Fwd: Segmentation Fault when httpd child processes reach MaxRequestsPerChild

[Robert Rigg <riggs685@xxxxxxxxx>]

All httpd child processes Segmentation fault near MaxRequestsPerChild, seemingly when it is time for the process to recycle.  MaxRequestsPerChild currently set to 10000.  I am also not able to reproduce this on a test system.  Child process exits clean when attached with gdb.  Child process also exits clean on stops/restarts.

    [notice] child pid 14054 exit signal Segmentation fault (11)

#Info:

RHEL 6.4

    Server version: Apache/2.2.15 (Unix)
    Server built:   Apr 29 2013 04:13:12
    Server's Module Magic Number: 20051115:25
    Server loaded:  APR 1.3.9, APR-Util 1.3.9
    Compiled using: APR 1.3.9, APR-Util 1.3.9
    Architecture:   64-bit
    Server MPM:     Prefork
      threaded:     no
        forked:     yes (variable process count)
    Server compiled with....
     -D APACHE_MPM_DIR="server/mpm/prefork"
     -D APR_HAS_SENDFILE
     -D APR_HAS_MMAP
     -D APR_HAVE_IPV6 (IPv4-mapped addresses enabled)
     -D APR_USE_SYSVSEM_SERIALIZE
     -D APR_USE_PTHREAD_SERIALIZE
     -D SINGLE_LISTEN_UNSERIALIZED_ACCEPT
     -D APR_HAS_OTHER_CHILD
     -D AP_HAVE_RELIABLE_PIPED_LOGS
     -D DYNAMIC_MODULE_LIMIT=128
     -D HTTPD_ROOT="/etc/httpd"
     -D SUEXEC_BIN="/usr/sbin/suexec"
     -D DEFAULT_PIDLOG="run/httpd.pid"
     -D DEFAULT_SCOREBOARD="logs/apache_runtime_status"
     -D DEFAULT_LOCKFILE="logs/accept.lock"
     -D DEFAULT_ERRORLOG="logs/error_log"
     -D AP_TYPES_CONFIG_FILE="conf/mime.types"
     -D SERVER_CONFIG_FILE="conf/httpd.conf"

 

#

    [debug] prefork.c(1018): AcceptMutex: sysvsem (default: sysvsem)

#gdb bt sample:

    Program terminated with signal 11, Segmentation fault.
    #0  __pthread_mutex_lock (mutex=0x0) at pthread_mutex_lock.c:50
    50        unsigned int type = PTHREAD_MUTEX_TYPE (mutex);

#strace sample:

*Filtered

        open("/etc/pki/nssdb/pkcs11.txt", O_RDONLY) = 23

        close(23)                               = 0
        open("/etc/ld.so.cache", O_RDONLY)      = 23
        close(23)                               = 0
        open("/usr/lib64/libnsssysinit.so", O_RDONLY) = 23
        close(23)                               = 0
        ...
        open("/etc/pki/nssdb/cert9.db", O_RDONLY) = 23
        fcntl(23, F_GETFD)                      = 0
        fcntl(23, F_SETFD, FD_CLOEXEC)          = 0
        fstat(23, {st_dev=makedev(8, 3), st_ino=1047848, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, 
        st_blksize=4096, st_blocks=24, st_size=9216, st_atime=2010/01/12-15:18:17, st_mtime=2010/01/12-15:18:17
        , st_ctime=2013/08/20-09:59:34}) = 0
        lseek(23, 0, SEEK_SET)                  = 0
        read(23, "SQLite format 3\0\4\0\1\1\0@  \0\0\0\1\0\0\0\0"..., 100) = 100
        fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
        fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741826, len=510}) = 0
        fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
        fstat(23, {st_dev=makedev(8, 3), st_ino=1047848, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, 
        st_blksize=4096, st_blocks=24, st_size=9216, st_atime=2010/01/12-15:18:17, st_mtime=2010/01/12-15:18:17
        , st_ctime=2013/08/20-09:59:34}) = 0
        lseek(23, 0, SEEK_SET)                  = 0
        read(23, "SQLite format 3\0\4\0\1\1\0@  \0\0\0\1\0\0\0\0"..., 1024) = 1024
        lseek(23, 3072, SEEK_SET)               = 3072
        read(23, "\r\0\0\0\1\0J\0\0J\3\315\0\0\0\0\0\0\0\0\0\0\0\2073\1\7\27\37\37\1\216"..., 1024) = 1024
        lseek(23, 5120, SEEK_SET)               = 5120
        read(23, "\r\0\0\0\5\2\302\0\3\212\3\275\3D\3\4\2\302\0\0\0\0\0\0\0\0\0\0\0\0\0\0"..., 1024) = 1024
        fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 0
        fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
        fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741826, len=510}) = 0
        fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
        fstat(23, {st_dev=makedev(8, 3), st_ino=1047848, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, 
        st_blksize=4096, st_blocks=24, st_size=9216, st_atime=2010/01/12-15:18:17, st_mtime=2010/01/12-15:18:17
        , st_ctime=2013/08/20-09:59:34}) = 0
        
        ...
        
    rt_sigprocmask(SIG_BLOCK, [INT], NULL, 8)      = 0
    rt_sigaction(SIGINT, {0x7f8dc4ec0e50, [], SA_RESTORER, 0x7f8dc33f0920}, {0x7f8db3507f0c, ~[ILL ABRT BUS FPE KILL SEGV USR2 STOP XCPU XFSZ SYS RTMIN RT_1], SA_RESTORER|SA_SIGINFO, 0x7f8dc33f0920}, 8) = 0
    rt_sigprocmask(SIG_UNBLOCK, [INT], NULL, 8) = 0
    munmap(0x7f8dae20f000, 2178616) = 0
    munmap(0x7f8daeced000, 2129488)         = 0
    munmap(0x7f8daead9000, 2176864)         = 0
    munmap(0x7f8dae89c000, 2343352)         = 0
    munmap(0x7f8dae627000, 2574912)         = 0
    munmap(0x7f8dae423000, 2109528)         = 0
    munmap(0x7f8daeef5000, 2142192)         = 0
    munmap(0x7f8daf100000, 2125616)         = 0
    munmap(0x7f8daf307000, 2128512) = 0
    munmap(0x7f8daf50f000, 2107408) = 0
    munmap(0x7f8daf712000, 2103968) = 0
    munmap(0x7f8daf914000, 2111904) = 0
    munmap(0x7f8dafb18000, 2162656) = 0
    munmap(0x7f8dafd28000, 2140264)         = 0
    munmap(0x7f8db0911000, 2116672) = 0
    munmap(0x7f8db044f000, 2099376)            = 0
    munmap(0x7f8db0650000, 2885912)                      = 0
    munmap(0x7f8db0b16000, 2123736)                      = 0
    munmap(0x7f8db0d1d000, 2357704) = 0
    munmap(0x7f8db11ec000, 2119816) = 0
    munmap(0x7f8db13f2000, 2125296)         = 0
    munmap(0x7f8db15f9000, 2198440)         = 0
    munmap(0x7f8db467b000, 2289928)         = 0
    munmap(0x7f8db48ab000, 2232272) = 0
    munmap(0x7f8db4e50000, 2149768) = 0
    munmap(0x7f8db4acc000, 3684744) = 0
    munmap(0x7f8db5290000, 2142072) = 0
    munmap(0x7f8db505d000, 2303840)                              = 0
    munmap(0x7f8db549b000, 4278992)     = 0
    munmap(0x7f8db58b0000, 2148288)         = 0
    munmap(0x7f8db5abd000, 2131392) = 0
    munmap(0x7f8db6d48000, 2440032)         = 0
    munmap(0x7f8db6aab000, 2737840)         = 0
    munmap(0x7f8db655d000, 2165496) = 0
    munmap(0x7f8db676e000, 3394936) = 0
    munmap(0x7f8db6337000, 2250552)         = 0
    munmap(0x7f8db60e7000, 2423648)         = 0
    munmap(0x7f8db5ec9000, 2217576)         = 0
    munmap(0x7f8db5cc6000, 2106112)         = 0
    munmap(0x7f8db6f9c000, 3939304)         = 0
    munmap(0x7f8db735e000, 2268048)         = 0
    fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
    fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741826, len=510}) = 0
    fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
    access("/etc/pki/nssdb/cert9.db-journal", F_OK)                              = -1 ENOENT (No such file or directory)
    fstat(23, {st_dev=makedev(8, 3), st_ino=1047848, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=24, st_size=9216, st_atime=2010/01/12-15:18:17, st_mtime=2010/01/12-15:18:17, st_ctime=2013/08/20-09:59:34}) = 0
    lseek(23, 24, SEEK_SET) = 24
    read(23, "\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 16
    fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 0
    fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741824, len=1})                              = 0
    fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741826, len=510}) = 0
    fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
    access("/etc/pki/nssdb/cert9.db-journal", F_OK) = -1 ENOENT (No such file or directory)
    fstat(23, {st_dev=makedev(8, 3), st_ino=1047848, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=24, st_size=9216, st_atime=2010/01/12-15:18:17, st_mtime=2010/01/12-15:18:17, st_ctime=2013/08/20-09:59:34}) = 0
    lseek(23, 24, SEEK_SET)                 = 24
    read(23, "\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 16
    fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 0
    brk(0x7f8dc6191000)                     = 0x7f8dc6191000
    munmap(0x7f8db7e3e000, 2161288)         = 0
    munmap(0x7f8db7bea000, 2438600)         = 0
    munmap(0x7f8db79b8000, 2301736)         = 0
    munmap(0x7f8db7588000, 2257152)         = 0
    close(8)                                = 0
    close(7)                                = 0
    fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
    fcntl(23, F_SETLK, {type=F_RDLCK, whence=SEEK_SET, start=1073741826, len=510}) = 0
    fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=1073741824, len=1}) = 0
    access("/etc/pki/nssdb/cert9.db-journal", F_OK) = -1 ENOENT (No such file or directory)
    fstat(23, {st_dev=makedev(8, 3), st_ino=1047848, st_mode=S_IFREG|0644, st_nlink=1, st_uid=0, st_gid=0, st_blksize=4096, st_blocks=24, st_size=9216, st_atime=2010/01/12-15:18:17, st_mtime=2010/01/12-15:18:17, st_ctime=2013/08/20-09:59:34}) = 0
    lseek(23, 24, SEEK_SET) = 24
    read(23, "\0\0\0\1\0\0\0\0\0\0\0\0\0\0\0\0", 16) = 16
    fcntl(23, F_SETLK, {type=F_UNLCK, whence=SEEK_SET, start=0, len=0}) = 0
    --- SIGSEGV (Segmentation fault) @ 0 (0) ---
    chdir("/apache2/apache-dumps") = 0
    rt_sigaction(SIGSEGV, {SIG_DFL, [], SA_RESTORER|SA_INTERRUPT, 0x7f8dc3760500}, {SIG_DFL, [], SA_RESTORER|SA_RESETHAND, 0x7f8dc3760500}, 8) = 0
    kill(26317, SIGSEGV) = 0
    rt_sigreturn(0x66cd) = 140246846382624
    --- SIGSEGV (Segmentation fault) @ 0 (0) ---