[LU-18571] Fix Coverity issues introduced by "LU-14288 nodemap: Use nidmasks for IPv6 NIDs"

• Type: Bug
• Resolution: Fixed
• Priority: Minor
• Fix Version/s: Lustre 2.17.0
• Affects Version/s: Lustre 2.17.0
• Labels: coverity patch
• Severity: 3
• Assignee: Sebastien Buisson
• Reporter: Sebastien Buisson

Description

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*** CID 451797:  Null pointer dereferences  (NULL_RETURNS)
/lustre/ptlrpc/nodemap_range.c: 115 in range_create()
109     		snprintf(nidstr, sizeof(nidstr), "%s",
110     			 libcfs_nidstr(start_nid));
111     
112     		c = strchr(nidstr, '@');
113     
114     		/* net = @<net> */
   CID 451797:  Null pointer dereferences  (NULL_RETURNS)
   Dereferencing a pointer that might be "NULL" "c" when calling "strscpy".
115     		strscpy(net, c, sizeof(net));
116     
117     		*c = '\0';
118     
119     		/* nidstr = <addr>/<prefix_length> */
120     		snprintf(c, sizeof(nidstr) - strlen(nidstr), "/%u", netmask);

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*** CID 451795:  Integer handling issues  (CONSTANT_EXPRESSION_RESULT)
/lustre/ptlrpc/nodemap_range.c: 96 in range_create()
90     		/* +4 for '/<prefix_length>' */
91     		char nidstr[LNET_NIDSTR_SIZE + 4];
92     		char net[LNET_NIDSTR_SIZE];
93     		char *c;
94     		int rc;
95     
   CID 451795:  Integer handling issues  (CONSTANT_EXPRESSION_RESULT)
   "netmask > 999" is always false regardless of the values of its operands. This occurs as the logical operand of "if".
96     		if (netmask > 999) {
97     			/* If the netmask is somehow more than three characters
98     			 * then the logic below could truncate it which could
99     			 * result in creating a valid netmask value from bad
100     			 * input.
101     			 * cfs_parse_nidlist() will check whether the netmask