The segmentation fault[1] is due to a NULL pointer dereference[2] at :
sudo-1.8.16/plugins/sudoers/pwutil.c[3]
[1] Core was generated by `sudo bash'.
Program terminated with signal SIGSEGV, Segmentation fault.
#0 0x00007fa01c0a6944 in sudo_getgrgid (gid=7241)
at /build/sudo-g3ghsu/sudo-1.8.16/plugins/sudoers/pwutil.c:462
462 /build/sudo-g3ghsu/sudo-1.8.16/plugins/sudoers/pwutil.c: No such file or
directory.
[2] (gdb) p item->d.gr
$1 = (struct group *) 0x0
[3] - sudo-1.8.16/plugins/sudoers/pwutil.c:462
449 * Get a group entry by gid and allocate space for it.
450 */
451 struct group *
452 sudo_getgrgid(gid_t gid)
453 {
454 struct cache_item key, *item;
455 struct rbnode *node;
456 debug_decl(sudo_getgrgid, SUDOERS_DEBUG_NSS)
457
458 key.k.gid = gid;
459 getauthregistry(NULL, key.registry);
460 if ((node = rbfind(grcache_bygid, &key)) != NULL) {
461 item = node->data;
462 sudo_debug_printf(SUDO_DEBUG_DEBUG,
463 "%s: gid %u [%s] -> group %s [%s] (cache hit)", __func__,
464 (unsigned int)gid, key.registry, item->d.gr->gr_name,
465 item->registry);
466 goto done;
467 }
Three months ago, a additional debugging for pwutil functions has been
introduced[4] upstream.
The addition is exactly where the segfault happen. I think it is worth looking
this commit as a starting point.
[4] https://www.sudo.ws/repos/sudo/rev/908b83c3acbb
changeset 10331:908b83c3acbb
Additional debugging for pwutil functions.
author Todd C. Miller <todd.mil...@courtesan.com>
date Fri, 22 Jan 2016 17:04:59 -0700 (3 months ago)
parents 5a2921412663
children 5113a3c04494
files plugins/sudoers/pwutil.c
...
Thanks,
Eric
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You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to sudo in Ubuntu.
https://bugs.launchpad.net/bugs/1565567
Title:
segv in sudo_getgrgid
Status in sudo package in Ubuntu:
Confirmed
Bug description:
If the user is in a group with no name (because libnss-db got removed
and the group was defined there, for example...) then:
the call to sudo_debug_printf in sudo_getgrgid
(plugins/sudoers/pwutil.c, line 462) causes a SEGV when trying to get
item->d.gr->gr_name (since item->d.gr is NULL).
To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/sudo/+bug/1565567/+subscriptions
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