[PATCH v2 net-next 1/5] ptp: clockmatrix: bug fix for idtcm_strverscmp

From: min.li.xe
Date: Tue Nov 17 2020 - 11:07:25 EST


From: Min Li <min.li.xe@xxxxxxxxxxx>

Feed kstrtou8 with NULL terminated string.

Changes since v1:
-Only strcpy 15 characters to leave 1 space for '\0'

Signed-off-by: Min Li <min.li.xe@xxxxxxxxxxx>
---
drivers/ptp/ptp_clockmatrix.c | 52 +++++++++++++++++++++++++++++++------------
1 file changed, 38 insertions(+), 14 deletions(-)

diff --git a/drivers/ptp/ptp_clockmatrix.c b/drivers/ptp/ptp_clockmatrix.c
index e020faf..efe5639 100644
--- a/drivers/ptp/ptp_clockmatrix.c
+++ b/drivers/ptp/ptp_clockmatrix.c
@@ -103,42 +103,66 @@ static int timespec_to_char_array(struct timespec64 const *ts,
return 0;
}

-static int idtcm_strverscmp(const char *ver1, const char *ver2)
+static int idtcm_strverscmp(const char *version1, const char *version2)
{
u8 num1;
u8 num2;
int result = 0;
+ char ver1[16];
+ char ver2[16];
+ char *cur1;
+ char *cur2;
+ char *next1;
+ char *next2;
+
+ strncpy(ver1, version1, 15);
+ strncpy(ver2, version2, 15);
+ cur1 = ver1;
+ cur2 = ver2;

/* loop through each level of the version string */
while (result == 0) {
+ next1 = strchr(cur1, '.');
+ next2 = strchr(cur2, '.');
+
+ /* kstrtou8 could fail for dot */
+ if (next1) {
+ *next1 = '\0';
+ next1++;
+ }
+
+ if (next2) {
+ *next2 = '\0';
+ next2++;
+ }
+
/* extract leading version numbers */
- if (kstrtou8(ver1, 10, &num1) < 0)
+ if (kstrtou8(cur1, 10, &num1) < 0)
return -1;

- if (kstrtou8(ver2, 10, &num2) < 0)
+ if (kstrtou8(cur2, 10, &num2) < 0)
return -1;

/* if numbers differ, then set the result */
- if (num1 < num2)
+ if (num1 < num2) {
result = -1;
- else if (num1 > num2)
+ } else if (num1 > num2) {
result = 1;
- else {
+ } else {
/* if numbers are the same, go to next level */
- ver1 = strchr(ver1, '.');
- ver2 = strchr(ver2, '.');
- if (!ver1 && !ver2)
+ if (!next1 && !next2)
break;
- else if (!ver1)
+ else if (!next1) {
result = -1;
- else if (!ver2)
+ } else if (!next2) {
result = 1;
- else {
- ver1++;
- ver2++;
+ } else {
+ cur1 = next1;
+ cur2 = next2;
}
}
}
+
return result;
}

--
2.7.4