https://bugs.openldap.org/show_bug.cgi?id=9940

Issue ID: 9940 Summary: slapadd segfault with -w on a subordinate database Product: OpenLDAP Version: 2.5.13 Hardware: x86_64 OS: Linux Status: UNCONFIRMED Keywords: needs_review Severity: normal Priority: --- Component: slapd Assignee: bugs@openldap.org Reporter: dhawes@gmail.com Target Milestone: ---

I've noticed sporadic segfaults when using slapadd with -w and an LDIF that contains entries on a subordinate database. Removing -w prevents the segfault. I finally had some time to look at this, and the results are odder than I expected.

gdb bt:

===== Program terminated with signal SIGSEGV, Segmentation fault. #0 0x000055c2096c1ffd in dnIsSuffix (dn=0x55c20b82c7b8, suffix=0x55c20b749520) at dn.c:1192 1192 if ( d > 1 && !DN_SEPARATOR( dn->bv_val[ d - 1 ] ) ) { (gdb) bt #0 0x000055c2096c1ffd in dnIsSuffix (dn=0x55c20b82c7b8, suffix=0x55c20b749520) at dn.c:1192 #1 0x000055c20974262e in glue_back_select (be=0x7fff683fc5a0, dn=0x55c20b82c7b8) at backglue.c:77 #2 0x000055c209745473 in glue_entry_release_rw (op=0x7fff683fc840, e=0x55c20b82c7a0, rw=0) at backglue.c:927 #3 0x000055c20974824d in overlay_entry_release_ov (op=0x7fff683fc840, e=0x55c20b82c7a0, rw=0, on=0x55c20b78d870) at backover.c:439 #4 0x000055c20974841f in over_entry_release_rw (op=0x7fff683fc840, e=0x55c20b82c7a0, rw=0) at backover.c:483 #5 0x000055c2096b5f94 in be_entry_release_rw (op=0x7fff683fc840, e=0x55c20b82c7a0, rw=0) at backend.c:958 #6 0x000055c209750a3d in slap_tool_update_ctxcsn (progname=0x55c209813b08 "slapadd", sid=18446744073709551615, bvtext=0x7fff683fca20) at slapcommon.c:1015 #7 0x000055c20974e108 in slapadd (argc=11, argv=0x7fff683fce68) at slapadd.c:502 #8 0x000055c209672e56 in main (argc=11, argv=0x7fff683fce68) at main.c:723 (gdb) print *dn $1 = {bv_len = 94291905136528, bv_val = 0x0} =====

dn->bv_val is NULL in this case. This dumb patch prevents the segfault, but does not fix the root issue:

===== --- openldap-2.5.13/servers/slapd/dn.c 2022-07-14 13:09:57.000000000 -0400 +++ openldap-2.5.13-mod/servers/slapd/dn.c 2022-10-25 21:14:13.068933734 -0400 @@ -1188,6 +1188,11 @@ return 0; }

+ /* dn is null */ + if (dn->bv_val == NULL) { + return 0; + } + /* no rdn separator or escaped rdn separator */ if ( d > 1 && !DN_SEPARATOR( dn->bv_val[ d - 1 ] ) ) { return 0; =====

When I started creating a minimal config for this issue, things got stranger. First, the config:

===== include /usr/local/openldap-2.5.13/etc/openldap/schema/core.schema

database mdb suffix "ou=Subordinate,dc=vt,dc=edu" subordinate rootdn "cn=Manager,dc=vt,dc=edu" directory /usr/local/openldap-2.5.13/var/openldap-data/subordinate maxsize 17179869184 index objectClass eq index uid,entryCSN,entryUUID eq

database mdb suffix "dc=vt,dc=edu" rootdn "cn=Manager,dc=vt,dc=edu" directory /usr/local/openldap-2.5.13/var/openldap-data/mdb maxsize 17179869184 index objectClass eq index uid,entryCSN,entryUUID eq =====

The LDIF:

===== dn: dc=vt,dc=edu objectClass: dcObject objectClass: organization o: Virginia Tech dc: vt structuralObjectClass: organization entryUUID: e906e392-731f-1034-98c4-c3e119ef52ff creatorsName: cn=Manager,dc=vt,dc=edu createTimestamp: 20150409161915Z entryCSN: 20150409161915.467619Z#000000#000#000000 modifiersName: cn=Manager,dc=vt,dc=edu modifyTimestamp: 20150409161915Z contextCSN: 20221025003300.622285Z#000000#000#000000

dn: ou=Subordinate,dc=vt,dc=edu objectClass: dcObject objectClass: organizationalUnit dc: vt ou: subordinate structuralObjectClass: organizationalUnit entryUUID: 40b0b450-7321-1034-9e54-3f41091a54c5 creatorsName: cn=Manager,dc=vt,dc=edu createTimestamp: 20150409162852Z entryCSN: 20150409162852.039034Z#000000#000#000000 modifiersName: cn=Manager,dc=vt,dc=edu modifyTimestamp: 20150409162852Z =====

Unfortunately, that config and LDIF did not result in a segfault, but I noticed that in my LDIFs that do, there is data after the subordinate entry, but that data is commented out. Adding a small comment did not affect things, but adding a large comment at the end of the LDIF did (4113 characters):

===== #000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000a =====

If you remove the 'a' from the end of that comment, there is no segfault.

Note that this is sporadic, so I'm running in a loop to detect it:

for i in {1..10}; do rm /usr/local/openldap-2.5.13/var/openldap-data/*/*.mdb; slapadd -q -w -b dc=vt,dc=edu -l ./minimal.ldif; done;

This also seems to be the case with entries after the subordinate entry that have long attribute values (1027 characters, only tested with dc):

===== dn: ou=1,dc=vt,dc=edu objectClass: dcObject objectClass: organizationalUnit dc: 00000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000000a ou: 1 structuralObjectClass: organizationalUnit entryUUID: 40b0b450-7321-1034-9e54-3f41091a54c5 creatorsName: cn=Manager,dc=vt,dc=edu createTimestamp: 20150409162852Z entryCSN: 20150409162852.039034Z#000000#000#000000 modifiersName: cn=Manager,dc=vt,dc=edu modifyTimestamp: 20150409162852Z =====

Remove the 'a' from the end of dc, and no segfault.

I hope that's enough information to recreate this issue. I'm still looking at it, but I haven't found the root cause yet.