Subject: Re: bug#34141: Stackoverflow triggered at lib/regexec.c:1948

From: Assaf Gordon <[email-masked]>
Date: Sun, 20 Jan 2019 02:20:57 -0700

(forwarding to gnulib)

Hello,

Hongxu Chen reported a stack-overflow in regexec.
I suspect it is the same as the one reported here:
   https://lists.gnu.org/r/bug-gnulib/2018-09/msg00066.html

But just in case, the full report is below.

regards,
  - assaf

On 2019-01-19 10:58 p.m., Hongxu Chen wrote:
> Hi,
> 
>      Latest sed (4.7.4-f8503-dirty; and prior to this, e.g. 4.4) may trigger
> a stack overflow error by executing the following command.
> 
>      echo 0 | ./sed '/\(\)\(\1\(\)\1\(\)\)*/c0'    # equivalently sed -f
> c01.sed c01.in
> 
>      ASan reports like this:
> AddressSanitizer:DEADLYSIGNAL
> 
> 
> 
> =================================================================
> 
> 
> 
> ==26879==ERROR: AddressSanitizer: stack-overflow on address 0x7ffea609bff8
> (pc 0x0000005b0b76 bp 0x7ffea609c090 sp 0x7ffea609bf20 T0)
> 
> 
>      #0 0x5b0b75 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1912:18
> 
> 
>      #1 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #2 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #3 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #4 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #5 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #6 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #7 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> ...
>      #247 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #248 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
>      #249 0x5b0ed3 in check_dst_limits_calc_pos_1
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1948:7
> 
> 
> 
> 
> 
> 
> SUMMARY: AddressSanitizer: stack-overflow
> /home/hongxu/FOT/sed-O0/./lib/regexec.c:1912:18 in
> check_dst_limits_calc_pos_1
> 
> ==26879==ABORTING
> 
> Best Regards,
> Hongxu
>