WSL2-Linux-Kernel/fs
Liu Bo 671c9a69f4 btrfs: fix reading stale metadata blocks after degraded raid1 mounts
commit 02a3307aa9 upstream.

If a btree block, aka. extent buffer, is not available in the extent
buffer cache, it'll be read out from the disk instead, i.e.

btrfs_search_slot()
  read_block_for_search()  # hold parent and its lock, go to read child
    btrfs_release_path()
    read_tree_block()  # read child

Unfortunately, the parent lock got released before reading child, so
commit 5bdd3536cb ("Btrfs: Fix block generation verification race") had
used 0 as parent transid to read the child block.  It forces
read_tree_block() not to check if parent transid is different with the
generation id of the child that it reads out from disk.

A simple PoC is included in btrfs/124,

0. A two-disk raid1 btrfs,

1. Right after mkfs.btrfs, block A is allocated to be device tree's root.

2. Mount this filesystem and put it in use, after a while, device tree's
   root got COW but block A hasn't been allocated/overwritten yet.

3. Umount it and reload the btrfs module to remove both disks from the
   global @fs_devices list.

4. mount -odegraded dev1 and write some data, so now block A is allocated
   to be a leaf in checksum tree.  Note that only dev1 has the latest
   metadata of this filesystem.

5. Umount it and mount it again normally (with both disks), since raid1
   can pick up one disk by the writer task's pid, if btrfs_search_slot()
   needs to read block A, dev2 which does NOT have the latest metadata
   might be read for block A, then we got a stale block A.

6. As parent transid is not checked, block A is marked as uptodate and
   put into the extent buffer cache, so the future search won't bother
   to read disk again, which means it'll make changes on this stale
   one and make it dirty and flush it onto disk.

To avoid the problem, parent transid needs to be passed to
read_tree_block().

In order to get a valid parent transid, we need to hold the parent's
lock until finishing reading child.

This patch needs to be slightly adapted for stable kernels, the
&first_key parameter added to read_tree_block() is from 4.16+
(581c176041). The fix is to replace 0 by 'gen'.

Fixes: 5bdd3536cb ("Btrfs: Fix block generation verification race")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-05-22 18:54:01 +02:00
..
9p fs/9p: Compare qid.path in v9fs_test_inode 2017-11-30 08:40:49 +00:00
adfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
affs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
afs afs: Fix missing error handling in afs_write_end() 2018-03-03 10:24:32 +01:00
autofs4 autofs: mount point create should honour passed in mode 2018-04-24 09:36:39 +02:00
befs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
btrfs btrfs: fix reading stale metadata blocks after degraded raid1 mounts 2018-05-22 18:54:01 +02:00
cachefiles License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ceph ceph: fix rsize/wsize capping in ceph_direct_read_write() 2018-05-16 10:10:27 +02:00
cifs smb3: directory sync should not return an error 2018-05-16 10:10:30 +02:00
coda coda: fix 'kernel memory exposure attempt' in fsync 2017-11-24 08:37:05 +01:00
configfs
cramfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
crypto fscrypt: lock mutex before checking for bounce page pool 2017-11-30 08:40:44 +00:00
debugfs Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-07-15 12:00:42 -07:00
devpts devpts: fix error handling in devpts_mntget() 2018-02-16 20:23:11 +01:00
dlm License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ecryptfs eCryptfs: use after free in ecryptfs_release_messaging() 2017-11-30 08:40:45 +00:00
efivarfs VFS: Kill off s_options and helpers 2017-07-11 06:09:21 -04:00
efs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
exofs Merge branch 'for-4.14/block' of git://git.kernel.dk/linux-block 2017-09-07 11:59:42 -07:00
exportfs
ext2 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ext4 ext4: fix bitmap position validation 2018-05-01 12:58:07 -07:00
f2fs f2fs: avoid hungtask when GC encrypted block if io_bits is set 2018-04-26 11:02:09 +02:00
fat fs/fat/inode.c: fix sb_rdonly() change 2017-12-05 11:26:29 +01:00
freevxfs
fscache License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fuse fuse: fix READDIRPLUS skipping an entry 2017-10-25 16:34:27 +02:00
gfs2 GFS2: Take inode off order_write list when setting jdata flag 2017-12-20 10:10:29 +01:00
hfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hfsplus License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hostfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hpfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
hugetlbfs hugetlbfs: fix bug in pgoff overflow checking 2018-04-19 08:56:21 +02:00
isofs isofs: fix timestamps beyond 2027 2017-11-30 08:40:45 +00:00
jbd2 ext4: set h_journal if there is a failure starting a reserved handle 2018-05-01 12:58:06 -07:00
jffs2 jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path 2018-04-26 11:02:12 +02:00
jfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
kernfs kernfs: fix regression in kernfs_fop_write caused by wrong type 2018-02-16 20:22:59 +01:00
lockd race of lockd inetaddr notifiers vs nlmsvc_rqst change 2018-02-03 17:39:08 +01:00
minix License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ncpfs staging: ncpfs: memory corruption in ncp_read_kernel() 2018-03-28 18:24:43 +02:00
nfs nfs: Do not convert nfs_idmap_cache_timeout to jiffies 2018-04-26 11:02:08 +02:00
nfs_common lockd: fix "list_add double add" caused by legacy signal interface 2018-02-03 17:39:08 +01:00
nfsd nfsd: fix incorrect umasks 2018-04-19 08:56:21 +02:00
nilfs2 nilfs2: fix race condition that causes file system corruption 2017-11-30 08:40:44 +00:00
nls License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
notify fanotify: fix logic of events on child 2018-04-24 09:36:38 +02:00
ntfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
ocfs2 ocfs2: return error when we attempt to access a dirty bh in jbd2 2018-04-26 11:02:14 +02:00
omfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
openpromfs
orangefs orangefs_kill_sb(): deal with allocation failures 2018-04-24 09:36:38 +02:00
overlayfs ovl: fix lookup with middle layer opaque dir and absolute path redirects 2018-04-19 08:56:21 +02:00
proc proc: do not access cmdline nor environ from file-backed areas 2018-05-19 10:20:27 +02:00
pstore License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
qnx4 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
qnx6 License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
quota quota: Check for register_shrinker() failure. 2018-02-03 17:39:11 +01:00
ramfs mm: make pagevec_lookup() update index 2017-09-06 17:27:26 -07:00
reiserfs fs/reiserfs/journal.c: add missing resierfs_warning() arg 2018-04-24 09:36:22 +02:00
romfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
squashfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
sysfs sysfs: symlink: export sysfs_create_link_nowarn() 2018-03-31 18:10:38 +02:00
sysv License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
tracefs VFS: Don't use save/replace_mount_options if not using generic_show_options 2017-07-06 03:31:46 -04:00
ubifs ubifs: Fix uninitialized variable in search_dh_cookie() 2018-04-26 11:02:07 +02:00
udf udf: Fix leak of UTF-16 surrogates into encoded strings 2018-04-24 09:36:38 +02:00
ufs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xfs xfs: prevent creating negative-sized file via INSERT_RANGE 2018-05-09 09:51:52 +02:00
Kconfig fs/Kconfig: kill CONFIG_PERCPU_RWSEM some more 2017-07-12 16:26:00 -07:00
Kconfig.binfmt
Makefile License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
aio.c fs/aio: Use RCU accessors for kioctx_table->table[] 2018-03-21 12:06:43 +01:00
anon_inodes.c
attr.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
bad_inode.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
binfmt_aout.c fs: fix kernel_read prototype 2017-09-04 19:05:15 -04:00
binfmt_elf.c Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
binfmt_elf_fdpic.c Merge branch 'work.set_fs' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs 2017-09-14 18:13:32 -07:00
binfmt_em86.c
binfmt_flat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
binfmt_misc.c fs/binfmt_misc.c: node could be NULL when evicting inode 2017-10-13 16:18:33 -07:00
binfmt_script.c exec: load_script: kill the onstack interp[BINPRM_BUF_SIZE] array 2017-10-03 17:54:25 -07:00
block_dev.c fs/mpage.c: fix mpage_writepage() for pages with buffers 2017-10-13 16:18:33 -07:00
buffer.c fs: guard_bio_eod() needs to consider partitions 2017-11-30 08:40:45 +00:00
char_dev.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
compat.c
compat_binfmt_elf.c
compat_ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
coredump.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
dax.c fs/dax.c: release PMD lock even when there is no PMD support in DAX 2018-04-26 11:02:14 +02:00
dcache.c VFS: close race between getcwd() and d_move() 2018-04-12 12:32:13 +02:00
dcookies.c
direct-io.c direct-io: Fix sleep in atomic due to sync AIO 2018-03-08 22:41:06 -08:00
drop_caches.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
eventfd.c
eventpoll.c fs/epoll: use faster rb_first_cached() 2017-09-08 18:26:49 -07:00
exec.c exec: avoid gcc-8 warning for get_task_comm 2018-03-03 10:24:21 +01:00
fcntl.c fcntl: don't cap l_start and l_end values for F_GETLK64 in compat syscall 2017-12-17 15:07:59 +01:00
fhandle.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
file.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
file_table.c fput: Don't reinvent the wheel but use existing llist API 2017-08-28 00:50:23 -04:00
filesystems.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs-writeback.c bdi: Fix oops in wb_workfn() 2018-05-16 10:10:25 +02:00
fs_pin.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
fs_struct.c
inode.c Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2017-09-13 09:11:44 -07:00
internal.h Merge branch 'overlayfs-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/vfs 2017-09-13 09:11:44 -07:00
ioctl.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
iomap.c fs: invalidate page cache after end_io() in dio completion 2017-10-16 12:11:56 -07:00
libfs.c fs: convert __generic_file_fsync to use errseq_t based reporting 2017-07-06 07:02:29 -04:00
locks.c locks: restore a warn for leaked locks on close 2017-07-21 13:57:31 -04:00
mbcache.c mbcache: initialize entry->e_referenced in mb_cache_entry_create() 2018-02-22 15:42:25 +01:00
mount.h License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
mpage.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
namei.c getname_kernel() needs to make sure that ->name != ->iname in long case 2018-04-19 08:56:19 +02:00
namespace.c Don't leak MNT_INTERNAL away from internal mounts 2018-04-24 09:36:39 +02:00
no-block.c
nsfs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
open.c ovl: don't allow writing ioctl on lower layer 2017-09-05 12:53:12 +02:00
pipe.c pipe: fix off-by-one error when checking buffer limits 2018-02-16 20:23:05 +01:00
pnode.c
pnode.h
posix_acl.c
proc_namespace.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
read_write.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
readdir.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
select.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
seq_file.c seq_file: fix incomplete reset on read from zero offset 2018-02-22 15:42:28 +01:00
signalfd.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
splice.c fs: move kernel_write to fs/read_write.c 2017-09-04 19:05:15 -04:00
stack.c
stat.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
statfs.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
super.c sget(): handle failures of register_shrinker() 2018-03-03 10:24:24 +01:00
sync.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
timerfd.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
userfaultfd.c userfaultfd: clear the vma->vm_userfaultfd_ctx if UFFD_EVENT_FORK fails 2018-01-10 09:31:17 +01:00
utimes.c License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
xattr.c lsm: fix smack_inode_removexattr and xattr_getsecurity memleak 2017-10-04 18:03:15 +11:00