSA-2026:55445
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.6 Extended Update Support Via RHSA-2026:56574 https://access.redhat.com/errata/RHSA-2026:56574
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:59663 https://access.redhat.com/errata/RHSA-2026:59663
This issue has been addressed in the following products: Red Hat Enterprise Linux 9.2 Update Services for SAP Solutions Via RHSA-2026:59662 https://access.redhat.com/errata/RHSA-2026:59662
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2026:61692 https://access.redhat.com/errata/RHSA-2026:61692
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Extended Lifecycle Support Via RHSA-2026:63189 https://access.redhat.com/errata/RHSA-2026:63189