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| author | Jonathan Wakely <jwakely@redhat.com> | 2024-12-13 10:54:29 +0000 |
|---|---|---|
| committer | Jonathan Wakely <redi@gcc.gnu.org> | 2024-12-13 13:06:12 +0000 |
| commit | 959a80a46dbc4d3ad1bf8560dfacb585ccd8cac4 (patch) | |
| tree | f4c0105c598759280db6d283ec48ce39f761bb11 | |
| parent | 233860f005ccd76c7604cf0eac18b9eda3d984f4 (diff) | |
| download | gcc-959a80a46dbc4d3ad1bf8560dfacb585ccd8cac4.zip gcc-959a80a46dbc4d3ad1bf8560dfacb585ccd8cac4.tar.gz gcc-959a80a46dbc4d3ad1bf8560dfacb585ccd8cac4.tar.bz2 | |
libstdc++: Fix uninitialized data in std::basic_spanbuf::seekoff
I noticed a -Wmaybe-uninitialized warning for this function, which turns
out to be correct. If the caller passes a valid std::ios_base::seekdir
value then there's no problem, but if they pass std::seekdir(999) then
we don't initialize the __base variable before adding it to __off.
Rather than initialize it to an arbitrary value, we should return an
error.
Also add [[unlikely]] attributes to the paths that return an error.
libstdc++-v3/ChangeLog:
* include/std/spanstream (basic_spanbuf::seekoff): Return an
error for invalid seekdir values.
| -rw-r--r-- | libstdc++-v3/include/std/spanstream | 8 |
1 files changed, 5 insertions, 3 deletions
diff --git a/libstdc++-v3/include/std/spanstream b/libstdc++-v3/include/std/spanstream index 98ad3fa..23a340a 100644 --- a/libstdc++-v3/include/std/spanstream +++ b/libstdc++-v3/include/std/spanstream @@ -168,7 +168,7 @@ template<typename _CharT, typename _Traits> } else { - off_type __base; + off_type __base{}; __which &= (ios_base::in|ios_base::out); if (__which == ios_base::out) @@ -182,11 +182,13 @@ template<typename _CharT, typename _Traits> } else if (__way == ios_base::end) __base = _M_buf.size(); + else /* way is not ios::beg, ios::cur, or ios::end */ [[unlikely]] + return __ret; - if (__builtin_add_overflow(__base, __off, &__off)) + if (__builtin_add_overflow(__base, __off, &__off)) [[unlikely]] return __ret; - if (__off < 0 || __off > _M_buf.size()) + if (__off < 0 || __off > _M_buf.size()) [[unlikely]] return __ret; if (__which & ios_base::in) |