glibc's tst-makecontext2 testcase uncovered a bug in __cont_link_context. If the function misses to reserve shadow space for the calls to setcontext/cygwin_exit, both functions could overwrite memory beyond the stack configured in uc_stack. * exceptions.cc (__cont_link_context): x86_64: align stack and reserve shadow space for subsequent function calls, otherwise suffer potential buffer overflow. Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
THIS SOFTWARE IS PROVIDED ``AS IS'' AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. Cygwin documentation is available on the net at http://cygwin.com You might especially be interested in http://cygwin.com/faq/faq.programming.html#faq.programming.building-cygwin