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wchar/wcsstr: fix the variable overflow bug

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Signed-off-by: guoshichao <guoshichao@xiaomi.com>
This commit is contained in:
guoshichao
2024-04-26 11:54:02 +08:00
committed by Xiang Xiao
parent ca1e007a22
commit d74e37d9db
1 changed files with 40 additions and 10 deletions
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libs/libc/wchar/lib_wcsstr.c
+40 -10
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@@ -39,7 +39,7 @@ static FAR wchar_t *twoway_wcsstr(FAR const wchar_t *h, FAR const wchar_t *n)
{ {
FAR const wchar_t *z; FAR const wchar_t *z;
size_t l; size_t l;
size_t ip; ssize_t ip;
size_t jp; size_t jp;
size_t k; size_t k;
size_t p; size_t p;
@@ -54,7 +54,10 @@ static FAR wchar_t *twoway_wcsstr(FAR const wchar_t *h, FAR const wchar_t *n)
/* hit the end of h */ /* hit the end of h */
if (n[l]) return 0; if (n[l])
{
return 0;
}
/* Compute maximal suffix */ /* Compute maximal suffix */
@@ -114,8 +117,14 @@ static FAR wchar_t *twoway_wcsstr(FAR const wchar_t *h, FAR const wchar_t *n)
} }
} }
if (ip + 1 > ms + 1) ms = ip; if (ip + 1 > ms + 1)
else p = p0; {
ms = ip;
}
else
{
p = p0;
}
/* Periodic needle? */ /* Periodic needle? */
@@ -150,7 +159,10 @@ static FAR wchar_t *twoway_wcsstr(FAR const wchar_t *h, FAR const wchar_t *n)
if (z2) if (z2)
{ {
z = z2; z = z2;
if (z - h < l) return 0; if (z - h < l)
{
return 0;
}
} }
else z += grow; else z += grow;
} }
@@ -169,7 +181,11 @@ static FAR wchar_t *twoway_wcsstr(FAR const wchar_t *h, FAR const wchar_t *n)
for (k = ms + 1; k > mem && n[k - 1] == h[k - 1]; k--); for (k = ms + 1; k > mem && n[k - 1] == h[k - 1]; k--);
if (k <= mem) return (FAR wchar_t *)h; if (k <= mem)
{
return (FAR wchar_t *)h;
}
h += p; h += p;
mem = mem0; mem = mem0;
} }
@@ -200,14 +216,28 @@ FAR wchar_t *wcsstr(FAR const wchar_t *h, FAR const wchar_t *n)
{ {
/* Return immediately on empty needle or haystack */ /* Return immediately on empty needle or haystack */
if (!n[0]) return (FAR wchar_t *)h; if (!n[0])
if (!h[0]) return 0; {
return (FAR wchar_t *)h;
}
if (!h[0])
{
return 0;
}
/* Use faster algorithms for short needles */ /* Use faster algorithms for short needles */
h = wcschr(h, *n); h = wcschr(h, *n);
if (!h || !n[1]) return (FAR wchar_t *)h; if (!h || !n[1])
if (!h[1]) return 0; {
return (FAR wchar_t *)h;
}
if (!h[1])
{
return 0;
}
return twoway_wcsstr(h, n); return twoway_wcsstr(h, n);
} }