[PATCH 6.4 124/800] nfc: llcp: fix possible use of uninitialized variable in nfc_llcp_send_connect()

Greg Kroah-Hartman
2023-07-16T19:58:36Z

From: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>

[ 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>
---
net/nfc/llcp_commands.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/nfc/llcp_commands.c b/net/nfc/llcp_commands.c
index 41e3a20c89355..cdb001de06928 100644
--- 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;
--
2.39.2