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* [Bug c++/105115] New: `demangle_const` causes infinite recursion and stack overflow
@ 2022-03-31 0:32 ronghua at iu dot edu
2022-05-17 18:22 ` [Bug c++/105115] " ronghua at iu dot edu
2022-05-17 20:44 ` ronghua at iu dot edu
0 siblings, 2 replies; 3+ messages in thread
From: ronghua at iu dot edu @ 2022-03-31 0:32 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105115
Bug ID: 105115
Summary: `demangle_const` causes infinite recursion and stack
overflow
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
Assignee: unassigned at gcc dot gnu.org
Reporter: ronghua at iu dot edu
Target Milestone: ---
Created attachment 52721
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=52721&action=edit
output.txt is output of ASAN, and inf-recursion is the poc
At commit `b8e92c571baed4e794bd62b7bf417fa8bbaf5c95` of `binutils-gdb`, the
given poc can produces crash on `cxxfilt`:
build2/binutils/cxxfilt < inf-recursion
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/105115] `demangle_const` causes infinite recursion and stack overflow
2022-03-31 0:32 [Bug c++/105115] New: `demangle_const` causes infinite recursion and stack overflow ronghua at iu dot edu
@ 2022-05-17 18:22 ` ronghua at iu dot edu
2022-05-17 20:44 ` ronghua at iu dot edu
1 sibling, 0 replies; 3+ messages in thread
From: ronghua at iu dot edu @ 2022-05-17 18:22 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105115
--- Comment #1 from ronghua at iu dot edu ---
Hello, It's already more than one month since my post, and the bug still exists
at latest commit (e.i. e84412c6a3c3eed1a4eca5fe18f329bfa7efea40), so I would
like to know why it is still `UNCONFIRMED`.
Thanks.
^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug c++/105115] `demangle_const` causes infinite recursion and stack overflow
2022-03-31 0:32 [Bug c++/105115] New: `demangle_const` causes infinite recursion and stack overflow ronghua at iu dot edu
2022-05-17 18:22 ` [Bug c++/105115] " ronghua at iu dot edu
@ 2022-05-17 20:44 ` ronghua at iu dot edu
1 sibling, 0 replies; 3+ messages in thread
From: ronghua at iu dot edu @ 2022-05-17 20:44 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=105115
--- Comment #2 from ronghua at iu dot edu ---
The simplified PoC:
$ echo _RYAbB2_ | ./binutils/cxxfilt
Segmentation fault
Root Cause Analysis:
1. In `rust_demangle_callback`, "_R" at beginning causes `rdm.version ==
0`[1][2], so `demangle_path` in the else-branch is called[3] with `rdm.sym ==
"YAbB2_"`, with `rdm.next` field initialized to 0.
2. Next char 'Y' causes `demangle_type` to be called[4] in a switch-case
branch, with `rdm.next == 1`.
3. Next char 'A' causes `demangle_type` to be called first[5] to consume char
'b', then `demangle_const` is called[6] with `rdm.next == 3`.
4. Next char 'B' is consumed[7], and "2_" is parsed as `integer_62`[8] to be
value 3, and this vlaue is assigned to `rdm.next`, then `demangle_const` is
called recursively[9]. However, currently the situation is `rdm.next == 3`
again, which is exactly same as last call to `demangle_const`, and this causes
infinite recursion.
[1]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L1356
[2]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L1362
[3]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L1453
[4]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L759
[5]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L934
[6]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L938
[7]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L1151
[8]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L1153
[9]
https://github.com/bminor/binutils-gdb/blob/626d0e40e55c35a4f143b70def498734e8ed3c2a/libiberty/rust-demangle.c#L1158
Possible Fix:
The infinite recursion check added in this
[commit](https://github.com/bminor/binutils-gdb/commit/f10f8617a302f45dae721eae0cd659911f03d864)
should also be applied to `demangle_const`
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-05-17 20:44 UTC | newest]
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2022-03-31 0:32 [Bug c++/105115] New: `demangle_const` causes infinite recursion and stack overflow ronghua at iu dot edu
2022-05-17 18:22 ` [Bug c++/105115] " ronghua at iu dot edu
2022-05-17 20:44 ` ronghua at iu dot edu
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