ip: ipmaddr.c: Fix possible integer underflow in read_igmp()
Static analyzer pointed out a potential error:
Possible integer underflow: left operand is tainted. An integer underflow
may occur due to arithmetic operation (unsigned subtraction) between variable
'len' and value '1', when 'len' is tainted { [0, 18446744073709551615] }
The fix adds a check for 'len == 0' before accessing the last character of
the name, and skips the current line in such cases to avoid the underflow.
Reported-by: SVACE static analyzer
Signed-off-by: Anton Moryakov <ant.v.moryakov@gmail.com>
Signed-off-by: David Ahern <dsahern@kernel.org>
diff --git a/ip/ipmaddr.c b/ip/ipmaddr.c
index 2418b30..462b409 100644
--- a/ip/ipmaddr.c
+++ b/ip/ipmaddr.c
@@ -150,6 +150,8 @@
sscanf(buf, "%d%s", &m.index, m.name);
len = strlen(m.name);
+ if (len == 0)
+ continue;
if (m.name[len - 1] == ':')
m.name[len - 1] = '\0';
continue;
