.
Thread 1 (Thread 0x7fe37ea7f740 (LWP 21173)):
#0  0x00007fe37ca3acc9 in __GI_raise (sig=sig@entry=6) at ../nptl/sysdeps/unix/sysv/linux/raise.c:56
        resultvar = 0
        pid = 21173
        selftid = 21173
#1  0x00007fe37ca3e0d8 in __GI_abort () at abort.c:89
        save_stage = 2
        act = {__sigaction_handler = {sa_handler = 0x11, sa_sigaction = 0x11}, sa_mask = {__val = {0, 140737384262256, 140615057325420, 140615059481032, 140615059482464, 140615059469504, 140615059470760, 140615059267584, 140615059268864, 140615059270128, 140615059263488, 140615059264752, 140615059266008, 140615059259392, 140615059260656, 140615059261912}}, sa_flags = 2124951552, sa_restorer = 0x7fe37eab99f8 <_rtld_global+2456>}
        sigs = {__val = {32, 0 <repeats 15 times>}}
#2  0x00007fe37ca77f24 in __libc_message (do_abort=do_abort@entry=1, fmt=fmt@entry=0x7fe37cb866c8 "*** Error in `%s': %s: 0x%s ***\n") at ../sysdeps/posix/libc_fatal.c:175
        ap = {{gp_offset = 40, fp_offset = 0, overflow_arg_area = 0x7ffff9cbad70, reg_save_area = 0x7ffff9cbad00}}
        fd = 2
        on_2 = <optimized out>
        list = <optimized out>
        nlist = <optimized out>
        cp = <optimized out>
        written = <optimized out>
#3  0x00007fe37ca841fe in malloc_printerr (ptr=<optimized out>, str=0x7fe37cb827b9 "free(): invalid pointer", action=1) at malloc.c:4996
        buf = "00007fe35816daf8"
        cp = <optimized out>
#4  _int_free (av=<optimized out>, p=<optimized out>, have_lock=0) at malloc.c:3840
        size = <optimized out>
        fb = <optimized out>
        nextchunk = <optimized out>
        nextsize = <optimized out>
        nextinuse = <optimized out>
        prevsize = <optimized out>
        bck = <optimized out>
        fwd = <optimized out>
        errstr = <optimized out>
        locked = <optimized out>
#5  0x000000000068efcb in php_module_shutdown () at /build/buildd/php5-5.5.9+dfsg/main/main.c:2384
No locals.
#6  0x0000000000461cc6 in main (argc=7, argv=0x1898360) at /build/buildd/php5-5.5.9+dfsg/sapi/cli/php_cli.c:1393
        c = <optimized out>
        exit_status = 0
        module_started = 1
        sapi_started = 1
        php_optarg = 0x1898490 "print ini_get(\"session.gc_maxlifetime\");"
        php_optind = 7
        use_extended_info = 0
        ini_path_override = 0x18984d0 "0\324\236\001"
        ini_entries = 0x1898710 "\270\067\334|\343\177"
        ini_entries_len = 25
        ini_ignore = 0
        sapi_module = <optimized out>