Revision 85bd839983778fcd0c1c043327b14a046e979b39 authored by Gu Zheng on 10 June 2015, 18:14:43 UTC, committed by Linus Torvalds on 10 June 2015, 23:43:43 UTC
Izumi found the following oops when hot re-adding a node:

    BUG: unable to handle kernel paging request at ffffc90008963690
    IP: __wake_up_bit+0x20/0x70
    Oops: 0000 [#1] SMP
    CPU: 68 PID: 1237 Comm: rs:main Q:Reg Not tainted 4.1.0-rc5 #80
    Hardware name: FUJITSU PRIMEQUEST2800E/SB, BIOS PRIMEQUEST 2000 Series BIOS Version 1.87 04/28/2015
    task: ffff880838df8000 ti: ffff880017b94000 task.ti: ffff880017b94000
    RIP: 0010:[<ffffffff810dff80>]  [<ffffffff810dff80>] __wake_up_bit+0x20/0x70
    RSP: 0018:ffff880017b97be8  EFLAGS: 00010246
    RAX: ffffc90008963690 RBX: 00000000003c0000 RCX: 000000000000a4c9
    RDX: 0000000000000000 RSI: ffffea101bffd500 RDI: ffffc90008963648
    RBP: ffff880017b97c08 R08: 0000000002000020 R09: 0000000000000000
    R10: 0000000000000000 R11: 0000000000000000 R12: ffff8a0797c73800
    R13: ffffea101bffd500 R14: 0000000000000001 R15: 00000000003c0000
    FS:  00007fcc7ffff700(0000) GS:ffff880874800000(0000) knlGS:0000000000000000
    CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
    CR2: ffffc90008963690 CR3: 0000000836761000 CR4: 00000000001407e0
    Call Trace:
      unlock_page+0x6d/0x70
      generic_write_end+0x53/0xb0
      xfs_vm_write_end+0x29/0x80 [xfs]
      generic_perform_write+0x10a/0x1e0
      xfs_file_buffered_aio_write+0x14d/0x3e0 [xfs]
      xfs_file_write_iter+0x79/0x120 [xfs]
      __vfs_write+0xd4/0x110
      vfs_write+0xac/0x1c0
      SyS_write+0x58/0xd0
      system_call_fastpath+0x12/0x76
    Code: 5d c3 66 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 48 89 e5 48 83 ec 20 65 48 8b 04 25 28 00 00 00 48 89 45 f8 31 c0 48 8d 47 48 <48> 39 47 48 48 c7 45 e8 00 00 00 00 48 c7 45 f0 00 00 00 00 48
    RIP  [<ffffffff810dff80>] __wake_up_bit+0x20/0x70
     RSP <ffff880017b97be8>
    CR2: ffffc90008963690

Reproduce method (re-add a node)::
  Hot-add nodeA --> remove nodeA --> hot-add nodeA (panic)

This seems an use-after-free problem, and the root cause is
zone->wait_table was not set to *NULL* after free it in
try_offline_node.

When hot re-add a node, we will reuse the pgdat of it, so does the zone
struct, and when add pages to the target zone, it will init the zone
first (including the wait_table) if the zone is not initialized.  The
judgement of zone initialized is based on zone->wait_table:

	static inline bool zone_is_initialized(struct zone *zone)
	{
		return !!zone->wait_table;
	}

so if we do not set the zone->wait_table to *NULL* after free it, the
memory hotplug routine will skip the init of new zone when hot re-add
the node, and the wait_table still points to the freed memory, then we
will access the invalid address when trying to wake up the waiting
people after the i/o operation with the page is done, such as mentioned
above.

Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Reported-by: Taku Izumi <izumi.taku@jp.fujitsu.com>
Reviewed by: Yasuaki Ishimatsu <isimatu.yasuaki@jp.fujitsu.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Tang Chen <tangchen@cn.fujitsu.com>
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 5879ae5
Raw File
ide-pnp.c
/*
 * This file provides autodetection for ISA PnP IDE interfaces.
 * It was tested with "ESS ES1868 Plug and Play AudioDrive" IDE interface.
 *
 * Copyright (C) 2000 Andrey Panin <pazke@donpac.ru>
 *
 * 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, or (at your option)
 * any later version.
 *
 * You should have received a copy of the GNU General Public License
 * (for example /usr/src/linux/COPYING); if not, write to the Free
 * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
 */

#include <linux/init.h>
#include <linux/pnp.h>
#include <linux/ide.h>
#include <linux/module.h>

#define DRV_NAME "ide-pnp"

/* Add your devices here :)) */
static struct pnp_device_id idepnp_devices[] = {
	/* Generic ESDI/IDE/ATA compatible hard disk controller */
	{.id = "PNP0600", .driver_data = 0},
	{.id = ""}
};

static const struct ide_port_info ide_pnp_port_info = {
	.host_flags		= IDE_HFLAG_NO_DMA,
	.chipset		= ide_generic,
};

static int idepnp_probe(struct pnp_dev *dev, const struct pnp_device_id *dev_id)
{
	struct ide_host *host;
	unsigned long base, ctl;
	int rc;
	struct ide_hw hw, *hws[] = { &hw };

	printk(KERN_INFO DRV_NAME ": generic PnP IDE interface\n");

	if (!(pnp_port_valid(dev, 0) && pnp_port_valid(dev, 1) && pnp_irq_valid(dev, 0)))
		return -1;

	base = pnp_port_start(dev, 0);
	ctl = pnp_port_start(dev, 1);

	if (!request_region(base, 8, DRV_NAME)) {
		printk(KERN_ERR "%s: I/O resource 0x%lX-0x%lX not free.\n",
				DRV_NAME, base, base + 7);
		return -EBUSY;
	}

	if (!request_region(ctl, 1, DRV_NAME)) {
		printk(KERN_ERR "%s: I/O resource 0x%lX not free.\n",
				DRV_NAME, ctl);
		release_region(base, 8);
		return -EBUSY;
	}

	memset(&hw, 0, sizeof(hw));
	ide_std_init_ports(&hw, base, ctl);
	hw.irq = pnp_irq(dev, 0);

	rc = ide_host_add(&ide_pnp_port_info, hws, 1, &host);
	if (rc)
		goto out;

	pnp_set_drvdata(dev, host);

	return 0;
out:
	release_region(ctl, 1);
	release_region(base, 8);

	return rc;
}

static void idepnp_remove(struct pnp_dev *dev)
{
	struct ide_host *host = pnp_get_drvdata(dev);

	ide_host_remove(host);

	release_region(pnp_port_start(dev, 1), 1);
	release_region(pnp_port_start(dev, 0), 8);
}

static struct pnp_driver idepnp_driver = {
	.name		= "ide",
	.id_table	= idepnp_devices,
	.probe		= idepnp_probe,
	.remove		= idepnp_remove,
};

module_pnp_driver(idepnp_driver);
MODULE_LICENSE("GPL");
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