[PATCH net 02/20] can: j1939: transport: j1939_session_fresh_new(): initialize receive buffer

Marc Kleine-Budde <[email protected]> Wed, 29 Jul 2026 12:12:42 +0200
Newsgroups org.kernel.vger.linux-can,org.kernel.vger.netdev
Message-ID <[email protected]>
From: Oleksij Rempel <[email protected]>

Zero the allocated buffer in j1939_session_fresh_new() to ensure it
contains no residual data.

While there is a potential performance impact if users allocate maximum
sized ETP buffers, most real-world use cases are not noticeably affected
since the maximum known buffer size is typically around 65K.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: Ji'an Zhou <[email protected]>
Message-ID: <CAPAUci5dykCLjoijqkUtFqJFesgncrD7+S6y_V=gjbFkY2Tifg@mail.gmail.com>
Signed-off-by: Oleksij Rempel <[email protected]>
Link: https://patch.msgid.link/[email protected]
Cc: [email protected]
[mkl: add Message-ID]
Signed-off-by: Marc Kleine-Budde <[email protected]>
---
 net/can/j1939/transport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/can/j1939/transport.c b/net/can/j1939/transport.c
index 98f96362b20f..8fcfd13e5e6f 100644
--- a/net/can/j1939/transport.c
+++ b/net/can/j1939/transport.c
@@ -1581,7 +1581,7 @@ j1939_session *j1939_session_fresh_new(struct j1939_priv *priv,
 	}
 
 	/* alloc data area */
-	skb_put(skb, size);
+	skb_put_zero(skb, size);
 	/* skb is recounted in j1939_session_new() */
 	return session;
 }
-- 
2.53.0