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Revision 1d6a821277aaa0cdd666278aaff93298df313d41 authored by Marc Zyngier on 15 February 2016, 17:04:04 UTC, committed by Marc Zyngier on 24 February 2016, 11:53:09 UTC 
arm/arm64: KVM: Feed initialized memory to MMIO accesses
 
On an MMIO access, we always copy the on-stack buffer info
the shared "run" structure, even if this is a read access.
This ends up leaking up to 8 bytes of uninitialized memory
into userspace, depending on the size of the access.

An obvious fix for this one is to only perform the copy if
this is an actual write.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
1 parent 236cf17
Raw File
proc.c 
/* FS-Cache statistics viewing interface
 *
 * Copyright (C) 2007 Red Hat, Inc. All Rights Reserved.
 * Written by David Howells (dhowells@redhat.com)
 *
 * 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.
 */

#define FSCACHE_DEBUG_LEVEL OPERATION
#include <linux/module.h>
#include <linux/proc_fs.h>
#include <linux/seq_file.h>
#include "internal.h"

/*
 * initialise the /proc/fs/fscache/ directory
 */
int __init fscache_proc_init(void)
{
	_enter("");

	if (!proc_mkdir("fs/fscache", NULL))
		goto error_dir;

#ifdef CONFIG_FSCACHE_STATS
	if (!proc_create("fs/fscache/stats", S_IFREG | 0444, NULL,
			 &fscache_stats_fops))
		goto error_stats;
#endif

#ifdef CONFIG_FSCACHE_HISTOGRAM
	if (!proc_create("fs/fscache/histogram", S_IFREG | 0444, NULL,
			 &fscache_histogram_fops))
		goto error_histogram;
#endif

#ifdef CONFIG_FSCACHE_OBJECT_LIST
	if (!proc_create("fs/fscache/objects", S_IFREG | 0444, NULL,
			 &fscache_objlist_fops))
		goto error_objects;
#endif

	_leave(" = 0");
	return 0;

#ifdef CONFIG_FSCACHE_OBJECT_LIST
error_objects:
#endif
#ifdef CONFIG_FSCACHE_HISTOGRAM
	remove_proc_entry("fs/fscache/histogram", NULL);
error_histogram:
#endif
#ifdef CONFIG_FSCACHE_STATS
	remove_proc_entry("fs/fscache/stats", NULL);
error_stats:
#endif
	remove_proc_entry("fs/fscache", NULL);
error_dir:
	_leave(" = -ENOMEM");
	return -ENOMEM;
}

/*
 * clean up the /proc/fs/fscache/ directory
 */
void fscache_proc_cleanup(void)
{
#ifdef CONFIG_FSCACHE_OBJECT_LIST
	remove_proc_entry("fs/fscache/objects", NULL);
#endif
#ifdef CONFIG_FSCACHE_HISTOGRAM
	remove_proc_entry("fs/fscache/histogram", NULL);
#endif
#ifdef CONFIG_FSCACHE_STATS
	remove_proc_entry("fs/fscache/stats", NULL);
#endif
	remove_proc_entry("fs/fscache", NULL);
}
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