From 25fe2c9c4cd2e97c5f5b69f3aefe69aad3057936 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Tue, 12 Jan 2021 17:21:21 +0100 Subject: [PATCH] smc: fix out of bound access in smc_nl_get_sys_info() smc_clc_get_hostname() sets the host pointer to a buffer which is not NULL-terminated (see smc_clc_init()). Reported-by: syzbot+f4708c391121cfc58396@syzkaller.appspotmail.com Fixes: 099b990bd11a ("net/smc: Add support for obtaining system information") Signed-off-by: Karsten Graul Signed-off-by: Jakub Kicinski --- net/smc/smc_core.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c index 59342b5..8d866b4 100644 --- a/net/smc/smc_core.c +++ b/net/smc/smc_core.c @@ -246,7 +246,8 @@ int smc_nl_get_sys_info(struct sk_buff *skb, struct netlink_callback *cb) goto errattr; smc_clc_get_hostname(&host); if (host) { - snprintf(hostname, sizeof(hostname), "%s", host); + memcpy(hostname, host, SMC_MAX_HOSTNAME_LEN); + hostname[SMC_MAX_HOSTNAME_LEN] = 0; if (nla_put_string(skb, SMC_NLA_SYS_LOCAL_HOST, hostname)) goto errattr; } -- 2.7.4