| Summary: | LEB decoding error | ||
|---|---|---|---|
| Product: | binutils | Reporter: | laurent.stacul |
| Component: | binutils | Assignee: | Nick Clifton <nickc> |
| Status: | RESOLVED FIXED | ||
| Severity: | normal | CC: | nickc, pinskia, romain.geissler |
| Priority: | P2 | ||
| Version: | 2.34 | ||
| Target Milestone: | --- | ||
| See Also: | https://gcc.gnu.org/bugzilla/show_bug.cgi?id=104238 | ||
| Host: | Target: | ||
| Build: | Last reconfirmed: | 2020-08-28 00:00:00 | |
The master branch has been updated by Nick Clifton <nickc@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=08d7da7dc9e130cbaf072c2588e1b392c2d7503e commit 08d7da7dc9e130cbaf072c2588e1b392c2d7503e Author: Nick Clifton <nickc@redhat.com> Date: Fri Aug 28 16:04:49 2020 +0100 Fix a bogus error message from the DWARF LEB129 decoder when trying to read a signed LEB128 value containing the largest possible signed negative integer value. PR 26548 * dwarf.c (read_leb128): When checking for overflow of a signed read, use a signed shift. Hi Laurent, Thanks for reporting this problem. I have checked in a small patch which I believe will resolve the problem. Cheers Nick (In reply to Nick Clifton from comment #2) > Hi Laurent, > > Thanks for reporting this problem. I have checked in a small patch > which I believe will resolve the problem. > > Cheers > Nick Thanks very much for such a rapid patch ! Regards, Laurent Hi Nick, Thanks for this patch. Do you think we should also backport it in the release branch 2.35 ? Cheers, Romain The binutils-2_35-branch branch has been updated by Nick Clifton <nickc@sourceware.org>: https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=1f1ded87c9250deb986067eac6d53663f3f69e09 commit 1f1ded87c9250deb986067eac6d53663f3f69e09 Author: Nick Clifton <nickc@redhat.com> Date: Thu Sep 3 15:52:53 2020 +0100 Import a patch from mainline to fix a spurious overflow error when decoding negative LEB128 values. PR 26548 * dwarf.c (read_leb128): When checking for overflow of a signed read, use a signed shift. (In reply to Romain Geissler from comment #4) > Thanks for this patch. Do you think we should also backport it in the > release branch 2.35 ? Yup. Done. :-) |
Let's consider the following program: #include <limits> #include <iostream> int main(int argc, const char *argv[]) { std::cout << std::numeric_limits<long>::min() <<std::endl; return 0; } This program works as expected. If I compile it with the debug symbols (g++ -g), and try to retrieve the debug info with readelf: > readelf --debug-dump=info a.out I have the following behaviour: - version <= 2.33: no error - version == 2.34: Error: LEB value too large - version == 2.35: Error: /workdir/src/binutils-2.35.0/binutils/dwarf.c:2231: read LEB value is too large to store in destination variable It fails when decoding the DW_TAG_variable describing '_ZN9__gnu_cxx24__numeric_traits_integerIlE5__minE'. Laurent System information: OS: Ubuntu 20.04 LTS g++: (Ubuntu 9.3.0-10ubuntu2) 9.3.0 GNU readelf (GNU Binutils for Ubuntu) 2.34 (I also reproduce the described problem with other combinations of the binutils (up to 2.35) and gcc (up to 11 experimental)).