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Revision 91874ecf32e41b5d86a4cb9d60e0bee50d828058 authored by Dmitry Safonov on 05 August 2018, 00:35:53 UTC, committed by David S. Miller on 05 August 2018, 00:52:51 UTC 
netlink: Don't shift on 64 for ngroups
 
It's legal to have 64 groups for netlink_sock.

As user-supplied nladdr->nl_groups is __u32, it's possible to subscribe
only to first 32 groups.

The check for correctness of .bind() userspace supplied parameter
is done by applying mask made from ngroups shift. Which broke Android
as they have 64 groups and the shift for mask resulted in an overflow.

Fixes: 61f4b23769f0 ("netlink: Don't shift with UB on nlk->ngroups")
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Steffen Klassert <steffen.klassert@secunet.com>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Reported-and-Tested-by: Nathan Chancellor <natechancellor@gmail.com>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
1 parent 5dbfb6e
Raw File
cmpdi2.c 
/*
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, see the file COPYING, or write
 * to the Free Software Foundation, Inc.
 */

#include <linux/export.h>

#include <linux/libgcc.h>

word_type notrace __cmpdi2(long long a, long long b)
{
	const DWunion au = {
		.ll = a
	};
	const DWunion bu = {
		.ll = b
	};

	if (au.s.high < bu.s.high)
		return 0;
	else if (au.s.high > bu.s.high)
		return 2;

	if ((unsigned int) au.s.low < (unsigned int) bu.s.low)
		return 0;
	else if ((unsigned int) au.s.low > (unsigned int) bu.s.low)
		return 2;

	return 1;
}
EXPORT_SYMBOL(__cmpdi2);
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