From: Xin Long lucien.xin@gmail.com
commit 8c63bf9ab4be8b83bd8c34aacfd2f1d2c8901c8a upstream.
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 lucien.xin@gmail.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- net/tipc/netlink_compat.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-)
--- a/net/tipc/netlink_compat.c +++ b/net/tipc/netlink_compat.c @@ -738,7 +738,12 @@ static int tipc_nl_compat_link_set(struc
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;