6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Ömer Mete Kaya [ Upstream commit c04981e42d94f39c1dba965cc462a046e946a6c5 ] When service_name_len is 0, kmemdup() returns ZERO_SIZE_PTR which passes the NULL check, causing nfc_llcp_send_connect() to attempt building a zero-length service name TLV and fail with -ENOMEM. Fix by setting service_name to NULL directly when service_name_len is 0. Fixes: d646960f7986 ("NFC: Initial LLCP support") Signed-off-by: Ömer Mete Kaya Link: https://patch.msgid.link/20260909122029.34081-1-omermetekaya0@gmail.com Signed-off-by: David Heidelberg Signed-off-by: Sasha Levin --- net/nfc/llcp_sock.c | 16 ++++++++++------ 1 file changed, 10 insertions(+), 6 deletions(-) diff --git a/net/nfc/llcp_sock.c b/net/nfc/llcp_sock.c index f9d35711eb9a7..0601ddb4304aa 100644 --- a/net/nfc/llcp_sock.c +++ b/net/nfc/llcp_sock.c @@ -759,12 +759,16 @@ static int llcp_sock_connect(struct socket *sock, struct sockaddr *_addr, llcp_sock->service_name_len = min_t(unsigned int, addr->service_name_len, NFC_LLCP_MAX_SERVICE_NAME); - llcp_sock->service_name = kmemdup(addr->service_name, - llcp_sock->service_name_len, - GFP_KERNEL); - if (!llcp_sock->service_name) { - ret = -ENOMEM; - goto sock_llcp_release; + if (llcp_sock->service_name_len == 0) { + llcp_sock->service_name = NULL; + } else { + llcp_sock->service_name = kmemdup(addr->service_name, + llcp_sock->service_name_len, + GFP_KERNEL); + if (!llcp_sock->service_name) { + ret = -ENOMEM; + goto sock_llcp_release; + } } nfc_llcp_sock_link(&local->connecting_sockets, sk); -- 2.53.0