To make overflows as obvious as possible and to prevent code from blithely proceeding with a truncated string. This also has a side-effect to fix a compilation warning when using GCC 8.2.1. net/netfilter/ipset/ip_set_core.c: In function 'ip_set_sockfn_get': net/netfilter/ipset/ip_set_core.c:2027:3: warning: 'strncpy' writing 32 bytes into a region of size 2 overflows the destination [-Wstringop-overflow=] Signed-off-by: Qian Cai <cai@xxxxxx> --- Changes since v1: * Checked the return value. net/netfilter/ipset/ip_set_core.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/net/netfilter/ipset/ip_set_core.c b/net/netfilter/ipset/ip_set_core.c index 1577f2f76060..c6f82556f7f2 100644 --- a/net/netfilter/ipset/ip_set_core.c +++ b/net/netfilter/ipset/ip_set_core.c @@ -2024,8 +2024,11 @@ ip_set_sockfn_get(struct sock *sk, int optval, void __user *user, int *len) } nfnl_lock(NFNL_SUBSYS_IPSET); set = ip_set(inst, req_get->set.index); - strncpy(req_get->set.name, set ? set->name : "", - IPSET_MAXNAMELEN); + if (strscpy(req_get->set.name, set ? set->name : "", + IPSET_MAXNAMELEN) == -E2BIG) { + ret = -E2BIG; + goto done; + } nfnl_unlock(NFNL_SUBSYS_IPSET); goto copy; } -- 2.17.2 (Apple Git-113)