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Fix #15124 FN bufferAccessOutOfBounds with wmemcpy() #8951

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Fix #15124 FN bufferAccessOutOfBounds with wmemcpy() #8951

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8c6a368
Update std.cfg
chrchr-github Oct 21, 2026
1367f16
Update std.c
chrchr-github Oct 21, 2026
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8 changes: 4 additions & 4 deletions cfg/std.cfg
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Original file line number Diff line number Diff line change
Expand Up @@ -3974,12 +3974,12 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
<arg nr="1" direction="in">
<not-null/>
<not-uninit/>
<minsize type="argvalue" arg="3"/>
<minsize type="argvalue" arg="3" baseType="wchar_t"/>
</arg>
<arg nr="2" direction="in">
<not-null/>
<not-uninit/>
<minsize type="argvalue" arg="3"/>
<minsize type="argvalue" arg="3" baseType="wchar_t"/>
</arg>
<arg nr="3" direction="in">
<not-uninit/>
Expand Down Expand Up @@ -4016,12 +4016,12 @@ The obsolete function 'gets' is called. With 'gets' you'll get a buffer overrun
<not-overlapping-data ptr1-arg="1" ptr2-arg="2" count-arg="3"/>
<arg nr="1" direction="out">
<not-null/>
<minsize type="argvalue" arg="3"/>
<minsize type="argvalue" arg="3" baseType="wchar_t"/>
</arg>
<arg nr="2" direction="in">
<not-null/>
<not-uninit/>
<minsize type="argvalue" arg="3"/>
<minsize type="argvalue" arg="3" baseType="wchar_t"/>

@dmcppcheck dmcppcheck Oct 22, 2026

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AI review

wmemmove, wmemset and wmemchr in this file, and wmempcpy in cfg/gnu.cfg (lines 662/667), also take a count of wide characters. They still use <minsize type="argvalue" arg="3"/> without baseType="wchar_t", so they have the same false negative. For example, wchar_t a[4]; wmemmove(a, L"abcd", 5); and wmemset(a, L'x', 5); give no warning with this PR. Please fix them here too and add tests.

</arg>
<arg nr="3" direction="in">
<not-uninit/>
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14 changes: 14 additions & 0 deletions test/cfg/std.c
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Original file line number Diff line number Diff line change
Expand Up @@ -616,6 +616,20 @@ void bufferAccessOutOfBounds_wcsncpy()
wcsncpy(s, L"abc", 17);
}

void bufferAccessOutOfBounds_wmemcpy()
{
wchar_t a[4];
// cppcheck-suppress bufferAccessOutOfBounds
wmemcpy(a, L"abcd", 5);
}

int bufferAccessOutOfBounds_wmemcmp(const wchar_t* b)
{
const wchar_t a[4] = { L'a', L'b', L'c', L'd' };
// cppcheck-suppress bufferAccessOutOfBounds
return wmemcmp(a, b, 5);
}

int nullPointer_wcsncmp(const wchar_t* s1, const wchar_t* s2, size_t n)
{
// cppcheck-suppress nullPointer
Expand Down
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