Hi,
I am running my C program on ubuntu.
It happens rarely though, may be once in 100 times. Any help will be appreciated.

Ubuntu details, sample code snippet, gdb stack provided below.

Regards,
-Rajnish

ubuntu details: -
$ cat /etc/os-release
PRETTY_NAME="Ubuntu 22.04.2 LTS"
NAME="Ubuntu"
VERSION_ID="22.04"
VERSION="22.04.2 LTS (Jammy Jellyfish)"
VERSION_CODENAME=jammy
ID=ubuntu
ID_LIKE=debian
HOME_URL="https://www.ubuntu.com/"
SUPPORT_URL="https://help.ubuntu.com/"
BUG_REPORT_URL="https://bugs.launchpad.net/ubuntu/"
PRIVACY_POLICY_URL="https://www.ubuntu.com/legal/terms-and-policies/privacy-policy"
UBUNTU_CODENAME=jammy

C code snippet that crashes once in 100 times (approx) -
void *connectWithFscsv(void *arg)
{ char *start_time = (char*)calloc(128, sizeof(char));
getCurrTime(&start_time);
pthread_t threadId = pthread_self();
struct ThreadArgs *args = (struct ThreadArgs *)arg;
char *ip = args->ip;
char *tlsver = args->tlsver;
struct json_object *json_extn = args->json_obj;

printf("%s: %s %s thread started with id: %lu started at: %s\n", __func__, ip, tlsver, threadId, start_time);

Callee :-
if (pthread_create(createThreadId, NULL, connectWithFscsv, (void *)(targ)) != 0)
{
printf("%s: threadId: %lu error: failed to create fscsv thread for: %s %s\n", __func__, threadId, targ->ip, targ->tlsver);
json_object_object_add(json_extn, "error", json_object_new_string("threading error - FSCSV thread creation failed"));
return 0;
}

gdb stacktrace :-
Program terminated with signal SIGABRT, Aborted.
#0 __pthread_kill_implementation (no_tid=0, signo=6, threadid=140246469416512) at ./nptl/pthread_kill.c:44
44 ./nptl/pthread_kill.c: No such file or directory.
[Current thread is 1 (Thread 0x7f8dacfd9640 (LWP 464))]
(gdb) bt
#0 __pthread_kill_implementation (no_tid=0, signo=6, threadid=140246469416512) at ./nptl/pthread_kill.c:44
#1 __pthread_kill_internal (signo=6, threadid=140246469416512) at ./nptl/pthread_kill.c:78
#2 __GI___pthread_kill (threadid=140246469416512, signo=signo@entry=6) at ./nptl/pthread_kill.c:89
#3 0x00007f8db4846476 in __GI_raise (sig=sig@entry=6) at ../sysdeps/posix/raise.c:26
#4 0x00007f8db482c7f3 in __GI_abort () at ./stdlib/abort.c:79
#5 0x00007f8db488d6f6 in __libc_message (action=action@entry=do_abort, fmt=fmt@entry=0x7f8db49dfb8c "%s\n") at ../sysdeps/posix/libc_fatal.c:155
#6 0x00007f8db48a4d7c in malloc_printerr (str=str@entry=0x7f8db49e27b0 "double free or corruption (out)") at ./malloc/malloc.c:5664
#7 0x00007f8db48a6ef0 in _int_free (av=0x7f8db4a1dc80 <main_arena>, p=0x7f8d98029d70, have_lock=<optimized out>) at ./malloc/malloc.c:4588
#8 0x00007f8db48a972d in __GI___libc_free (mem=<optimized out>) at ./malloc/malloc.c:3391
#9 tcache_thread_shutdown () at ./malloc/malloc.c:3227
#10 __malloc_arena_thread_freeres () at ./malloc/arena.c:1003
#11 0x00007f8db48ac24a in __libc_thread_freeres () at ./malloc/thread-freeres.c:44
#12 0x00007f8db48989cf in start_thread (arg=<optimized out>) at ./nptl/pthread_create.c:456
#13 0x00007f8db4929bb4 in clone () at ../sysdeps/unix/sysv/linux/x86_64/clone.S:100

Am 17.09.23 um 08:37 schrieb Rajnish Kumar:
> I am running my C program on ubuntu.
> It happens rarely though, may be once in 100 times. Any help will be appreciated.
>
> Ubuntu details, sample code snippet, gdb stack provided below.

This ist most like a corrupted heap.
Somewhere in you program is a buffer overflow or some memory access
after free.

If it happens to work mostly a race condition is likely involved too.

Marcel