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String: Add overflow tests for strnlen, memchr, and strncat [BZ #27974]

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This commit adds tests for a bug in the wide char variant of the
functions where the implementation may assume that maxlen for wcsnlen
or n for wmemchr/strncat will not overflow when multiplied by
sizeof(wchar_t).

These tests show the following implementations failing on x86_64:

wcsnlen-sse4_1
wcsnlen-avx2

wmemchr-sse2
wmemchr-avx2

strncat would fail as well if it where on a system that prefered
either of the wcsnlen implementations that failed as it relies on
wcsnlen.

Signed-off-by: Noah Goldstein <goldstein.w.n@gmail.com>
Reviewed-by: H.J. Lu <hjl.tools@gmail.com>
This commit is contained in:
Noah Goldstein
2021-06-09 16:17:14 -04:00
parent 6f573a27b6
commit da5a6fba0f
3 changed files with 130 additions and 3 deletions
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33
string/test-strnlen.c
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@@ -89,6 +89,38 @@ do_test (size_t align, size_t len, size_t maxlen, int max_char)
do_one_test (impl, (CHAR *) (buf + align), maxlen, MIN (len, maxlen));
}
static void
do_overflow_tests (void)
{
size_t i, j, len;
const size_t one = 1;
uintptr_t buf_addr = (uintptr_t) buf1;
for (i = 0; i < 750; ++i)
{
do_test (0, i, SIZE_MAX - i, BIG_CHAR);
do_test (0, i, i - buf_addr, BIG_CHAR);
do_test (0, i, -buf_addr - i, BIG_CHAR);
do_test (0, i, SIZE_MAX - buf_addr - i, BIG_CHAR);
do_test (0, i, SIZE_MAX - buf_addr + i, BIG_CHAR);
len = 0;
for (j = 8 * sizeof(size_t) - 1; j ; --j)
{
len |= one << j;
do_test (0, i, len - i, BIG_CHAR);
do_test (0, i, len + i, BIG_CHAR);
do_test (0, i, len - buf_addr - i, BIG_CHAR);
do_test (0, i, len - buf_addr + i, BIG_CHAR);
do_test (0, i, ~len - i, BIG_CHAR);
do_test (0, i, ~len + i, BIG_CHAR);
do_test (0, i, ~len - buf_addr - i, BIG_CHAR);
do_test (0, i, ~len - buf_addr + i, BIG_CHAR);
}
}
}
static void
do_random_tests (void)
{
@@ -283,6 +315,7 @@ test_main (void)
do_random_tests ();
do_page_tests ();
do_page_2_tests ();
do_overflow_tests ();
return ret;
}