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Revision b5d281f6c16dd432b618bdfd36ddba1a58d5b603 authored by Christian Marangi on 19 June 2022, 22:03:51 UTC, committed by Chanwoo Choi on 29 June 2022, 20:11:17 UTC 
PM / devfreq: Rework freq_table to be local to devfreq struct
 
On a devfreq PROBE_DEFER, the freq_table in the driver profile struct,
is never reset and may be leaved in an undefined state.

This comes from the fact that we store the freq_table in the driver
profile struct that is commonly defined as static and not reset on
PROBE_DEFER.
We currently skip the reinit of the freq_table if we found
it's already defined since a driver may declare his own freq_table.

This logic is flawed in the case devfreq core generate a freq_table, set
it in the profile struct and then PROBE_DEFER, freeing the freq_table.
In this case devfreq will found a NOT NULL freq_table that has been
freed, skip the freq_table generation and probe the driver based on the
wrong table.

To fix this and correctly handle PROBE_DEFER, use a local freq_table and
max_state in the devfreq struct and never modify the freq_table present
in the profile struct if it does provide it.

Fixes: 0ec09ac2cebe ("PM / devfreq: Set the freq_table of devfreq device")
Cc: stable@vger.kernel.org
Signed-off-by: Christian Marangi <ansuelsmth@gmail.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
1 parent f44b799
Raw File
list_debug.c 
/*
 * Copyright 2006, Red Hat, Inc., Dave Jones
 * Released under the General Public License (GPL).
 *
 * This file contains the linked list validation for DEBUG_LIST.
 */

#include <linux/export.h>
#include <linux/list.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/rculist.h>

/*
 * Check that the data structures for the list manipulations are reasonably
 * valid. Failures here indicate memory corruption (and possibly an exploit
 * attempt).
 */

bool __list_add_valid(struct list_head *new, struct list_head *prev,
		      struct list_head *next)
{
	if (CHECK_DATA_CORRUPTION(next->prev != prev,
			"list_add corruption. next->prev should be prev (%px), but was %px. (next=%px).\n",
			prev, next->prev, next) ||
	    CHECK_DATA_CORRUPTION(prev->next != next,
			"list_add corruption. prev->next should be next (%px), but was %px. (prev=%px).\n",
			next, prev->next, prev) ||
	    CHECK_DATA_CORRUPTION(new == prev || new == next,
			"list_add double add: new=%px, prev=%px, next=%px.\n",
			new, prev, next))
		return false;

	return true;
}
EXPORT_SYMBOL(__list_add_valid);

bool __list_del_entry_valid(struct list_head *entry)
{
	struct list_head *prev, *next;

	prev = entry->prev;
	next = entry->next;

	if (CHECK_DATA_CORRUPTION(next == LIST_POISON1,
			"list_del corruption, %px->next is LIST_POISON1 (%px)\n",
			entry, LIST_POISON1) ||
	    CHECK_DATA_CORRUPTION(prev == LIST_POISON2,
			"list_del corruption, %px->prev is LIST_POISON2 (%px)\n",
			entry, LIST_POISON2) ||
	    CHECK_DATA_CORRUPTION(prev->next != entry,
			"list_del corruption. prev->next should be %px, but was %px. (prev=%px)\n",
			entry, prev->next, prev) ||
	    CHECK_DATA_CORRUPTION(next->prev != entry,
			"list_del corruption. next->prev should be %px, but was %px. (next=%px)\n",
			entry, next->prev, next))
		return false;

	return true;

}
EXPORT_SYMBOL(__list_del_entry_valid);
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