We have a RHEL 6.4 server with httpd 2.2.32, acting as a front-end for UID user authentication. Once authenticated, users are passed to the back-end Windows/Mysql database server on a private network, via ProxyPass/ProxyPassReverse.
PROBLEM: Pages are occasionally (40-50 times/day) being randomly truncated, which is always accompanied by a segmentation fault in the httpd error log:
[Thu Oct 13 14:44:08 2016] [notice] child pid 22716 exit signal Segmentation fault (11)
[root@vlsched ~]# gdb /apacheSSLDEV2/bin/httpd ./apacheSSLDEV2-core
GNU gdb (GDB) Red Hat Enterprise Linux (7.2-60.el6)
Copyright (C) 2010 Free Software Foundation, Inc.
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This GDB was configured as "x86_64-redhat-linux-gnu".
For bug reporting instructions, please see:
Reading symbols from /apacheSSLDEV2/bin/httpd...done.
[New Thread 9796]
Missing separate debuginfo for /apacheSSLDEV2/lib/libaprutil-1.so.0
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/62/b961ed72279546bd42cee2d0c8d7ed0dec4298
Missing separate debuginfo for /apacheSSLDEV2/lib/libexpat.so.0
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/24/bb06c86683c9950e3e54d45ba40c1e786ecab9
Missing separate debuginfo for /apacheSSLDEV2/lib/libapr-1.so.0
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/0f/dae46acd31f1b37a5fe8484aee0792f3a45b4a
Missing separate debuginfo for /apacheSSLDEV2/modules/libopentoken.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/37/05fa4039609e067223023de62e7c134b87249a
Missing separate debuginfo for /apacheSSLDEV2/modules/mod_pf.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/22/b4b932110efff022a7fb96c3f595941a98e44c
Missing separate debuginfo for /apacheSSLDEV2/modules/mod_headers.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/35/b1c2680d26276521c2ed92eab8960a56ac1d87
Missing separate debuginfo for /apacheSSLDEV2/modules/mod_proxy.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/19/195f789e0f7d6e07cf5c44e252739bfe593f53
Missing separate debuginfo for /apacheSSLDEV2/modules/mod_proxy_connect.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/15/8eff1555e28ab232f30e4f93ac01ca60036b68
Missing separate debuginfo for /apacheSSLDEV2/modules/mod_proxy_ftp.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/b4/cfd85c4493265f65af9f6bd1f0074d25bf0459
Missing separate debuginfo for /apacheSSLDEV2/modules/mod_proxy_http.so
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/a1/5e9bb81f6c0efee08919907a35281df586e948
Missing separate debuginfo for
Try: yum --disablerepo='*' --enablerepo='*-debug*' install /usr/lib/debug/.build-id/b5/d86fbcf0ccb03331e6c7c73897b96845e0a4eb
Reading symbols from /usr/lib64/libssl.so.10...(no debugging symbols found)...done.
Loaded symbols for /usr/lib64/libssl.so.10
Reading symbols from /usr/lib64/libcrypto.so.10...(no debugging symbols found)...done.
Loaded symbols for /usr/lib64/libcrypto.so.10
Reading symbols from /lib64/libm.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib64/libm.so.6
Reading symbols from /apacheSSLDEV2/lib/libaprutil-1.so.0...done.
Loaded symbols for /apacheSSLDEV2/lib/libaprutil-1.so.0
Reading symbols from /apacheSSLDEV2/lib/libexpat.so.0...done.
Loaded symbols for /apacheSSLDEV2/lib/libexpat.so.0
Reading symbols from /apacheSSLDEV2/lib/libapr-1.so.0...done.
Loaded symbols for /apacheSSLDEV2/lib/libapr-1.so.0
Reading symbols from /lib64/librt.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/librt.so.1
Reading symbols from /lib64/libcrypt.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/libcrypt.so.1
Reading symbols from /lib64/libpthread.so.0...(no debugging symbols found)...done.
[Thread debugging using libthread_db enabled]
Loaded symbols for /lib64/libpthread.so.0
Reading symbols from /lib64/libc.so.6...(no debugging symbols found)...done.
Loaded symbols for /lib64/libc.so.6
Reading symbols from /lib64/libgssapi_krb5.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/libgssapi_krb5.so.2
Reading symbols from /lib64/libkrb5.so.3...(no debugging symbols found)...done.
Loaded symbols for /lib64/libkrb5.so.3
Reading symbols from /lib64/libcom_err.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/libcom_err.so.2
Reading symbols from /lib64/libk5crypto.so.3...(no debugging symbols found)...done.
Loaded symbols for /lib64/libk5crypto.so.3
Reading symbols from /lib64/libdl.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/libdl.so.2
Reading symbols from /lib64/libz.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/libz.so.1
Reading symbols from /lib64/ld-linux-x86-64.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/ld-linux-x86-64.so.2
Reading symbols from /lib64/libfreebl3.so...(no debugging symbols found)...done.
Loaded symbols for /lib64/libfreebl3.so
Reading symbols from /lib64/libkrb5support.so.0...(no debugging symbols found)...done.
Loaded symbols for /lib64/libkrb5support.so.0
Reading symbols from /lib64/libkeyutils.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/libkeyutils.so.1
Reading symbols from /lib64/libresolv.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/libresolv.so.2
Reading symbols from /lib64/libselinux.so.1...(no debugging symbols found)...done.
Loaded symbols for /lib64/libselinux.so.1
Reading symbols from /lib64/libnss_files.so.2...(no debugging symbols found)...done.
Loaded symbols for /lib64/libnss_files.so.2
Reading symbols from /apacheSSLDEV2/modules/libopentoken.so...(no debugging symbols found)...done.
Loaded symbols for /apacheSSLDEV2/modules/libopentoken.so
Reading symbols from /apacheSSLDEV2/modules/mod_pf.so...(no debugging symbols found)...done.
Loaded symbols for /apacheSSLDEV2/modules/mod_pf.so
Reading symbols from /apacheSSLDEV2/modules/mod_headers.so...done.
Loaded symbols for /apacheSSLDEV2/modules/mod_headers.so
Reading symbols from /apacheSSLDEV2/modules/mod_proxy.so...done.
Loaded symbols for /apacheSSLDEV2/modules/mod_proxy.so
Reading symbols from /apacheSSLDEV2/modules/mod_proxy_connect.so...done.
Loaded symbols for /apacheSSLDEV2/modules/mod_proxy_connect.so
Reading symbols from /apacheSSLDEV2/modules/mod_proxy_ftp.so...done.
Loaded symbols for /apacheSSLDEV2/modules/mod_proxy_ftp.so
Reading symbols from /apacheSSLDEV2/modules/mod_proxy_http.so...done.
Loaded symbols for /apacheSSLDEV2/modules/mod_proxy_http.so
Core was generated by `/apacheSSLDEV2/bin/httpd -k start'.
Program terminated with signal 11, Segmentation fault.
#0 apr_table_clear (t=0x101131d5503060f) at tables/apr_tables.c:467
467 t->a.nelts = 0;
Missing separate debuginfos, use: debuginfo-install glibc-2.12-1.107.el6_4.2.x86_64 keyutils-libs-1.4-4.el6.x86_64 krb5-libs-1.10.3-10.el6.x86_64 libcom_err-1.41.12-14.el6.x86_64 libselinux-2.0.94-5.3.el6.x86_64 nss-softokn-freebl-3.12.9-11.el6.x86_64 openssl-1.0.1e-48.el6_8.1.x86_64 zlib-1.2.3-29.el6.x86_64
(gdb) bt full
#0 apr_table_clear (t=0x101131d5503060f) at tables/apr_tables.c:467
No locals.
#1 0x0000000000472116 in read_chunked_trailers (f=<value optimized out>, b=<value optimized out>, mode=AP_MODE_READBYTES,
block=APR_BLOCK_READ, readbytes=8192) at http_filters.c:286
rv = <value optimized out>
e = <value optimized out>
saved_headers_in = 0x1164440
saved_status = 200
r = 0x1175cb0
#2 ap_http_filter (f=<value optimized out>, b=<value optimized out>, mode=AP_MODE_READBYTES, block=APR_BLOCK_READ, readbytes=8192)
at http_filters.c:551
conf = 0x10c0c08
e = <value optimized out>
ctx = 0x1164748
rv = <value optimized out>
http_error = 413
bb = <value optimized out>
again = 1
#3 0x00007f99d70a983d in ap_proxy_http_process_response (p=0x115e878, r=<value optimized out>, backend=0x11423b0, origin=0x10cc4a0,
conf=0x10db2b8, server_portstr=0x7fff1f2f0000 "") at mod_proxy_http.c:1770
readbytes = 3716
rv = <value optimized out>
mode = <value optimized out>
finish = 0
rc = <value optimized out>
c = 0x114e1b0
buffer = "\000\nte\000 Wed, 12 Oct 2016 13:35:02 GMT\000\n859-1\000\n\000\000\000\000\200IF", '\000' <repeats 14 times>"\343, .\037\377\177\000\000p'\360×\177\000\000\000\000\000\000\000\000\000\000]\255\346t", '\000' <repeats 12 times>"\240,
(... User data deleted here....)
buf = <value optimized out>
keepchar = <value optimized out>
rp = 0x1175cb0
e = <value optimized out>
bb = 0x1175c70
tmp_bb = 0x1163e18
pass_bb = 0x1175c90
len = 15
backasswards = <value optimized out>
interim_response = 0
pread_len = <value optimized out>
save_table = <value optimized out>
backend_broke = 0
hop_by_hop_hdrs = {0x7f99d70ac405 "Keep-Alive", 0x7f99d70ac772 "Proxy-Authenticate", 0x7f99d70ac650 "TE",
0x7f99d70ac653 "Trailer", 0x7f99d70ac65b "Upgrade", 0x0}
i = <value optimized out>
te = 0x1164368 "chunked"
original_status = 200
proxy_status = 200
original_status_line = 0x0
proxy_status_line = <value optimized out>
#4 0x00007f99d70aac5f in proxy_http_handler (r=0x115e8f0, worker=<value optimized out>, conf=0x7fff1f2f0088,
url="" "/jsp/userListForm.jsp?mode=manage", proxyname=0x1155f88 "8\277\024\001", proxyport=50336) at mod_proxy_http.c:2036
status = <value optimized out>
server_portstr = "\000\350\025\001\000\000\000\000\370\263\r\001", '\000' <repeats 12 times>"\370, \263\r\001\000\000\000"
scheme = <value optimized out>
proxy_function = 0x7f99d70ac577 "HTTP"
u = <value optimized out>
backend = 0x11423b0
is_ssl = 18300184
c = 0x114e1b0
p = 0x115e878
uri = <value optimized out>
#5 0x00007f99d76bce62 in proxy_run_scheme_handler (r=0x115e8f0, worker=0x10dbf10, conf=0x10db2b8,
url="" "http://(... URL deleted here ...)", proxyhost=0x0, proxyport=0) at mod_proxy.c:2415
pHook = <value optimized out>
n = <value optimized out>
rv = -1
#6 0x00007f99d76c1457 in proxy_handler (r=0x115e8f0) at mod_proxy.c:1031
url = "" "http://(... URL deleted here ...)"
uri = 0x117340e "http://(... URL deleted here ...)"
scheme = 0x1173c00 "http"
p = 0x7fff1f2f01b8 "\340\353\025\001"
p2 = <value optimized out>
sconf = <value optimized out>
conf = 0x10db2b8
proxies = 0x10db3f8
ents = 0x10db418
i = <value optimized out>
access_status = 0
direct_connect = <value optimized out>
str = <value optimized out>
maxfwd = <value optimized out>
balancer = 0x0
worker = 0x10dbf10
attempts = 0
max_attempts = 0
list = <value optimized out>
#7 0x0000000000441680 in ap_run_handler (r=0x115e8f0) at config.c:158
pHook = <value optimized out>
n = <value optimized out>
rv = -1
#8 0x0000000000444cae in ap_invoke_handler (r=0x115e8f0) at config.c:376
handler = <value optimized out>
p = <value optimized out>
result = 0
old_handler = 0x7f99d76c827d "proxy-server"
ignore = <value optimized out>
#9 0x0000000000470650 in ap_process_request (r=0x115e8f0) at http_request.c:294
access_status = <value optimized out>
#10 0x000000000046d5b0 in ap_process_http_connection (c=0x114e1b0) at http_core.c:190
r = 0x115e8f0
csd = 0x0
#11 0x0000000000448c10 in ap_run_process_connection (c=0x114e1b0) at connection.c:43
pHook = <value optimized out>
n = <value optimized out>
rv = -1
#12 0x0000000000484188 in child_main (child_num_arg=<value optimized out>) at prefork.c:667
current_conn = 0x114e1b0
csd = 0x114dfc0
ptrans = 0x114df48
allocator = 0x1133850
status = <value optimized out>
i = <value optimized out>
lr = <value optimized out>
pollset = 0x114c0d8
sbh = 0x114c0d0
bucket_alloc = 0x1155f88
last_poll_idx = 0
#13 0x0000000000484484 in make_child (s=0x10ba930, slot=6) at prefork.c:768
pid = 0
#14 0x00000000004850d7 in perform_idle_server_maintenance (_pconf=<value optimized out>, plog=<value optimized out>,
s=<value optimized out>) at prefork.c:903
i = <value optimized out>
idle_count = <value optimized out>
ws = <value optimized out>
free_length = <value optimized out>
free_slots = {6, 7, 17985288, 0, 17541424, 0, 17985288, 0, 17985336, 0, 4438247, 0, 17985288, 0, 17985248, 0, 17985248, 0,
4578767, 0, 17985248, 0, 14, 0, 17958728, 0, 8, 0, 17580504, 0, 17555880, 0}
last_non_dead = <value optimized out>
total_non_dead = <value optimized out>
#15 ap_mpm_run (_pconf=<value optimized out>, plog=<value optimized out>, s=<value optimized out>) at prefork.c:1107
status = 17506872
pid = {pid = -1, in = 0x7f99d7f1e13b, out = 0x8, err = 0x10b4158}
child_slot = <value optimized out>
exitwhy = 0
processed_status = <value optimized out>
index = <value optimized out>
remaining_children_to_start = 0
rv = <value optimized out>
#16 0x000000000042da64 in main (argc=3, argv=0x7fff1f2f0748) at main.c:753
c = 0 '\000'
configtestonly = <value optimized out>
confname = 0x48e5ce "conf/httpd.conf"
def_server_root = 0x48e5bf "/apacheSSLDEV2"
temp_error_log = 0x0
error = <value optimized out>
process = 0x10ba930
server_conf = 0x10ba930
pglobal = 0x10b2148
pconf = 0x10b4158
plog = 0x10c41d8
ptemp = 0x10be1a8
pcommands = 0x10b6168
opt = 0x10b6258
rv = <value optimized out>
mod = <value optimized out>
optarg = 0x7fff1f2f06c0 "v\225b\213|\203\313Ov\225\262^\241\345C\260"
signal_server = <value optimized out>
(gdb)
