<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/can, branch v5.14.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>can: j1939: j1939_xtp_rx_dat_one(): fix rxtimer value between consecutive TP.DT to 750ms</title>
<updated>2021-07-24T17:02:24+00:00</updated>
<author>
<name>Zhang Changzhong</name>
<email>zhangchangzhong@huawei.com</email>
</author>
<published>2021-07-06T11:00:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c6eea1c8bda56737752465a298dc6ce07d6b8ce3'/>
<id>c6eea1c8bda56737752465a298dc6ce07d6b8ce3</id>
<content type='text'>
For receive side, the max time interval between two consecutive TP.DT
should be 750ms.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/1625569210-47506-1-git-send-email-zhangchangzhong@huawei.com
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Zhang Changzhong &lt;zhangchangzhong@huawei.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
For receive side, the max time interval between two consecutive TP.DT
should be 750ms.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/1625569210-47506-1-git-send-email-zhangchangzhong@huawei.com
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Zhang Changzhong &lt;zhangchangzhong@huawei.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_session_deactivate(): clarify lifetime of session object</title>
<updated>2021-07-24T17:01:53+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2021-07-14T11:16:02+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0c71437dd50dd687c15d8ca80b3b68f10bb21d63'/>
<id>0c71437dd50dd687c15d8ca80b3b68f10bb21d63</id>
<content type='text'>
The j1939_session_deactivate() is decrementing the session ref-count and
potentially can free() the session. This would cause use-after-free
situation.

However, the code calling j1939_session_deactivate() does always hold
another reference to the session, so that it would not be free()ed in
this code path.

This patch adds a comment to make this clear and a WARN_ON, to ensure
that future changes will not violate this requirement. Further this
patch avoids dereferencing the session pointer as a precaution to avoid
use-after-free if the session is actually free()ed.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210714111602.24021-1-o.rempel@pengutronix.de
Reported-by: Xiaochen Zou &lt;xzou017@ucr.edu&gt;
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The j1939_session_deactivate() is decrementing the session ref-count and
potentially can free() the session. This would cause use-after-free
situation.

However, the code calling j1939_session_deactivate() does always hold
another reference to the session, so that it would not be free()ed in
this code path.

This patch adds a comment to make this clear and a WARN_ON, to ensure
that future changes will not violate this requirement. Further this
patch avoids dereferencing the session pointer as a precaution to avoid
use-after-free if the session is actually free()ed.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210714111602.24021-1-o.rempel@pengutronix.de
Reported-by: Xiaochen Zou &lt;xzou017@ucr.edu&gt;
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: raw: raw_setsockopt(): fix raw_rcv panic for sock UAF</title>
<updated>2021-07-24T17:00:14+00:00</updated>
<author>
<name>Ziyang Xuan</name>
<email>william.xuanziyang@huawei.com</email>
</author>
<published>2021-07-22T07:08:19+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=54f93336d000229f72c26d8a3f69dd256b744528'/>
<id>54f93336d000229f72c26d8a3f69dd256b744528</id>
<content type='text'>
We get a bug during ltp can_filter test as following.

===========================================
[60919.264984] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[60919.265223] PGD 8000003dda726067 P4D 8000003dda726067 PUD 3dda727067 PMD 0
[60919.265443] Oops: 0000 [#1] SMP PTI
[60919.265550] CPU: 30 PID: 3638365 Comm: can_filter Kdump: loaded Tainted: G        W         4.19.90+ #1
[60919.266068] RIP: 0010:selinux_socket_sock_rcv_skb+0x3e/0x200
[60919.293289] RSP: 0018:ffff8d53bfc03cf8 EFLAGS: 00010246
[60919.307140] RAX: 0000000000000000 RBX: 000000000000001d RCX: 0000000000000007
[60919.320756] RDX: 0000000000000001 RSI: ffff8d5104a8ed00 RDI: ffff8d53bfc03d30
[60919.334319] RBP: ffff8d9338056800 R08: ffff8d53bfc29d80 R09: 0000000000000001
[60919.347969] R10: ffff8d53bfc03ec0 R11: ffffb8526ef47c98 R12: ffff8d53bfc03d30
[60919.350320] perf: interrupt took too long (3063 &gt; 2500), lowering kernel.perf_event_max_sample_rate to 65000
[60919.361148] R13: 0000000000000001 R14: ffff8d53bcf90000 R15: 0000000000000000
[60919.361151] FS:  00007fb78b6b3600(0000) GS:ffff8d53bfc00000(0000) knlGS:0000000000000000
[60919.400812] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[60919.413730] CR2: 0000000000000010 CR3: 0000003e3f784006 CR4: 00000000007606e0
[60919.426479] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[60919.439339] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[60919.451608] PKRU: 55555554
[60919.463622] Call Trace:
[60919.475617]  &lt;IRQ&gt;
[60919.487122]  ? update_load_avg+0x89/0x5d0
[60919.498478]  ? update_load_avg+0x89/0x5d0
[60919.509822]  ? account_entity_enqueue+0xc5/0xf0
[60919.520709]  security_sock_rcv_skb+0x2a/0x40
[60919.531413]  sk_filter_trim_cap+0x47/0x1b0
[60919.542178]  ? kmem_cache_alloc+0x38/0x1b0
[60919.552444]  sock_queue_rcv_skb+0x17/0x30
[60919.562477]  raw_rcv+0x110/0x190 [can_raw]
[60919.572539]  can_rcv_filter+0xbc/0x1b0 [can]
[60919.582173]  can_receive+0x6b/0xb0 [can]
[60919.591595]  can_rcv+0x31/0x70 [can]
[60919.600783]  __netif_receive_skb_one_core+0x5a/0x80
[60919.609864]  process_backlog+0x9b/0x150
[60919.618691]  net_rx_action+0x156/0x400
[60919.627310]  ? sched_clock_cpu+0xc/0xa0
[60919.635714]  __do_softirq+0xe8/0x2e9
[60919.644161]  do_softirq_own_stack+0x2a/0x40
[60919.652154]  &lt;/IRQ&gt;
[60919.659899]  do_softirq.part.17+0x4f/0x60
[60919.667475]  __local_bh_enable_ip+0x60/0x70
[60919.675089]  __dev_queue_xmit+0x539/0x920
[60919.682267]  ? finish_wait+0x80/0x80
[60919.689218]  ? finish_wait+0x80/0x80
[60919.695886]  ? sock_alloc_send_pskb+0x211/0x230
[60919.702395]  ? can_send+0xe5/0x1f0 [can]
[60919.708882]  can_send+0xe5/0x1f0 [can]
[60919.715037]  raw_sendmsg+0x16d/0x268 [can_raw]

It's because raw_setsockopt() concurrently with
unregister_netdevice_many(). Concurrent scenario as following.

	cpu0						cpu1
raw_bind
raw_setsockopt					unregister_netdevice_many
						unlist_netdevice
dev_get_by_index				raw_notifier
raw_enable_filters				......
can_rx_register
can_rcv_list_find(..., net-&gt;can.rx_alldev_list)

......

sock_close
raw_release(sock_a)

......

can_receive
can_rcv_filter(net-&gt;can.rx_alldev_list, ...)
raw_rcv(skb, sock_a)
BUG

After unlist_netdevice(), dev_get_by_index() return NULL in
raw_setsockopt(). Function raw_enable_filters() will add sock
and can_filter to net-&gt;can.rx_alldev_list. Then the sock is closed.
Followed by, we sock_sendmsg() to a new vcan device use the same
can_filter. Protocol stack match the old receiver whose sock has
been released on net-&gt;can.rx_alldev_list in can_rcv_filter().
Function raw_rcv() uses the freed sock. UAF BUG is triggered.

We can find that the key issue is that net_device has not been
protected in raw_setsockopt(). Use rtnl_lock to protect net_device
in raw_setsockopt().

Fixes: c18ce101f2e4 ("[CAN]: Add raw protocol")
Link: https://lore.kernel.org/r/20210722070819.1048263-1-william.xuanziyang@huawei.com
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
We get a bug during ltp can_filter test as following.

===========================================
[60919.264984] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[60919.265223] PGD 8000003dda726067 P4D 8000003dda726067 PUD 3dda727067 PMD 0
[60919.265443] Oops: 0000 [#1] SMP PTI
[60919.265550] CPU: 30 PID: 3638365 Comm: can_filter Kdump: loaded Tainted: G        W         4.19.90+ #1
[60919.266068] RIP: 0010:selinux_socket_sock_rcv_skb+0x3e/0x200
[60919.293289] RSP: 0018:ffff8d53bfc03cf8 EFLAGS: 00010246
[60919.307140] RAX: 0000000000000000 RBX: 000000000000001d RCX: 0000000000000007
[60919.320756] RDX: 0000000000000001 RSI: ffff8d5104a8ed00 RDI: ffff8d53bfc03d30
[60919.334319] RBP: ffff8d9338056800 R08: ffff8d53bfc29d80 R09: 0000000000000001
[60919.347969] R10: ffff8d53bfc03ec0 R11: ffffb8526ef47c98 R12: ffff8d53bfc03d30
[60919.350320] perf: interrupt took too long (3063 &gt; 2500), lowering kernel.perf_event_max_sample_rate to 65000
[60919.361148] R13: 0000000000000001 R14: ffff8d53bcf90000 R15: 0000000000000000
[60919.361151] FS:  00007fb78b6b3600(0000) GS:ffff8d53bfc00000(0000) knlGS:0000000000000000
[60919.400812] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[60919.413730] CR2: 0000000000000010 CR3: 0000003e3f784006 CR4: 00000000007606e0
[60919.426479] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[60919.439339] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[60919.451608] PKRU: 55555554
[60919.463622] Call Trace:
[60919.475617]  &lt;IRQ&gt;
[60919.487122]  ? update_load_avg+0x89/0x5d0
[60919.498478]  ? update_load_avg+0x89/0x5d0
[60919.509822]  ? account_entity_enqueue+0xc5/0xf0
[60919.520709]  security_sock_rcv_skb+0x2a/0x40
[60919.531413]  sk_filter_trim_cap+0x47/0x1b0
[60919.542178]  ? kmem_cache_alloc+0x38/0x1b0
[60919.552444]  sock_queue_rcv_skb+0x17/0x30
[60919.562477]  raw_rcv+0x110/0x190 [can_raw]
[60919.572539]  can_rcv_filter+0xbc/0x1b0 [can]
[60919.582173]  can_receive+0x6b/0xb0 [can]
[60919.591595]  can_rcv+0x31/0x70 [can]
[60919.600783]  __netif_receive_skb_one_core+0x5a/0x80
[60919.609864]  process_backlog+0x9b/0x150
[60919.618691]  net_rx_action+0x156/0x400
[60919.627310]  ? sched_clock_cpu+0xc/0xa0
[60919.635714]  __do_softirq+0xe8/0x2e9
[60919.644161]  do_softirq_own_stack+0x2a/0x40
[60919.652154]  &lt;/IRQ&gt;
[60919.659899]  do_softirq.part.17+0x4f/0x60
[60919.667475]  __local_bh_enable_ip+0x60/0x70
[60919.675089]  __dev_queue_xmit+0x539/0x920
[60919.682267]  ? finish_wait+0x80/0x80
[60919.689218]  ? finish_wait+0x80/0x80
[60919.695886]  ? sock_alloc_send_pskb+0x211/0x230
[60919.702395]  ? can_send+0xe5/0x1f0 [can]
[60919.708882]  can_send+0xe5/0x1f0 [can]
[60919.715037]  raw_sendmsg+0x16d/0x268 [can_raw]

It's because raw_setsockopt() concurrently with
unregister_netdevice_many(). Concurrent scenario as following.

	cpu0						cpu1
raw_bind
raw_setsockopt					unregister_netdevice_many
						unlist_netdevice
dev_get_by_index				raw_notifier
raw_enable_filters				......
can_rx_register
can_rcv_list_find(..., net-&gt;can.rx_alldev_list)

......

sock_close
raw_release(sock_a)

......

can_receive
can_rcv_filter(net-&gt;can.rx_alldev_list, ...)
raw_rcv(skb, sock_a)
BUG

After unlist_netdevice(), dev_get_by_index() return NULL in
raw_setsockopt(). Function raw_enable_filters() will add sock
and can_filter to net-&gt;can.rx_alldev_list. Then the sock is closed.
Followed by, we sock_sendmsg() to a new vcan device use the same
can_filter. Protocol stack match the old receiver whose sock has
been released on net-&gt;can.rx_alldev_list in can_rcv_filter().
Function raw_rcv() uses the freed sock. UAF BUG is triggered.

We can find that the key issue is that net_device has not been
protected in raw_setsockopt(). Use rtnl_lock to protect net_device
in raw_setsockopt().

Fixes: c18ce101f2e4 ("[CAN]: Add raw protocol")
Link: https://lore.kernel.org/r/20210722070819.1048263-1-william.xuanziyang@huawei.com
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net</title>
<updated>2021-06-29T22:45:27+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2021-06-29T22:45:27+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=b6df00789e2831fff7a2c65aa7164b2a4dcbe599'/>
<id>b6df00789e2831fff7a2c65aa7164b2a4dcbe599</id>
<content type='text'>
Trivial conflict in net/netfilter/nf_tables_api.c.

Duplicate fix in tools/testing/selftests/net/devlink_port_split.py
- take the net-next version.

skmsg, and L4 bpf - keep the bpf code but remove the flags
and err params.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Trivial conflict in net/netfilter/nf_tables_api.c.

Duplicate fix in tools/testing/selftests/net/devlink_port_split.py
- take the net-next version.

skmsg, and L4 bpf - keep the bpf code but remove the flags
and err params.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: sock: introduce sk_error_report</title>
<updated>2021-06-29T18:28:21+00:00</updated>
<author>
<name>Alexander Aring</name>
<email>aahringo@redhat.com</email>
</author>
<published>2021-06-27T22:48:21+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e3ae2365efc14269170a6326477e669332271ab3'/>
<id>e3ae2365efc14269170a6326477e669332271ab3</id>
<content type='text'>
This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.

Signed-off-by: Alexander Aring &lt;aahringo@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>
This patch introduces a function wrapper to call the sk_error_report
callback. That will prepare to add additional handling whenever
sk_error_report is called, for example to trace socket errors.

Signed-off-by: Alexander Aring &lt;aahringo@redhat.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_sk_setsockopt(): prevent allocation of j1939 filter for optlen == 0</title>
<updated>2021-06-24T06:28:51+00:00</updated>
<author>
<name>Norbert Slusarek</name>
<email>nslusarek@gmx.net</email>
</author>
<published>2021-06-20T12:38:42+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=aaf473d0100f64abc88560e2bea905805bcf2a8e'/>
<id>aaf473d0100f64abc88560e2bea905805bcf2a8e</id>
<content type='text'>
If optval != NULL and optlen == 0 are specified for SO_J1939_FILTER in
j1939_sk_setsockopt(), memdup_sockptr() will return ZERO_PTR for 0
size allocation. The new filter will be mistakenly assigned ZERO_PTR.
This patch checks for optlen != 0 and filter will be assigned NULL in
case of optlen == 0.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210620123842.117975-1-nslusarek@gmx.net
Signed-off-by: Norbert Slusarek &lt;nslusarek@gmx.net&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
If optval != NULL and optlen == 0 are specified for SO_J1939_FILTER in
j1939_sk_setsockopt(), memdup_sockptr() will return ZERO_PTR for 0
size allocation. The new filter will be mistakenly assigned ZERO_PTR.
This patch checks for optlen != 0 and filter will be assigned NULL in
case of optlen == 0.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/r/20210620123842.117975-1-nslusarek@gmx.net
Signed-off-by: Norbert Slusarek &lt;nslusarek@gmx.net&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_sk_init(): set SOCK_RCU_FREE to call sk_destruct() after RCU is done</title>
<updated>2021-06-19T21:54:00+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2021-06-17T13:06:23+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=22c696fed25c63c7f67508309820358b94a96b6d'/>
<id>22c696fed25c63c7f67508309820358b94a96b6d</id>
<content type='text'>
Set SOCK_RCU_FREE to let RCU to call sk_destruct() on completion.
Without this patch, we will run in to j1939_can_recv() after priv was
freed by j1939_sk_release()-&gt;j1939_sk_sock_destruct()

Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback")
Link: https://lore.kernel.org/r/20210617130623.12705-1-o.rempel@pengutronix.de
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Reported-by: Thadeu Lima de Souza Cascardo &lt;cascardo@canonical.com&gt;
Reported-by: syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Set SOCK_RCU_FREE to let RCU to call sk_destruct() on completion.
Without this patch, we will run in to j1939_can_recv() after priv was
freed by j1939_sk_release()-&gt;j1939_sk_sock_destruct()

Fixes: 25fe97cb7620 ("can: j1939: move j1939_priv_put() into sk_destruct callback")
Link: https://lore.kernel.org/r/20210617130623.12705-1-o.rempel@pengutronix.de
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Reported-by: Thadeu Lima de Souza Cascardo &lt;cascardo@canonical.com&gt;
Reported-by: syzbot+bdf710cfc41c186fdff3@syzkaller.appspotmail.com
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: isotp: isotp_release(): omit unintended hrtimer restart on socket release</title>
<updated>2021-06-19T21:54:00+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2021-06-18T17:37:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=14a4696bc3118ba49da28f79280e1d55603aa737'/>
<id>14a4696bc3118ba49da28f79280e1d55603aa737</id>
<content type='text'>
When closing the isotp socket, the potentially running hrtimers are
canceled before removing the subscription for CAN identifiers via
can_rx_unregister().

This may lead to an unintended (re)start of a hrtimer in
isotp_rcv_cf() and isotp_rcv_fc() in the case that a CAN frame is
received by isotp_rcv() while the subscription removal is processed.

However, isotp_rcv() is called under RCU protection, so after calling
can_rx_unregister, we may call synchronize_rcu in order to wait for
any RCU read-side critical sections to finish. This prevents the
reception of CAN frames after hrtimer_cancel() and therefore the
unintended (re)start of the hrtimers.

Link: https://lore.kernel.org/r/20210618173713.2296-1-socketcan@hartkopp.net
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
When closing the isotp socket, the potentially running hrtimers are
canceled before removing the subscription for CAN identifiers via
can_rx_unregister().

This may lead to an unintended (re)start of a hrtimer in
isotp_rcv_cf() and isotp_rcv_fc() in the case that a CAN frame is
received by isotp_rcv() while the subscription removal is processed.

However, isotp_rcv() is called under RCU protection, so after calling
can_rx_unregister, we may call synchronize_rcu in order to wait for
any RCU read-side critical sections to finish. This prevents the
reception of CAN frames after hrtimer_cancel() and therefore the
unintended (re)start of the hrtimers.

Link: https://lore.kernel.org/r/20210618173713.2296-1-socketcan@hartkopp.net
Fixes: e057dd3fc20f ("can: add ISO 15765-2:2016 transport protocol")
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: gw: synchronize rcu operations before removing gw job entry</title>
<updated>2021-06-19T21:53:43+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2021-06-18T17:36:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=fb8696ab14adadb2e3f6c17c18ed26b3ecd96691'/>
<id>fb8696ab14adadb2e3f6c17c18ed26b3ecd96691</id>
<content type='text'>
can_can_gw_rcv() is called under RCU protection, so after calling
can_rx_unregister(), we have to call synchronize_rcu in order to wait
for any RCU read-side critical sections to finish before removing the
kmem_cache entry with the referenced gw job entry.

Link: https://lore.kernel.org/r/20210618173645.2238-1-socketcan@hartkopp.net
Fixes: c1aabdf379bc ("can-gw: add netlink based CAN routing")
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
can_can_gw_rcv() is called under RCU protection, so after calling
can_rx_unregister(), we have to call synchronize_rcu in order to wait
for any RCU read-side critical sections to finish before removing the
kmem_cache entry with the referenced gw job entry.

Link: https://lore.kernel.org/r/20210618173645.2238-1-socketcan@hartkopp.net
Fixes: c1aabdf379bc ("can-gw: add netlink based CAN routing")
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: bcm: delay release of struct bcm_op after synchronize_rcu()</title>
<updated>2021-06-19T21:47:32+00:00</updated>
<author>
<name>Thadeu Lima de Souza Cascardo</name>
<email>cascardo@canonical.com</email>
</author>
<published>2021-06-19T16:18:13+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d5f9023fa61ee8b94f37a93f08e94b136cf1e463'/>
<id>d5f9023fa61ee8b94f37a93f08e94b136cf1e463</id>
<content type='text'>
can_rx_register() callbacks may be called concurrently to the call to
can_rx_unregister(). The callbacks and callback data, though, are
protected by RCU and the struct sock reference count.

So the callback data is really attached to the life of sk, meaning
that it should be released on sk_destruct. However, bcm_remove_op()
calls tasklet_kill(), and RCU callbacks may be called under RCU
softirq, so that cannot be used on kernels before the introduction of
HRTIMER_MODE_SOFT.

However, bcm_rx_handler() is called under RCU protection, so after
calling can_rx_unregister(), we may call synchronize_rcu() in order to
wait for any RCU read-side critical sections to finish. That is,
bcm_rx_handler() won't be called anymore for those ops. So, we only
free them, after we do that synchronize_rcu().

Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
Link: https://lore.kernel.org/r/20210619161813.2098382-1-cascardo@canonical.com
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Reported-by: syzbot+0f7e7e5e2f4f40fa89c0@syzkaller.appspotmail.com
Reported-by: Norbert Slusarek &lt;nslusarek@gmx.net&gt;
Signed-off-by: Thadeu Lima de Souza Cascardo &lt;cascardo@canonical.com&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
can_rx_register() callbacks may be called concurrently to the call to
can_rx_unregister(). The callbacks and callback data, though, are
protected by RCU and the struct sock reference count.

So the callback data is really attached to the life of sk, meaning
that it should be released on sk_destruct. However, bcm_remove_op()
calls tasklet_kill(), and RCU callbacks may be called under RCU
softirq, so that cannot be used on kernels before the introduction of
HRTIMER_MODE_SOFT.

However, bcm_rx_handler() is called under RCU protection, so after
calling can_rx_unregister(), we may call synchronize_rcu() in order to
wait for any RCU read-side critical sections to finish. That is,
bcm_rx_handler() won't be called anymore for those ops. So, we only
free them, after we do that synchronize_rcu().

Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
Link: https://lore.kernel.org/r/20210619161813.2098382-1-cascardo@canonical.com
Cc: linux-stable &lt;stable@vger.kernel.org&gt;
Reported-by: syzbot+0f7e7e5e2f4f40fa89c0@syzkaller.appspotmail.com
Reported-by: Norbert Slusarek &lt;nslusarek@gmx.net&gt;
Signed-off-by: Thadeu Lima de Souza Cascardo &lt;cascardo@canonical.com&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
</feed>
