* RFA: Another Rust demangler recursion limit
@ 2022-07-01 15:12 Nick Clifton
2022-07-01 16:53 ` Jeff Law
0 siblings, 1 reply; 3+ messages in thread
From: Nick Clifton @ 2022-07-01 15:12 UTC (permalink / raw)
To: jeffreyalaw; +Cc: gcc-patches
[-- Attachment #1: Type: text/plain, Size: 606 bytes --]
Hi Jeff,
[I am sending this to your directly since you seem to be the only one
reviewing these patches].
Hot on the heels of the fix for the recursion problem in demangle_const
a binutils user has filed another PoC that exposes a problem in
demangle_path_maybe_open_generics():
https://sourceware.org/bugzilla/show_bug.cgi?id=29312#c1
I have redirected them to file a bug report with the gcc system, but in
the hopes of getting a fix in quickly I am also attaching a patch
here. It just does the obvious thing of adding a recursion counter
and limit to the function.
Cheers
Nick
[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #2: rust-demangle.c.patch --]
[-- Type: text/x-patch, Size: 911 bytes --]
diff --git a/libiberty/rust-demangle.c b/libiberty/rust-demangle.c
index 36afcfae278..d6daf23af27 100644
--- a/libiberty/rust-demangle.c
+++ b/libiberty/rust-demangle.c
@@ -1082,6 +1082,18 @@ demangle_path_maybe_open_generics (struct rust_demangler *rdm)
if (rdm->errored)
return open;
+ if (rdm->recursion != RUST_NO_RECURSION_LIMIT)
+ {
+ ++ rdm->recursion;
+ if (rdm->recursion > RUST_MAX_RECURSION_COUNT)
+ {
+ /* FIXME: There ought to be a way to report
+ that the recursion limit has been reached. */
+ rdm->errored = 1;
+ goto end_of_func;
+ }
+ }
+
if (eat (rdm, 'B'))
{
backref = parse_integer_62 (rdm);
@@ -1107,6 +1119,11 @@ demangle_path_maybe_open_generics (struct rust_demangler *rdm)
}
else
demangle_path (rdm, 0);
+
+ end_of_func:
+ if (rdm->recursion != RUST_NO_RECURSION_LIMIT)
+ -- rdm->recursion;
+
return open;
}
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: RFA: Another Rust demangler recursion limit
2022-07-01 15:12 RFA: Another Rust demangler recursion limit Nick Clifton
@ 2022-07-01 16:53 ` Jeff Law
2022-07-04 10:08 ` Nick Clifton
0 siblings, 1 reply; 3+ messages in thread
From: Jeff Law @ 2022-07-01 16:53 UTC (permalink / raw)
To: Nick Clifton; +Cc: gcc-patches
On 7/1/2022 9:12 AM, Nick Clifton wrote:
> Hi Jeff,
>
> [I am sending this to your directly since you seem to be the only one
> reviewing these patches].
>
> Hot on the heels of the fix for the recursion problem in demangle_const
> a binutils user has filed another PoC that exposes a problem in
> demangle_path_maybe_open_generics():
>
> https://sourceware.org/bugzilla/show_bug.cgi?id=29312#c1
>
> I have redirected them to file a bug report with the gcc system, but in
> the hopes of getting a fix in quickly I am also attaching a patch
> here. It just does the obvious thing of adding a recursion counter
> and limit to the function.
OK. And yes, I wish someone else was looking at this stuff. Rust isn't
really on my radar right now...
jeff
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: RFA: Another Rust demangler recursion limit
2022-07-01 16:53 ` Jeff Law
@ 2022-07-04 10:08 ` Nick Clifton
0 siblings, 0 replies; 3+ messages in thread
From: Nick Clifton @ 2022-07-04 10:08 UTC (permalink / raw)
To: Jeff Law; +Cc: gcc-patches
Hi Jeff,
> OK.
Thanks.
> And yes, I wish someone else was looking at this stuff. Rust isn't really on my radar right now...
I have been toying with the idea of putting myself forward as a maintainer
for the libiberty sources. I just wish that I had more free time...
Cheers
Nick
^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2022-07-04 10:08 UTC | newest]
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2022-07-01 15:12 RFA: Another Rust demangler recursion limit Nick Clifton
2022-07-01 16:53 ` Jeff Law
2022-07-04 10:08 ` Nick Clifton
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