[lttng-dev] [PATCH/babeltrace] Fix babeltrace-log crash

[Mathieu Desnoyers]

* Hui Zhu (teawater at gmail.com) wrote:
> Hi,
> 
> Got a crash with babeltrace-log.
> 
> #0  0x00007ffff744504c in free () from /lib/x86_64-linux-gnu/libc.so.6
> #1  0x00007ffff7ba6fc9 in munmap_align (mma=0x7ffff7ffe620) at
> ../../../babeltrace/include/babeltrace/mmap-align.h:78
> #2  0x00007ffff7ba82db in ctf_packet_seek (stream_pos=0x7fffffffde60,
> index=0, whence=0)
>     at ../../../babeltrace/formats/ctf/ctf.c:623
> #3  0x00007ffff7ba8141 in ctf_init_pos (pos=0x7fffffffde60, fd=8, open_flags=2)
>     at ../../../babeltrace/formats/ctf/ctf.c:576
> #4  0x0000000000401146 in trace_text (output=8, input=0x7ffff7779340
> <_IO_2_1_stdin_>)
>     at ../../babeltrace/converter/babeltrace-log.c:233
> #5  main (argc=<optimized out>, argv=<optimized out>) at
> ../../babeltrace/converter/babeltrace-log.c:342
> 
> This issue because pos is used before it init.  This patch init it in
> function ctf_init_pos.

Merged as:


commit 36741bea2b53007c29ac0391ee9086722e00653a
Author: Hui Zhu <teawater at gmail.com>
Date:   Fri Sep 7 08:36:28 2012 -0400

    Fix babeltrace-log uninitialized memory
    
    Got a crash with babeltrace-log.
    
    ../../../babeltrace/include/babeltrace/mmap-align.h:78
    index=0, whence=0)
        at ../../../babeltrace/formats/ctf/ctf.c:623
        at ../../../babeltrace/formats/ctf/ctf.c:576
    <_IO_2_1_stdin_>)
        at ../../babeltrace/converter/babeltrace-log.c:233
    ../../babeltrace/converter/babeltrace-log.c:342
    
    This issue because pos is used before it init.  This patch init it in
    function ctf_init_pos.
    
    Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers at efficios.com>

Thanks!

Mathieu


> 
> Thanks,
> Hui
> 
> --- a/formats/ctf/ctf.c
> +++ b/formats/ctf/ctf.c
> @@ -550,6 +550,7 @@ error:
> 
>  void ctf_init_pos(struct ctf_stream_pos *pos, int fd, int open_flags)
>  {
> +	memset(pos, 0, sizeof(*pos));
>  	pos->fd = fd;
>  	if (fd >= 0) {
>  		pos->packet_cycles_index = g_array_new(FALSE, TRUE,
> 
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-- 
Mathieu Desnoyers
Operating System Efficiency R&D Consultant
EfficiOS Inc.
http://www.efficios.com