linux-stable.git/drivers/block/drbd, branch linux-3.12.y

drbd: Fix kernel_sendmsg() usage - potential NULL deref

2016-11-24T15:23:46+00:00

commit d8e9e5e80e882b4f90cba7edf1e6cb7376e52e54 upstream.

Don't pass a size larger than iov_len to kernel_sendmsg().
Otherwise it will cause a NULL pointer deref when kernel_sendmsg()
returns with rv < size.

DRBD as external module has been around in the kernel 2.4 days already.
We used to be compatible to 2.4 and very early 2.6 kernels,
we used to use
 rv = sock_sendmsg(sock, &msg, iov.iov_len);
then later changed to
 rv = kernel_sendmsg(sock, &msg, &iov, 1, size);
when we should have used
 rv = kernel_sendmsg(sock, &msg, &iov, 1, iov.iov_len);

tcp_sendmsg() used to totally ignore the size parameter.
 57be5bd ip: convert tcp_sendmsg() to iov_iter primitives
changes that, and exposes our long standing error.

Even with this error exposed, to trigger the bug, we would need to have
an environment (config or otherwise) causing us to not use sendpage()
for larger transfers, a failing connection, and have it fail "just at the
right time".  Apparently that was unlikely enough for most, so this went
unnoticed for years.

Still, it is known to trigger at least some of these,
and suspected for the others:
[0] http://lists.linbit.com/pipermail/drbd-user/2016-July/023112.html
[1] http://lists.linbit.com/pipermail/drbd-dev/2016-March/003362.html
[2] https://forums.grsecurity.net/viewtopic.php?f=3&t=4546
[3] https://ubuntuforums.org/showthread.php?t=2336150
[4] http://e2.howsolveproblem.com/i/1175162/

This should go into 4.9,
and into all stable branches since and including v4.0,
which is the first to contain the exposing change.

It is correct for all stable branches older than that as well
(which contain the DRBD driver; which is 2.6.33 and up).

It requires a small "conflict" resolution for v4.4 and earlier, with v4.5
we dropped the comment block immediately preceding the kernel_sendmsg().

Fixes: b411b3637fa7 ("The DRBD driver")
Cc: viro@zeniv.linux.org.uk
Cc: christoph.lechleitner@iteg.at
Cc: wolfgang.glas@iteg.at
Reported-by: Christoph Lechleitner 
Tested-by: Christoph Lechleitner 
Signed-off-by: Richard Weinberger 
[changed oneliner to be "obvious" without context; more verbose message]
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Jiri Slaby

drbd: merge_bvec_fn: properly remap bvm->bi_bdev

2015-01-29T14:45:10+00:00

commit 3b9d35d744bb5139f9fed57f38c019bb8c7d351c upstream.

This was not noticed for many years. Affects operation if
md raid is used a backing device for DRBD.

CC: stable@kernel.org # v3.2+
Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Jiri Slaby

drbd: compute the end before rb_insert_augmented()

2014-11-13T18:02:21+00:00

commit 82cfb90bc99d7b7e0ec62d0505b9d4f06805d5db upstream.

Commit 98683650 "Merge branch 'drbd-8.4_ed6' into
for-3.8-drivers-drbd-8.4_ed6" switches to the new augment API, but the
new API requires that the tree is augmented before rb_insert_augmented()
is called, which is missing.

So we add the augment-code to drbd_insert_interval() when it travels the
tree up to down before rb_insert_augmented().  See the example in
include/linux/interval_tree_generic.h or Documentation/rbtree.txt.

drbd_insert_interval() may cancel the insertion when traveling, in this
case, the just added augment-code does nothing before cancel since the
@this node is already in the subtrees in this case.

CC: Michel Lespinasse 
Signed-off-by: Lai Jiangshan 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner 
Signed-off-by: Jens Axboe 
Signed-off-by: Jiri Slaby

drbd: fix regression 'out of mem, failed to invoke fence-peer helper'

2014-10-13T14:09:21+00:00

commit bbc1c5e8ad6dfebf9d13b8a4ccdf66c92913eac9 upstream.

Since linux kernel 3.13, kthread_run() internally uses
wait_for_completion_killable().  We sometimes may use kthread_run()
while we still have a signal pending, which we used to kick our threads
out of potentially blocking network functions, causing kthread_run() to
mistake that as a new fatal signal and fail.

Fix: flush_signals() before kthread_run().

Signed-off-by: Philipp Reisner 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Jens Axboe 
Signed-off-by: Jiri Slaby

treewide: Add __GFP_NOWARN to k.alloc calls with v.alloc fallbacks

2013-08-20T11:06:40+00:00

Don't emit OOM warnings when k.alloc calls fail when
there there is a v.alloc immediately afterwards.

Converted a kmalloc/vmalloc with memset to kzalloc/vzalloc.

Signed-off-by: Joe Perches 
Acked-by: "Theodore Ts'o" 
Signed-off-by: Jiri Kosina

drbd: Allow online change of al-stripes and al-stripe-size

2013-06-28T14:04:36+00:00

Allow to change the AL layout with an resize operation. For that
the reisze command gets two new fields: al_stripes and al_stripe_size.

In order to make the operation crash save:
1) Lock out all IO and MD-IO
2) Write the super block with MDF_PRIMARY_IND clear
3) write the bitmap to the new location (all zeros, since
   we allow only while connected)
4) Initialize the new AL-area
5) Write the super block with the restored MDF_PRIMARY_IND.
6) Unfreeze all IO

Since the AL-layout has no influence on the protocol, this operation
needs to be beforemed on both sides of a resource (if intended).

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner 
Signed-off-by: Jens Axboe

drbd: Constants should be UPPERCASE

2013-06-28T14:04:36+00:00

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner 
Signed-off-by: Jens Axboe

drbd: Ignore the exit code of a fence-peer handler if it returns too late

2013-06-28T14:04:36+00:00

In case the connection was established and lost again before
the a fence-peer handler returns, ignore the exit code of this
instance. (And use the exit code of the later started instance)

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner 
Signed-off-by: Jens Axboe

drbd: Fix rcu_read_lock balance on error path

2013-06-28T14:04:36+00:00

Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner 
Signed-off-by: Jens Axboe

drbd: fix error return code in drbd_init()

2013-06-28T14:04:36+00:00

Fix to return a negative error code from the error handling
case instead of 0, as returned elsewhere in this function.

Signed-off-by: Wei Yongjun 
Signed-off-by: Lars Ellenberg 
Signed-off-by: Andreas Gruenbacher 
Signed-off-by: Philipp Reisner 
Signed-off-by: Jens Axboe