Re: Patch bash42-005 causes SIGSEGV

[Evangelos Foutras]

On 01/03/11 15:36, Evangelos Foutras wrote:
> Configuration Information [Automatically generated, do not change]:
> Machine: x86_64
> OS: linux-gnu
> Compiler: gcc
> Compilation CFLAGS:  -DPROGRAM='bash' -DCONF_HOSTTYPE='x86_64' 
> -DCONF_OSTYPE='linux-gnu' -DCONF_MACHTYPE='x86_64-unknown-linux-gnu' 
> -DCONF_VENDOR='unknown' -DLOCALEDIR='/usr/share/locale' -DPACKAGE='bash' 
> -DSHELL -DHAVE_CONFIG_H   -I.  -I. -I./include -I./lib   -march=x86-64 
> -mtune=generic -O2 -pipe 
> -DDEFAULT_PATH_VALUE='/usr/local/bin:/usr/bin:/bin:/usr/local/sbin:/usr/sbin:/sbin'
>  -DSTANDARD_UTILS_PATH='/usr/bin:/bin:/usr/sbin:/sbin' 
> -DSYS_BASHRC='/etc/bash.bashrc' -DSYS_BASH_LOGOUT='/etc/bash.bash_logout'
> uname output: Linux foutbox 2.6.37-ARCH #1 SMP PREEMPT Fri Feb 18 18:32:16 
> CET 2011 x86_64 AMD Phenom(tm) II X6 1090T Processor AuthenticAMD GNU/Linux
> Machine Type: x86_64-unknown-linux-gnu
> 
> Bash Version: 4.2
> Patch Level: 5
> Release Status: release
> 
> Description:
>       It appears that the chkexport function introduced in this patch level
>       is prone to a segmentation fault.
> 
> Repeat-By:
>       A simple `bash -c 'unset TZ'` is enough to trigger the segmentation
>       fault on my system.
> 
> Fix:
>       Maybe check the value returned by find_variable in chkexport to ensure
>       it's not NULL? I noticed this is done in other places where
>       find_variable is used, so I think it makes sense to do it here too.

I'm also attaching the backtrace I got from gdb.

gdb.txt
Description: Text document