Thanks for reporting this bug. This appears to be a NULL dereference, and does not seem exploitable. I have unmarked it security/private. Please feel free to report other bugs you may find.
$ ps auwwx | grep newgrp root 23490 0.0 0.0 21900 1064 pts/13 S 14:09 0:00 newgrp testing $ sudo gdb $(which newgrp) 23490 ... 0x00002b81453ebb05 in waitpid () from /lib/libc.so.6 (gdb) cont Continuing. Program received signal SIGSEGV, Segmentation fault. 0x0000000000402903 in ?? () (gdb) info reg rax 0x0 0 ... (gdb) x/5i $pc 0x402903 <[EMAIL PROTECTED]>: mov (%rax),%r9 ** Changed in: shadow (Ubuntu) Importance: Undecided => Low Status: New => Confirmed ** Visibility changed to: Public ** This bug is no longer flagged as a security issue -- newgrp segfaults on exit when default group isn't in /etc/groups https://bugs.launchpad.net/bugs/130205 You received this bug notification because you are a member of Ubuntu Bugs, which is a direct subscriber. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs