Race condition in the ia32 compatibility code for the execve system call in Linux kernel 2.4 before 2.4.31 and 2.6 before 2.6.6 allows local users to cause a denial of service (kernel panic) and possibly execute arbitrary code via a concurrent thread that increments a pointer count after the nargs function has counted the pointers, but before the count is copied from user space to kernel space, which leads to a buffer overflow.