Bug 87681

Summary: Recursive Stack Overflow within function d_name, d_encoding, and d_local_name in cp-demangle.c, as demonstrated by "nm -C"
Product: gcc Reporter: N1705695H
Component: demanglerAssignee: Not yet assigned to anyone <unassigned>
Status: RESOLVED FIXED    
Severity: normal CC: nickc
Priority: P3    
Version: unknown   
Target Milestone: ---   
Host: Target:
Build: Known to work:
Known to fail: Last reconfirmed:
Attachments: POC

Description N1705695H 2018-10-22 06:48:08 UTC 
Created attachment 44876 [details]
POC

An issue was discovered in cp-demangle.c in GNU libiberty, as distributed in GNU Binutils 2.31. Stack Exhaustion occurs in the C++ demangling functions provided by libiberty, and there is a stack consumption problem caused by recursive stack frames: d_name, d_encoding, and d_local_name.

Please use the "./nm -C $POC" to reproduce the bug. This result can trigger different Stack Overflow, you can try several times.


To reproduce this bug. You need to build bintuils-2.31 with ASAN. Here is the compile Option. Another approach is to set the break Point and debug it, then see the back trace.

> CC=clang LDFLAGS="-ldl" CFLAGS="-DFORTIFY_SOURCE=2 -fstack-protector-all -fsanitize=undefined,address -fno-omit-frame-pointer -g -O0 -Wno-error" ./configure --disable-shared --disable-gdb --disable-libdecnumber --disable-sim

The ASAN dumps the stack trace as follows:

> AddressSanitizer:DEADLYSIGNAL
> =================================================================
> ==18186==ERROR: AddressSanitizer: stack-overflow on address 0x7ffeca00cf98 (pc 0x0000008e8b7a bp 0x7ffeca00d080 sp 0x7ffeca00cfa0 T0)
>     #0 0x8e8b79 in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:28
>     #1 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #2 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     #3 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>     #4 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #5 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     #6 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>     #7 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #8 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     #9 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>     #10 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #11 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     #12 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>     #13 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #14 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     #15 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>     #16 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #17 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     ...
>     #246 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>     #247 0x8dcc1d in d_encoding binutils-2.31/libiberty/./cp-demangle.c:1312:12
>     #248 0x8ea4d3 in d_local_name binutils-2.31/libiberty/./cp-demangle.c:3590:14
>     #249 0x8e8b7e in d_name binutils-2.31/libiberty/./cp-demangle.c:1411:14
>  SUMMARY: AddressSanitizer: stack-overflow binutils-2.31/libiberty/./cp-demangle.c:1411:28 in d_name
>  ==19901==ABORTING
>  00000000 AAborted
Comment 1 Nick Clifton 2018-12-07 10:34:02 UTC 
Author: nickc
Date: Fri Dec  7 10:33:30 2018
New Revision: 266886

URL: https://gcc.gnu.org/viewcvs?rev=266886&root=gcc&view=rev
Log:
Add a recursion limit to libiberty's demangling code.  The limit is enabled by default, but can be disabled via a new demangling option.

include	* demangle.h (DMGL_NO_RECURSE_LIMIT): Define.
        (DEMANGLE_RECURSION_LIMIT): Define

	PR 87681
	PR 87675
	PR 87636
	PR 87350
	PR 87335
libiberty * cp-demangle.h (struct d_info): Add recursion_level field.
	* cp-demangle.c (d_function_type): Add recursion counter.
	If the recursion limit is reached and the check is not disabled,
	then return with a failure result.
	(cplus_demangle_init_info): Initialise the recursion_level field.
        (d_demangle_callback): If the recursion limit is enabled, check
	for a mangled string that is so long that there is not enough
	stack space for the local arrays.
        * cplus-dem.c (struct work): Add recursion_level field.
	(squangle_mop_up): Set the numb and numk fields to zero.
	(work_stuff_copy_to_from): Handle the case where a btypevec or 
	ktypevec field is NULL.
	(demangle_nested_args): Add recursion counter.  If
	the recursion limit is not disabled and reached, return with a
	failure result.

Modified:
    trunk/include/ChangeLog
    trunk/include/demangle.h
    trunk/libiberty/ChangeLog
    trunk/libiberty/cp-demangle.c
    trunk/libiberty/cp-demangle.h
    trunk/libiberty/cplus-dem.c
Comment 2 Nick Clifton 2018-12-07 12:52:53 UTC 
Fixed by commit 266886.