linux/fs
Oleg Nesterov d2005e3f41 userfaultfd: don't pin the user memory in userfaultfd_file_create()
userfaultfd_file_create() increments mm->mm_users; this means that the
memory won't be unmapped/freed if mm owner exits/execs, and UFFDIO_COPY
after that can populate the orphaned mm more.

Change userfaultfd_file_create() and userfaultfd_ctx_put() to use
mm->mm_count to pin mm_struct.  This means that
atomic_inc_not_zero(mm->mm_users) is needed when we are going to
actually play with this memory.  Except handle_userfault() path doesn't
need this, the caller must already have a reference.

The patch adds the new trivial helper, mmget_not_zero(), it can have
more users.

Link: http://lkml.kernel.org/r/20160516172254.GA8595@redhat.com
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Cc: Andrea Arcangeli <aarcange@redhat.com>
Cc: Michal Hocko <mhocko@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-05-20 17:58:30 -07:00
..
9p
adfs
affs
afs
autofs4
befs
bfs
btrfs Merge branch 'work.lookups' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 10:28:45 -07:00
cachefiles
ceph Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 10:08:45 -07:00
cifs Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
coda
configfs
cramfs
crypto
debugfs
devpts
dlm
ecryptfs Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 11:51:59 -07:00
efivarfs
efs
exofs
exportfs
ext2
ext4
f2fs
fat
freevxfs
fscache
fuse
gfs2 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 10:08:45 -07:00
hfs
hfsplus
hostfs
hpfs
hugetlbfs
isofs
jbd2
jffs2
jfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 10:08:45 -07:00
kernfs
lockd
logfs
minix
ncpfs
nfs Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
nfs_common
nfsd
nilfs2
nls
notify fsnotify: avoid spurious EMFILE errors from inotify_init() 2016-05-19 19:12:14 -07:00
ntfs
ocfs2 ocfs2: clean up an unneeded goto in ocfs2_put_slot() 2016-05-19 19:12:14 -07:00
omfs
openpromfs
orangefs
overlayfs
proc Merge branch 'akpm' (patches from Andrew) 2016-05-19 20:00:06 -07:00
pstore
qnx4
qnx6
quota
ramfs tmpfs/ramfs: fix VM_MAYSHARE mappings for NOMMU 2016-05-20 17:58:30 -07:00
reiserfs
romfs
squashfs
sysfs
sysv
tracefs
ubifs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 10:08:45 -07:00
udf
ufs
xfs Merge branch 'work.lookups' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 10:28:45 -07:00
aio.c
anon_inodes.c
attr.c
bad_inode.c
binfmt_aout.c
binfmt_elf.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 11:51:59 -07:00
binfmt_elf_fdpic.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 11:51:59 -07:00
binfmt_em86.c
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
block_dev.c
buffer.c mm, page_alloc: avoid looking up the first zone in a zonelist twice 2016-05-19 19:12:14 -07:00
char_dev.c
compat.c
compat_binfmt_elf.c
compat_ioctl.c
coredump.c
dax.c
dcache.c Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 11:51:59 -07:00
dcookies.c
direct-io.c
drop_caches.c
eventfd.c
eventpoll.c fs: poll/select/recvmmsg: use timespec64 for timeout events 2016-05-19 19:12:14 -07:00
exec.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
fcntl.c
fhandle.c
file.c
file_table.c
filesystems.c
fs-writeback.c mm,writeback: don't use memory reserves for wb_start_writeback 2016-05-20 17:58:30 -07:00
fs_pin.c
fs_struct.c
inode.c
internal.h
ioctl.c
Kconfig
Kconfig.binfmt
libfs.c
locks.c
Makefile
mbcache.c
mount.h
mpage.c
namei.c Merge branch 'next' of git://git.kernel.org/pub/scm/linux/kernel/git/jmorris/linux-security 2016-05-19 09:21:36 -07:00
namespace.c
no-block.c
nsfs.c
open.c
pipe.c
pnode.c
pnode.h
posix_acl.c
proc_namespace.c
read_write.c Merge branch 'work.iov_iter' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2016-05-18 11:46:23 -07:00
readdir.c
select.c fs: poll/select/recvmmsg: use timespec64 for timeout events 2016-05-19 19:12:14 -07:00
seq_file.c
signalfd.c
splice.c
stack.c
stat.c
statfs.c
super.c
sync.c
timerfd.c
userfaultfd.c userfaultfd: don't pin the user memory in userfaultfd_file_create() 2016-05-20 17:58:30 -07:00
utimes.c
xattr.c