diff mbox series

[net,1/2] smc: fix out of bound access in smc_nl_get_sys_info()

Message ID 20210112162122.26832-2-kgraul@linux.ibm.com (mailing list archive)
State Accepted
Commit 25fe2c9c4cd2e97c5f5b69f3aefe69aad3057936
Delegated to: Netdev Maintainers
Headers show
Series net/smc: fix out of bound access in netlink interface | expand

Checks

Context Check Description
netdev/cover_letter success Link
netdev/fixes_present success Link
netdev/patch_count success Link
netdev/tree_selection success Clearly marked for net
netdev/subject_prefix success Link
netdev/cc_maintainers warning 1 maintainers not CCed: guvenc@linux.ibm.com
netdev/source_inline success Was 0 now: 0
netdev/verify_signedoff success Link
netdev/module_param success Was 0 now: 0
netdev/build_32bit success Errors and warnings before: 0 this patch: 0
netdev/kdoc success Errors and warnings before: 0 this patch: 0
netdev/verify_fixes success Link
netdev/checkpatch success total: 0 errors, 0 warnings, 0 checks, 9 lines checked
netdev/build_allmodconfig_warn success Errors and warnings before: 0 this patch: 0
netdev/header_inline success Link
netdev/stable success Stable not CCed

Commit Message

Karsten Graul Jan. 12, 2021, 4:21 p.m. UTC 
From: Jakub Kicinski <kuba@kernel.org>

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: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
---
 net/smc/smc_core.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/net/smc/smc_core.c b/net/smc/smc_core.c
index 59342b519e34..8d866b4ed8f6 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;
 	}