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Subject[PATCH][next] perf tests: fix out of bounds access on array fd when cnt is 100
Date
From: Colin Ian King <colin.king@canonical.com>

Currently when cnt is 100 an array bounds overflow occurs on the assignment
of fd[cnt]. Fix this by performing the bounds check on cnt before writing
to fd.

Detected by cppcheck:
tools/perf/tests/bp_account.c:115: (warning) Either the condition
'cnt==100' is redundant or the array 'fd[100]' is accessed at index 100,
which is out of bounds.

Fixes: 032db28e5fa3 ("perf tests: Add breakpoint accounting/modify test")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
---
tools/perf/tests/bp_account.c | 8 +++-----
1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/tools/perf/tests/bp_account.c b/tools/perf/tests/bp_account.c
index 2f75fa0c4fef..9e88d7608951 100644
--- a/tools/perf/tests/bp_account.c
+++ b/tools/perf/tests/bp_account.c
@@ -107,16 +107,14 @@ static int detect_cnt(bool is_x)
int fd[100], cnt = 0, i;

while (1) {
- fd[cnt] = __event(is_x, addr, &attr);
-
- if (fd[cnt] < 0)
- break;
-
if (cnt == 100) {
pr_debug("way too many debug registers, fix the test\n");
return 0;
}
+ fd[cnt] = __event(is_x, addr, &attr);

+ if (fd[cnt] < 0)
+ break;
cnt++;
}

--
2.15.1
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