From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from metis.whiteo.stw.pengutronix.de (metis.whiteo.stw.pengutronix.de [185.203.201.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 9286C1FAC30 for ; Mon, 2 Dec 2024 09:00:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=185.203.201.7 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733130057; cv=none; b=gmb/YHQcB16SDpzUgd23IN0e95/SEEizjk29zieRamGy1RjdRn7KJ6M+ZD/IRFVlrXB02D//JGg1D7Kg7G1lY00o8edRSTgPzPLOQolbAeV+wRlT0UPPYZLSy/OoxiIpCtd/n+rFPrRKTfjL1SAsxoMZtREF2GEh8WrDOB2HNXc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733130057; c=relaxed/simple; bh=h8cCRu1JLjpWd3QOPsuwi9HGbd5UzGSlJPlOIXjshk8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=ONSZZGV3t1Tv9LdwDgn4wZpfWoDEXtwJ2z28Po5AJqdFFMvfZVFTSonl1JUPKiqnohlPhH+KFK5iEWV0eSM70k3umpRcEZcHhDY6vnUgEawkQFeyZOaydNAZtn8+OkLSHC3uN8bhlcyg0ueYGU4wmiB6lptMEMZTdMqljmxyCG4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de; spf=pass smtp.mailfrom=pengutronix.de; arc=none smtp.client-ip=185.203.201.7 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=pengutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=pengutronix.de Received: from drehscheibe.grey.stw.pengutronix.de ([2a0a:edc0:0:c01:1d::a2]) by metis.whiteo.stw.pengutronix.de with esmtps (TLS1.3:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1tI2IW-0007jT-DA for linux-can@vger.kernel.org; Mon, 02 Dec 2024 10:00:52 +0100 Received: from moin.white.stw.pengutronix.de ([2a0a:edc0:0:b01:1d::7b] helo=bjornoya.blackshift.org) by drehscheibe.grey.stw.pengutronix.de with esmtps (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1tI2IS-001Gch-3C for linux-can@vger.kernel.org; Mon, 02 Dec 2024 10:00:49 +0100 Received: from dspam.blackshift.org (localhost [127.0.0.1]) by bjornoya.blackshift.org (Postfix) with SMTP id 6F4A638339D for ; Mon, 02 Dec 2024 09:00:49 +0000 (UTC) Received: from hardanger.blackshift.org (unknown [172.20.34.65]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (Client did not present a certificate) by bjornoya.blackshift.org (Postfix) with ESMTPS id 3C527383344; Mon, 02 Dec 2024 09:00:46 +0000 (UTC) Received: from blackshift.org (localhost [::1]) by hardanger.blackshift.org (OpenSMTPD) with ESMTP id 6478a1cf; Mon, 2 Dec 2024 09:00:44 +0000 (UTC) From: Marc Kleine-Budde To: netdev@vger.kernel.org Cc: davem@davemloft.net, kuba@kernel.org, linux-can@vger.kernel.org, kernel@pengutronix.de, Dmitry Antipov , syzbot+d4e8dc385d9258220c31@syzkaller.appspotmail.com, Oleksij Rempel , Marc Kleine-Budde Subject: [PATCH net 15/15] can: j1939: j1939_session_new(): fix skb reference counting Date: Mon, 2 Dec 2024 09:55:49 +0100 Message-ID: <20241202090040.1110280-16-mkl@pengutronix.de> X-Mailer: git-send-email 2.45.2 In-Reply-To: <20241202090040.1110280-1-mkl@pengutronix.de> References: <20241202090040.1110280-1-mkl@pengutronix.de> Precedence: bulk X-Mailing-List: linux-can@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-SA-Exim-Connect-IP: 2a0a:edc0:0:c01:1d::a2 X-SA-Exim-Mail-From: mkl@pengutronix.de X-SA-Exim-Scanned: No (on metis.whiteo.stw.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-can@vger.kernel.org From: Dmitry Antipov Since j1939_session_skb_queue() does an extra skb_get() for each new skb, do the same for the initial one in j1939_session_new() to avoid refcount underflow. Reported-by: syzbot+d4e8dc385d9258220c31@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=d4e8dc385d9258220c31 Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol") Signed-off-by: Dmitry Antipov Tested-by: Oleksij Rempel Acked-by: Oleksij Rempel Link: https://patch.msgid.link/20241105094823.2403806-1-dmantipov@yandex.ru [mkl: clean up commit message] Signed-off-by: Marc Kleine-Budde --- 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 319f47df3330..95f7a7e65a73 100644 --- a/net/can/j1939/transport.c +++ b/net/can/j1939/transport.c @@ -1505,7 +1505,7 @@ static struct j1939_session *j1939_session_new(struct j1939_priv *priv, session->state = J1939_SESSION_NEW; skb_queue_head_init(&session->skb_queue); - skb_queue_tail(&session->skb_queue, skb); + skb_queue_tail(&session->skb_queue, skb_get(skb)); skcb = j1939_skb_to_cb(skb); memcpy(&session->skcb, skcb, sizeof(session->skcb)); -- 2.45.2