Revision da094e42848e3c36feaa3b5271e53983fd45424f authored by Prakash Gupta on 18 August 2017, 22:16:21 UTC, committed by Linus Torvalds on 18 August 2017, 22:32:02 UTC
name[] in cma_debugfs_add_one() can only accommodate 16 chars including
NULL to store sprintf output.  It's common for cma device name to be
larger than 15 chars.  This can cause stack corrpution.  If the gcc
stack protector is turned on, this can cause a panic due to stack
corruption.

Below is one example trace:

  Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in:
  ffffff8e69a75730
  Call trace:
     dump_backtrace+0x0/0x2c4
     show_stack+0x20/0x28
     dump_stack+0xb8/0xf4
     panic+0x154/0x2b0
     print_tainted+0x0/0xc0
     cma_debugfs_init+0x274/0x290
     do_one_initcall+0x5c/0x168
     kernel_init_freeable+0x1c8/0x280

Fix the short sprintf buffer in cma_debugfs_add_one() by using
scnprintf() instead of sprintf().

Link: http://lkml.kernel.org/r/1502446217-21840-1-git-send-email-guptap@codeaurora.org
Fixes: f318dd083c81 ("cma: Store a name in the cma structure")
Signed-off-by: Prakash Gupta <guptap@codeaurora.org>
Acked-by: Laura Abbott <labbott@redhat.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
1 parent eb61b59
Raw File
topology.h
/*
 * include/linux/topology.h
 *
 * Written by: Matthew Dobson, IBM Corporation
 *
 * Copyright (C) 2002, IBM Corp.
 *
 * All rights reserved.
 *
 * 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, GOOD TITLE or
 * NON INFRINGEMENT.  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, write to the Free Software
 * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 * Send feedback to <colpatch@us.ibm.com>
 */
#ifndef _LINUX_TOPOLOGY_H
#define _LINUX_TOPOLOGY_H

#include <linux/cpumask.h>
#include <linux/bitops.h>
#include <linux/mmzone.h>
#include <linux/smp.h>
#include <linux/percpu.h>
#include <asm/topology.h>

#ifndef nr_cpus_node
#define nr_cpus_node(node) cpumask_weight(cpumask_of_node(node))
#endif

#define for_each_node_with_cpus(node)			\
	for_each_online_node(node)			\
		if (nr_cpus_node(node))

int arch_update_cpu_topology(void);

/* Conform to ACPI 2.0 SLIT distance definitions */
#define LOCAL_DISTANCE		10
#define REMOTE_DISTANCE		20
#ifndef node_distance
#define node_distance(from,to)	((from) == (to) ? LOCAL_DISTANCE : REMOTE_DISTANCE)
#endif
#ifndef RECLAIM_DISTANCE
/*
 * If the distance between nodes in a system is larger than RECLAIM_DISTANCE
 * (in whatever arch specific measurement units returned by node_distance())
 * and node_reclaim_mode is enabled then the VM will only call node_reclaim()
 * on nodes within this distance.
 */
#define RECLAIM_DISTANCE 30
#endif
#ifndef PENALTY_FOR_NODE_WITH_CPUS
#define PENALTY_FOR_NODE_WITH_CPUS	(1)
#endif

#ifdef CONFIG_USE_PERCPU_NUMA_NODE_ID
DECLARE_PER_CPU(int, numa_node);

#ifndef numa_node_id
/* Returns the number of the current Node. */
static inline int numa_node_id(void)
{
	return raw_cpu_read(numa_node);
}
#endif

#ifndef cpu_to_node
static inline int cpu_to_node(int cpu)
{
	return per_cpu(numa_node, cpu);
}
#endif

#ifndef set_numa_node
static inline void set_numa_node(int node)
{
	this_cpu_write(numa_node, node);
}
#endif

#ifndef set_cpu_numa_node
static inline void set_cpu_numa_node(int cpu, int node)
{
	per_cpu(numa_node, cpu) = node;
}
#endif

#else	/* !CONFIG_USE_PERCPU_NUMA_NODE_ID */

/* Returns the number of the current Node. */
#ifndef numa_node_id
static inline int numa_node_id(void)
{
	return cpu_to_node(raw_smp_processor_id());
}
#endif

#endif	/* [!]CONFIG_USE_PERCPU_NUMA_NODE_ID */

#ifdef CONFIG_HAVE_MEMORYLESS_NODES

/*
 * N.B., Do NOT reference the '_numa_mem_' per cpu variable directly.
 * It will not be defined when CONFIG_HAVE_MEMORYLESS_NODES is not defined.
 * Use the accessor functions set_numa_mem(), numa_mem_id() and cpu_to_mem().
 */
DECLARE_PER_CPU(int, _numa_mem_);
extern int _node_numa_mem_[MAX_NUMNODES];

#ifndef set_numa_mem
static inline void set_numa_mem(int node)
{
	this_cpu_write(_numa_mem_, node);
	_node_numa_mem_[numa_node_id()] = node;
}
#endif

#ifndef node_to_mem_node
static inline int node_to_mem_node(int node)
{
	return _node_numa_mem_[node];
}
#endif

#ifndef numa_mem_id
/* Returns the number of the nearest Node with memory */
static inline int numa_mem_id(void)
{
	return raw_cpu_read(_numa_mem_);
}
#endif

#ifndef cpu_to_mem
static inline int cpu_to_mem(int cpu)
{
	return per_cpu(_numa_mem_, cpu);
}
#endif

#ifndef set_cpu_numa_mem
static inline void set_cpu_numa_mem(int cpu, int node)
{
	per_cpu(_numa_mem_, cpu) = node;
	_node_numa_mem_[cpu_to_node(cpu)] = node;
}
#endif

#else	/* !CONFIG_HAVE_MEMORYLESS_NODES */

#ifndef numa_mem_id
/* Returns the number of the nearest Node with memory */
static inline int numa_mem_id(void)
{
	return numa_node_id();
}
#endif

#ifndef node_to_mem_node
static inline int node_to_mem_node(int node)
{
	return node;
}
#endif

#ifndef cpu_to_mem
static inline int cpu_to_mem(int cpu)
{
	return cpu_to_node(cpu);
}
#endif

#endif	/* [!]CONFIG_HAVE_MEMORYLESS_NODES */

#ifndef topology_physical_package_id
#define topology_physical_package_id(cpu)	((void)(cpu), -1)
#endif
#ifndef topology_core_id
#define topology_core_id(cpu)			((void)(cpu), 0)
#endif
#ifndef topology_sibling_cpumask
#define topology_sibling_cpumask(cpu)		cpumask_of(cpu)
#endif
#ifndef topology_core_cpumask
#define topology_core_cpumask(cpu)		cpumask_of(cpu)
#endif

#ifdef CONFIG_SCHED_SMT
static inline const struct cpumask *cpu_smt_mask(int cpu)
{
	return topology_sibling_cpumask(cpu);
}
#endif

static inline const struct cpumask *cpu_cpu_mask(int cpu)
{
	return cpumask_of_node(cpu_to_node(cpu));
}


#endif /* _LINUX_TOPOLOGY_H */
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