In the Linux kernel, the following vulnerability has been resolved: dm cache: fix out-of-bounds access to the dirty bitset when resizing dm-cache checks the dirty bits of the cache blocks to be dropped when shrinking the fast device, but an index bug in bitset iteration causes out-of-bounds access. Reproduce steps: 1. create a cache device of 1024 cache blocks (128 bytes dirty bitset) dmsetup create cmeta --table "0 8192 linear /dev/sdc 0" dmsetup create cdata --table "0 131072 linear /dev/sdc 8192" dmsetup create corig --table "0 524288 linear /dev/sdc 262144" dd if=/dev/zero of=/dev/mapper/cmeta bs=4k count=1 oflag=direct dmsetup create cache --table "0 524288 cache /dev/mapper/cmeta \ /dev/mapper/cdata /dev/mapper/corig 128 2 metadata2 writethrough smq 0" 2. shrink the fast device to 512 cache blocks, triggering out-of-bounds access to the dirty bitset (offset 0x80) dmsetup suspend cache dmsetup reload cdata --table "0 65536 linear /dev/sdc 8192" dmsetup resume cdata dmse…