From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp134-32.sina.com.cn (smtp134-32.sina.com.cn [180.149.134.32]) (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 AC0741CF2B1 for ; Thu, 3 Oct 2024 23:35:06 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=180.149.134.32 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727998515; cv=none; b=Kcazqh9/eTuTDEUuLWA06nNd7bji1eGo4a1RNDLGRyjTUPwZKqL/tv2JA/gzRbEWwCh9k7qOdU6K9le4Qlr0OliatwBDmVjeRVk2czdkhgcH7TEf07Q9nCRx8EkgePi0MwCit73w/KOH0GqANxsVzCD1PMHILMlUww7P4U0csj4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1727998515; c=relaxed/simple; bh=3woJkjGUddP3kur6qF8w7Nq0F98nXvjCoUytNpvgTl4=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=g6VMYDHjA1aNzovJZFXC8LZXwW9esfSdd+hMw9R0/CmKJV2+1DrCIcmRlI2ZHfkZVQuyhhCUY+Xxzlp7Ua488IDpSyOMJtw80JVy0NMG5EgV84Wjqv82Sxx/6crXYiG9FaSK0pw8Lt7NHtyCXsZrSCVH3LTaBpuOzSPeCwyPxSo= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; arc=none smtp.client-ip=180.149.134.32 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([113.118.68.49]) by sina.com (10.185.250.21) with ESMTP id 66FF2A250000688C; Thu, 4 Oct 2024 07:35:03 +0800 (CST) X-Sender: hdanton@sina.com X-Auth-ID: hdanton@sina.com Authentication-Results: sina.com; spf=none smtp.mailfrom=hdanton@sina.com; dkim=none header.i=none; dmarc=none action=none header.from=hdanton@sina.com X-SMAIL-MID: 6250673408462 X-SMAIL-UIID: 1B12A4FF89A14B7EA2CD1CD75E5153D5-20241004-073503-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [can?] WARNING: refcount bug in sk_skb_reason_drop Date: Fri, 4 Oct 2024 07:34:52 +0800 Message-Id: <20241003233452.2044-1-hdanton@sina.com> In-Reply-To: <66fec2e2.050a0220.9ec68.0046.GAE@google.com> References: Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit On Thu, 03 Oct 2024 09:14:26 -0700 > syzbot found the following issue on: > > HEAD commit: a430d95c5efa Merge tag 'lsm-pr-20240911' of git://git.kern.. > git tree: upstream > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=15b9a607980000 #syz test --- x/net/can/j1939/transport.c +++ y/net/can/j1939/transport.c @@ -1506,6 +1506,7 @@ static struct j1939_session *j1939_sessi skb_queue_head_init(&session->skb_queue); skb_queue_tail(&session->skb_queue, skb); + skb_get(skb); skcb = j1939_skb_to_cb(skb); memcpy(&session->skcb, skcb, sizeof(session->skcb)); --