linux-stable.git/fs/jbd2, branch v3.12.45

jbd2: fix r_count overflows leading to buffer overflow in journal recovery

2015-06-03T09:33:11+00:00

commit e531d0bceb402e643a4499de40dd3fa39d8d2e43 upstream.

The journal revoke block recovery code does not check r_count for
sanity, which means that an evil value of r_count could result in
the kernel reading off the end of the revoke table and into whatever
garbage lies beyond.  This could crash the kernel, so fix that.

However, in testing this fix, I discovered that the code to write
out the revoke tables also was not correctly checking to see if the
block was full -- the current offset check is fine so long as the
revoke table space size is a multiple of the record size, but this
is not true when either journal_csum_v[23] are set.

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Signed-off-by: Jiri Slaby

ext4: fix NULL pointer dereference when journal restart fails

2015-06-03T09:33:11+00:00

commit 9d506594069355d1fb2de3f9104667312ff08ed3 upstream.

Currently when journal restart fails, we'll have the h_transaction of
the handle set to NULL to indicate that the handle has been effectively
aborted. We handle this situation quietly in the jbd2_journal_stop() and just
free the handle and exit because everything else has been done before we
attempted (and failed) to restart the journal.

Unfortunately there are a number of problems with that approach
introduced with commit

41a5b913197c "jbd2: invalidate handle if jbd2_journal_restart()
fails"

First of all in ext4 jbd2_journal_stop() will be called through
__ext4_journal_stop() where we would try to get a hold of the superblock
by dereferencing h_transaction which in this case would lead to NULL
pointer dereference and crash.

In addition we're going to free the handle regardless of the refcount
which is bad as well, because others up the call chain will still
reference the handle so we might potentially reference already freed
memory.

Moreover it's expected that we'll get aborted handle as well as detached
handle in some of the journalling function as the error propagates up
the stack, so it's unnecessary to call WARN_ON every time we get
detached handle.

And finally we might leak some memory by forgetting to free reserved
handle in jbd2_journal_stop() in the case where handle was detached from
the transaction (h_transaction is NULL).

Fix the NULL pointer dereference in __ext4_journal_stop() by just
calling jbd2_journal_stop() quietly as suggested by Jan Kara. Also fix
the potential memory leak in jbd2_journal_stop() and use proper
handle refcounting before we attempt to free it to avoid use-after-free
issues.

And finally remove all WARN_ON(!transaction) from the code so that we do
not get random traces when something goes wrong because when journal
restart fails we will get to some of those functions.

Signed-off-by: Lukas Czerner 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Jan Kara 
Signed-off-by: Jiri Slaby

jbd2: free bh when descriptor block checksum fails

2014-11-13T18:02:32+00:00

commit 064d83892e9ba547f7d4eae22cbca066d95210ce upstream.

Free the buffer head if the journal descriptor block fails checksum
verification.

This is the jbd2 port of the e2fsprogs patch "e2fsck: free bh on csum
verify error in do_one_pass".

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Reviewed-by: Eric Sandeen 
Signed-off-by: Jiri Slaby

jbd2: fix descriptor block size handling errors with journal_csum

2014-09-17T13:12:22+00:00

commit db9ee220361de03ee86388f9ea5e529eaad5323c upstream.

It turns out that there are some serious problems with the on-disk
format of journal checksum v2.  The foremost is that the function to
calculate descriptor tag size returns sizes that are too big.  This
causes alignment issues on some architectures and is compounded by the
fact that some parts of jbd2 use the structure size (incorrectly) to
determine the presence of a 64bit journal instead of checking the
feature flags.

Therefore, introduce journal checksum v3, which enlarges the
descriptor block tag format to allow for full 32-bit checksums of
journal blocks, fix the journal tag function to return the correct
sizes, and fix the jbd2 recovery code to use feature flags to
determine 64bitness.

Add a few function helpers so we don't have to open-code quite so
many pieces.

Switching to a 16-byte block size was found to increase journal size
overhead by a maximum of 0.1%, to convert a 32-bit journal with no
checksumming to a 32-bit journal with checksum v3 enabled.

Signed-off-by: Darrick J. Wong 
Reported-by: TR Reardon 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

jbd2: fix infinite loop when recovering corrupt journal blocks

2014-09-17T13:12:21+00:00

commit 022eaa7517017efe4f6538750c2b59a804dc7df7 upstream.

When recovering the journal, don't fall into an infinite loop if we
encounter a corrupt journal block.  Instead, just skip the block and
return an error, which fails the mount and thus forces the user to run
a full filesystem fsck.

Signed-off-by: Darrick J. Wong 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

ext4: disable synchronous transaction batching if max_batch_time==0

2014-07-18T13:51:26+00:00

commit 5dd214248f94d430d70e9230bda72f2654ac88a8 upstream.

The mount manpage says of the max_batch_time option,

	This optimization can be turned off entirely
	by setting max_batch_time to 0.

But the code doesn't do that.  So fix the code to do
that.

Signed-off-by: Eric Sandeen 
Signed-off-by: Theodore Ts'o 
Signed-off-by: Jiri Slaby

jbd2: fix use after free in jbd2_journal_start_reserved()

2014-03-05T16:13:41+00:00

commit 92e3b40537707001d17bbad800d150ab04e53bf4 upstream.

If start_this_handle() fails then it leads to a use after free of
"handle".

Signed-off-by: Dan Carpenter 
Signed-off-by: "Theodore Ts'o" 
Signed-off-by: Jiri Slaby

jbd2: don't BUG but return ENOSPC if a handle runs out of space

2014-01-09T20:25:15+00:00

commit f6c07cad081ba222d63623d913aafba5586c1d2c upstream.

If a handle runs out of space, we currently stop the kernel with a BUG
in jbd2_journal_dirty_metadata().  This makes it hard to figure out
what might be going on.  So return an error of ENOSPC, so we can let
the file system layer figure out what is going on, to make it more
likely we can get useful debugging information).  This should make it
easier to debug problems such as the one which was reported by:

    https://bugzilla.kernel.org/show_bug.cgi?id=44731

The only two callers of this function are ext4_handle_dirty_metadata()
and ocfs2_journal_dirty().  The ocfs2 function will trigger a
BUG_ON(), which means there will be no change in behavior.  The ext4
function will call ext4_error_inode() which will print the useful
debugging information and then handle the situation using ext4's error
handling mechanisms (i.e., which might mean halting the kernel or
remounting the file system read-only).

Also, since both file systems already call WARN_ON(), drop the WARN_ON
from jbd2_journal_dirty_metadata() to avoid two stack traces from
being displayed.

Signed-off-by: "Theodore Ts'o" 
Cc: ocfs2-devel@oss.oracle.com
Acked-by: Joel Becker 
Signed-off-by: Greg Kroah-Hartman

jbd2: Fix endian mixing problems in the checksumming code

2013-08-28T18:59:58+00:00

In the jbd2 checksumming code, explicitly declare separate variables with
endianness information so that we don't get confused and screw things up again.
Also fixes sparse warnings.

Signed-off-by: Darrick J. Wong 
Signed-off-by: "Theodore Ts'o"

jbd2: invalidate handle if jbd2_journal_restart() fails

2013-07-01T12:12:41+00:00

If jbd2_journal_restart() fails the handle will have been disconnected
from the current transaction.  In this situation, the handle must not
be used for for any jbd2 function other than jbd2_journal_stop().
Enforce this with by treating a handle which has a NULL transaction
pointer as an aborted handle, and issue a kernel warning if
jbd2_journal_extent(), jbd2_journal_get_write_access(),
jbd2_journal_dirty_metadata(), etc. is called with an invalid handle.

This commit also fixes a bug where jbd2_journal_stop() would trip over
a kernel jbd2 assertion check when trying to free an invalid handle.

Also move the responsibility of setting current->journal_info to
start_this_handle(), simplifying the three users of this function.

Signed-off-by: "Theodore Ts'o" 
Reported-by: Younger Liu 
Cc: Jan Kara