nfc: llcp: fix possible use of uninitialized variable in nfc_llcp_send_connect()

[ Upstream commit 0d9b41daa5907756a31772d8af8ac5ff25cf17c1 ]

If sock->service_name is NULL, the local variable
service_name_tlv_length will not be assigned by nfc_llcp_build_tlv(),
later leading to using value frmo the stack.  Smatch warning:

  net/nfc/llcp_commands.c:442 nfc_llcp_send_connect() error: uninitialized symbol 'service_name_tlv_length'.

Fixes: de9e5aeb4f40 ("NFC: llcp: Fix usage of llcp_add_tlv()")
Signed-off-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index 41e3a20..cdb001d 100644 (file)
--- a/net/nfc/llcp_commands.c
+++ b/net/nfc/llcp_commands.c
@@ -390,7 +390,8 @@ int nfc_llcp_send_connect(struct nfc_llcp_sock *sock)
        const u8 *service_name_tlv = NULL;
        const u8 *miux_tlv = NULL;
        const u8 *rw_tlv = NULL;
-       u8 service_name_tlv_length, miux_tlv_length,  rw_tlv_length, rw;
+       u8 service_name_tlv_length = 0;
+       u8 miux_tlv_length,  rw_tlv_length, rw;
        int err;
        u16 size = 0;
        __be16 miux;