Bug 994

Summary:	Segfault in sudoers.so 1.9.8 on ArchLinux after update
Product:	Sudo	Reporter:	NIgel K <nkukard>
Component:	Sudoers	Assignee:	Todd C. Miller <Todd.Miller>
Status:	RESOLVED FIXED
Severity:	high
Priority:	low
Version:	1.9.8
Hardware:	PC
OS:	Linux

Description NIgel K 2021-09-16 10:05:04 MDT

Hi there,

I'm using ArchLinux and just updated to 1.9.8. I also am using sssd with "sudoers: files sss" in my /etc/nsswitch.conf file. Removing this line works around the issue.

[   56.360844] sudo[2105]: segfault at 8 ip 00007f78af03372a sp 00007ffdfe42abd0 error 4 in sudoers.so[7f78aeff8000+5e000]
[  358.525901] sudo[3022]: segfault at 8 ip 00007fd23fbce72a sp 00007ffc6a158940 error 4 in sudoers.so[7fd23fb93000+5e000]
[  429.123798] sudo[3255]: segfault at 8 ip 00007f0c46ae272a sp 00007ffdeb628cb0 error 4 in sudoers.so[7f0c46aa7000+5e000]
[  451.748556] sudo[3292]: segfault at 8 ip 00007f253f2f272a sp 00007fffbe4ac900 error 4 in sudoers.so[7f253f2b7000+5e000]
[  559.698998] sudo[3511]: segfault at 8 ip 00007f1891bda72a sp 00007ffec42b1c20 error 4 in sudoers.so[7f1891b9f000+5e000]
[  741.884927] sudo[4017]: segfault at 8 ip 00007f53c116572a sp 00007ffd4e798710 error 4 in sudoers.so[7f53c112a000+5e000]

I'm just having an issue getting a core dump, probably because its a suid binary. I'm happy to do whatever testing is needed to pin this one down.

Reverting to 1.9.7p2 works.

Comment 1 NIgel K 2021-09-16 10:53:07 MDT

I tested the fix in #993 with the same result. I'll try compile with debugging info next and get a backtrace.

Comment 2 Todd C. Miller 2021-09-16 11:09:32 MDT

I'm able to reproduce this on CentOS with an IPA user.

Comment 3 Todd C. Miller 2021-09-16 11:36:26 MDT

Fixed by https://www.sudo.ws/repos/sudo/rev/91d0379b068a

Comment 4 Todd C. Miller 2021-09-16 13:30:57 MDT

sudo 1.9.8p1 is out now which includes the fix.