From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 524E2146586; Thu, 11 Apr 2024 10:02:50 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712829770; cv=none; b=lbpfW0+a7mg2m/k5ji655v6Qcx3GomLdk5E3V7rRkf2jKGg3lSxml3S3MGEHlnSg8rcd2zzeeucgMW6YCpaI0k2LkzUm/JLf64Ds/Yu6V4l4QFjkJbtp+poBh6Y1QITp8Kr/sTzpIZ2Zb6rQvWbLye6klqX1YxZMEBcMR8zPZN8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1712829770; c=relaxed/simple; bh=qSby5htH1b5p6cHfDUIYv8mCWaEmyoHDFm+a8zpdIq0=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cAE/iwM0oUEPVOBOZti+AxjAGfIfrZXIf2btdTb/JQ0y64nZX7/ky3JvaN14kCosklIADqItzHEPtGVVpX5SUN363PHSpU4dC1AEKDbXZqzNmk90+yCuqixrDhdPOGs/hH4Rd024wjDsWYa2S0q1OmjjRqzzU3s7JEyD7ZU9f8k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=GmUY8hLo; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="GmUY8hLo" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C89BFC433F1; Thu, 11 Apr 2024 10:02:49 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1712829770; bh=qSby5htH1b5p6cHfDUIYv8mCWaEmyoHDFm+a8zpdIq0=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=GmUY8hLo2iqDcQHB7rUhAz82XeK2aAt1LqTbvq3Gq/QTb9tUHRRiDkZbRd5n0K8MJ QVkpLWtAiyPV1osbRvIQkhV2wkl06Va+eNhi8DaxAa3xJyLGiVXub4CoTUrW+6RtvI Xv1rRQ7mZipl11M9KhGXOhRzT1BnOmTNRD+wreSw= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, "Matthew Wilcox (Oracle)" , Siddh Raman Pant , Christoph Hellwig , Jens Axboe , Genjian Zhang , syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com Subject: [PATCH 4.19 099/175] loop: Check for overflow while configuring loop Date: Thu, 11 Apr 2024 11:55:22 +0200 Message-ID: <20240411095422.549754053@linuxfoundation.org> X-Mailer: git-send-email 2.44.0 In-Reply-To: <20240411095419.532012976@linuxfoundation.org> References: <20240411095419.532012976@linuxfoundation.org> User-Agent: quilt/0.67 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 4.19-stable review patch. If anyone has any objections, please let me know. ------------------ From: Siddh Raman Pant [ Upstream commit c490a0b5a4f36da3918181a8acdc6991d967c5f3 ] The userspace can configure a loop using an ioctl call, wherein a configuration of type loop_config is passed (see lo_ioctl()'s case on line 1550 of drivers/block/loop.c). This proceeds to call loop_configure() which in turn calls loop_set_status_from_info() (see line 1050 of loop.c), passing &config->info which is of type loop_info64*. This function then sets the appropriate values, like the offset. loop_device has lo_offset of type loff_t (see line 52 of loop.c), which is typdef-chained to long long, whereas loop_info64 has lo_offset of type __u64 (see line 56 of include/uapi/linux/loop.h). The function directly copies offset from info to the device as follows (See line 980 of loop.c): lo->lo_offset = info->lo_offset; This results in an overflow, which triggers a warning in iomap_iter() due to a call to iomap_iter_done() which has: WARN_ON_ONCE(iter->iomap.offset > iter->pos); Thus, check for negative value during loop_set_status_from_info(). Bug report: https://syzkaller.appspot.com/bug?id=c620fe14aac810396d3c3edc9ad73848bf69a29e Reported-and-tested-by: syzbot+a8e049cd3abd342936b6@syzkaller.appspotmail.com Cc: stable@vger.kernel.org Reviewed-by: Matthew Wilcox (Oracle) Signed-off-by: Siddh Raman Pant Reviewed-by: Christoph Hellwig Link: https://lore.kernel.org/r/20220823160810.181275-1-code@siddh.me Signed-off-by: Jens Axboe Signed-off-by: Genjian Zhang Signed-off-by: Greg Kroah-Hartman --- drivers/block/loop.c | 5 +++++ 1 file changed, 5 insertions(+) --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -1271,6 +1271,11 @@ loop_set_status_from_info(struct loop_de lo->lo_offset = info->lo_offset; lo->lo_sizelimit = info->lo_sizelimit; + + /* loff_t vars have been assigned __u64 */ + if (lo->lo_offset < 0 || lo->lo_sizelimit < 0) + return -EOVERFLOW; + memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); lo->lo_file_name[LO_NAME_SIZE-1] = 0;