linux-stable/fs
David Rientjes cbce468a26 mm: close PageTail race
commit 668f9abbd4 upstream.

Commit bf6bddf192 ("mm: introduce compaction and migration for
ballooned pages") introduces page_count(page) into memory compaction
which dereferences page->first_page if PageTail(page).

This results in a very rare NULL pointer dereference on the
aforementioned page_count(page).  Indeed, anything that does
compound_head(), including page_count() is susceptible to racing with
prep_compound_page() and seeing a NULL or dangling page->first_page
pointer.

This patch uses Andrea's implementation of compound_trans_head() that
deals with such a race and makes it the default compound_head()
implementation.  This includes a read memory barrier that ensures that
if PageTail(head) is true that we return a head page that is neither
NULL nor dangling.  The patch then adds a store memory barrier to
prep_compound_page() to ensure page->first_page is set.

This is the safest way to ensure we see the head page that we are
expecting, PageTail(page) is already in the unlikely() path and the
memory barriers are unfortunately required.

Hugetlbfs is the exception, we don't enforce a store memory barrier
during init since no race is possible.

Signed-off-by: David Rientjes <rientjes@google.com>
Cc: Holger Kiehl <Holger.Kiehl@dwd.de>
Cc: Christoph Lameter <cl@linux.com>
Cc: Rafael Aquini <aquini@redhat.com>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-04-03 12:02:37 -07:00
..
9p consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
adfs adfs: delayed freeing of sbi 2013-10-24 23:43:27 -04:00
affs remove obsolete references to powertweak 2013-11-27 20:34:32 -08:00
afs Merge branch 'fscache' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs into linux-next 2013-10-28 19:36:46 -04:00
autofs4 autofs4: make freeing sbi rcu-delayed 2013-10-24 23:43:27 -04:00
befs befs: split symlink iops in two - for short and long symlinks resp. 2013-10-24 23:34:50 -04:00
bfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
btrfs Btrfs: fix data corruption when reading/updating compressed extents 2014-03-23 21:44:19 -07:00
cachefiles Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
ceph ceph: Avoid data inconsistency due to d-cache aliasing in readpage() 2013-12-13 09:11:38 -08:00
cifs CIFS: Fix too big maxBuf size for SMB3 mounts 2014-03-06 22:06:10 -08:00
coda coda_revalidate_inode(): switch to passing inode... 2013-11-09 00:16:21 -05:00
configfs configfs: fix race between dentry put and lookup 2013-11-21 16:42:27 -08:00
cramfs cramfs: mark as obsolete 2013-11-13 12:09:12 +09:00
debugfs debugfs: use list_next_entry() in debugfs_remove_recursive() 2013-11-13 12:09:24 +09:00
devpts devpts: plug the memory leak in kill_sb 2013-11-13 12:09:36 +09:00
dlm genetlink: only pass array to genl_register_family_with_ops() 2013-11-19 16:39:05 -05:00
ecryptfs Quiet static checkers by removing unneeded conditionals 2013-11-22 10:58:14 -08:00
efivarfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
efs efs: iget_locked() doesn't return an ERR_PTR() 2013-08-24 12:10:22 -04:00
exofs ore: Fix wrong math in allocation of per device BIO 2014-02-13 13:55:32 -08:00
exportfs exportfs: fix quadratic behavior in filehandle lookup 2013-11-09 00:16:38 -05:00
ext2 ext2: Fix oops in ext2_get_block() called from ext2_quota_write() 2013-12-04 12:26:51 +01:00
ext3 Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2013-11-13 15:25:47 +09:00
ext4 ext4: atomically set inode->i_flags in ext4_set_inode_flags() 2014-04-03 12:02:34 -07:00
f2fs f2fs: issue more large discard command 2013-11-11 09:36:32 +09:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs [readdir] convert freevxfs 2013-06-29 12:56:53 +04:00
fscache Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
fuse fuse: fix pipe_buf_operations 2014-02-13 13:55:27 -08:00
gfs2 GFS2: Increase i_writecount during gfs2_setattr_chown 2014-01-29 05:06:18 -08:00
hfs fs/hfs/btree.h: remove duplicate defines 2013-11-13 12:09:32 +09:00
hfsplus block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
hostfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
hpfs hpfs: remember free space 2014-02-06 11:34:10 -08:00
hppfs clean up scary strncpy(dst, src, strlen(src)) uses 2013-07-03 16:07:41 -07:00
hugetlbfs cope with potentially long ->d_dname() output for shmem/hugetlb 2013-08-24 12:10:17 -04:00
isofs isofs: don't pass dentry to isofs_hash{i,}_common() 2013-10-24 23:34:59 -04:00
jbd jbd: Revert "jbd: remove dependency on __GFP_NOFAIL" 2013-10-31 20:37:15 +01:00
jbd2 jbd2: fix use after free in jbd2_journal_start_reserved() 2014-03-06 22:06:09 -08:00
jffs2 jffs2: do not support the MLC nand 2013-10-27 16:27:07 -07:00
jfs Just a patch to fix an oops in an error path. 2013-10-22 09:01:11 +01:00
lockd lockd: send correct lock when granting a delayed lock. 2014-02-22 13:34:46 -08:00
logfs block: submit_bio_wait() conversions 2013-11-24 16:33:41 -07:00
minix fs/minix: Drop dependency on H8300 2013-09-16 18:20:25 -07:00
ncpfs ncpfs: rcu-delay unload_nls() and freeing ncp_server 2013-10-24 23:43:28 -04:00
nfs NFSv4: Use the correct net namespace in nfs4_update_server 2014-03-31 10:05:14 -07:00
nfs_common
nfsd nfsd: when reusing an existing repcache entry, unhash it first 2013-12-10 20:34:44 -05:00
nilfs2 nilfs2: fix segctor bug that causes file system corruption 2014-01-15 14:19:42 +07:00
nls
notify compat: fix sys_fanotify_mark 2014-02-13 13:55:31 -08:00
ntfs iget/iget5: don't bother with ->i_lock until we find a match 2013-11-09 00:16:31 -05:00
ocfs2 ocfs2 syncs the wrong range... 2014-03-23 21:43:59 -07:00
omfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
openpromfs [readdir] convert openpromfs 2013-06-29 12:56:32 +04:00
proc mm: close PageTail race 2014-04-03 12:02:37 -07:00
pstore pstore: Don't allow high traffic options on fragile devices 2013-12-20 13:12:01 -08:00
qnx4 qnx4: i_sb is never NULL 2013-11-09 00:16:32 -05:00
qnx6 [readdir] convert qnx6 2013-06-29 12:56:39 +04:00
quota quota: Fix race between dqput() and dquot_scan_active() 2014-03-06 22:06:28 -08:00
ramfs initmpfs: move rootfs code from fs/ramfs/ to init/ 2013-09-11 15:59:37 -07:00
reiserfs reiserfs: fix race with flush_used_journal_lists and flush_journal_list 2013-09-24 11:24:21 +02:00
romfs [readdir] convert romfs 2013-06-29 12:56:29 +04:00
squashfs Squashfs: fix failure to unlock pages on decompress error 2013-11-24 01:02:50 +00:00
sysfs sysfs: give different locking key to regular and bin files 2013-12-07 21:22:00 -08:00
sysv sysv: Add forgotten superblock lock init for v7 fs 2013-09-29 22:02:02 -04:00
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
udf udf: fix for pathetic mount times in case of invalid file system 2013-10-18 22:39:07 +02:00
ufs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
xfs Revert "writeback: do not sync data dirtied after sync start" 2014-03-06 22:06:22 -08:00
aio.c Merge git://git.kvack.org/~bcrl/aio-next 2013-12-22 11:03:49 -08:00
anon_inodes.c ... and kill anon_inode_getfile_private() 2013-11-09 00:16:28 -05:00
attr.c fs: fix iversion handling 2014-03-06 22:06:18 -08:00
bad_inode.c [readdir] ->readdir() is gone 2013-06-29 12:57:04 +04:00
binfmt_aout.c dump_skip(): dump_seek() replacement taking coredump_params 2013-11-09 00:16:26 -05:00
binfmt_elf_fdpic.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_elf.c elf{,_fdpic} coredump: get rid of pointless if (siginfo->si_signo) 2013-11-09 00:16:30 -05:00
binfmt_em86.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
binfmt_flat.c new helper: read_code() 2013-04-29 15:40:23 -04:00
binfmt_misc.c binfmt_misc: reuse string_unescape_inplace() 2013-04-30 17:04:03 -07:00
binfmt_script.c
binfmt_som.c
bio-integrity.c bio-integrity: Fix bio_integrity_verify segment start bug 2014-03-23 21:44:20 -07:00
bio.c bio: fix argument of __bio_add_page() for max_sectors > 0xffff 2013-11-18 12:31:27 -07:00
block_dev.c a trivial writeback fix 2013-09-13 23:06:40 -04:00
buffer.c mm: __set_page_dirty uses spin_lock_irqsave instead of spin_lock_irq 2014-02-20 11:10:09 -08:00
char_dev.c Merge branch 'for-3.13/core' of git://git.kernel.dk/linux-block 2013-11-14 12:08:14 +09:00
compat_binfmt_elf.c
compat_ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
compat.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
coredump.c dump_emit(): use __kernel_write(), not vfs_write() 2013-11-15 22:04:09 -05:00
coredump.h
dcache.c make prepend_name() work correctly when called with negative *buflen 2014-04-03 12:02:36 -07:00
dcookies.c fs/compat: fix lookup_dcookie() parameter handling 2014-02-13 13:55:31 -08:00
direct-io.c direct-io: Use return from cmpxchg to decide of assignment happened 2013-09-09 10:47:42 -07:00
drop_caches.c shrinker: add node awareness 2013-09-10 18:56:31 -04:00
eventfd.c
eventpoll.c epoll: do not take the nested ep->mtx on EPOLL_CTL_DEL 2014-01-02 14:40:30 -08:00
exec.c Merge git://git.infradead.org/users/eparis/audit 2013-11-21 19:18:14 -08:00
fcntl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
fhandle.c
file_table.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
file.c fs/file.c:fdtable: avoid triggering OOMs from alloc_fdmem 2014-02-22 13:34:40 -08:00
filesystems.c
fs_struct.c seqcount: Add lockdep functionality to seqcount/seqlock structures 2013-11-06 12:40:26 +01:00
fs-writeback.c Revert "writeback: do not sync data dirtied after sync start" 2014-03-06 22:06:22 -08:00
generic_acl.c
inode.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
internal.h get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
ioctl.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
ioprio.c
Kconfig efivarfs: Move to fs/efivarfs 2013-04-17 13:25:09 +01:00
Kconfig.binfmt fs: make binfmt support for #! scripts modular and removable 2013-04-30 17:04:04 -07:00
libfs.c consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
locks.c locks: missing unlock on error in generic_add_lease() 2013-11-13 07:30:53 -05:00
Makefile Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-05-01 17:51:54 -07:00
mbcache.c fs: convert fs shrinkers to new scan/count API 2013-09-10 18:56:31 -04:00
mount.h switch mnt_hash to hlist 2014-04-03 12:02:37 -07:00
mpage.c
namei.c rcuwalk: recheck mount_lock after mountpoint crossing attempts 2014-04-03 12:02:34 -07:00
namespace.c switch mnt_hash to hlist 2014-04-03 12:02:37 -07:00
no-block.c
open.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
pipe.c vfs: fix subtle use-after-free of pipe_inode_info 2013-12-02 09:44:51 -08:00
pnode.c switch mnt_hash to hlist 2014-04-03 12:02:37 -07:00
pnode.h switch mnt_hash to hlist 2014-04-03 12:02:37 -07:00
posix_acl.c
proc_namespace.c don't bother with vfsmount_lock in mounts_poll() 2013-10-24 23:34:59 -04:00
read_write.c fs/compat: fix parameter handling for compat readv/writev syscalls 2014-02-13 13:55:31 -08:00
readdir.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
select.c Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2013-11-13 15:34:18 +09:00
seq_file.c seq_file: always clear m->count when we free m->buf 2013-11-18 19:07:53 -08:00
signalfd.c
splice.c fuse: fix pipe_buf_operations 2014-02-13 13:55:27 -08:00
stack.c
stat.c vfs: split out vfs_getattr_nosec 2013-11-09 00:16:31 -05:00
statfs.c vfs: allow O_PATH file descriptors for fstatfs() 2013-10-12 13:12:31 -07:00
super.c get rid of s_files and files_lock 2013-11-09 00:16:20 -05:00
sync.c Revert "writeback: do not sync data dirtied after sync start" 2014-03-06 22:06:22 -08:00
timerfd.c timerfd: Add alarm timers 2013-05-29 12:57:34 -07:00
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr_acl.c
xattr.c