linux-stable.git/fs/ext4/super.c, branch linux-4.8.y

ext4: do not perform data journaling when data is encrypted

2017-01-06T10:16:22+00:00

commit 73b92a2a5e97d17cc4d5c4fe9d724d3273fb6fd2 upstream.

Currently data journalling is incompatible with encryption: enabling both
at the same time has never been supported by design, and would result in
unpredictable behavior. However, users are not precluded from turning on
both features simultaneously. This change programmatically replaces data
journaling for encrypted regular files with ordered data journaling mode.

Background:
Journaling encrypted data has not been supported because it operates on
buffer heads of the page in the page cache. Namely, when the commit
happens, which could be up to five seconds after caching, the commit
thread uses the buffer heads attached to the page to copy the contents of
the page to the journal. With encryption, it would have been required to
keep the bounce buffer with ciphertext for up to the aforementioned five
seconds, since the page cache can only hold plaintext and could not be
used for journaling. Alternatively, it would be required to setup the
journal to initiate a callback at the commit time to perform deferred
encryption - in this case, not only would the data have to be written
twice, but it would also have to be encrypted twice. This level of
complexity was not justified for a mode that in practice is very rarely
used because of the overhead from the data journalling.

Solution:
If data=journaled has been set as a mount option for a filesystem, or if
journaling is enabled on a regular file, do not perform journaling if the
file is also encrypted, instead fall back to the data=ordered mode for the
file.

Rationale:
The intent is to allow seamless and proper filesystem operation when
journaling and encryption have both been enabled, and have these two
conflicting features gracefully resolved by the filesystem.

Fixes: 4461471107b7
Signed-off-by: Sergey Karamov 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: add sanity checking to count_overhead()

2017-01-06T10:16:22+00:00

commit c48ae41bafe31e9a66d8be2ced4e42a6b57fa814 upstream.

The commit "ext4: sanity check the block and cluster size at mount
time" should prevent any problems, but in case the superblock is
modified while the file system is mounted, add an extra safety check
to make sure we won't overrun the allocated buffer.

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: fix in-superblock mount options processing

2017-01-06T10:16:22+00:00

commit 5aee0f8a3f42c94c5012f1673420aee96315925a upstream.

Fix a large number of problems with how we handle mount options in the
superblock.  For one, if the string in the superblock is long enough
that it is not null terminated, we could run off the end of the string
and try to interpret superblocks fields as characters.  It's unlikely
this will cause a security problem, but it could result in an invalid
parse.  Also, parse_options is destructive to the string, so in some
cases if there is a comma-separated string, it would be modified in
the superblock.  (Fortunately it only happens on file systems with a
1k block size.)

Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

ext4: use more strict checks for inodes_per_block on mount

2017-01-06T10:16:22+00:00

commit cd6bb35bf7f6d7d922509bf50265383a0ceabe96 upstream.

Centralize the checks for inodes_per_block and be more strict to make
sure the inodes_per_block_group can't end up being zero.

Signed-off-by: Theodore Ts'o 
Reviewed-by: Andreas Dilger 
Signed-off-by: Greg Kroah-Hartman

ext4: sanity check the block and cluster size at mount time

2016-11-26T08:56:55+00:00

commit 8cdf3372fe8368f56315e66bea9f35053c418093 upstream.

If the block size or cluster size is insane, reject the mount.  This
is important for security reasons (although we shouldn't be just
depending on this check).

Ref: http://www.securityfocus.com/archive/1/539661
Ref: https://bugzilla.redhat.com/show_bug.cgi?id=1332506
Reported-by: Borislav Petkov 
Reported-by: Nikolay Borisov 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Greg Kroah-Hartman

Merge tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2016-08-29T19:37:11+00:00

Pull ext4 fixes from Ted Ts'o:
 "Fix bugs that could cause kernel deadlocks or file system corruption
  while moving xattrs to expand the extended inode.

  Also add some sanity checks to the block group descriptors to make
  sure we don't end up overwriting the superblock"

* tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: avoid deadlock when expanding inode size
  ext4: properly align shifted xattrs when expanding inodes
  ext4: fix xattr shifting when expanding inodes part 2
  ext4: fix xattr shifting when expanding inodes
  ext4: validate that metadata blocks do not overlap superblock
  ext4: reserve xattr index for the Hurd

ext4: validate that metadata blocks do not overlap superblock

2016-08-01T04:51:02+00:00

A number of fuzzing failures seem to be caused by allocation bitmaps
or other metadata blocks being pointed at the superblock.

This can cause kernel BUG or WARNings once the superblock is
overwritten, so validate the group descriptor blocks to make sure this
doesn't happen.

Cc: stable@vger.kernel.org
Signed-off-by: Theodore Ts'o

Merge tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4

2016-07-27T01:35:55+00:00

Pull ext4 updates from Ted Ts'o:
 "The major change this cycle is deleting ext4's copy of the file system
  encryption code and switching things over to using the copies in
  fs/crypto.  I've updated the MAINTAINERS file to add an entry for
  fs/crypto listing Jaeguk Kim and myself as the maintainers.

  There are also a number of bug fixes, most notably for some problems
  found by American Fuzzy Lop (AFL) courtesy of Vegard Nossum.  Also
  fixed is a writeback deadlock detected by generic/130, and some
  potential races in the metadata checksum code"

* tag 'ext4_for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (21 commits)
  ext4: verify extent header depth
  ext4: short-cut orphan cleanup on error
  ext4: fix reference counting bug on block allocation error
  MAINTAINRES: fs-crypto maintainers update
  ext4 crypto: migrate into vfs's crypto engine
  ext2: fix filesystem deadlock while reading corrupted xattr block
  ext4: fix project quota accounting without quota limits enabled
  ext4: validate s_reserved_gdt_blocks on mount
  ext4: remove unused page_idx
  ext4: don't call ext4_should_journal_data() on the journal inode
  ext4: Fix WARN_ON_ONCE in ext4_commit_super()
  ext4: fix deadlock during page writeback
  ext4: correct error value of function verifying dx checksum
  ext4: avoid modifying checksum fields directly during checksum verification
  ext4: check for extents that wrap around
  jbd2: make journal y2038 safe
  jbd2: track more dependencies on transaction commit
  jbd2: move lockdep tracking to journal_s
  jbd2: move lockdep instrumentation for jbd2 handles
  ext4: respect the nobarrier mount option in nojournal mode
  ...

ext4: short-cut orphan cleanup on error

2016-07-15T03:21:35+00:00

If we encounter a filesystem error during orphan cleanup, we should stop.
Otherwise, we may end up in an infinite loop where the same inode is
processed again and again.

    EXT4-fs (loop0): warning: checktime reached, running e2fsck is recommended
    EXT4-fs error (device loop0): ext4_mb_generate_buddy:758: group 2, block bitmap and bg descriptor inconsistent: 6117 vs 0 free clusters
    Aborting journal on device loop0-8.
    EXT4-fs (loop0): Remounting filesystem read-only
    EXT4-fs error (device loop0) in ext4_free_blocks:4895: Journal has aborted
    EXT4-fs error (device loop0) in ext4_do_update_inode:4893: Journal has aborted
    EXT4-fs error (device loop0) in ext4_do_update_inode:4893: Journal has aborted
    EXT4-fs error (device loop0) in ext4_ext_remove_space:3068: IO failure
    EXT4-fs error (device loop0) in ext4_ext_truncate:4667: Journal has aborted
    EXT4-fs error (device loop0) in ext4_orphan_del:2927: Journal has aborted
    EXT4-fs error (device loop0) in ext4_do_update_inode:4893: Journal has aborted
    EXT4-fs (loop0): Inode 16 (00000000618192a0): orphan list check failed!
    [...]
    EXT4-fs (loop0): Inode 16 (0000000061819748): orphan list check failed!
    [...]
    EXT4-fs (loop0): Inode 16 (0000000061819bf0): orphan list check failed!
    [...]

See-also: c9eb13a9105 ("ext4: fix hang when processing corrupted orphaned inode list")
Cc: Jan Kara 
Signed-off-by: Vegard Nossum 
Signed-off-by: Theodore Ts'o 
Cc: stable@vger.kernel.org

ext4 crypto: migrate into vfs's crypto engine

2016-07-10T18:01:03+00:00

This patch removes the most parts of internal crypto codes.
And then, it modifies and adds some ext4-specific crypt codes to use the generic
facility.

Signed-off-by: Jaegeuk Kim 
Signed-off-by: Theodore Ts'o