Re: [Bug-wget] wget 1.17 segfaults under openSUSE 13.1 (x86_64; glibc 2.18)

[Darshit Shah]

This looks similar to another segfault I've seen. I'm not sure since when it exists in the code, but I did come across one recently. That case was caused when --trust-server-names -N and --content-disposition were all provided to Wget. A wrong logic condition causes Wget to work on output_filename = NULL which eventually resents in a segfault. I'm assuming the case you've provided is very similar to what I've seen. I was using Clang when I saw this issue. Unfortunately, I'm currently swamped with other work and am unable to look more deeply into this. The stack trace provided does match my explanation above, so we should be able to track it down and fix it. Some interplay of multiple options is causing this bug, though I can't explain why it works with one GCC version and not with another. The way I see it, it was a logic bug in the code.

Unfortunately, On 11/20, Schleusener, Jens wrote:

Hi,



I could reduce the problem to this usage case:

wget -N --content-disposition http://ftp.gnu.org/gnu/wget/

while the usage of only "-N" or "--content-disposition" let wget work.



Program terminated with signal SIGSEGV, Segmentation fault.
#0  0x00007f5b0899d42a in strlen () from /lib64/libc.so.6
(gdb) bt
#0  0x00007f5b0899d42a in strlen () from /lib64/libc.so.6
#1  0x0000000000420cdf in set_file_timestamp ()
#2  0x00000000004241e0 in http_loop ()
#3  0x0000000000433619 in retrieve_url ()
#4  0x000000000042c64b in main ()

The used gcc version is
4.8.1
and a "rpm -qf /lib64/libc.so.6" issues
glibc-2.18-4.38.1.x86_64


4.8.5
and a "rpm -qf /lib64/libc.so.6" issues
glibc-2.19-17.4.x86_64

Regards

Jens

under some conditions I get with a self-compiled wget 1.17 binary on a 64-bit openSUSE 13.1 Linux system a segmentation fault (but the self-compiled wget 1.16.3 works correctly). Sorry, I am not a C expert but nevertheless I tried to use gdb on the resulting core dump as best I could with the following result: On a newer openSUSE Leap 42.1 Linux system the "identically" compiled wget doesn't segfault and works ok. On that system the gcc version is

--
Thanking You,
Darshit Shah

signature.asc
Description: PGP signature