[git commit] networking: fix potential overflow in ife_print6()

Denys Vlasenko vda.linux at googlemail.com
Wed Aug 14 15:43:05 UTC 2013

commit: http://git.busybox.net/busybox/commit/?id=6761d7da83b54027be441ec942ca25eecdc58f62
branch: http://git.busybox.net/busybox/commit/?id=refs/heads/master

devname is used by fscanf to store a string specified by '%20s'.

Extract from the man for the '%s' specifier:
Matches a sequence of non-white-space characters; the next pointer must be a
pointer to character array that is long enough to hold the input sequence and
the terminating null byte ('\0'), which is added automatically. The input
string stops at white space or at the maximum field width, whichever occurs

Hence, the right length is 20 + 1 for the '\0'.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel at 6wind.com>
Signed-off-by: Denys Vlasenko <vda.linux at googlemail.com>
 networking/interface.c |    2 +-
 1 files changed, 1 insertions(+), 1 deletions(-)

diff --git a/networking/interface.c b/networking/interface.c
index 3dc5b36..bf7d2b1 100644
--- a/networking/interface.c
+++ b/networking/interface.c
@@ -874,7 +874,7 @@ static void print_bytes_scaled(unsigned long long ull, const char *end)
 static void ife_print6(struct interface *ptr)
 	FILE *f;
-	char addr6[40], devname[20];
+	char addr6[40], devname[21];
 	struct sockaddr_in6 sap;
 	int plen, scope, dad_status, if_idx;
 	char addr6p[8][5];

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