scsi: mpi3mr: Fix missing mrioc->evtack_cmds initialization

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: scsi: mpi3mr: Fix missing mrioc->evtack_cmds initialization Commit c1af985d27da ("scsi: mpi3mr: Add Event acknowledgment logic") introduced an array mrioc->evtack_cmds but initialization of the array elements was missed. They are just zero cleared. The function mpi3mr_complete_evt_ack() refers host_tag field of the elements. Due to the zero value of the host_tag field, the function calls clear_bit() for mrico->evtack_cmds_bitmap with wrong bit index. This results in memory access to invalid address and "BUG: KASAN: use-after-free". This BUG was observed at eHBA-9600 firmware update to version 8.3.1.0. To fix it, add the missing initialization of mrioc->evtack_cmds.

References

• https://git.kernel.org/stable/c/4e0dfdb48a824deac3dfbc67fb856ef2aee13529
• https://git.kernel.org/stable/c/67989091e11a974003ddf2ec39bc613df8eadd83
• https://git.kernel.org/stable/c/e39ea831ebad4ab15c4748cb62a397a8abcca36e