From Bugzilla Helper: User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.5) Gecko/20030927 Description of problem: System seems unstable with 2.6 kernel and exec shield installed. I have seen emacs, find, gcc and prelink fail with segfaults. Version-Release number of selected component (if applicable): 2.6.0-0.test7.1.57 How reproducible: Always Steps to Reproduce: 1.Install 2.6.0-0.test7.1.57 kernel 2. set /proc/sys/kernel/exec_shield to 1 3. run rpmbuild --rebuild prelink*src.rpm 4. Build crashes 5. set /proc/sys/kernel/exec_shield to 0 6. run rpmbuild --rebuild prelink*src.rpm 7. Build succeeds Actual Results: Seg faults Expected Results: No Seg Faults Additional info: I am doing this testing on an box with SELinux enabled. Although I have turned off the SELinux and still seen this behaviour. The crashes do not happen in the same place ever time. I have started emacs had it crash and recall command and it works.
Created attachment 95234 [details] reproducer program for kernel stack bug This test program reproduces the bug every time run with an argument >= 2. This happens for me even with /proc/sys/kernel/exec-shield set to 0, on kernel-smp-2.6.0-0.test7.1.59.i686 (on dual PIII). It does not happen with my own build of vanilla 2.6.
Created attachment 95237 [details] fix for overflow in expand_stack rlimit check I think I got it by dead reckoning. When the limit is set to RLIM_INFINITY, the check in expand_stack will overflow and give a false positive. I haven't tried this patch, but it probably fixes it.
Seems to be fixed.