From: Xiaoming Ni Date: Thu, 25 Mar 2021 03:51:13 +0000 (+0800) Subject: nfc: Avoid endless loops caused by repeated llcp_sock_connect() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=4b5db93e7f2afbdfe3b78e37879a85290187e6f1;p=linux.git nfc: Avoid endless loops caused by repeated llcp_sock_connect() When sock_wait_state() returns -EINPROGRESS, "sk->sk_state" is LLCP_CONNECTING. In this case, llcp_sock_connect() is repeatedly invoked, nfc_llcp_sock_link() will add sk to local->connecting_sockets twice. sk->sk_node->next will point to itself, that will make an endless loop and hang-up the system. To fix it, check whether sk->sk_state is LLCP_CONNECTING in llcp_sock_connect() to avoid repeated invoking. Fixes: b4011239a08e ("NFC: llcp: Fix non blocking sockets connections") Reported-by: "kiyin(尹亮)" Link: https://www.openwall.com/lists/oss-security/2020/11/01/1 Cc: #v3.11 Signed-off-by: Xiaoming Ni Signed-off-by: David S. Miller --- diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index 59172614b249c..a3b46f8888033 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -673,6 +673,10 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, ret = -EISCONN; goto error; } + if (sk->sk_state == LLCP_CONNECTING) { + ret = -EINPROGRESS; + goto error; + } dev = nfc_get_device(addr->dev_idx); if (dev == NULL) {