Integer signedness error in the ip_set_srcfilter function in the IP Multicast Filter in uts/common/inet/ip/ip_multi.c in the kernel in Sun Solaris 10 and OpenSolaris before snv_92 allows local users to execute arbitrary code in other Solaris Zones via an SIOCSIPMSFILTER IOCTL request with a large value of the imsf->imsf_numsrc field, which triggers an out-of-bounds write of kernel memory.  NOTE: this was reported as an integer overflow, but the root cause involves the bypass of a signed comparison.