Re: Segmentation fault when -x is added and variable contains nulls

[Pierre Gaston]

On Thu, Feb 6, 2014 at 3:38 PM, Chet Ramey <chet.ramey@case.edu> wrote:

> On 2/5/14 10:51 PM, Dan Jacobson wrote:
> > # su - nobody
> > No directory, logging in with HOME=/
> > $ cat /tmp/r
> > LC_CTYPE=zh_TW.UTF-8 N=$(echo 統一|iconv -t big5 -f utf-8) sh -xc ': $N'
> > $ sh /tmp/r
> > /tmp/r: line 1:  4551 Segmentation fault      LC_CTYPE=zh_TW.UTF-8
> N=$(echo 統一|iconv -t big5 -f utf-8) sh -xc ': $N'
> >
> > Something about that embedded null.
> > bash, version 4.3.0(1)-rc1 (i486-pc-linux-gnu)
>
> Probably.  How about a stack traceback from gdb?
>
> --
> ``The lyf so short, the craft so long to lerne.'' - Chaucer
>                  ``Ars longa, vita brevis'' - Hippocrates
> Chet Ramey, ITS, CWRU    chet@case.edu
> http://cnswww.cns.cwru.edu/~chet/
>
>

With bash 3.2.25(1)-release

$ LC_CTYPE=zh_TW.UTF-8 N=$(echo  統一|iconv -t big5 -f utf-8) sh -xc ': $N'
+ : $'\262\316\244@'

With bash-rc1 I can reproduce it with: bash -xc $': \262\316\244@'


Core was generated by `./bash -xc : $N'.
Program terminated with signal 11, Segmentation fault.
#0  ansic_quote (str=<value optimized out>, flags=<value optimized out>,
rlen=0x0) at strtrans.c:282
282               *r++ = c;
(gdb) bt
#0  ansic_quote (str=<value optimized out>, flags=<value optimized out>,
rlen=0x0) at strtrans.c:282
#1  0x00000000004303af in xtrace_print_word_list (list=0xa175ce8,
xtflags=<value optimized out>) at print_cmd.c:543
#2  0x0000000000436a0b in execute_simple_command (simple_command=0xa1750c8,
pipe_in=-1, pipe_out=-1, async=0, fds_to_close=0xa175128) at
execute_cmd.c:4008
#3  0x00000000004342d5 in execute_command_internal (command=0xa175088,
asynchronous=0, pipe_in=-1, pipe_out=-1, fds_to_close=0xa175128) at
execute_cmd.c:784
#4  0x0000000000475dd2 in parse_and_execute (string=<value optimized out>,
from_file=0x4b5d58 "-c", flags=<value optimized out>) at evalstring.c:359
#5  0x000000000041ec14 in run_one_command (command=0x7fffbdc94b0b ": $N")
at shell.c:1339
#6  0x000000000041fcaf in main (argc=<value optimized out>,
argv=0x7fffbdc928c8, env=0x7fffbdc928e8) at shell.c:694
(gdb) q