Crash while triming the retro changelog #1537

389-ds-bot · 2020-09-12T23:48:56Z

Cloned from Pagure issue: https://pagure.io/389-ds-base/issue/48206

Created at 2015-06-25 19:38:57 by tbordaz (@tbordaz)
Closed as Fixed
Assigned to mreynolds (@mreynolds389)
Associated bugzillas
- https://bugzilla.redhat.com/show_bug.cgi?id=1244970
- https://bugzilla.redhat.com/show_bug.cgi?id=1244926

Community use on Centos is running 389-ds-base-1.3.3.1-16.el7_1.x86_64

When trimming the retroCL, it deletes an entry. Then retrieve the entry from the cache (no creation of tombstone) to remove it from the cache.
Apparently if the entry cachen is small, it can fail to retrieve it and not testing this special condition

389-ds-bot · 2020-09-12T23:48:58Z

Comment from tbordaz (@tbordaz) at 2015-06-25 19:49:19

The crash occurs:

Thread 1 (Thread 0x7f4edf9cb700 (LWP 27506)):
0  cache_unlock_entry (cache=0x7f4ee17305d8, e=0x0) at ldap/servers/slapd/back-ldbm/cache.c:1568
1  0x00007f4ed3b1ec08 in ldbm_back_delete (pb=0x7f4ea80164c0) at ldap/servers/slapd/back-ldbm/ldbm_delete.c:1278
2  0x00007f4edf58a0f0 in op_shared_delete (pb=pb@entry=0x7f4ea80164c0) at ldap/servers/slapd/delete.c:364
3  0x00007f4edf58a2a2 in delete_internal_pb (pb=pb@entry=0x7f4ea80164c0) at ldap/servers/slapd/delete.c:242
4  0x00007f4edf58a553 in slapi_delete_internal_pb (pb=pb@entry=0x7f4ea80164c0) at ldap/servers/slapd/delete.c:185
5  0x00007f4ed239bafe in delete_changerecord (cnum=cnum@entry=52314) at ldap/servers/plugins/retrocl/retrocl_trim.c:117
6  0x00007f4ed239bdd1 in trim_changelog () at ldap/servers/plugins/retrocl/retrocl_trim.c:316
7  changelog_trim_thread_fn (arg=<optimized out>) at ldap/servers/plugins/retrocl/retrocl_trim.c:359
8  0x00007f4edd9ca7bb in _pt_root () from /lib64/libnspr4.so
9  0x00007f4edd36bdf5 in start_thread () from /lib64/libpthread.so.0
10 0x00007f4edd0991ad in clone () from /lib64/libc.so.6

The problem could be trigger by small cn=changelog entry cache

[25/Jun/2015:15:04:33 +0200] - 389-Directory/1.3.3.1 B2015.118.1941 starting up
[25/Jun/2015:15:04:35 +0200] - WARNING -- Minimum cache size is 512000 -- rounding up
[25/Jun/2015:15:04:36 +0200] - WARNING -- Minimum cache size is 512000 -- rounding up
[25/Jun/2015:15:04:36 +0200] - WARNING -- Minimum cache size is 512000 -- rounding up
[25/Jun/2015:15:04:36 +0200] - WARNING -- Minimum cache size is 512000 -- rounding up
[25/Jun/2015:15:04:37 +0200] - WARNING: changelog: entry cache size 512000B is less than db size 36683776B; We recommend to increase the entry cache size nsslapd-cachememsize.
[25/Jun/2015:15:04:37 +0200] - I'm resizing my cache now...cache was 3689347 and is now 2951477

The bug could be at https://git.fedorahosted.org/cgit/389/ds.git/tree/ldap/servers/slapd/back-ldbm/ldbm_delete.c#n1264. If '!create_tombstone_entry' (that is the case for cn=changelog), 'e' was updated and so could be NULL.