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Filipe Manana ae3968b416 Btrfs: fix data corruption when deduplicating between different files
commit de02b9f6bb upstream.

If we deduplicate extents between two different files we can end up
corrupting data if the source range ends at the size of the source file,
the source file's size is not aligned to the filesystem's block size
and the destination range does not go past the size of the destination
file size.

Example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt

  $ xfs_io -f -c "pwrite -S 0x6b 0 2518890" /mnt/foo
  # The first byte with a value of 0xae starts at an offset (2518890)
  # which is not a multiple of the sector size.
  $ xfs_io -c "pwrite -S 0xae 2518890 102398" /mnt/foo

  # Confirm the file content is full of bytes with values 0x6b and 0xae.
  $ od -t x1 /mnt/foo
  0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
  *
  11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae
  11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
  *
  11777540 ae ae ae ae ae ae ae ae
  11777550

  # Create a second file with a length not aligned to the sector size,
  # whose bytes all have the value 0x6b, so that its extent(s) can be
  # deduplicated with the first file.
  $ xfs_io -f -c "pwrite -S 0x6b 0 557771" /mnt/bar

  # Now deduplicate the entire second file into a range of the first file
  # that also has all bytes with the value 0x6b. The destination range's
  # end offset must not be aligned to the sector size and must be less
  # then the offset of the first byte with the value 0xae (byte at offset
  # 2518890).
  $ xfs_io -c "dedupe /mnt/bar 0 1957888 557771" /mnt/foo

  # The bytes in the range starting at offset 2515659 (end of the
  # deduplication range) and ending at offset 2519040 (start offset
  # rounded up to the block size) must all have the value 0xae (and not
  # replaced with 0x00 values). In other words, we should have exactly
  # the same data we had before we asked for deduplication.
  $ od -t x1 /mnt/foo
  0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
  *
  11467540 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b ae ae ae ae ae ae
  11467560 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
  *
  11777540 ae ae ae ae ae ae ae ae
  11777550

  # Unmount the filesystem and mount it again. This guarantees any file
  # data in the page cache is dropped.
  $ umount /dev/sdb
  $ mount /dev/sdb /mnt

  $ od -t x1 /mnt/foo
  0000000 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b
  *
  11461300 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 6b 00 00 00 00 00
  11461320 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
  *
  11470000 ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae ae
  *
  11777540 ae ae ae ae ae ae ae ae
  11777550

  # The bytes in range 2515659 to 2519040 have a value of 0x00 and not a
  # value of 0xae, data corruption happened due to the deduplication
  # operation.

So fix this by rounding down, to the sector size, the length used for the
deduplication when the following conditions are met:

  1) Source file's range ends at its i_size;
  2) Source file's i_size is not aligned to the sector size;
  3) Destination range does not cross the i_size of the destination file.

Fixes: e1d227a42e ("btrfs: Handle unaligned length in extent_same")
CC: stable@vger.kernel.org # 4.2+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-09-19 22:43:36 +02:00
..
9p fs/9p/xattr.c: catch the error of p9_client_clunk when setting xattr failed 2018-09-09 19:55:55 +02:00
adfs License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
affs affs_lookup(): close a race with affs_remove_link() 2018-05-30 07:51:47 +02:00
afs afs: Fix directory permissions check 2018-07-08 15:30:51 +02:00
autofs4 autofs: fix slab out of bounds read in getname_kernel() 2018-07-22 14:28:49 +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 data corruption when deduplicating between different files 2018-09-19 22:43:36 +02:00
cachefiles cachefiles: Wait rather than BUG'ing on "Unexpected object collision" 2018-09-05 09:26:29 +02:00
ceph ceph: fix dentry leak in splice_dentry() 2018-08-24 13:09:07 +02:00
cifs smb3: check for and properly advertise directory lease support 2018-09-19 22:43:36 +02:00
coda coda: fix 'kernel memory exposure attempt' in fsync 2017-11-24 08:37:05 +01:00
configfs configfs: Introduce config_item_get_unless_zero() 2017-06-12 13:20:20 +02:00
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: use unbound workqueue for decryption 2018-08-03 07:50:32 +02:00
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: resolve devpts bind-mounts 2018-07-17 11:39:26 +02:00
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: don't pass up plaintext names when using filename encryption 2018-06-21 04:02:42 +09:00
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 dax: change bdev_dax_supported() to support boolean returns 2018-07-11 16:29:22 +02:00
ext4 ext4: reset error code in ext4_find_entry in fallback 2018-09-05 09:26:36 +02:00
f2fs f2fs: fix to clear PG_checked flag in set_page_dirty() 2018-09-15 09:45:29 +02:00
fat fat: validate ->i_start before using 2018-09-15 09:45:27 +02:00
freevxfs
fscache fscache: Allow cancelled operations to be enqueued 2018-09-05 09:26:29 +02:00
fuse fuse: Add missed unlock_page() to fuse_readpages_fill() 2018-09-05 09:26:38 +02:00
gfs2 gfs2: Fix fallocate chunk size 2018-05-30 07:52:35 +02:00
hfs hfs: prevent crash on exit from failed search 2018-09-15 09:45:26 +02:00
hfsplus hfsplus: fix NULL dereference in hfsplus_lookup() 2018-09-15 09:45:27 +02:00
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 potential memory leak in mount option parsing 2018-06-21 04:02:41 +09:00
jbd2 jbd2: don't mark block as modified if the handle is out of credits 2018-07-11 16:29:16 +02:00
jffs2 do d_instantiate/unlock_new_inode combinations safely 2018-05-30 07:51:47 +02:00
jfs jfs: Fix inconsistency between memory allocation and ea_buf->max_size 2018-08-09 12:16:39 +02:00
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 NFSv4: Fix error handling in nfs4_sp4_select_mode() 2018-09-15 09:45:30 +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 potential use-after-free in nfsd4_decode_getdeviceinfo 2018-08-03 07:50:22 +02:00
nilfs2 do d_instantiate/unlock_new_inode combinations safely 2018-05-30 07:51:47 +02:00
nls License cleanup: add SPDX GPL-2.0 license identifier to files with no license 2017-11-02 11:10:55 +01:00
notify fsnotify: fix ignore mask logic in send_to_group() 2018-06-21 04:02:41 +09:00
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: ip_alloc_sem should be taken in ocfs2_get_block() 2018-07-22 14:28:42 +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: report attributes_mask and attributes for statx 2018-06-26 08:06:33 +08:00
overlayfs ovl: fix wrong use of impure dir cache in ovl_iterate() 2018-09-09 19:55:58 +02:00
proc fs/proc/kcore.c: use __pa_symbol() for KCORE_TEXT list entries 2018-09-15 09:45:27 +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 fs/quota: Fix spectre gadget in do_quotactl 2018-09-09 19:56:02 +02:00
ramfs mm: make pagevec_lookup() update index 2017-09-06 17:27:26 -07:00
reiserfs reiserfs: change j_timestamp type to time64_t 2018-09-15 09:45:27 +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 Squashfs: Compute expected length from inode size rather than block length 2018-09-05 09:26:32 +02:00
sysfs scsi: sysfs: Introduce sysfs_{un,}break_active_protection() 2018-09-05 09:26:41 +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 synced_i_size calculation for xattr inodes 2018-09-09 19:56:00 +02:00
udf udf: Detect incorrect directory size 2018-07-03 11:25:03 +02:00
ufs do d_instantiate/unlock_new_inode combinations safely 2018-05-30 07:51:47 +02:00
xfs xfs: don't call xfs_da_shrink_inode with NULL bp 2018-08-09 12:16:39 +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 fix io_destroy()/aio_complete() race 2018-06-05 11:41:54 +02:00
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 fs, elf: make sure to page align bss in load_elf_library 2018-07-17 11:39:29 +02:00
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: do not allow offset overflow 2018-06-26 08:06:33 +08:00
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 blkdev: __blkdev_direct_IO_simple: fix leak in error case 2018-08-03 07:50:42 +02:00
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 fs/dcache.c: fix kmemcheck splat at take_dentry_name_snapshot() 2018-09-15 09:45:28 +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 There has been a fair amount of activity in the docs tree this time 2017-07-03 21:13:25 -07:00
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 Fix up non-directory creation in SGID directories 2018-07-17 11:39:27 +02:00
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 fix __legitimize_mnt()/mntput() race 2018-08-15 18:12:48 +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 mnt: Make propagate_umount less slow for overlapping mount propagation trees 2017-05-23 08:41:17 -05:00
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 fs: don't scan the inode cache before SB_BORN is set 2018-05-30 07:51:47 +02:00
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: remove uffd flags from vma->vm_flags if UFFD_EVENT_FORK fails 2018-08-06 16:20:49 +02:00
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 getxattr: use correct xattr length 2018-09-09 19:56:01 +02:00