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Revision 07718be265680dcf496347d475ce1a5442f55ad7 authored by Maxim Mikityanskiy on 10 June 2021, 16:40:30 UTC, committed by David S. Miller on 10 June 2021, 21:26:18 UTC 
mptcp: Fix out of bounds when parsing TCP options
 
The TCP option parser in mptcp (mptcp_get_options) could read one byte
out of bounds. When the length is 1, the execution flow gets into the
loop, reads one byte of the opcode, and if the opcode is neither
TCPOPT_EOL nor TCPOPT_NOP, it reads one more byte, which exceeds the
length of 1.

This fix is inspired by commit 9609dad263f8 ("ipv4: tcp_input: fix stack
out of bounds when parsing TCP options.").

Cc: Young Xiao <92siuyang@gmail.com>
Fixes: cec37a6e41aa ("mptcp: Handle MP_CAPABLE options for outgoing connections")
Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com>
Reviewed-by: Mat Martineau <mathew.j.martineau@linux.intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 5fc177a
Raw File
lowlevel.c 
/*
 * lowlevel.c
 *
 * PURPOSE
 *  Low Level Device Routines for the UDF filesystem
 *
 * COPYRIGHT
 *	This file is distributed under the terms of the GNU General Public
 *	License (GPL). Copies of the GPL can be obtained from:
 *		ftp://prep.ai.mit.edu/pub/gnu/GPL
 *	Each contributing author retains all rights to their own work.
 *
 *  (C) 1999-2001 Ben Fennema
 *
 * HISTORY
 *
 *  03/26/99 blf  Created.
 */

#include "udfdecl.h"

#include <linux/blkdev.h>
#include <linux/cdrom.h>
#include <linux/uaccess.h>

#include "udf_sb.h"

unsigned int udf_get_last_session(struct super_block *sb)
{
	struct cdrom_device_info *cdi = disk_to_cdi(sb->s_bdev->bd_disk);
	struct cdrom_multisession ms_info;

	if (!cdi) {
		udf_debug("CDROMMULTISESSION not supported.\n");
		return 0;
	}

	ms_info.addr_format = CDROM_LBA;
	if (cdrom_multisession(cdi, &ms_info) == 0) {
		udf_debug("XA disk: %s, vol_desc_start=%d\n",
			  ms_info.xa_flag ? "yes" : "no", ms_info.addr.lba);
		if (ms_info.xa_flag) /* necessary for a valid ms_info.addr */
			return ms_info.addr.lba;
	}
	return 0;
}

unsigned long udf_get_last_block(struct super_block *sb)
{
	struct block_device *bdev = sb->s_bdev;
	struct cdrom_device_info *cdi = disk_to_cdi(bdev->bd_disk);
	unsigned long lblock = 0;

	/*
	 * The cdrom layer call failed or returned obviously bogus value?
	 * Try using the device size...
	 */
	if (!cdi || cdrom_get_last_written(cdi, &lblock) || lblock == 0)
		lblock = i_size_read(bdev->bd_inode) >> sb->s_blocksize_bits;

	if (lblock)
		return lblock - 1;
	return 0;
}
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