<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/vhost, branch linux-3.14.y</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>target: Add TFO-&gt;abort_task for aborted task resources release</title>
<updated>2016-03-09T23:33:28+00:00</updated>
<author>
<name>Nicholas Bellinger</name>
<email>nab@linux-iscsi.org</email>
</author>
<published>2014-03-22T21:55:56+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=17b1c6c856dda6cf21ce8217244623a1bd890d77'/>
<id>17b1c6c856dda6cf21ce8217244623a1bd890d77</id>
<content type='text'>
commit 131e6abc674edb9f9a59090bb35bf6650569b7e7 upstream.

Now that TASK_ABORTED status is not generated for all cases by
TMR ABORT_TASK + LUN_RESET, a new TFO-&gt;abort_task() caller is
necessary in order to give fabric drivers a chance to unmap
hardware / software resources before the se_cmd descriptor is
released via the normal TFO-&gt;release_cmd() codepath.

This patch adds TFO-&gt;aborted_task() in core_tmr_abort_task()
in place of the original transport_send_task_abort(), and
also updates all fabric drivers to implement this caller.

The fabric drivers that include changes to perform cleanup
via -&gt;aborted_task() are:

  - iscsi-target
  - iser-target
  - srpt
  - tcm_qla2xxx

The fabric drivers that currently set -&gt;aborted_task() to
NOPs are:

  - loopback
  - tcm_fc
  - usb-gadget
  - sbp-target
  - vhost-scsi

For the latter five, there appears to be no additional cleanup
required before invoking TFO-&gt;release_cmd() to release the
se_cmd descriptor.

v2 changes:
  - Move -&gt;aborted_task() call into transport_cmd_finish_abort (Alex)

Cc: Alex Leung &lt;amleung21@yahoo.com&gt;
Cc: Mark Rustad &lt;mark.d.rustad@intel.com&gt;
Cc: Roland Dreier &lt;roland@kernel.org&gt;
Cc: Vu Pham &lt;vu@mellanox.com&gt;
Cc: Chris Boot &lt;bootc@bootc.net&gt;
Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Giridhar Malavali &lt;giridhar.malavali@qlogic.com&gt;
Cc: Saurav Kashyap &lt;saurav.kashyap@qlogic.com&gt;
Cc: Quinn Tran &lt;quinn.tran@qlogic.com&gt;
Cc: Sagi Grimberg &lt;sagig@mellanox.com&gt;
Cc: Or Gerlitz &lt;ogerlitz@mellanox.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 131e6abc674edb9f9a59090bb35bf6650569b7e7 upstream.

Now that TASK_ABORTED status is not generated for all cases by
TMR ABORT_TASK + LUN_RESET, a new TFO-&gt;abort_task() caller is
necessary in order to give fabric drivers a chance to unmap
hardware / software resources before the se_cmd descriptor is
released via the normal TFO-&gt;release_cmd() codepath.

This patch adds TFO-&gt;aborted_task() in core_tmr_abort_task()
in place of the original transport_send_task_abort(), and
also updates all fabric drivers to implement this caller.

The fabric drivers that include changes to perform cleanup
via -&gt;aborted_task() are:

  - iscsi-target
  - iser-target
  - srpt
  - tcm_qla2xxx

The fabric drivers that currently set -&gt;aborted_task() to
NOPs are:

  - loopback
  - tcm_fc
  - usb-gadget
  - sbp-target
  - vhost-scsi

For the latter five, there appears to be no additional cleanup
required before invoking TFO-&gt;release_cmd() to release the
se_cmd descriptor.

v2 changes:
  - Move -&gt;aborted_task() call into transport_cmd_finish_abort (Alex)

Cc: Alex Leung &lt;amleung21@yahoo.com&gt;
Cc: Mark Rustad &lt;mark.d.rustad@intel.com&gt;
Cc: Roland Dreier &lt;roland@kernel.org&gt;
Cc: Vu Pham &lt;vu@mellanox.com&gt;
Cc: Chris Boot &lt;bootc@bootc.net&gt;
Cc: Sebastian Andrzej Siewior &lt;bigeasy@linutronix.de&gt;
Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Giridhar Malavali &lt;giridhar.malavali@qlogic.com&gt;
Cc: Saurav Kashyap &lt;saurav.kashyap@qlogic.com&gt;
Cc: Quinn Tran &lt;quinn.tran@qlogic.com&gt;
Cc: Sagi Grimberg &lt;sagig@mellanox.com&gt;
Cc: Or Gerlitz &lt;ogerlitz@mellanox.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vhost/scsi: potential memory corruption</title>
<updated>2015-11-09T20:50:26+00:00</updated>
<author>
<name>Dan Carpenter</name>
<email>dan.carpenter@oracle.com</email>
</author>
<published>2015-02-05T07:37:33+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6c6216a01ac816230882c35de819e36ad1c40b0d'/>
<id>6c6216a01ac816230882c35de819e36ad1c40b0d</id>
<content type='text'>
commit 59c816c1f24df0204e01851431d3bab3eb76719c upstream.

This code in vhost_scsi_make_tpg() is confusing because we limit "tpgt"
to UINT_MAX but the data type of "tpg-&gt;tport_tpgt" and that is a u16.

I looked at the context and it turns out that in
vhost_scsi_set_endpoint(), "tpg-&gt;tport_tpgt" is used as an offset into
the vs_tpg[] array which has VHOST_SCSI_MAX_TARGET (256) elements so
anything higher than 255 then it is invalid.  I have made that the limit
now.

In vhost_scsi_send_evt() we mask away values higher than 255, but now
that the limit has changed, we don't need the mask.

Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Cc: Ray Yang &lt;ray.yang@mediatek.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 59c816c1f24df0204e01851431d3bab3eb76719c upstream.

This code in vhost_scsi_make_tpg() is confusing because we limit "tpgt"
to UINT_MAX but the data type of "tpg-&gt;tport_tpgt" and that is a u16.

I looked at the context and it turns out that in
vhost_scsi_set_endpoint(), "tpg-&gt;tport_tpgt" is used as an offset into
the vs_tpg[] array which has VHOST_SCSI_MAX_TARGET (256) elements so
anything higher than 255 then it is invalid.  I have made that the limit
now.

In vhost_scsi_send_evt() we mask away values higher than 255, but now
that the limit has changed, we don't need the mask.

Signed-off-by: Dan Carpenter &lt;dan.carpenter@oracle.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Cc: Ray Yang &lt;ray.yang@mediatek.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vhost: actually track log eventfd file</title>
<updated>2015-08-10T19:21:06+00:00</updated>
<author>
<name>Marc-André Lureau</name>
<email>marcandre.lureau@redhat.com</email>
</author>
<published>2015-07-17T13:32:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a0a45c374d8478fb4ec2e3b4949e394d75ceb11a'/>
<id>a0a45c374d8478fb4ec2e3b4949e394d75ceb11a</id>
<content type='text'>
commit 7932c0bd7740f4cd2aa168d3ce0199e7af7d72d5 upstream.

While reviewing vhost log code, I found out that log_file is never
set. Note: I haven't tested the change (QEMU doesn't use LOG_FD yet).

Signed-off-by: Marc-André Lureau &lt;marcandre.lureau@redhat.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 7932c0bd7740f4cd2aa168d3ce0199e7af7d72d5 upstream.

While reviewing vhost log code, I found out that log_file is never
set. Note: I haven't tested the change (QEMU doesn't use LOG_FD yet).

Signed-off-by: Marc-André Lureau &lt;marcandre.lureau@redhat.com&gt;
Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vhost-scsi: Add missing virtio-scsi -&gt; TCM attribute conversion</title>
<updated>2015-01-27T16:18:58+00:00</updated>
<author>
<name>Nicholas Bellinger</name>
<email>nab@linux-iscsi.org</email>
</author>
<published>2014-12-21T18:42:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=24d2683ee34ce75c48969b9b0fdce138e43e6d01'/>
<id>24d2683ee34ce75c48969b9b0fdce138e43e6d01</id>
<content type='text'>
commit 46243860806bdc2756f3ce8ac86b4d7c616bcd6c upstream.

While looking at hch's recent conversion to drop the MSG_*_TAG
definitions, I noticed a long standing bug in vhost-scsi where
the VIRTIO_SCSI_S_* attribute definitions where incorrectly
being passed directly into target_submit_cmd_map_sgls().

This patch adds the missing virtio-scsi to TCM/SAM task attribute
conversion.

Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit 46243860806bdc2756f3ce8ac86b4d7c616bcd6c upstream.

While looking at hch's recent conversion to drop the MSG_*_TAG
definitions, I noticed a long standing bug in vhost-scsi where
the VIRTIO_SCSI_S_* attribute definitions where incorrectly
being passed directly into target_submit_cmd_map_sgls().

This patch adds the missing virtio-scsi to TCM/SAM task attribute
conversion.

Cc: Christoph Hellwig &lt;hch@lst.de&gt;
Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;


</pre>
</div>
</content>
</entry>
<entry>
<title>vhost-scsi: Take configfs group dependency during VHOST_SCSI_SET_ENDPOINT</title>
<updated>2014-12-06T23:55:38+00:00</updated>
<author>
<name>Nicholas Bellinger</name>
<email>nab@linux-iscsi.org</email>
</author>
<published>2014-10-08T06:19:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bb3e74b92f723ab7d1ab07a17807fd7f75f2c3ed'/>
<id>bb3e74b92f723ab7d1ab07a17807fd7f75f2c3ed</id>
<content type='text'>
commit ab8edab132829b26dd13db6caca3c242cce35dc1 upstream.

This patch addresses a bug where individual vhost-scsi configfs endpoint
groups can be removed from below while active exports to QEMU userspace
still exist, resulting in an OOPs.

It adds a configfs_depend_item() in vhost_scsi_set_endpoint() to obtain
an explicit dependency on se_tpg-&gt;tpg_group in order to prevent individual
vhost-scsi WWPN endpoints from being released via normal configfs methods
while an QEMU ioctl reference still exists.

Also, add matching configfs_undepend_item() in vhost_scsi_clear_endpoint()
to release the dependency, once QEMU's reference to the individual group
at /sys/kernel/config/target/vhost/$WWPN/$TPGT is released.

(Fix up vhost_scsi_clear_endpoint() error path - DanC)

Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Stefan Hajnoczi &lt;stefanha@redhat.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
commit ab8edab132829b26dd13db6caca3c242cce35dc1 upstream.

This patch addresses a bug where individual vhost-scsi configfs endpoint
groups can be removed from below while active exports to QEMU userspace
still exist, resulting in an OOPs.

It adds a configfs_depend_item() in vhost_scsi_set_endpoint() to obtain
an explicit dependency on se_tpg-&gt;tpg_group in order to prevent individual
vhost-scsi WWPN endpoints from being released via normal configfs methods
while an QEMU ioctl reference still exists.

Also, add matching configfs_undepend_item() in vhost_scsi_clear_endpoint()
to release the dependency, once QEMU's reference to the individual group
at /sys/kernel/config/target/vhost/$WWPN/$TPGT is released.

(Fix up vhost_scsi_clear_endpoint() error path - DanC)

Cc: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Cc: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Cc: Stefan Hajnoczi &lt;stefanha@redhat.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>vhost: validate vhost_get_vq_desc return value</title>
<updated>2014-03-28T20:10:35+00:00</updated>
<author>
<name>Michael S. Tsirkin</name>
<email>mst@redhat.com</email>
</author>
<published>2014-03-27T10:53:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=a39ee449f96a2cd44ce056d8a0a112211a9b1a1f'/>
<id>a39ee449f96a2cd44ce056d8a0a112211a9b1a1f</id>
<content type='text'>
vhost fails to validate negative error code
from vhost_get_vq_desc causing
a crash: we are using -EFAULT which is 0xfffffff2
as vector size, which exceeds the allocated size.

The code in question was introduced in commit
8dd014adfea6f173c1ef6378f7e5e7924866c923
    vhost-net: mergeable buffers support

CVE-2014-0055

Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
vhost fails to validate negative error code
from vhost_get_vq_desc causing
a crash: we are using -EFAULT which is 0xfffffff2
as vector size, which exceeds the allocated size.

The code in question was introduced in commit
8dd014adfea6f173c1ef6378f7e5e7924866c923
    vhost-net: mergeable buffers support

CVE-2014-0055

Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vhost: fix total length when packets are too short</title>
<updated>2014-03-28T20:07:31+00:00</updated>
<author>
<name>Michael S. Tsirkin</name>
<email>mst@redhat.com</email>
</author>
<published>2014-03-27T10:00:26+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d8316f3991d207fe32881a9ac20241be8fa2bad0'/>
<id>d8316f3991d207fe32881a9ac20241be8fa2bad0</id>
<content type='text'>
When mergeable buffers are disabled, and the
incoming packet is too large for the rx buffer,
get_rx_bufs returns success.

This was intentional in order for make recvmsg
truncate the packet and then handle_rx would
detect err != sock_len and drop it.

Unfortunately we pass the original sock_len to
recvmsg - which means we use parts of iov not fully
validated.

Fix this up by detecting this overrun and doing packet drop
immediately.

CVE-2014-0077

Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When mergeable buffers are disabled, and the
incoming packet is too large for the rx buffer,
get_rx_bufs returns success.

This was intentional in order for make recvmsg
truncate the packet and then handle_rx would
detect err != sock_len and drop it.

Unfortunately we pass the original sock_len to
recvmsg - which means we use parts of iov not fully
validated.

Fix this up by detecting this overrun and doing packet drop
immediately.

CVE-2014-0077

Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending</title>
<updated>2014-03-02T03:33:09+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2014-03-02T03:33:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=702256e604ec143f69b391485ab32b2948772838'/>
<id>702256e604ec143f69b391485ab32b2948772838</id>
<content type='text'>
Pull SCSI target fixes from Nicholas Bellinger:
 "The bulk of the series are bugfixes for qla2xxx target NPIV support
  that went in for v3.14-rc1.  Also included are a few DIF related
  fixes, a qla2xxx fix (Cc'ed to stable) from Greg W., and vhost/scsi
  protocol version related fix from Venkatesh.

  Also just a heads up that a series to address a number of issues with
  iser-target active I/O reset/shutdown is still being tested, and will
  be included in a separate -rc6 PULL request"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  vhost/scsi: Check LUN structure byte 0 is set to 1, per spec
  qla2xxx: Fix kernel panic on selective retransmission request
  Target/sbc: Don't use sg as iterator in sbc_verify_read
  target: Add DIF sense codes in transport_generic_request_failure
  target/sbc: Fix sbc_dif_copy_prot addr offset bug
  tcm_qla2xxx: Fix NAA formatted name for NPIV WWPNs
  tcm_qla2xxx: Perform configfs depend/undepend for base_tpg
  tcm_qla2xxx: Add NPIV specific enable/disable attribute logic
  qla2xxx: Check + fail when npiv_vports_inuse exists in shutdown
  qla2xxx: Fix qlt_lport_register base_vha callback race
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull SCSI target fixes from Nicholas Bellinger:
 "The bulk of the series are bugfixes for qla2xxx target NPIV support
  that went in for v3.14-rc1.  Also included are a few DIF related
  fixes, a qla2xxx fix (Cc'ed to stable) from Greg W., and vhost/scsi
  protocol version related fix from Venkatesh.

  Also just a heads up that a series to address a number of issues with
  iser-target active I/O reset/shutdown is still being tested, and will
  be included in a separate -rc6 PULL request"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  vhost/scsi: Check LUN structure byte 0 is set to 1, per spec
  qla2xxx: Fix kernel panic on selective retransmission request
  Target/sbc: Don't use sg as iterator in sbc_verify_read
  target: Add DIF sense codes in transport_generic_request_failure
  target/sbc: Fix sbc_dif_copy_prot addr offset bug
  tcm_qla2xxx: Fix NAA formatted name for NPIV WWPNs
  tcm_qla2xxx: Perform configfs depend/undepend for base_tpg
  tcm_qla2xxx: Add NPIV specific enable/disable attribute logic
  qla2xxx: Check + fail when npiv_vports_inuse exists in shutdown
  qla2xxx: Fix qlt_lport_register base_vha callback race
</pre>
</div>
</content>
</entry>
<entry>
<title>vhost/scsi: Check LUN structure byte 0 is set to 1, per spec</title>
<updated>2014-02-25T00:19:43+00:00</updated>
<author>
<name>Venkatesh Srinivas</name>
<email>venkateshs@google.com</email>
</author>
<published>2014-02-24T22:13:32+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=7fe412d07d881020022a188b95c63a19b651a391'/>
<id>7fe412d07d881020022a188b95c63a19b651a391</id>
<content type='text'>
The virtio spec requires byte 0 of the virtio-scsi LUN structure
to be '1'.

Signed-off-by: Venkatesh Srinivas &lt;venkateshs@google.com&gt;
Reviewed-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The virtio spec requires byte 0 of the virtio-scsi LUN structure
to be '1'.

Signed-off-by: Venkatesh Srinivas &lt;venkateshs@google.com&gt;
Reviewed-by: Paolo Bonzini &lt;pbonzini@redhat.com&gt;
Signed-off-by: Nicholas Bellinger &lt;nab@linux-iscsi.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>vhost: fix a theoretical race in device cleanup</title>
<updated>2014-02-13T23:47:30+00:00</updated>
<author>
<name>Michael S. Tsirkin</name>
<email>mst@redhat.com</email>
</author>
<published>2014-02-13T09:45:11+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b0c057ca7e835b36c6050c7627634b664796c1d6'/>
<id>b0c057ca7e835b36c6050c7627634b664796c1d6</id>
<content type='text'>
vhost_zerocopy_callback accesses VQ right after it drops a ubuf
reference.  In theory, this could race with device removal which waits
on the ubuf kref, and crash on use after free.

Do all accesses within rcu read side critical section, and synchronize
on release.

Since callbacks are always invoked from bh, synchronize_rcu_bh seems
enough and will help release complete a bit faster.

Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Acked-by: Jason Wang &lt;jasowang@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
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<pre>
vhost_zerocopy_callback accesses VQ right after it drops a ubuf
reference.  In theory, this could race with device removal which waits
on the ubuf kref, and crash on use after free.

Do all accesses within rcu read side critical section, and synchronize
on release.

Since callbacks are always invoked from bh, synchronize_rcu_bh seems
enough and will help release complete a bit faster.

Signed-off-by: Michael S. Tsirkin &lt;mst@redhat.com&gt;
Acked-by: Jason Wang &lt;jasowang@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
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