CVE-2026-53059

*** Pendiente de traducción *** In the Linux kernel, the following vulnerability has been resolved:<br /> <br /> dm log: fix out-of-bounds write due to region_count overflow<br /> <br /> The local variable region_count in create_log_context() is declared as<br /> unsigned int (32-bit), but dm_sector_div_up() returns sector_t (64-bit).<br /> When a device-mapper target has a sufficiently large ti-&gt;len with a small<br /> region_size, the division result can exceed UINT_MAX. The truncated<br /> value is then used to calculate bitset_size, causing clean_bits,<br /> sync_bits, and recovering_bits to be allocated far smaller than needed<br /> for the actual number of regions.<br /> <br /> Subsequent log operations (log_set_bit, log_clear_bit, log_test_bit) use<br /> region indices derived from the full untruncated region space, causing<br /> out-of-bounds writes to kernel heap memory allocated by vmalloc.<br /> <br /> This can be reproduced by creating a mirror target whose region_count<br /> overflows 32 bits:<br /> <br /> dmsetup create bigzero --table &amp;#39;0 8589934594 zero&amp;#39;<br /> dmsetup create mymirror --table &amp;#39;0 8589934594 mirror \<br /> core 2 2 nosync 2 /dev/mapper/bigzero 0 \<br /> /dev/mapper/bigzero 0&amp;#39;<br /> <br /> The status output confirms the truncation (sync_count=1 instead of<br /> 4294967297, because 0x100000001 was truncated to 1):<br /> <br /> $ dmsetup status mymirror<br /> 0 8589934594 mirror 2 254:1 254:1 1/4294967297 ...<br /> <br /> This leads to a kernel crash in core_in_sync:<br /> <br /> BUG: scheduling while atomic: (udev-worker)/9150/0x00000000<br /> RIP: 0010:core_in_sync+0x14/0x30 [dm_log]<br /> CR2: 0000000000000008<br /> Fixing recursive fault but reboot is needed!<br /> <br /> Fix by widening the local region_count to sector_t and adding an<br /> explicit overflow check before the value is assigned to lc-&gt;region_count.