From: Jakub Kicinski <kuba@kernel.org>
Date: Tue, 12 Jan 2021 17:21:21 +0100
Subject: smc: fix out of bound access in smc_nl_get_sys_info()
Git-commit: 25fe2c9c4cd2e97c5f5b69f3aefe69aad3057936
Patch-mainline: v5.11-rc4
References: jsc#SLE-15862 bsc#1180744 LTC#186340
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 <kgraul@linux.ibm.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Acked-by: Petr Tesarik <ptesarik@suse.com>
---
net/smc/smc_core.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
--- 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 *
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;
}