[Bug demangler/98916] New: stack overflow in cxxfilt, str_buf_reserve, rust-demangle.c:1432

[featherrain26 at gmail dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=98916

            Bug ID: 98916
           Summary: stack overflow in cxxfilt, str_buf_reserve,
                    rust-demangle.c:1432
           Product: gcc
           Version: 11.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: demangler
          Assignee: unassigned at gcc dot gnu.org
          Reporter: featherrain26 at gmail dot com
  Target Milestone: ---

Created attachment 50107
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=50107&action=edit
POC

Hi, there.

There is a stack overflow in the newest version(2eda57ef) of cxxfilt,
rust-demangle.c:1432 related to path demangling, which directly causes a
segmentation fault.

System information:
Description:    Ubuntu 16.04.6 LTS
Release:        16.04
Codename:       xenial
gcc version:    5.4 

To reproduce, the compile flag is:
CFLAGS="-g -O0 -fsanitize=address" ./configure;make

then run
cxxfilt < poc

Here is the trace reported by ASAN:
==6400==ERROR: AddressSanitizer: stack-overflow on address 0x7ffedc582fe8 (pc
0x000000969e78 bp 0x7ffedcd81750 sp 0x7ffedc582fe8 T0)
     #0 0x969e77 in str_buf_reserve ../../libiberty/rust-demangle.c:1432
     #1 0x969e77 in str_buf_append ../../libiberty/rust-demangle.c:1486
     #2 0x969e77 in str_buf_demangle_callback
../../libiberty/rust-demangle.c:1497
     #3 0x7ffedcd8174f  (<unknown module>)

 SUMMARY: AddressSanitizer: stack-overflow ../../libiberty/rust-demangle.c:1432
str_buf_reserve
 ==6400==ABORTING