From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ot1-f72.google.com (mail-ot1-f72.google.com [209.85.210.72]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 6BF8718DB2A for ; Wed, 22 Apr 2026 02:12:16 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.210.72 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776823937; cv=none; b=K8tsK9WUvAOheBwJbx6zXVabeeKJry9XUH5M6QnyDatCTjvi0IJ3gjISok/A0CBwaIVDW4wemwwBxXq4ahAfPG7UZwnK6Fwh71CZobHvFi0g7YNcf4LvNI5aPXYsh6/2N/luoLASEBz1XCkMG8bFKApz2XsyMGKVJw1KuUXO4Iw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1776823937; c=relaxed/simple; bh=aQ3HBUjuOUn/24dO9X6JOJXSqNwvDSIrGbLk2NUHYiE=; h=MIME-Version:Date:In-Reply-To:Message-ID:Subject:From:To: Content-Type; b=VzJXhxeH3HsaQvhiXfTQYgda//1ODIBjEsjyrWVJJnZkVcp6mmUDl04eLjZbpBWThp5CvUAyC+Mr98eVAno8rfNyqWN9lOarhXwX3NptyDm2cn2FUg+lpLlIVEqqctyT6nx8+SBA+JwRAQZ4R17Cf461I19ZYwRoMhJBp56eLIs= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com; arc=none smtp.client-ip=209.85.210.72 Authentication-Results: smtp.subspace.kernel.org; dmarc=fail (p=none dis=none) header.from=syzkaller.appspotmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=M3KW2WVRGUFZ5GODRSRYTGD7.apphosting.bounces.google.com Received: by mail-ot1-f72.google.com with SMTP id 46e09a7af769-7dbc56f5290so12122640a34.0 for ; Tue, 21 Apr 2026 19:12:16 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20251104; t=1776823935; x=1777428735; h=to:from:subject:message-id:in-reply-to:date:mime-version :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=IanodQBYKLwJmWbPLGxS+ZCzOXiHVbOD/G10Bfh4Y5E=; b=Nuby/uN8xEfoo0xj5pkOfuSv9l5JMgN7cSjLigGL94B082m9IIbko9nrj+8JoPGPYE 1YcFHx5B7/XHgeXFE2YU5tCWBuqt2iiP57JA+0EUCSbL/H/+A9s3rW/srbzls1iWbAW2 z8yWFB5VCBfwkQodOlOEN7c7glAOavKQyojfGWUZBuw84W8szGeGhthExxzM3Mb++rbr CrseVPWa+lqfmnf8oKhpl9xufJM8noYY6SXeR4cSjVb1Qi6lNHjcz4U264Ht/m8RU2S0 bZ+GLytzCI4k+M9QmYU/B2HMV57YHOzj0LFQyDSAvQHQ1YJOqFLbK+ch23AA2xhLS6fS odIA== X-Gm-Message-State: AOJu0Yw/c5YXH1R1GFM2UJamP+eTPWJlp3bSc1pyzhWS5/lf1mIvKKX3 gs8vLEoKUHeY+VYRJchuiuj74F8e01Lwy2vAlaYJRVFTkeskVEUStg1WngNPgM2H6wlzxPn9S/G pOkr3XUx0GcfJyFe849VBSJQpV4IwM3t+JYtoPxEYhBPFrESQuBjdYobiDqc= Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Received: by 2002:a05:6820:604:b0:689:7cd7:259e with SMTP id 006d021491bc7-69462f44c08mr12247976eaf.57.1776823935335; Tue, 21 Apr 2026 19:12:15 -0700 (PDT) Date: Tue, 21 Apr 2026 19:12:15 -0700 In-Reply-To: <69e8054c.a00a0220.9259.0016.GAE@google.com> X-Google-Appengine-App-Id: s~syzkaller X-Google-Appengine-App-Id-Alias: syzkaller Message-ID: <69e82e7f.a00a0220.17a17.0020.GAE@google.com> Subject: Forwarded: [PATCH] net: phonet: fix BUG_ON() in pn_socket_autobind() From: syzbot To: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Content-Type: text/plain; charset="UTF-8" For archival purposes, forwarding an incoming command email to linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com. *** Subject: [PATCH] net: phonet: fix BUG_ON() in pn_socket_autobind() Author: kartikey406@gmail.com #syz test: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git master pn_socket_autobind() calls pn_socket_bind() and treats -EINVAL as a signal that the socket was already bound, then uses BUG_ON() to verify it: if (err != -EINVAL) return err; BUG_ON(!pn_port(pn_sk(sock->sk)->sobject)); However, pn_socket_bind() returns -EINVAL in multiple cases: 1. address length too short 2. socket not in TCP_CLOSE state 3. socket already bound <- only intended case When -EINVAL comes from cases 1 or 2, sobject is still zero (never assigned), causing BUG_ON to fire and crash the kernel. Fix this by checking the bound state directly via pn_port(sobject) BEFORE calling pn_socket_bind(), eliminating the ambiguous -EINVAL interpretation entirely. Reported-by: syzbot+706f5eb79044e686c794@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=706f5eb79044e686c794 Signed-off-by: Deepanshu Kartikey --- net/phonet/socket.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) diff --git a/net/phonet/socket.c b/net/phonet/socket.c index c4af26357144..5a55e7d14e85 100644 --- a/net/phonet/socket.c +++ b/net/phonet/socket.c @@ -204,14 +204,14 @@ static int pn_socket_autobind(struct socket *sock) struct sockaddr_pn sa; int err; + if (pn_port(pn_sk(sock->sk)->sobject)) + return 0; /* socket was already bound */ + memset(&sa, 0, sizeof(sa)); sa.spn_family = AF_PHONET; err = pn_socket_bind(sock, (struct sockaddr_unsized *)&sa, sizeof(struct sockaddr_pn)); - if (err != -EINVAL) - return err; - BUG_ON(!pn_port(pn_sk(sock->sk)->sobject)); - return 0; /* socket was already bound */ + return err; } static int pn_socket_connect(struct socket *sock, struct sockaddr_unsized *addr, -- 2.43.0