From 1c075b192fe41030457cd4a5f7dea730412bca40 Mon Sep 17 00:00:00 2001 From: Xin Long Date: Fri, 4 Nov 2022 16:48:53 -0400 Subject: [PATCH] tipc: fix the msg->req tlv len check in tipc_nl_compat_name_table_dump_header This is a follow-up for commit 974cb0e3e7c9 ("tipc: fix uninit-value in tipc_nl_compat_name_table_dump") where it should have type casted sizeof(..) to int to work when TLV_GET_DATA_LEN() returns a negative value. syzbot reported a call trace because of it: BUG: KMSAN: uninit-value in ... tipc_nl_compat_name_table_dump+0x841/0xea0 net/tipc/netlink_compat.c:934 __tipc_nl_compat_dumpit+0xab2/0x1320 net/tipc/netlink_compat.c:238 tipc_nl_compat_dumpit+0x991/0xb50 net/tipc/netlink_compat.c:321 tipc_nl_compat_recv+0xb6e/0x1640 net/tipc/netlink_compat.c:1324 genl_family_rcv_msg_doit net/netlink/genetlink.c:731 [inline] genl_family_rcv_msg net/netlink/genetlink.c:775 [inline] genl_rcv_msg+0x103f/0x1260 net/netlink/genetlink.c:792 netlink_rcv_skb+0x3a5/0x6c0 net/netlink/af_netlink.c:2501 genl_rcv+0x3c/0x50 net/netlink/genetlink.c:803 netlink_unicast_kernel net/netlink/af_netlink.c:1319 [inline] netlink_unicast+0xf3b/0x1270 net/netlink/af_netlink.c:1345 netlink_sendmsg+0x1288/0x1440 net/netlink/af_netlink.c:1921 sock_sendmsg_nosec net/socket.c:714 [inline] sock_sendmsg net/socket.c:734 [inline] Reported-by: syzbot+e5dbaaa238680ce206ea@syzkaller.appspotmail.com Fixes: 974cb0e3e7c9 ("tipc: fix uninit-value in tipc_nl_compat_name_table_dump") Signed-off-by: Xin Long Link: https://lore.kernel.org/r/ccd6a7ea801b15aec092c3b532a883b4c5708695.1667594933.git.lucien.xin@gmail.com Signed-off-by: Jakub Kicinski --- net/tipc/netlink_compat.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index fc68733..dfea27a 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -880,7 +880,7 @@ static int tipc_nl_compat_name_table_dump_header(struct tipc_nl_compat_msg *msg) }; ntq = (struct tipc_name_table_query *)TLV_DATA(msg->req); - if (TLV_GET_DATA_LEN(msg->req) < sizeof(struct tipc_name_table_query)) + if (TLV_GET_DATA_LEN(msg->req) < (int)sizeof(struct tipc_name_table_query)) return -EINVAL; depth = ntohl(ntq->depth); -- 2.7.4