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
Makefile
#
# Makefile for the Linux filesystems.
#
# 14 Sep 2000, Christoph Hellwig <hch@infradead.org>
# Rewritten to use lists instead of if-statements.
# 

obj-y :=	open.o read_write.o file_table.o super.o \
		char_dev.o stat.o exec.o pipe.o namei.o fcntl.o \
		ioctl.o readdir.o select.o dcache.o inode.o \
		attr.o bad_inode.o file.o filesystems.o namespace.o \
		seq_file.o xattr.o libfs.o fs-writeback.o \
		pnode.o splice.o sync.o utimes.o \
		stack.o fs_struct.o statfs.o fs_pin.o nsfs.o

ifeq ($(CONFIG_BLOCK),y)
obj-y +=	buffer.o block_dev.o direct-io.o mpage.o
else
obj-y +=	no-block.o
endif

obj-$(CONFIG_PROC_FS) += proc_namespace.o

obj-y				+= notify/
obj-$(CONFIG_EPOLL)		+= eventpoll.o
obj-$(CONFIG_ANON_INODES)	+= anon_inodes.o
obj-$(CONFIG_SIGNALFD)		+= signalfd.o
obj-$(CONFIG_TIMERFD)		+= timerfd.o
obj-$(CONFIG_EVENTFD)		+= eventfd.o
obj-$(CONFIG_AIO)               += aio.o
obj-$(CONFIG_FS_DAX)		+= dax.o
obj-$(CONFIG_FILE_LOCKING)      += locks.o
obj-$(CONFIG_COMPAT)		+= compat.o compat_ioctl.o
obj-$(CONFIG_BINFMT_AOUT)	+= binfmt_aout.o
obj-$(CONFIG_BINFMT_EM86)	+= binfmt_em86.o
obj-$(CONFIG_BINFMT_MISC)	+= binfmt_misc.o
obj-$(CONFIG_BINFMT_SCRIPT)	+= binfmt_script.o
obj-$(CONFIG_BINFMT_ELF)	+= binfmt_elf.o
obj-$(CONFIG_COMPAT_BINFMT_ELF)	+= compat_binfmt_elf.o
obj-$(CONFIG_BINFMT_ELF_FDPIC)	+= binfmt_elf_fdpic.o
obj-$(CONFIG_BINFMT_FLAT)	+= binfmt_flat.o

obj-$(CONFIG_FS_MBCACHE)	+= mbcache.o
obj-$(CONFIG_FS_POSIX_ACL)	+= posix_acl.o
obj-$(CONFIG_NFS_COMMON)	+= nfs_common/
obj-$(CONFIG_COREDUMP)		+= coredump.o
obj-$(CONFIG_SYSCTL)		+= drop_caches.o

obj-$(CONFIG_FHANDLE)		+= fhandle.o

obj-y				+= quota/

obj-$(CONFIG_PROC_FS)		+= proc/
obj-$(CONFIG_KERNFS)		+= kernfs/
obj-$(CONFIG_SYSFS)		+= sysfs/
obj-$(CONFIG_CONFIGFS_FS)	+= configfs/
obj-y				+= devpts/

obj-$(CONFIG_PROFILING)		+= dcookies.o
obj-$(CONFIG_DLM)		+= dlm/
 
# Do not add any filesystems before this line
obj-$(CONFIG_FSCACHE)		+= fscache/
obj-$(CONFIG_REISERFS_FS)	+= reiserfs/
obj-$(CONFIG_EXT3_FS)		+= ext3/ # Before ext2 so root fs can be ext3
obj-$(CONFIG_EXT2_FS)		+= ext2/
# We place ext4 after ext2 so plain ext2 root fs's are mounted using ext2
# unless explicitly requested by rootfstype
obj-$(CONFIG_EXT4_FS)		+= ext4/
obj-$(CONFIG_JBD)		+= jbd/
obj-$(CONFIG_JBD2)		+= jbd2/
obj-$(CONFIG_CRAMFS)		+= cramfs/
obj-$(CONFIG_SQUASHFS)		+= squashfs/
obj-y				+= ramfs/
obj-$(CONFIG_HUGETLBFS)		+= hugetlbfs/
obj-$(CONFIG_CODA_FS)		+= coda/
obj-$(CONFIG_MINIX_FS)		+= minix/
obj-$(CONFIG_FAT_FS)		+= fat/
obj-$(CONFIG_BFS_FS)		+= bfs/
obj-$(CONFIG_ISO9660_FS)	+= isofs/
obj-$(CONFIG_HFSPLUS_FS)	+= hfsplus/ # Before hfs to find wrapped HFS+
obj-$(CONFIG_HFS_FS)		+= hfs/
obj-$(CONFIG_ECRYPT_FS)		+= ecryptfs/
obj-$(CONFIG_VXFS_FS)		+= freevxfs/
obj-$(CONFIG_NFS_FS)		+= nfs/
obj-$(CONFIG_EXPORTFS)		+= exportfs/
obj-$(CONFIG_NFSD)		+= nfsd/
obj-$(CONFIG_LOCKD)		+= lockd/
obj-$(CONFIG_NLS)		+= nls/
obj-$(CONFIG_SYSV_FS)		+= sysv/
obj-$(CONFIG_CIFS)		+= cifs/
obj-$(CONFIG_NCP_FS)		+= ncpfs/
obj-$(CONFIG_HPFS_FS)		+= hpfs/
obj-$(CONFIG_NTFS_FS)		+= ntfs/
obj-$(CONFIG_UFS_FS)		+= ufs/
obj-$(CONFIG_EFS_FS)		+= efs/
obj-$(CONFIG_JFFS2_FS)		+= jffs2/
obj-$(CONFIG_LOGFS)		+= logfs/
obj-$(CONFIG_UBIFS_FS)		+= ubifs/
obj-$(CONFIG_AFFS_FS)		+= affs/
obj-$(CONFIG_ROMFS_FS)		+= romfs/
obj-$(CONFIG_QNX4FS_FS)		+= qnx4/
obj-$(CONFIG_QNX6FS_FS)		+= qnx6/
obj-$(CONFIG_AUTOFS4_FS)	+= autofs4/
obj-$(CONFIG_ADFS_FS)		+= adfs/
obj-$(CONFIG_FUSE_FS)		+= fuse/
obj-$(CONFIG_OVERLAY_FS)	+= overlayfs/
obj-$(CONFIG_UDF_FS)		+= udf/
obj-$(CONFIG_SUN_OPENPROMFS)	+= openpromfs/
obj-$(CONFIG_OMFS_FS)		+= omfs/
obj-$(CONFIG_JFS_FS)		+= jfs/
obj-$(CONFIG_XFS_FS)		+= xfs/
obj-$(CONFIG_9P_FS)		+= 9p/
obj-$(CONFIG_AFS_FS)		+= afs/
obj-$(CONFIG_NILFS2_FS)		+= nilfs2/
obj-$(CONFIG_BEFS_FS)		+= befs/
obj-$(CONFIG_HOSTFS)		+= hostfs/
obj-$(CONFIG_HPPFS)		+= hppfs/
obj-$(CONFIG_CACHEFILES)	+= cachefiles/
obj-$(CONFIG_DEBUG_FS)		+= debugfs/
obj-$(CONFIG_TRACING)		+= tracefs/
obj-$(CONFIG_OCFS2_FS)		+= ocfs2/
obj-$(CONFIG_BTRFS_FS)		+= btrfs/
obj-$(CONFIG_GFS2_FS)           += gfs2/
obj-$(CONFIG_F2FS_FS)		+= f2fs/
obj-y				+= exofs/ # Multiple modules
obj-$(CONFIG_CEPH_FS)		+= ceph/
obj-$(CONFIG_PSTORE)		+= pstore/
obj-$(CONFIG_EFIVAR_FS)		+= efivarfs/
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