From 8c63bf9ab4be8b83bd8c34aacfd2f1d2c8901c8a Mon Sep 17 00:00:00 2001 From: Xin Long Date: Sun, 31 Mar 2019 22:50:09 +0800 Subject: tipc: check link name with right length in tipc_nl_compat_link_set A similar issue as fixed by Patch "tipc: check bearer name with right length in tipc_nl_compat_bearer_enable" was also found by syzbot in tipc_nl_compat_link_set(). The length to check with should be 'TLV_GET_DATA_LEN(msg->req) - offsetof(struct tipc_link_config, name)'. Reported-by: syzbot+de00a87b8644a582ae79@syzkaller.appspotmail.com Signed-off-by: Xin Long Signed-off-by: David S. Miller --- net/tipc/netlink_compat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) (limited to 'net/tipc') diff --git a/net/tipc/netlink_compat.c b/net/tipc/netlink_compat.c index 5f8e53cca222..0bfd03d67fdd 100644 --- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -771,7 +771,12 @@ static int tipc_nl_compat_link_set(struct tipc_nl_compat_cmd_doit *cmd, lc = (struct tipc_link_config *)TLV_DATA(msg->req); - len = min_t(int, TLV_GET_DATA_LEN(msg->req), TIPC_MAX_LINK_NAME); + len = TLV_GET_DATA_LEN(msg->req); + len -= offsetof(struct tipc_link_config, name); + if (len <= 0) + return -EINVAL; + + len = min_t(int, len, TIPC_MAX_LINK_NAME); if (!string_is_valid(lc->name, len)) return -EINVAL; -- cgit v1.2.3-59-g8ed1b