Integer overflow in the _ctl_do_mpt_command function in
drivers/scsi/mpt2sas/mpt2sas_ctl.c in the Linux kernel 2.6.38 and earlier
might allow local users to gain privileges or cause a denial of service
(memory corruption) via an ioctl call specifying a crafted value that
triggers a heap-based buffer overflow.

Dan Rosenberg discovered that MPT devices did not correctly validate
certain values in ioctl calls. If these drivers were loaded, a local
attacker could exploit this to read arbitrary kernel memory, leading to a
loss of privacy.