linux/fs
Tejun Heo b7ce40cff0 kernfs: cache atomic_write_len in kernfs_open_file
While implementing atomic_write_len, 4d3773c4bb ("kernfs: implement
kernfs_ops->atomic_write_len") moved data copy from userland inside
kernfs_get_active() and kernfs_open_file->mutex so that
kernfs_ops->atomic_write_len can be accessed before copying buffer
from userland; unfortunately, this could lead to locking order
inversion involving mmap_sem if copy_from_user() takes a page fault.

  ======================================================
  [ INFO: possible circular locking dependency detected ]
  3.14.0-rc4-next-20140228-sasha-00011-g4077c67-dirty #26 Tainted: G        W
  -------------------------------------------------------
  trinity-c236/10658 is trying to acquire lock:
   (&of->mutex#2){+.+.+.}, at: [<fs/kernfs/file.c:487>] kernfs_fop_mmap+0x54/0x120

  but task is already holding lock:
   (&mm->mmap_sem){++++++}, at: [<mm/util.c:397>] vm_mmap_pgoff+0x6e/0xe0

  which lock already depends on the new lock.

  the existing dependency chain (in reverse order) is:

 -> #1 (&mm->mmap_sem){++++++}:
	 [<kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131>] validate_chain+0x6c5/0x7b0
	 [<kernel/locking/lockdep.c:3182>] __lock_acquire+0x4cd/0x5a0
	 [<arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602>] lock_acquire+0x182/0x1d0
	 [<mm/memory.c:4188>] might_fault+0x7e/0xb0
	 [<arch/x86/include/asm/uaccess.h:713 fs/kernfs/file.c:291>] kernfs_fop_write+0xd8/0x190
	 [<fs/read_write.c:473>] vfs_write+0xe3/0x1d0
	 [<fs/read_write.c:523 fs/read_write.c:515>] SyS_write+0x5d/0xa0
	 [<arch/x86/kernel/entry_64.S:749>] tracesys+0xdd/0xe2

 -> #0 (&of->mutex#2){+.+.+.}:
	 [<kernel/locking/lockdep.c:1840>] check_prev_add+0x13f/0x560
	 [<kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131>] validate_chain+0x6c5/0x7b0
	 [<kernel/locking/lockdep.c:3182>] __lock_acquire+0x4cd/0x5a0
	 [<arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602>] lock_acquire+0x182/0x1d0
	 [<kernel/locking/mutex.c:470 kernel/locking/mutex.c:571>] mutex_lock_nested+0x6a/0x510
	 [<fs/kernfs/file.c:487>] kernfs_fop_mmap+0x54/0x120
	 [<mm/mmap.c:1573>] mmap_region+0x310/0x5c0
	 [<mm/mmap.c:1365>] do_mmap_pgoff+0x385/0x430
	 [<mm/util.c:399>] vm_mmap_pgoff+0x8f/0xe0
	 [<mm/mmap.c:1416 mm/mmap.c:1374>] SyS_mmap_pgoff+0x1b0/0x210
	 [<arch/x86/kernel/sys_x86_64.c:72>] SyS_mmap+0x1d/0x20
	 [<arch/x86/kernel/entry_64.S:749>] tracesys+0xdd/0xe2

  other info that might help us debug this:

   Possible unsafe locking scenario:

	 CPU0                    CPU1
	 ----                    ----
    lock(&mm->mmap_sem);
				 lock(&of->mutex#2);
				 lock(&mm->mmap_sem);
    lock(&of->mutex#2);

   *** DEADLOCK ***

  1 lock held by trinity-c236/10658:
   #0:  (&mm->mmap_sem){++++++}, at: [<mm/util.c:397>] vm_mmap_pgoff+0x6e/0xe0

  stack backtrace:
  CPU: 2 PID: 10658 Comm: trinity-c236 Tainted: G        W 3.14.0-rc4-next-20140228-sasha-00011-g4077c67-dirty #26
   0000000000000000 ffff88011911fa48 ffffffff8438e945 0000000000000000
   0000000000000000 ffff88011911fa98 ffffffff811a0109 ffff88011911fab8
   ffff88011911fab8 ffff88011911fa98 ffff880119128cc0 ffff880119128cf8
  Call Trace:
   [<lib/dump_stack.c:52>] dump_stack+0x52/0x7f
   [<kernel/locking/lockdep.c:1213>] print_circular_bug+0x129/0x160
   [<kernel/locking/lockdep.c:1840>] check_prev_add+0x13f/0x560
   [<include/linux/spinlock.h:343 mm/slub.c:1933>] ? deactivate_slab+0x511/0x550
   [<kernel/locking/lockdep.c:1945 kernel/locking/lockdep.c:2131>] validate_chain+0x6c5/0x7b0
   [<kernel/locking/lockdep.c:3182>] __lock_acquire+0x4cd/0x5a0
   [<mm/mmap.c:1552>] ? mmap_region+0x24a/0x5c0
   [<arch/x86/include/asm/current.h:14 kernel/locking/lockdep.c:3602>] lock_acquire+0x182/0x1d0
   [<fs/kernfs/file.c:487>] ? kernfs_fop_mmap+0x54/0x120
   [<kernel/locking/mutex.c:470 kernel/locking/mutex.c:571>] mutex_lock_nested+0x6a/0x510
   [<fs/kernfs/file.c:487>] ? kernfs_fop_mmap+0x54/0x120
   [<kernel/sched/core.c:2477>] ? get_parent_ip+0x11/0x50
   [<fs/kernfs/file.c:487>] ? kernfs_fop_mmap+0x54/0x120
   [<fs/kernfs/file.c:487>] kernfs_fop_mmap+0x54/0x120
   [<mm/mmap.c:1573>] mmap_region+0x310/0x5c0
   [<mm/mmap.c:1365>] do_mmap_pgoff+0x385/0x430
   [<mm/util.c:397>] ? vm_mmap_pgoff+0x6e/0xe0
   [<mm/util.c:399>] vm_mmap_pgoff+0x8f/0xe0
   [<kernel/rcu/update.c:97>] ? __rcu_read_unlock+0x44/0xb0
   [<fs/file.c:641>] ? dup_fd+0x3c0/0x3c0
   [<mm/mmap.c:1416 mm/mmap.c:1374>] SyS_mmap_pgoff+0x1b0/0x210
   [<arch/x86/kernel/sys_x86_64.c:72>] SyS_mmap+0x1d/0x20
   [<arch/x86/kernel/entry_64.S:749>] tracesys+0xdd/0xe2

Fix it by caching atomic_write_len in kernfs_open_file during open so
that it can be determined without accessing kernfs_ops in
kernfs_fop_write().  This restores the structure of kernfs_fop_write()
before 4d3773c4bb with updated @len determination logic.

Signed-off-by: Tejun Heo <tj@kernel.org>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
References: http://lkml.kernel.org/g/53113485.2090407@oracle.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2014-03-08 22:08:29 -08:00
..
9p Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
adfs adfs: delayed freeing of sbi 2013-10-24 23:43:27 -04:00
affs affs: use ->kill_sb() to simplify ->put_super() and failure exits of ->mount() 2014-01-25 03:13:01 -05:00
afs afs: proc cells and rootcell are writeable 2014-02-01 10:59:39 -08:00
autofs4 autofs: fix symlinks aren't checked for expiry 2014-01-23 16:36:59 -08:00
befs befs: iget_locked() doesn't return an ERR_PTR 2014-01-25 03:14:38 -05:00
bfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
btrfs Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs 2014-02-16 11:05:27 -08:00
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: fix __dcache_readdir() 2014-02-17 12:37:13 -08:00
cifs Merge branch 'for-linus' of git://git.samba.org/sfrench/cifs-2.6 2014-02-17 13:50:11 -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: take headers to fs/cramfs 2014-01-25 03:13:02 -05:00
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 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next 2014-01-25 11:17:34 -08:00
ecryptfs ecryptfs: fix failure handling in ->readlink() 2014-01-25 03:13:00 -05:00
efivarfs consolidate simple ->d_delete() instances 2013-11-15 22:04:17 -05:00
efs efs: get rid of ->put_super() 2014-01-25 03:13:02 -05:00
exofs exofs: Print less in r4w 2014-01-23 18:54:14 +02:00
exportfs exportfs: fix quadratic behavior in filehandle lookup 2013-11-09 00:16:38 -05:00
ext2 ext2/3/4: use generic posix ACL infrastructure 2014-01-25 23:58:19 -05:00
ext3 Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
ext4 ext4: don't leave i_crtime.tv_sec uninitialized 2014-02-16 19:29:32 -05:00
f2fs Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
fat fat: rcu-delay unloading nls and freeing sbi 2013-10-24 23:43:28 -04:00
freevxfs
fscache FS-Cache: Handle removal of unadded object to the fscache_object_list rb tree 2014-02-17 13:47:35 -08:00
fuse Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-01-28 08:38:04 -08:00
gfs2 Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
hfs fs/hfs/btree.h: remove duplicate defines 2013-11-13 12:09:32 +09:00
hfsplus Merge branch 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2014-02-01 10:43:45 -08:00
hostfs um: hostfs: make functions static 2014-01-26 11:51:09 +01:00
hpfs hpfs: optimize quad buffer loading 2014-02-02 16:24:07 -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: Revise KERN_EMERG error messages 2013-12-04 12:27:46 +01:00
jbd2 jbd2: fix use after free in jbd2_journal_start_reserved() 2014-02-17 20:33:01 -05:00
jffs2 MTD updates for 3.14: 2014-01-28 18:56:37 -08:00
jfs jfs: set i_ctime when setting ACL 2014-02-13 15:56:05 -06:00
kernfs kernfs: cache atomic_write_len in kernfs_open_file 2014-03-08 22:08:29 -08:00
lockd lockd: send correct lock when granting a delayed lock. 2014-02-13 14:55:02 -05:00
logfs Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
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 Merge branch 'for-3.14-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/cgroup 2014-02-20 12:01:09 -08:00
nfs_common
nfsd nfsd4: fix acl buffer overrun 2014-02-11 13:48:11 -05:00
nilfs2 Merge branch 'for-3.14/core' of git://git.kernel.dk/linux-block 2014-01-30 11:19:05 -08:00
nls nls: have register_nls() set ->owner 2014-01-25 03:14:05 -05:00
notify fsnotify: Allocate overflow events with proper type 2014-02-25 11:18:06 +01:00
ntfs fix O_SYNC|O_APPEND syncing the wrong range on write() 2014-02-09 15:18:09 -05:00
ocfs2 ocfs2: check existence of old dentry in ocfs2_link() 2014-02-10 16:01:43 -08:00
omfs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
openpromfs
proc vmcore: prevent PT_NOTE p_memsz overflow during header update 2014-02-10 16:01:40 -08:00
pstore pstore: Don't allow high traffic options on fragile devices 2013-12-20 13:12:01 -08:00
qnx4 qnx4: clean qnx4_fill_super() up 2014-01-25 03:13:03 -05:00
qnx6
quota quota: Fix race between dqput() and dquot_scan_active() 2014-02-20 21:57:04 +01:00
ramfs fs/ramfs: move ramfs_aops to inode.c 2014-01-23 16:36:58 -08:00
reiserfs reiserfs: fix utterly brain-damaged indentation. 2014-02-17 13:46:33 -08:00
romfs romfs: fix returm err while getting inode in fill_super 2014-01-23 16:37:04 -08:00
squashfs Squashfs: fix failure to unlock pages on decompress error 2013-11-24 01:02:50 +00:00
sysfs Merge 3.14-rc5 into driver-core-next 2014-03-02 20:09:08 -08:00
sysv sysv: Add forgotten superblock lock init for v7 fs 2013-09-29 22:02:02 -04:00
ubifs fs/ubifs: use rbtree postorder iteration helper instead of opencoding 2014-01-23 16:37:03 -08:00
udf udf: Fix data corruption on file type conversion 2014-02-20 21:56:00 +01:00
ufs truncate: drop 'oldsize' truncate_pagecache() parameter 2013-09-12 15:38:02 -07:00
xfs Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs 2014-02-27 10:37:22 -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 2013-12-05 16:36:21 -06:00
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 fs: binfmt_elf: remove unused defines INTERPRETER_NONE and INTERPRETER_ELF 2014-01-23 16:36:58 -08:00
binfmt_em86.c file->f_op is never NULL... 2013-10-24 23:34:54 -04:00
binfmt_flat.c
binfmt_misc.c
binfmt_script.c
binfmt_som.c
bio-integrity.c fs: Mark function as static in fs/bio-integrity.c 2014-02-09 13:56:23 -07:00
bio.c block: Fix cloning of discard/write same bios 2014-02-11 08:40:45 -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 2014-02-06 13:48:51 -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 fs/compat_ioctl.c: fix an underflow issue (harmless) 2014-01-21 16:19:42 -08:00
compat.c [readdir] constify ->actor 2013-06-29 12:57:05 +04:00
coredump.c coredump: make __get_dumpable/get_dumpable inline, kill fs/coredump.h 2014-01-23 16:37:01 -08:00
dcache.c __dentry_path() fixes 2014-01-26 12:37:55 -05:00
dcookies.c fs/compat: fix lookup_dcookie() parameter handling 2014-01-29 16:22:40 -08:00
direct-io.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
drop_caches.c shrinker: add node awareness 2013-09-10 18:56:31 -04:00
eventfd.c eventfd_ctx_fdget(): use fdget() instead of fget() 2014-01-25 03:13:04 -05:00
eventpoll.c epoll: do not take the nested ep->mtx on EPOLL_CTL_DEL 2014-01-02 14:40:30 -08:00
exec.c execve: use 'struct filename *' for executable name passing 2014-02-05 12:54:53 -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 2014-02-10 16:01:41 -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" 2014-02-22 02:02:28 +01:00
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 kernfs: add CONFIG_KERNFS 2014-02-07 16:08:57 -08:00
Kconfig.binfmt
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 kernfs: add CONFIG_KERNFS 2014-02-07 16:08:57 -08:00
mbcache.c fs: convert fs shrinkers to new scan/count API 2013-09-10 18:56:31 -04:00
mount.h vfs: Is mounted should be testing mnt_ns for NULL or error. 2014-01-26 08:26:42 -05:00
mpage.c block: Abstract out bvec iterator 2013-11-23 22:33:47 -08:00
namei.c execve: use 'struct filename *' for executable name passing 2014-02-05 12:54:53 -08:00
namespace.c Driver core / sysfs patches for 3.14-rc1 2014-01-20 15:49:44 -08:00
no-block.c
open.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
pipe.c fs/pipe.c: skip file_update_time on frozen fs 2014-01-23 16:37:00 -08:00
pnode.c split __lookup_mnt() in two functions 2013-10-24 23:35:00 -04:00
pnode.h vfs: Don't copy mount bind mounts of /proc/<pid>/ns/mnt between namespaces 2013-08-26 18:42:15 -07:00
posix_acl.c fs: get_acl() must be allowed to return EOPNOTSUPP 2014-02-03 17:12:37 -05:00
proc_namespace.c fs/proc_namespace.c: simplify testing nsp and nsp->mnt_ns 2014-01-23 16:37:02 -08:00
read_write.c fs/compat: fix parameter handling for compat readv/writev syscalls 2014-01-29 16:22:39 -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 2014-01-22 19:36:57 +01:00
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 fs/super.c: sync ro remount after blocking writers 2014-01-31 14:29:36 -05:00
sync.c Revert "writeback: do not sync data dirtied after sync start" 2014-02-22 02:02:28 +01:00
timerfd.c
utimes.c locks: break delegations on any attribute modification 2013-11-09 00:16:44 -05:00
xattr.c