[PATCH] nfx: llcp: fix possible use of uninitialized variable in nfc_llcp_send_connect()

From: Krzysztof Kozlowski
Date: Sat May 13 2023 - 07:49:57 EST


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@xxxxxxxxxx>
---
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 41e3a20c8935..cdb001de0692 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;
--
2.34.1