I could no longer login/su after updating to pam-0.79-1 /etc/pam.d/system-auth contained: auth optional pam_tally.so no_magic_root account required pam_tally.so deny=5 no_magic_root causes the following to be logged pam_tally: unknown option; no_magic_root pam_tally: option deny=5 allowed in auth phase only pam_tally: unknown option; no_magic_root su(pam_unix)[16773]: session opened for user root by thomasz(uid=500) pam_tally: unknown option; no_magic_root kernel: su[16774]: segfault at 0000000000000000 rip 00002aaaadfbb530 rsp 00007ffffffff450 error 4 and with the options removed: su(pam_unix)[17007]: session opened for user root by thomasz(uid=500) su(pam_unix)[17007]: session closed for user root kernel: su[17008]: segfault at 0000000000000000 rip 00002aaaadfbb530 rsp 00007ffffffff450 error 4
The pam_tally module is redesigned in pam-0.79. This redesign was necessary to fix bug 60930. So you need to rearrange the options according to the README.pam_tally provided with the package. However su shouldn't segfault. So could you please attach your /etc/pam.d/system-auth and /etc/pam.d/su here and also could you please try to obtain a backtrace from the crashing su binary?
Actually it's not necessary anymore - I know where the bug is. Upgrade to pam-0.79-2 when it's available. However you will need to rearrange the options anyway.