syslog crashes with heap corruption in malloc.

[Gopinathan]

Hi,

The syslog function in my program  is crashing.  From the stack trace I
found that, the malloc function is causing heap correption in between
the syslog calls.  Iam using redhat6.1 with glibc2.1.x.i386.rpm.

To narrow down the problem, I have added some more syslog messages, that

time the application is not crashing.  So it is very clear that syslog
function in turn uses malloc (actually syslog calls vsyslog and vsyslog
calls malloc) and because of some reason it is corrupting the heap and
it crashes. Iam not using any signals in my program.  But Iam using
callback functions.  More informaiton, but I think this is nothing to do
with this bug, at the time of crash, the sysfs is almost 100% full (few
byets are left).  If I free the sysfs, it is not crashing.  What I
understood while searching google is this crash is because of heap
corruption.


This is my stack trace,

(gdb) bt
#0  0x258d3ea8 in malloc () from /lib/libc.so.6
#1  0x258d35ce in malloc () from /lib/libc.so.6
#2  0x258ce15c in open_memstream () from /lib/libc.so.6
#3  0x25929360 in vsyslog () from /lib/libc.so.6
#4  0x259292bf in syslog () from /lib/libc.so.6
:
:
:

I also checked with  MALLOC_CHECK_ environment variable It didnt helped
me.  Iam getting really bugged of with this bug.

It will be a very big relief, if somebody could help me out on this.

Thanks in advance
Gopinathan N