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| author | Yao Qi <yao.qi@linaro.org> | 2016-08-15 12:28:56 +0100 |
|---|---|---|
| committer | Yao Qi <yao.qi@linaro.org> | 2016-08-15 12:28:56 +0100 |
| commit | b31f9478185764487b1dcfb2803ed9c399c40ed1 (patch) | |
| tree | c389f702d1401602c7df7e9e73ed4c5d762a7755 /gdb/location.c | |
| parent | b69fc9d9f3b68420f7c2b5c57167a1f5c8fac279 (diff) | |
| download | gdb-b31f9478185764487b1dcfb2803ed9c399c40ed1.zip gdb-b31f9478185764487b1dcfb2803ed9c399c40ed1.tar.gz gdb-b31f9478185764487b1dcfb2803ed9c399c40ed1.tar.bz2 | |
Fix heap-buffer-overflow in explicit_location_lex_one
I build GDB with -fsanitize=address, and see the error in tests,
(gdb) PASS: gdb.linespec/ls-errs.exp: lang=C++: break 3 foo
break -line 3 foo^M
=================================================================^M
==4401==ERROR: AddressSanitizer: heap-buffer-overflow on address 0x603000047487 at pc 0x819d8e bp 0x7fff4e4e6bb0 sp 0x7fff4e4e6ba8^M
READ of size 1 at 0x603000047487 thread T0^[[1m^[[0m^M
#0 0x819d8d in explicit_location_lex_one /home/yao/SourceCode/gnu/gdb/git/gdb/location.c:502^M
#1 0x81a185 in string_to_explicit_location(char const**, language_defn const*, int) /home/yao/SourceCode/gnu/gdb/git/gdb/location.c:556^M
#2 0x81ac10 in string_to_event_location(char**, language_defn const*) /home/yao/SourceCode/gnu/gdb/git/gdb/location.c:687^
the code in question is:
> /* Special case: C++ operator,. */
> if (language->la_language == language_cplus
> && strncmp (*inp, "operator", 8) <--- [1]
> && (*inp)[9] == ',')
> (*inp) += 9;
> ++(*inp);
The error is caused by the access to (*inp)[9] if 9 is out of its bounds.
However [1] looks odd to me, because if strncmp returns true (non-zero),
the following check "(*inp)[9] == ','" makes no sense any more. I
suspect it was a typo in the code we meant to "strncmp () == 0". Another
problem in the code above is that if *inp is "operator,", we first
increment *inp by 9, and then increment it by one again, which is wrong
to me. We should only increment *inp by 8 to skip "operator", and go
back to the loop header to decide where we stop.
gdb:
2016-08-15 Yao Qi <yao.qi@linaro.org>
* location.c (explicit_location_lex_one): Compare the return
value of strncmp with zero. Don't check (*inp)[9]. Increment
*inp by 8.
Diffstat (limited to 'gdb/location.c')
| -rw-r--r-- | gdb/location.c | 5 |
1 files changed, 2 insertions, 3 deletions
diff --git a/gdb/location.c b/gdb/location.c index 071d262..65116c7 100644 --- a/gdb/location.c +++ b/gdb/location.c @@ -498,9 +498,8 @@ explicit_location_lex_one (const char **inp, { /* Special case: C++ operator,. */ if (language->la_language == language_cplus - && strncmp (*inp, "operator", 8) - && (*inp)[9] == ',') - (*inp) += 9; + && strncmp (*inp, "operator", 8) == 0) + (*inp) += 8; ++(*inp); } } |