I'm getting this message and i can't see why.my program creates threads.
valgrind output is this:

==28643== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 37 from 2)
==28643== malloc/free: in use at exit: 13,266 bytes in 32 blocks.
==28643== malloc/free: 1,524 allocs, 1,492 frees, 89,027 bytes allocated.
==28643== For counts of detected errors, rerun with: -v
==28643== searching for pointers to 32 not-freed blocks.
==28643== checked 162,412 bytes.
==28643==
==28643== 24 bytes in 1 blocks are still reachable in loss record 1 of 6
==28643== at 0x4022AB8: malloc (vg_replace_malloc.c:207)
==28643== by 0x4022BFC: realloc (vg_replace_malloc.c:429)
==28643== by 0x80532DD: (within /bin/ls)
==28643== by 0x804C354: (within /bin/ls)
==28643== by 0x804D25A: (within /bin/ls)
==28643== by 0x804E8C7: (within /bin/ls)
==28643== by 0x407904F: (below main) (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643==
==28643==
==28643== 118 bytes in 7 blocks are still reachable in loss record 2 of 6
==28643== at 0x4022AB8: malloc (vg_replace_malloc.c:207)
==28643== by 0x8053201: (within /bin/ls)
==28643== by 0x8052536: (within /bin/ls)
==28643== by 0x804E522: (within /bin/ls)
==28643== by 0x407904F: (below main) (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643==
==28643==
==28643== 312 (72 direct, 240 indirect) bytes in 2 blocks are definitely lost in loss record 3 of 6
==28643== at 0x4022AB8: malloc (vg_replace_malloc.c:207)
==28643== by 0x41479B2: (within /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x4148208: __nss_database_lookup (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x4745FDB: ???
==28643== by 0x474711C: ???
==28643== by 0x40F4EEB: getpwuid_r (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x40F489D: getpwuid (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x80522C4: (within /bin/ls)
==28643== by 0x804AAFB: (within /bin/ls)
==28643== by 0x804BB2C: (within /bin/ls)
==28643== by 0x804E7F9: (within /bin/ls)
==28643== by 0x407904F: (below main) (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643==
==28643==
==28643== 80 bytes in 10 blocks are indirectly lost in loss record 4 of 6
==28643== at 0x4022AB8: malloc (vg_replace_malloc.c:207)
==28643== by 0x414758B: __nss_lookup_function (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x4745FFB: ???
==28643== by 0x474711C: ???
==28643== by 0x40F4EEB: getpwuid_r (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x40F489D: getpwuid (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x80522C4: (within /bin/ls)
==28643== by 0x804AAFB: (within /bin/ls)
==28643== by 0x804BB2C: (within /bin/ls)
==28643== by 0x804E7F9: (within /bin/ls)
==28643== by 0x407904F: (below main) (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643==
==28643==
==28643== 160 bytes in 10 blocks are indirectly lost in loss record 5 of 6
==28643== at 0x4022AB8: malloc (vg_replace_malloc.c:207)
==28643== by 0x4134D0B: tsearch (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x414754D: __nss_lookup_function (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x4745FFB: ???
==28643== by 0x474711C: ???
==28643== by 0x40F4EEB: getpwuid_r (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x40F489D: getpwuid (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643== by 0x80522C4: (within /bin/ls)
==28643== by 0x804AAFB: (within /bin/ls)
==28643== by 0x804BB2C: (within /bin/ls)
==28643== by 0x804E7F9: (within /bin/ls)
==28643== by 0x407904F: (below main) (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643==
==28643==
==28643== 12,812 bytes in 2 blocks are still reachable in loss record 6 of 6
==28643== at 0x4022AB8: malloc (vg_replace_malloc.c:207)
==28643== by 0x8053326: (within /bin/ls)
==28643== by 0x804E7A0: (within /bin/ls)
==28643== by 0x407904F: (below main) (in /lib/tls/i686/cmov/libc-2.6.1.so)
==28643==
==28643== LEAK SUMMARY:
==28643== definitely lost: 72 bytes in 2 blocks.
==28643== indirectly lost: 240 bytes in 20 blocks.
==28643== possibly lost: 0 bytes in 0 blocks.
==28643== still reachable: 12,954 bytes in 10 blocks.
==28643== suppressed: 0 bytes in 0 blocks.

We can't see why either. If you provide a snippet of code, it may help. Are you doing something like this in your code?

No nothing like that. The double free error was for this:

templist = *ptraddr;
*ptraddr = (*ptraddr)->next;
free(templist);

but now it's solved. Now i get a malloc corruption(fast) for this:

while (*ptraddr != NULL)
ptraddr = &((*ptraddr)->next);
*ptraddr = malloc(sizeof(struct listnode));
(*ptraddr)->a = i;
(*ptraddr)->b = j;
(*ptraddr)->next = NULL;