(ITS#5623) slapd segfaults on syncrepl provider

[m.gr@gmx.de]

Full_Name: Matthias Grau
Version: 2.3.43
OS: irrelevant
URL: 
Submission from: (NULL) (195.200.70.23)


Slapd segfaults on a syncrepl provider.
This error occurs when the connections of several synchronous modify operations
are not disconnected correctly (e.g. network issues).

syncprov.c line 1707: m2 seems to be NULL in this case so m2->mi_next causes the
segfault.

Program received signal SIGSEGV, Segmentation fault.
[Switching to Thread -1243620448 (LWP 21810)]
0x08148dc3 in syncprov_op_mod (op=0xb6307450, rs=0xb5dfd264) at syncprov.c:1707
1707                                            for ( m2 = mt->mt_mods;
m2->mi_next != mi;
(gdb) bt
#0  0x08148dc3 in syncprov_op_mod (op=0xb6307450, rs=0xb5dfd264) at
syncprov.c:1707
#1  0x080c6184 in overlay_op_walk (op=0xb6307450, rs=0xb5dfd264,
which=op_modify, oi=0x825b470, on=0x825b560) at backover.c:640
#2  0x080c65dd in over_op_func (op=0xb6307450, rs=0xb5dfd264, which=op_modify)
at backover.c:702
#3  0x08088d1b in fe_op_modify (op=0xb6307450, rs=0xb5dfd264) at modify.c:395
#4  0x08089558 in do_modify (op=0xb6307450, rs=0xb5dfd264) at modify.c:200
#5  0x08071fd2 in connection_operation (ctx=0xb5dfd2d8, arg_v=0xb6307450) at
connection.c:1133
#6  0x08159b2a in ldap_int_thread_pool_wrapper (xpool=0x8225330) at tpool.c:478
#7  0xb7cfc34b in start_thread () from /lib/libpthread.so.0
#8  0xb7aea65e in clone () from /lib/libc.so.6
(gdb) print m2
$1 = (modinst *) 0x0