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Revision 07998281c268592963e1cd623fe6ab0270b65ae4 authored by Florian Westphal on 05 February 2021, 11:56:43 UTC, committed by Pablo Neira Ayuso on 08 February 2021, 23:04:14 UTC 
netfilter: conntrack: skip identical origin tuple in same zone only
 
The origin skip check needs to re-test the zone. Else, we might skip
a colliding tuple in the reply direction.

This only occurs when using 'directional zones' where origin tuples
reside in different zones but the reply tuples share the same zone.

This causes the new conntrack entry to be dropped at confirmation time
because NAT clash resolution was elided.

Fixes: 4e35c1cb9460240 ("netfilter: nf_nat: skip nat clash resolution for same-origin entries")
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
1 parent ce7536b
Raw File
unc.c 
// SPDX-License-Identifier: GPL-2.0-or-later
/*
 *   Copyright (C) 2020, Microsoft Corporation.
 *
 *   Author(s): Steve French <stfrench@microsoft.com>
 *              Suresh Jayaraman <sjayaraman@suse.de>
 *              Jeff Layton <jlayton@kernel.org>
 */

#include <linux/fs.h>
#include <linux/slab.h>
#include <linux/inet.h>
#include <linux/ctype.h>
#include "cifsglob.h"
#include "cifsproto.h"

/* extract the host portion of the UNC string */
char *extract_hostname(const char *unc)
{
	const char *src;
	char *dst, *delim;
	unsigned int len;

	/* skip double chars at beginning of string */
	/* BB: check validity of these bytes? */
	if (strlen(unc) < 3)
		return ERR_PTR(-EINVAL);
	for (src = unc; *src && *src == '\\'; src++)
		;
	if (!*src)
		return ERR_PTR(-EINVAL);

	/* delimiter between hostname and sharename is always '\\' now */
	delim = strchr(src, '\\');
	if (!delim)
		return ERR_PTR(-EINVAL);

	len = delim - src;
	dst = kmalloc((len + 1), GFP_KERNEL);
	if (dst == NULL)
		return ERR_PTR(-ENOMEM);

	memcpy(dst, src, len);
	dst[len] = '\0';

	return dst;
}

char *extract_sharename(const char *unc)
{
	const char *src;
	char *delim, *dst;
	int len;

	/* skip double chars at the beginning */
	src = unc + 2;

	/* share name is always preceded by '\\' now */
	delim = strchr(src, '\\');
	if (!delim)
		return ERR_PTR(-EINVAL);
	delim++;
	len = strlen(delim);

	/* caller has to free the memory */
	dst = kstrndup(delim, len, GFP_KERNEL);
	if (!dst)
		return ERR_PTR(-ENOMEM);

	return dst;
}
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