From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp153-163.sina.com.cn (smtp153-163.sina.com.cn [61.135.153.163]) (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 14EDB1E7C18 for ; Thu, 21 Aug 2025 08:48:03 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=61.135.153.163 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755766093; cv=none; b=Ca2h6rYOJJfB00D48rSgbOJwCpbV474ILwcg4SZxQ1tHpeZI5WHIlau1RSdTTdWt/scHvil2XDl8wZ7rF9+hSo1qrvL6M/7PD6ivu23SFsJ1VHhraqwr6plW+63dPB/5DmQzOJUjSo974yYtpNQSdE2YKr1aiUtRf41XRdYAPhk= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1755766093; c=relaxed/simple; bh=OsKkrYP2K1kZ5nL9zj3zSGW9MW+lhOQxhduKnhMKUJ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=TFyPYbRnkIKCjPb2uPYpMo4J7SRAz6jm8VyZYhtLdShZF88fgBT14CgLEdblr9c0qtCU8xctrd6IDb58Tyo9fSGoqeJZLTRJVpwmVs6cZeUZk4OT6MiP1PcXwO5o8FjWz/BqcYGGYlgifERU/xoQ6z7YXkcxTdT6tTtxl3pWvHU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com; spf=pass smtp.mailfrom=sina.com; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b=u8QbfY9E; arc=none smtp.client-ip=61.135.153.163 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=sina.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=sina.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=sina.com header.i=@sina.com header.b="u8QbfY9E" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=sina.com; s=201208; t=1755766084; bh=ASmlOtkq/5yE7hsUC/gPgPV7oXsMfgZPITdY5ZzM4xg=; h=From:Subject:Date:Message-ID; b=u8QbfY9EfduM9O2kYCYWym+r5b4iJYW8PHp0YW4wBbnzQpf9pcqV1Kbpf8CwoTCjx hj1taMc5pW7xj2hyak0UI3vwWexQTBYc45yDR790fe7qn26n51kGzhYKuzPGZizfW8 XEZwTLHVMiixmyxQu21ru3hCsHJMN8d6dbgof8Es= X-SMAIL-HELO: localhost.localdomain Received: from unknown (HELO localhost.localdomain)([114.249.58.236]) by sina.com (10.54.253.32) with ESMTP id 68A6DD3800005A96; Thu, 21 Aug 2025 16:47:53 +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: 8702004457044 X-SMAIL-UIID: 55F76CE797EA4A61B7127B1AF56606F0-20250821-164753-1 From: Hillf Danton To: syzbot Cc: linux-kernel@vger.kernel.org, syzkaller-bugs@googlegroups.com Subject: Re: [syzbot] [v9fs?] UBSAN: shift-out-of-bounds in v9fs_get_tree Date: Thu, 21 Aug 2025 16:47:33 +0800 Message-ID: <20250821084742.5216-1-hdanton@sina.com> In-Reply-To: <68a68b57.050a0220.3d78fd.0012.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 Wed, Aug 20, 2025 at 07:58:31PM -0700: > Hello, > > syzbot found the following issue on: > > HEAD commit: 3ac864c2d9bb Add linux-next specific files for 20250818 > git tree: linux-next > console+strace: https://syzkaller.appspot.com/x/log.txt?x=13706442580000 > kernel config: https://syzkaller.appspot.com/x/.config?x=6d1acc6b9e1fca1b > dashboard link: https://syzkaller.appspot.com/bug?extid=30c83da54e948f6e9436 > compiler: Debian clang version 20.1.7 (++20250616065708+6146a88f6049-1~exp1~20250616065826.132), Debian LLD 20.1.7 > syz repro: https://syzkaller.appspot.com/x/repro.syz?x=141586f0580000 > C reproducer: https://syzkaller.appspot.com/x/repro.c?x=124c9ba2580000 #syz test --- x/fs/9p/v9fs.c +++ y/fs/9p/v9fs.c @@ -302,6 +302,8 @@ int v9fs_parse_param(struct fs_context * p9_debug(P9_DEBUG_ERROR, "msize should be at least 4k\n"); return -EINVAL; } + if (result.uint_32 < P9_IOHDRSZ) + return -EINVAL; clnt->msize = result.uint_32; break; case Opt_trans: --