Race condition in the ptrace and utrace support in the Linux kernel 2.6.9 through 2.6.25, as used in Red Hat Enterprise Linux (RHEL) 4, allows local users to cause a denial of service (oops) via a long series of PTRACE_ATTACH ptrace calls to another user's process that trigger a conflict between utrace_detach and report_quiescent, related to "late ptrace_may_attach() check" and "race around &dead_engine_ops setting," a different vulnerability than CVE-2007-0771 and CVE-2008-1514. NOTE: this issue might only affect kernel versions before 2.6.16.x.

arch/s390/kernel/ptrace.c in Linux kernel 2.6.9, and other versions before 2.6.27-rc6, on s390 platforms allows local users to cause a denial of service (kernel panic) via the user-area-padding test from the ptrace testsuite in 31-bit mode, which triggers an invalid dereference.