<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/drivers/staging, branch v4.11.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>staging: comedi: jr3_pci: cope with jiffies wraparound</title>
<updated>2017-05-20T12:49:41+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2017-02-17T11:09:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=69f8945b4f38799b7b46de744acae8c9f447f8d7'/>
<id>69f8945b4f38799b7b46de744acae8c9f447f8d7</id>
<content type='text'>
commit 8ec04a491825e08068e92bed0bba7821893b6433 upstream.

The timer expiry routine `jr3_pci_poll_dev()` checks for expiry by
checking whether the absolute value of `jiffies` (stored in local
variable `now`) is greater than the expected expiry time in jiffy units.
This will fail when `jiffies` wraps around.  Also, it seems to make
sense to handle the expiry one jiffy earlier than the current test.  Use
`time_after_eq()` to check for expiry.

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&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 8ec04a491825e08068e92bed0bba7821893b6433 upstream.

The timer expiry routine `jr3_pci_poll_dev()` checks for expiry by
checking whether the absolute value of `jiffies` (stored in local
variable `now`) is greater than the expected expiry time in jiffy units.
This will fail when `jiffies` wraps around.  Also, it seems to make
sense to handle the expiry one jiffy earlier than the current test.  Use
`time_after_eq()` to check for expiry.

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: comedi: jr3_pci: fix possible null pointer dereference</title>
<updated>2017-05-20T12:49:41+00:00</updated>
<author>
<name>Ian Abbott</name>
<email>abbotti@mev.co.uk</email>
</author>
<published>2017-02-17T11:09:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6e4c973ac6292fc72b9d3818afb0221e3202f738'/>
<id>6e4c973ac6292fc72b9d3818afb0221e3202f738</id>
<content type='text'>
commit 45292be0b3db0b7f8286683b376e2d9f949d11f9 upstream.

For some reason, the driver does not consider allocation of the
subdevice private data to be a fatal error when attaching the COMEDI
device.  It tests the subdevice private data pointer for validity at
certain points, but omits some crucial tests.  In particular,
`jr3_pci_auto_attach()` calls `jr3_pci_alloc_spriv()` to allocate and
initialize the subdevice private data, but the same function
subsequently dereferences the pointer to access the `next_time_min` and
`next_time_max` members without checking it first.  The other missing
test is in the timer expiry routine `jr3_pci_poll_dev()`, but it will
crash before it gets that far.

Fix the bug by returning `-ENOMEM` from `jr3_pci_auto_attach()` as soon
as one of the calls to `jr3_pci_alloc_spriv()` returns `NULL`.  The
COMEDI core will subsequently call `jr3_pci_detach()` to clean up.

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&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 45292be0b3db0b7f8286683b376e2d9f949d11f9 upstream.

For some reason, the driver does not consider allocation of the
subdevice private data to be a fatal error when attaching the COMEDI
device.  It tests the subdevice private data pointer for validity at
certain points, but omits some crucial tests.  In particular,
`jr3_pci_auto_attach()` calls `jr3_pci_alloc_spriv()` to allocate and
initialize the subdevice private data, but the same function
subsequently dereferences the pointer to access the `next_time_min` and
`next_time_max` members without checking it first.  The other missing
test is in the timer expiry routine `jr3_pci_poll_dev()`, but it will
crash before it gets that far.

Fix the bug by returning `-ENOMEM` from `jr3_pci_auto_attach()` as soon
as one of the calls to `jr3_pci_alloc_spriv()` returns `NULL`.  The
COMEDI core will subsequently call `jr3_pci_detach()` to clean up.

Signed-off-by: Ian Abbott &lt;abbotti@mev.co.uk&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: sir: fill in missing fields and fix probe</title>
<updated>2017-05-20T12:49:41+00:00</updated>
<author>
<name>Sean Young</name>
<email>sean@mess.org</email>
</author>
<published>2017-03-25T10:31:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=99185235783a7479e6c28f508fbba79500e06fbd'/>
<id>99185235783a7479e6c28f508fbba79500e06fbd</id>
<content type='text'>
commit cf9ed9aa5b0c196b796d2728218e3c06b0f42d90 upstream.

Some fields are left blank.

Signed-off-by: Sean Young &lt;sean@mess.org&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@s-opensource.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 cf9ed9aa5b0c196b796d2728218e3c06b0f42d90 upstream.

Some fields are left blank.

Signed-off-by: Sean Young &lt;sean@mess.org&gt;
Signed-off-by: Mauro Carvalho Chehab &lt;mchehab@s-opensource.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: wilc1000: Fix problem with wrong vif index</title>
<updated>2017-05-20T12:49:41+00:00</updated>
<author>
<name>Aditya Shankar</name>
<email>aditya.shankar@microchip.com</email>
</author>
<published>2017-04-07T11:54:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=89cb8fcceab18f32ef637234b909a49649f475d9'/>
<id>89cb8fcceab18f32ef637234b909a49649f475d9</id>
<content type='text'>
commit 0e490657c7214cce33fbca3d88227298c5c968ae upstream.

The vif-&gt;idx value is always 0 for two interfaces.

wl-&gt;vif_num = 0;

loop {
     ...

     vif-&gt;idx = wl-&gt;vif_num;
     ...
     wl-&gt;vif_num = i;
      ....
     i++;
     ...
}

At present, vif-&gt;idx is assigned the value of wl-&gt;vif_num
at the beginning of this block and device is initialized
based on this index value.
In the next iteration, wl-&gt;vif_num is still 0 as it is only updated
later but gets assigned to vif-&gt;idx in the beginning. This causes problems
later when we try to reference a particular interface and also while
configuring the firmware.

This patch moves the assignment to vif-&gt;idx from the beginning
of the block to after wl-&gt;vif_num is updated with latest value of i.

Fixes: commit 735bb39ca3be ("staging: wilc1000: simplify vif[i]-&gt;ndev accesses")
Signed-off-by: Aditya Shankar &lt;aditya.shankar@microchip.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.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 0e490657c7214cce33fbca3d88227298c5c968ae upstream.

The vif-&gt;idx value is always 0 for two interfaces.

wl-&gt;vif_num = 0;

loop {
     ...

     vif-&gt;idx = wl-&gt;vif_num;
     ...
     wl-&gt;vif_num = i;
      ....
     i++;
     ...
}

At present, vif-&gt;idx is assigned the value of wl-&gt;vif_num
at the beginning of this block and device is initialized
based on this index value.
In the next iteration, wl-&gt;vif_num is still 0 as it is only updated
later but gets assigned to vif-&gt;idx in the beginning. This causes problems
later when we try to reference a particular interface and also while
configuring the firmware.

This patch moves the assignment to vif-&gt;idx from the beginning
of the block to after wl-&gt;vif_num is updated with latest value of i.

Fixes: commit 735bb39ca3be ("staging: wilc1000: simplify vif[i]-&gt;ndev accesses")
Signed-off-by: Aditya Shankar &lt;aditya.shankar@microchip.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: gdm724x: gdm_mux: fix use-after-free on module unload</title>
<updated>2017-05-20T12:49:40+00:00</updated>
<author>
<name>Johan Hovold</name>
<email>johan@kernel.org</email>
</author>
<published>2017-04-26T10:23:04+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=22d8767df90a1d4dd8a955e579e59ead617adcb7'/>
<id>22d8767df90a1d4dd8a955e579e59ead617adcb7</id>
<content type='text'>
commit b58f45c8fc301fe83ee28cad3e64686c19e78f1c upstream.

Make sure to deregister the USB driver before releasing the tty driver
to avoid use-after-free in the USB disconnect callback where the tty
devices are deregistered.

Fixes: 61e121047645 ("staging: gdm7240: adding LTE USB driver")
Cc: Won Kang &lt;wkang77@gmail.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.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 b58f45c8fc301fe83ee28cad3e64686c19e78f1c upstream.

Make sure to deregister the USB driver before releasing the tty driver
to avoid use-after-free in the USB disconnect callback where the tty
devices are deregistered.

Fixes: 61e121047645 ("staging: gdm7240: adding LTE USB driver")
Cc: Won Kang &lt;wkang77@gmail.com&gt;
Signed-off-by: Johan Hovold &lt;johan@kernel.org&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: vt6656: use off stack for out buffer USB transfers.</title>
<updated>2017-05-20T12:49:40+00:00</updated>
<author>
<name>Malcolm Priestley</name>
<email>tvboxspy@gmail.com</email>
</author>
<published>2017-04-22T10:14:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=af685eefa2769a171074344c1e1c2457ed5a347b'/>
<id>af685eefa2769a171074344c1e1c2457ed5a347b</id>
<content type='text'>
commit 12ecd24ef93277e4e5feaf27b0b18f2d3828bc5e upstream.

Since 4.9 mandated USB buffers be heap allocated this causes the driver
to fail.

Since there is a wide range of buffer sizes use kmemdup to create
allocated buffer.

Signed-off-by: Malcolm Priestley &lt;tvboxspy@gmail.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 12ecd24ef93277e4e5feaf27b0b18f2d3828bc5e upstream.

Since 4.9 mandated USB buffers be heap allocated this causes the driver
to fail.

Since there is a wide range of buffer sizes use kmemdup to create
allocated buffer.

Signed-off-by: Malcolm Priestley &lt;tvboxspy@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: vt6656: use off stack for in buffer USB transfers.</title>
<updated>2017-05-20T12:49:40+00:00</updated>
<author>
<name>Malcolm Priestley</name>
<email>tvboxspy@gmail.com</email>
</author>
<published>2017-04-22T10:14:58+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=5ba4fd334f607369cff4201107b58f0404e2f67e'/>
<id>5ba4fd334f607369cff4201107b58f0404e2f67e</id>
<content type='text'>
commit 05c0cf88bec588a7cb34de569acd871ceef26760 upstream.

Since 4.9 mandated USB buffers to be heap allocated. This causes
the driver to fail.

Create buffer for USB transfers.

Signed-off-by: Malcolm Priestley &lt;tvboxspy@gmail.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 05c0cf88bec588a7cb34de569acd871ceef26760 upstream.

Since 4.9 mandated USB buffers to be heap allocated. This causes
the driver to fail.

Create buffer for USB transfers.

Signed-off-by: Malcolm Priestley &lt;tvboxspy@gmail.com&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;

</pre>
</div>
</content>
</entry>
<entry>
<title>staging: android: ashmem: lseek failed due to no FMODE_LSEEK.</title>
<updated>2017-04-08T10:13:11+00:00</updated>
<author>
<name>Shuxiao Zhang</name>
<email>zhangshuxiao@xiaomi.com</email>
</author>
<published>2017-04-06T14:30:29+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=97fbfef6bd597888485b653175fb846c6998b60c'/>
<id>97fbfef6bd597888485b653175fb846c6998b60c</id>
<content type='text'>
vfs_llseek will check whether the file mode has
FMODE_LSEEK, no return failure. But ashmem can be
lseek, so add FMODE_LSEEK to ashmem file.

Comment From Greg Hackmann:
	ashmem_llseek() passes the llseek() call through to the backing
	shmem file.  91360b02ab48 ("ashmem: use vfs_llseek()") changed
	this from directly calling the file's llseek() op into a VFS
	layer call.  This also adds a check for the FMODE_LSEEK bit, so
	without that bit ashmem_llseek() now always fails with -ESPIPE.

Fixes: 91360b02ab48 ("ashmem: use vfs_llseek()")
Signed-off-by: Shuxiao Zhang &lt;zhangshuxiao@xiaomi.com&gt;
Tested-by: Greg Hackmann &lt;ghackmann@google.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt; # 3.18+
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
vfs_llseek will check whether the file mode has
FMODE_LSEEK, no return failure. But ashmem can be
lseek, so add FMODE_LSEEK to ashmem file.

Comment From Greg Hackmann:
	ashmem_llseek() passes the llseek() call through to the backing
	shmem file.  91360b02ab48 ("ashmem: use vfs_llseek()") changed
	this from directly calling the file's llseek() op into a VFS
	layer call.  This also adds a check for the FMODE_LSEEK bit, so
	without that bit ashmem_llseek() now always fails with -ESPIPE.

Fixes: 91360b02ab48 ("ashmem: use vfs_llseek()")
Signed-off-by: Shuxiao Zhang &lt;zhangshuxiao@xiaomi.com&gt;
Tested-by: Greg Hackmann &lt;ghackmann@google.com&gt;
Cc: stable &lt;stable@vger.kernel.org&gt; # 3.18+
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2017-03-15T04:31:23+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2017-03-15T04:31:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ae50dfd61665086e617cc9e554a1285d52765670'/>
<id>ae50dfd61665086e617cc9e554a1285d52765670</id>
<content type='text'>
Pull networking fixes from David Miller:

 1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver,
    from Steffen Klassert.

 2) Fix crashes when user tries to get_next_key on an LPM bpf map, from
    Alexei Starovoitov.

 3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from
    Michal Schmidt.

 4) We can get a divide by zero when TCP socket are morphed into
    listening state, fix from Eric Dumazet.

 5) Fix socket refcounting bugs in skb_complete_wifi_ack() and
    skb_complete_tx_timestamp(). From Eric Dumazet.

 6) Use after free in dccp_feat_activate_values(), also from Eric
    Dumazet.

 7) Like bonding team needs to use ETH_MAX_MTU as netdev-&gt;max_mtu, from
    Jarod Wilson.

 8) Fix use after free in vrf_xmit(), from David Ahern.

 9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from
    Alexey Kodanev.

10) Properly check napi_complete_done() return value in order to decide
    whether to re-enable IRQs or not in amd-xgbe driver, from Thomas
    Lendacky.

11) Fix double free of hwmon device in marvell phy driver, from Andrew
    Lunn.

12) Don't crash on malformed netlink attributes in act_connmark, from
    Etienne Noss.

13) Don't remove routes with a higher metric in ipv6 ECMP route replace,
    from Sabrina Dubroca.

14) Don't write into a cloned SKB in ipv6 fragmentation handling, from
    Florian Westphal.

15) Fix routing redirect races in dccp and tcp, basically the ICMP
    handler can't modify the socket's cached route in it's locked by the
    user at this moment. From Jon Maxwell.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits)
  qed: Enable iSCSI Out-of-Order
  qed: Correct out-of-bound access in OOO history
  qed: Fix interrupt flags on Rx LL2
  qed: Free previous connections when releasing iSCSI
  qed: Fix mapping leak on LL2 rx flow
  qed: Prevent creation of too-big u32-chains
  qed: Align CIDs according to DORQ requirement
  mlxsw: reg: Fix SPVMLR max record count
  mlxsw: reg: Fix SPVM max record count
  net: Resend IGMP memberships upon peer notification.
  dccp: fix memory leak during tear-down of unsuccessful connection request
  tun: fix premature POLLOUT notification on tun devices
  dccp/tcp: fix routing redirect race
  ucc/hdlc: fix two little issue
  vxlan: fix ovs support
  net: use net-&gt;count to check whether a netns is alive or not
  bridge: drop netfilter fake rtable unconditionally
  ipv6: avoid write to a possibly cloned skb
  net: wimax/i2400m: fix NULL-deref at probe
  isdn/gigaset: fix NULL-deref at probe
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:

 1) Ensure that mtu is at least IPV6_MIN_MTU in ipv6 VTI tunnel driver,
    from Steffen Klassert.

 2) Fix crashes when user tries to get_next_key on an LPM bpf map, from
    Alexei Starovoitov.

 3) Fix detection of VLAN fitlering feature for bnx2x VF devices, from
    Michal Schmidt.

 4) We can get a divide by zero when TCP socket are morphed into
    listening state, fix from Eric Dumazet.

 5) Fix socket refcounting bugs in skb_complete_wifi_ack() and
    skb_complete_tx_timestamp(). From Eric Dumazet.

 6) Use after free in dccp_feat_activate_values(), also from Eric
    Dumazet.

 7) Like bonding team needs to use ETH_MAX_MTU as netdev-&gt;max_mtu, from
    Jarod Wilson.

 8) Fix use after free in vrf_xmit(), from David Ahern.

 9) Don't do UDP Fragmentation Offload on IPComp ipsec packets, from
    Alexey Kodanev.

10) Properly check napi_complete_done() return value in order to decide
    whether to re-enable IRQs or not in amd-xgbe driver, from Thomas
    Lendacky.

11) Fix double free of hwmon device in marvell phy driver, from Andrew
    Lunn.

12) Don't crash on malformed netlink attributes in act_connmark, from
    Etienne Noss.

13) Don't remove routes with a higher metric in ipv6 ECMP route replace,
    from Sabrina Dubroca.

14) Don't write into a cloned SKB in ipv6 fragmentation handling, from
    Florian Westphal.

15) Fix routing redirect races in dccp and tcp, basically the ICMP
    handler can't modify the socket's cached route in it's locked by the
    user at this moment. From Jon Maxwell.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (108 commits)
  qed: Enable iSCSI Out-of-Order
  qed: Correct out-of-bound access in OOO history
  qed: Fix interrupt flags on Rx LL2
  qed: Free previous connections when releasing iSCSI
  qed: Fix mapping leak on LL2 rx flow
  qed: Prevent creation of too-big u32-chains
  qed: Align CIDs according to DORQ requirement
  mlxsw: reg: Fix SPVMLR max record count
  mlxsw: reg: Fix SPVM max record count
  net: Resend IGMP memberships upon peer notification.
  dccp: fix memory leak during tear-down of unsuccessful connection request
  tun: fix premature POLLOUT notification on tun devices
  dccp/tcp: fix routing redirect race
  ucc/hdlc: fix two little issue
  vxlan: fix ovs support
  net: use net-&gt;count to check whether a netns is alive or not
  bridge: drop netfilter fake rtable unconditionally
  ipv6: avoid write to a possibly cloned skb
  net: wimax/i2400m: fix NULL-deref at probe
  isdn/gigaset: fix NULL-deref at probe
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>net: Work around lockdep limitation in sockets that use sockets</title>
<updated>2017-03-10T02:23:27+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2017-03-09T08:09:05+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=cdfbabfb2f0ce983fdaa42f20e5f7842178fc01e'/>
<id>cdfbabfb2f0ce983fdaa42f20e5f7842178fc01e</id>
<content type='text'>
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to -&gt;accept() that is analogous to the one
     passed in to -&gt;create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells &lt;dhowells@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>
Lockdep issues a circular dependency warning when AFS issues an operation
through AF_RXRPC from a context in which the VFS/VM holds the mmap_sem.

The theory lockdep comes up with is as follows:

 (1) If the pagefault handler decides it needs to read pages from AFS, it
     calls AFS with mmap_sem held and AFS begins an AF_RXRPC call, but
     creating a call requires the socket lock:

	mmap_sem must be taken before sk_lock-AF_RXRPC

 (2) afs_open_socket() opens an AF_RXRPC socket and binds it.  rxrpc_bind()
     binds the underlying UDP socket whilst holding its socket lock.
     inet_bind() takes its own socket lock:

	sk_lock-AF_RXRPC must be taken before sk_lock-AF_INET

 (3) Reading from a TCP socket into a userspace buffer might cause a fault
     and thus cause the kernel to take the mmap_sem, but the TCP socket is
     locked whilst doing this:

	sk_lock-AF_INET must be taken before mmap_sem

However, lockdep's theory is wrong in this instance because it deals only
with lock classes and not individual locks.  The AF_INET lock in (2) isn't
really equivalent to the AF_INET lock in (3) as the former deals with a
socket entirely internal to the kernel that never sees userspace.  This is
a limitation in the design of lockdep.

Fix the general case by:

 (1) Double up all the locking keys used in sockets so that one set are
     used if the socket is created by userspace and the other set is used
     if the socket is created by the kernel.

 (2) Store the kern parameter passed to sk_alloc() in a variable in the
     sock struct (sk_kern_sock).  This informs sock_lock_init(),
     sock_init_data() and sk_clone_lock() as to the lock keys to be used.

     Note that the child created by sk_clone_lock() inherits the parent's
     kern setting.

 (3) Add a 'kern' parameter to -&gt;accept() that is analogous to the one
     passed in to -&gt;create() that distinguishes whether kernel_accept() or
     sys_accept4() was the caller and can be passed to sk_alloc().

     Note that a lot of accept functions merely dequeue an already
     allocated socket.  I haven't touched these as the new socket already
     exists before we get the parameter.

     Note also that there are a couple of places where I've made the accepted
     socket unconditionally kernel-based:

	irda_accept()
	rds_rcp_accept_one()
	tcp_accept_from_sock()

     because they follow a sock_create_kern() and accept off of that.

Whilst creating this, I noticed that lustre and ocfs don't create sockets
through sock_create_kern() and thus they aren't marked as for-kernel,
though they appear to be internal.  I wonder if these should do that so
that they use the new set of lock keys.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
</feed>
