From 0c8e253595bd80e4ddd73230d079e33cd5420b32 Mon Sep 17 00:00:00 2001 From: Phil Sutter Date: Tue, 15 Mar 2022 12:17:25 +0100 Subject: libxtables: Fix for warning in xtables_ipmask_to_numeric Gcc complains: | xtables.c: In function 'xtables_ipmask_to_numeric': | xtables.c:1491:34: warning: '__builtin___sprintf_chk' may write a terminating nul past the end of the destination [-Wformat-overflow=] | 1491 | sprintf(buf, "/%s", xtables_ipaddr_to_numeric(mask)); | | ^ Indeed, xtables_ipaddr_to_numeric() returns a pointer to a 20 byte buffer and xtables_ipmask_to_numeric() writes its content into a buffer of same size at offset 1. Yet length of returned string is deterministic as it is an IPv4 address. So shrink it to the minimum of 16 bytes which eliminates the warning as well. Fixes: a96166c24eaac ("libxtables: add xtables_ip[6]mask_to_cidr") Signed-off-by: Phil Sutter --- libxtables/xtables.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'libxtables/xtables.c') diff --git a/libxtables/xtables.c b/libxtables/xtables.c index 094cbd87..5f47f627 100644 --- a/libxtables/xtables.c +++ b/libxtables/xtables.c @@ -1418,7 +1418,7 @@ void xtables_param_act(unsigned int status, const char *p1, ...) const char *xtables_ipaddr_to_numeric(const struct in_addr *addrp) { - static char buf[20]; + static char buf[16]; const unsigned char *bytep = (const void *)&addrp->s_addr; sprintf(buf, "%u.%u.%u.%u", bytep[0], bytep[1], bytep[2], bytep[3]); -- cgit v1.2.3