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From Bugzilla Helper: User-Agent: Mozilla/4.77 [en] (Windows NT 5.0; U) Description of problem: I ran the Bastille-Linux hardening scripts. They set a hard file size limit of 100MB in /etc/security/limits.conf. I rebooted and logged into GNOME. I brought up a shell and su'd to root. When I exited the root shell, I got a bus error. I tried to su again and got the message 'File size limit exceeded'. I found a file .xauth/refcount/root/localhost.localdomain/unix:0 which was exactly the file size limit. How reproducible: Always Steps to Reproduce: 1. Set hard limit. 2. Log in to WM. 3. Start terminal window. 4. su 5. exit 6. "Bus error" 7. su 8. "File size limit exceeded" Actual Results: See steps 6 & 8. Expected Results: No error messages. Additional info: Strace shows an ftruncate() and a mmap2() on the offending file just before the error.
Looks like your xauth file is getting way too large (shouldn't be bigger than a couple of kbs). xauth problem, assigning there. (can't reproduce it here, by the way).
According to gdb, the bus error occurs at 0x401e8650 in _init() from /lib/security/pam_xauth.so. $(rpm -q pam) == pam-0.74-22 /etc/pam.d/su has: session optional pam_xauth.so /etc/pam.d/system_auth appears to be modified; running authconfig without changing any settings reproduces the modified file. So far I have not reproduced this except on an IBM eServer xSeries 230 (that's a Pentium III). The boot drive is an IBM ServerRAID.
Here's the end of an strace (note the 64-bit fs calls): stat64("/home/jpdalbec/.xauth/refcount/root/mail02.cc.ysu.edu/unix:0", {st_mode=S_IFREG|0600, st_size=34, ...}) = 0 open("/home/jpdalbec/.xauth/refcount/root/mail02.cc.ysu.edu/unix:0", O_RDWR|O_CREAT, 0600) = 3 time([995660143]) = 995660143 getpid() = 1666 rt_sigaction(SIGPIPE, {0x40141840, [], 0x4000000}, {SIG_DFL}, 8) = 0 socket(PF_UNIX, SOCK_DGRAM, 0) = 4 fcntl64(4, F_SETFD, FD_CLOEXEC) = 0 connect(4, {sin_family=AF_UNIX, path=" /dev/log"}, 16) = 0 send(4, "<87>Jul 20 16:15:43 pam_xauth[16"..., 115, 0) = 115 rt_sigaction(SIGPIPE, {SIG_DFL}, NULL, 8) = 0 close(4) = 0 ftruncate(3, 1075343265) = 0 mmap2(NULL, 1075343265, PROT_READ|PROT_WRITE, MAP_SHARED, 3, 0) = 0x40224000 --- SIGBUS (Bus error) --- I wonder where the 1075343265(0x40186FA1) comes from? Could the program be passing a pointer instead of a value? *** This bug has been marked as a duplicate of 49437 ***