toby@inf.ed.ac.uk wrote:

Full_Name: Toby Blake Version: 2.4.15 OS: Scientific Linux 5.2 URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (129.215.197.95)

Hi there,

I have been testing slapo-pcache/back-ldap for some time now, typically in student lab situations (to provide a localhost proxycaching slapd with back-ldap connecting (via gssapi) to several remote servers), initially using 2.3.x but I have recently moved to using the latest 2.4.x versions, as it's clear that's where the development effort is going.

I'm seeing quite a lot of crashes during my testing, with a few different backtraces. I don't know whether you would prefer I submitted these separately for different backtraces, so I'm opening this ITS to get the process started...

I have seen no way of reproducing these crashes.

I'm currently using:

• openldap-2.4.15 on scientific linux 5.2
• bdb 4.7.25 with 3 patches
• We build our own RPMs. I have openldap-2.4.15 with no optimisation (-O0) for the purposes of debugging.

The most common backtrace I see is an assertion failure in memory.c:152. Here's an example:

Program terminated with signal 6, Aborted. #0 0x00b8d402 in __kernel_vsyscall () (gdb) bt #0 0x00b8d402 in __kernel_vsyscall () #1 0x009e8d20 in raise () from /lib/libc.so.6 #2 0x009ea631 in abort () from /lib/libc.so.6 #3 0x00a20e6b in __libc_message () from /lib/libc.so.6 #4 0x00a28b16 in _int_free () from /lib/libc.so.6 #5 0x00a2c070 in free () from /lib/libc.so.6 #6 0x081d5746 in ber_memfree_x (p=0xa6809478, ctx=0x0) at memory.c:152 #7 0x081d630c in ber_bvarray_free_x (a=0x9049bb8, ctx=0x0) at memory.c:731 #8 0x081d6343 in ber_bvarray_free (a=0x9049bb8) at memory.c:741 #9 0x08079757 in attr_clean (a=0xb62d41bc) at attr.c:134

The problem seems to be here; apparently, the a->a_nvals array is being incorrectly freed. If you have those core files around, it would be interesting to see the contents of those attributes, e.g.

p *a p a->a_desc[0] p a->a_flags p a->a_nvals[0]

from within frame 9.

#10 0x0807983b in attrs_free (a=0xb62d41bc) at attr.c:196 #11 0x0807c059 in entry_clean (e=0xb5acfdbc) at entry.c:504 #12 0x0811ec17 in ldap_back_search (op=0xa680e5d8, rs=0xb5ad10e0) at search.c:354

Also, it would be interesting to see the parameters of the search; e.g.

p op->o_req_ndn p op->o_request.oq_search p op->o_request.oq_search.rs_filterstr p op->o_request.oq_search.rs_attrs[0] (unless NULL)

from within frame 12

#13 0x080f2b02 in overlay_op_walk (op=0xa680e5d8, rs=0xb5ad10e0, which=op_search, oi=0x8fa9208, on=0x0) at backover.c:669 #14 0x080f2d0a in over_op_func (op=0xa680e5d8, rs=0xb5ad10e0, which=op_search) at backover.c:721 #15 0x080f2dae in over_op_search (op=0xa680e5d8, rs=0xb5ad10e0) at backover.c:743 #16 0x080720d6 in fe_op_search (op=0xa680e5d8, rs=0xb5ad10e0) at search.c:366 #17 0x08071a2c in do_search (op=0xa680e5d8, rs=0xb5ad10e0) at search.c:217 #18 0x0806e705 in connection_operation (ctx=0xb5ad11d0, arg_v=0xa680e5d8) at connection.c:1097 #19 0x0806ebdf in connection_read_thread (ctx=0xb5ad11d0, argv=0x13) at connection.c:1223 #20 0x0819ecad in ldap_int_thread_pool_wrapper (xpool=0x8f86fa0) at tpool.c:663 #21 0x00b3346b in start_thread () from /lib/libpthread.so.0 #22 0x00a90dbe in clone () from /lib/libc.so.6 (gdb)

I have seen quite a few of these backtraces, although sometimes coming through slap_sl_free (and a couple of other places) instead of ber_bvarray_free_x.

Let me know what further information I can provide.

Finally, it would be great to see your slapd.conf.

p.

Ing. Pierangelo Masarati OpenLDAP Core Team

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