<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/can, branch v5.4.263</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>can: bcm: Fix UAF in bcm_proc_show()</title>
<updated>2023-07-27T06:37:40+00:00</updated>
<author>
<name>YueHaibing</name>
<email>yuehaibing@huawei.com</email>
</author>
<published>2023-07-15T09:25:43+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9533dbfac0ff7edd77a5fa2c24974b1d66c8b0a6'/>
<id>9533dbfac0ff7edd77a5fa2c24974b1d66c8b0a6</id>
<content type='text'>
commit 55c3b96074f3f9b0aee19bf93cd71af7516582bb upstream.

BUG: KASAN: slab-use-after-free in bcm_proc_show+0x969/0xa80
Read of size 8 at addr ffff888155846230 by task cat/7862

CPU: 1 PID: 7862 Comm: cat Not tainted 6.5.0-rc1-00153-gc8746099c197 #230
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
 &lt;TASK&gt;
 dump_stack_lvl+0xd5/0x150
 print_report+0xc1/0x5e0
 kasan_report+0xba/0xf0
 bcm_proc_show+0x969/0xa80
 seq_read_iter+0x4f6/0x1260
 seq_read+0x165/0x210
 proc_reg_read+0x227/0x300
 vfs_read+0x1d5/0x8d0
 ksys_read+0x11e/0x240
 do_syscall_64+0x35/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Allocated by task 7846:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 __kasan_kmalloc+0x9e/0xa0
 bcm_sendmsg+0x264b/0x44e0
 sock_sendmsg+0xda/0x180
 ____sys_sendmsg+0x735/0x920
 ___sys_sendmsg+0x11d/0x1b0
 __sys_sendmsg+0xfa/0x1d0
 do_syscall_64+0x35/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 7846:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x27/0x40
 ____kasan_slab_free+0x161/0x1c0
 slab_free_freelist_hook+0x119/0x220
 __kmem_cache_free+0xb4/0x2e0
 rcu_core+0x809/0x1bd0

bcm_op is freed before procfs entry be removed in bcm_release(),
this lead to bcm_proc_show() may read the freed bcm_op.

Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Reviewed-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230715092543.15548-1-yuehaibing@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 55c3b96074f3f9b0aee19bf93cd71af7516582bb upstream.

BUG: KASAN: slab-use-after-free in bcm_proc_show+0x969/0xa80
Read of size 8 at addr ffff888155846230 by task cat/7862

CPU: 1 PID: 7862 Comm: cat Not tainted 6.5.0-rc1-00153-gc8746099c197 #230
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
 &lt;TASK&gt;
 dump_stack_lvl+0xd5/0x150
 print_report+0xc1/0x5e0
 kasan_report+0xba/0xf0
 bcm_proc_show+0x969/0xa80
 seq_read_iter+0x4f6/0x1260
 seq_read+0x165/0x210
 proc_reg_read+0x227/0x300
 vfs_read+0x1d5/0x8d0
 ksys_read+0x11e/0x240
 do_syscall_64+0x35/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Allocated by task 7846:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 __kasan_kmalloc+0x9e/0xa0
 bcm_sendmsg+0x264b/0x44e0
 sock_sendmsg+0xda/0x180
 ____sys_sendmsg+0x735/0x920
 ___sys_sendmsg+0x11d/0x1b0
 __sys_sendmsg+0xfa/0x1d0
 do_syscall_64+0x35/0xb0
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Freed by task 7846:
 kasan_save_stack+0x1e/0x40
 kasan_set_track+0x21/0x30
 kasan_save_free_info+0x27/0x40
 ____kasan_slab_free+0x161/0x1c0
 slab_free_freelist_hook+0x119/0x220
 __kmem_cache_free+0xb4/0x2e0
 rcu_core+0x809/0x1bd0

bcm_op is freed before procfs entry be removed in bcm_release(),
this lead to bcm_proc_show() may read the freed bcm_op.

Fixes: ffd980f976e7 ("[CAN]: Add broadcast manager (bcm) protocol")
Signed-off-by: YueHaibing &lt;yuehaibing@huawei.com&gt;
Reviewed-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230715092543.15548-1-yuehaibing@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: avoid possible use-after-free when j1939_can_rx_register fails</title>
<updated>2023-06-14T08:59:57+00:00</updated>
<author>
<name>Fedor Pchelkin</name>
<email>pchelkin@ispras.ru</email>
</author>
<published>2023-05-26T17:19:10+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=2416bac0e7b21113aa8047ecf8e97c9d559e26a3'/>
<id>2416bac0e7b21113aa8047ecf8e97c9d559e26a3</id>
<content type='text'>
commit 9f16eb106aa5fce15904625661312623ec783ed3 upstream.

Syzkaller reports the following failure:

BUG: KASAN: use-after-free in kref_put include/linux/kref.h:64 [inline]
BUG: KASAN: use-after-free in j1939_priv_put+0x25/0xa0 net/can/j1939/main.c:172
Write of size 4 at addr ffff888141c15058 by task swapper/3/0

CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.10.144-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 &lt;IRQ&gt;
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 print_address_description.constprop.0+0x1c/0x220 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x145/0x190 mm/kasan/generic.c:192
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
 __refcount_sub_and_test include/linux/refcount.h:272 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 kref_put include/linux/kref.h:64 [inline]
 j1939_priv_put+0x25/0xa0 net/can/j1939/main.c:172
 j1939_sk_sock_destruct+0x44/0x90 net/can/j1939/socket.c:374
 __sk_destruct+0x4e/0x820 net/core/sock.c:1784
 rcu_do_batch kernel/rcu/tree.c:2485 [inline]
 rcu_core+0xb35/0x1a30 kernel/rcu/tree.c:2726
 __do_softirq+0x289/0x9a3 kernel/softirq.c:298
 asm_call_irq_on_stack+0x12/0x20
 &lt;/IRQ&gt;
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xe0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x136/0x200 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1095
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635

Allocated by task 1141:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc9/0xd0 mm/kasan/common.c:461
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 j1939_priv_create net/can/j1939/main.c:131 [inline]
 j1939_netdev_start+0x111/0x860 net/can/j1939/main.c:268
 j1939_sk_bind+0x8ea/0xd30 net/can/j1939/socket.c:485
 __sys_bind+0x1f2/0x260 net/socket.c:1645
 __do_sys_bind net/socket.c:1656 [inline]
 __se_sys_bind net/socket.c:1654 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1654
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

Freed by task 1141:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x112/0x170 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1542 [inline]
 slab_free_freelist_hook+0xad/0x190 mm/slub.c:1576
 slab_free mm/slub.c:3149 [inline]
 kfree+0xd9/0x3b0 mm/slub.c:4125
 j1939_netdev_start+0x5ee/0x860 net/can/j1939/main.c:300
 j1939_sk_bind+0x8ea/0xd30 net/can/j1939/socket.c:485
 __sys_bind+0x1f2/0x260 net/socket.c:1645
 __do_sys_bind net/socket.c:1656 [inline]
 __se_sys_bind net/socket.c:1654 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1654
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

It can be caused by this scenario:

CPU0					CPU1
j1939_sk_bind(socket0, ndev0, ...)
  j1939_netdev_start()
					j1939_sk_bind(socket1, ndev0, ...)
                                          j1939_netdev_start()
  mutex_lock(&amp;j1939_netdev_lock)
  j1939_priv_set(ndev0, priv)
  mutex_unlock(&amp;j1939_netdev_lock)
					  if (priv_new)
					    kref_get(&amp;priv_new-&gt;rx_kref)
					    return priv_new;
					  /* inside j1939_sk_bind() */
					  jsk-&gt;priv = priv
  j1939_can_rx_register(priv) // fails
  j1939_priv_set(ndev, NULL)
  kfree(priv)
					j1939_sk_sock_destruct()
					j1939_priv_put() // &lt;- uaf

To avoid this, call j1939_can_rx_register() under j1939_netdev_lock so
that a concurrent thread cannot process j1939_priv before
j1939_can_rx_register() returns.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Tested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20230526171910.227615-3-pchelkin@ispras.ru
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 9f16eb106aa5fce15904625661312623ec783ed3 upstream.

Syzkaller reports the following failure:

BUG: KASAN: use-after-free in kref_put include/linux/kref.h:64 [inline]
BUG: KASAN: use-after-free in j1939_priv_put+0x25/0xa0 net/can/j1939/main.c:172
Write of size 4 at addr ffff888141c15058 by task swapper/3/0

CPU: 3 PID: 0 Comm: swapper/3 Not tainted 5.10.144-syzkaller #0
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.12.0-1 04/01/2014
Call Trace:
 &lt;IRQ&gt;
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x107/0x167 lib/dump_stack.c:118
 print_address_description.constprop.0+0x1c/0x220 mm/kasan/report.c:385
 __kasan_report mm/kasan/report.c:545 [inline]
 kasan_report.cold+0x1f/0x37 mm/kasan/report.c:562
 check_memory_region_inline mm/kasan/generic.c:186 [inline]
 check_memory_region+0x145/0x190 mm/kasan/generic.c:192
 instrument_atomic_read_write include/linux/instrumented.h:101 [inline]
 atomic_fetch_sub_release include/asm-generic/atomic-instrumented.h:220 [inline]
 __refcount_sub_and_test include/linux/refcount.h:272 [inline]
 __refcount_dec_and_test include/linux/refcount.h:315 [inline]
 refcount_dec_and_test include/linux/refcount.h:333 [inline]
 kref_put include/linux/kref.h:64 [inline]
 j1939_priv_put+0x25/0xa0 net/can/j1939/main.c:172
 j1939_sk_sock_destruct+0x44/0x90 net/can/j1939/socket.c:374
 __sk_destruct+0x4e/0x820 net/core/sock.c:1784
 rcu_do_batch kernel/rcu/tree.c:2485 [inline]
 rcu_core+0xb35/0x1a30 kernel/rcu/tree.c:2726
 __do_softirq+0x289/0x9a3 kernel/softirq.c:298
 asm_call_irq_on_stack+0x12/0x20
 &lt;/IRQ&gt;
 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline]
 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline]
 do_softirq_own_stack+0xaa/0xe0 arch/x86/kernel/irq_64.c:77
 invoke_softirq kernel/softirq.c:393 [inline]
 __irq_exit_rcu kernel/softirq.c:423 [inline]
 irq_exit_rcu+0x136/0x200 kernel/softirq.c:435
 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1095
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635

Allocated by task 1141:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track mm/kasan/common.c:56 [inline]
 __kasan_kmalloc.constprop.0+0xc9/0xd0 mm/kasan/common.c:461
 kmalloc include/linux/slab.h:552 [inline]
 kzalloc include/linux/slab.h:664 [inline]
 j1939_priv_create net/can/j1939/main.c:131 [inline]
 j1939_netdev_start+0x111/0x860 net/can/j1939/main.c:268
 j1939_sk_bind+0x8ea/0xd30 net/can/j1939/socket.c:485
 __sys_bind+0x1f2/0x260 net/socket.c:1645
 __do_sys_bind net/socket.c:1656 [inline]
 __se_sys_bind net/socket.c:1654 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1654
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

Freed by task 1141:
 kasan_save_stack+0x1b/0x40 mm/kasan/common.c:48
 kasan_set_track+0x1c/0x30 mm/kasan/common.c:56
 kasan_set_free_info+0x1b/0x30 mm/kasan/generic.c:355
 __kasan_slab_free+0x112/0x170 mm/kasan/common.c:422
 slab_free_hook mm/slub.c:1542 [inline]
 slab_free_freelist_hook+0xad/0x190 mm/slub.c:1576
 slab_free mm/slub.c:3149 [inline]
 kfree+0xd9/0x3b0 mm/slub.c:4125
 j1939_netdev_start+0x5ee/0x860 net/can/j1939/main.c:300
 j1939_sk_bind+0x8ea/0xd30 net/can/j1939/socket.c:485
 __sys_bind+0x1f2/0x260 net/socket.c:1645
 __do_sys_bind net/socket.c:1656 [inline]
 __se_sys_bind net/socket.c:1654 [inline]
 __x64_sys_bind+0x6f/0xb0 net/socket.c:1654
 do_syscall_64+0x33/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xc6

It can be caused by this scenario:

CPU0					CPU1
j1939_sk_bind(socket0, ndev0, ...)
  j1939_netdev_start()
					j1939_sk_bind(socket1, ndev0, ...)
                                          j1939_netdev_start()
  mutex_lock(&amp;j1939_netdev_lock)
  j1939_priv_set(ndev0, priv)
  mutex_unlock(&amp;j1939_netdev_lock)
					  if (priv_new)
					    kref_get(&amp;priv_new-&gt;rx_kref)
					    return priv_new;
					  /* inside j1939_sk_bind() */
					  jsk-&gt;priv = priv
  j1939_can_rx_register(priv) // fails
  j1939_priv_set(ndev, NULL)
  kfree(priv)
					j1939_sk_sock_destruct()
					j1939_priv_put() // &lt;- uaf

To avoid this, call j1939_can_rx_register() under j1939_netdev_lock so
that a concurrent thread cannot process j1939_priv before
j1939_can_rx_register() returns.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Tested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20230526171910.227615-3-pchelkin@ispras.ru
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: change j1939_netdev_lock type to mutex</title>
<updated>2023-06-14T08:59:57+00:00</updated>
<author>
<name>Fedor Pchelkin</name>
<email>pchelkin@ispras.ru</email>
</author>
<published>2023-05-26T17:19:09+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=bf0245bd44c0913472fbfb26434906d4cb1b7caa'/>
<id>bf0245bd44c0913472fbfb26434906d4cb1b7caa</id>
<content type='text'>
commit cd9c790de2088b0d797dc4d244b4f174f9962554 upstream.

It turns out access to j1939_can_rx_register() needs to be serialized,
otherwise j1939_priv can be corrupted when parallel threads call
j1939_netdev_start() and j1939_can_rx_register() fails. This issue is
thoroughly covered in other commit which serializes access to
j1939_can_rx_register().

Change j1939_netdev_lock type to mutex so that we do not need to remove
GFP_KERNEL from can_rx_register().

j1939_netdev_lock seems to be used in normal contexts where mutex usage
is not prohibited.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Tested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20230526171910.227615-2-pchelkin@ispras.ru
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 cd9c790de2088b0d797dc4d244b4f174f9962554 upstream.

It turns out access to j1939_can_rx_register() needs to be serialized,
otherwise j1939_priv can be corrupted when parallel threads call
j1939_netdev_start() and j1939_can_rx_register() fails. This issue is
thoroughly covered in other commit which serializes access to
j1939_can_rx_register().

Change j1939_netdev_lock type to mutex so that we do not need to remove
GFP_KERNEL from can_rx_register().

j1939_netdev_lock seems to be used in normal contexts where mutex usage
is not prohibited.

Found by Linux Verification Center (linuxtesting.org) with Syzkaller.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Suggested-by: Alexey Khoroshilov &lt;khoroshilov@ispras.ru&gt;
Signed-off-by: Fedor Pchelkin &lt;pchelkin@ispras.ru&gt;
Tested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20230526171910.227615-2-pchelkin@ispras.ru
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_sk_send_loop_abort(): improved error queue handling in J1939 Socket</title>
<updated>2023-06-14T08:59:57+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2023-05-26T08:19:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=9eed68d62e2aa835b9366ba93062b7446bd47584'/>
<id>9eed68d62e2aa835b9366ba93062b7446bd47584</id>
<content type='text'>
commit 2a84aea80e925ecba6349090559754f8e8eb68ef upstream.

This patch addresses an issue within the j1939_sk_send_loop_abort()
function in the j1939/socket.c file, specifically in the context of
Transport Protocol (TP) sessions.

Without this patch, when a TP session is initiated and a Clear To Send
(CTS) frame is received from the remote side requesting one data packet,
the kernel dispatches the first Data Transport (DT) frame and then waits
for the next CTS. If the remote side doesn't respond with another CTS,
the kernel aborts due to a timeout. This leads to the user-space
receiving an EPOLLERR on the socket, and the socket becomes active.

However, when trying to read the error queue from the socket with
sock.recvmsg(, , socket.MSG_ERRQUEUE), it returns -EAGAIN,
given that the socket is non-blocking. This situation results in an
infinite loop: the user-space repeatedly calls epoll(), epoll() returns
the socket file descriptor with EPOLLERR, but the socket then blocks on
the recv() of ERRQUEUE.

This patch introduces an additional check for the J1939_SOCK_ERRQUEUE
flag within the j1939_sk_send_loop_abort() function. If the flag is set,
it indicates that the application has subscribed to receive error queue
messages. In such cases, the kernel can communicate the current transfer
state via the error queue. This allows for the function to return early,
preventing the unnecessary setting of the socket into an error state,
and breaking the infinite loop. It is crucial to note that a socket
error is only needed if the application isn't using the error queue, as,
without it, the application wouldn't be aware of transfer issues.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: David Jander &lt;david@protonic.nl&gt;
Tested-by: David Jander &lt;david@protonic.nl&gt;
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20230526081946.715190-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 2a84aea80e925ecba6349090559754f8e8eb68ef upstream.

This patch addresses an issue within the j1939_sk_send_loop_abort()
function in the j1939/socket.c file, specifically in the context of
Transport Protocol (TP) sessions.

Without this patch, when a TP session is initiated and a Clear To Send
(CTS) frame is received from the remote side requesting one data packet,
the kernel dispatches the first Data Transport (DT) frame and then waits
for the next CTS. If the remote side doesn't respond with another CTS,
the kernel aborts due to a timeout. This leads to the user-space
receiving an EPOLLERR on the socket, and the socket becomes active.

However, when trying to read the error queue from the socket with
sock.recvmsg(, , socket.MSG_ERRQUEUE), it returns -EAGAIN,
given that the socket is non-blocking. This situation results in an
infinite loop: the user-space repeatedly calls epoll(), epoll() returns
the socket file descriptor with EPOLLERR, but the socket then blocks on
the recv() of ERRQUEUE.

This patch introduces an additional check for the J1939_SOCK_ERRQUEUE
flag within the j1939_sk_send_loop_abort() function. If the flag is set,
it indicates that the application has subscribed to receive error queue
messages. In such cases, the kernel can communicate the current transfer
state via the error queue. This allows for the function to return early,
preventing the unnecessary setting of the socket into an error state,
and breaking the infinite loop. It is crucial to note that a socket
error is only needed if the application isn't using the error queue, as,
without it, the application wouldn't be aware of transfer issues.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: David Jander &lt;david@protonic.nl&gt;
Tested-by: David Jander &lt;david@protonic.nl&gt;
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/r/20230526081946.715190-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: recvmsg(): allow MSG_CMSG_COMPAT flag</title>
<updated>2023-05-30T11:44:06+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-04-06T11:08:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e658112893467b5f44a8d3810ee2dad976834645'/>
<id>e658112893467b5f44a8d3810ee2dad976834645</id>
<content type='text'>
commit 1db080cbdbab28752bbb1c86d64daf96253a5da1 upstream.

The control message provided by J1939 support MSG_CMSG_COMPAT but
blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user
space on 64 bit kernels.

Link: https://github.com/hartkopp/can-isotp/issues/59
Cc: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Suggested-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Tested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/20230505110308.81087-3-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 1db080cbdbab28752bbb1c86d64daf96253a5da1 upstream.

The control message provided by J1939 support MSG_CMSG_COMPAT but
blocked recvmsg() syscalls that have set this flag, i.e. on 32bit user
space on 64 bit kernels.

Link: https://github.com/hartkopp/can-isotp/issues/59
Cc: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Suggested-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Tested-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Link: https://lore.kernel.org/20230505110308.81087-3-mkl@pengutronix.de
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: j1939_tp_tx_dat_new(): fix out-of-bounds memory access</title>
<updated>2023-04-20T10:07:34+00:00</updated>
<author>
<name>Oleksij Rempel</name>
<email>o.rempel@pengutronix.de</email>
</author>
<published>2023-04-04T07:31:28+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=d2136f05690c272dfc9f9d6efcc51d5f53494b33'/>
<id>d2136f05690c272dfc9f9d6efcc51d5f53494b33</id>
<content type='text'>
commit b45193cb4df556fe6251b285a5ce44046dd36b4a upstream.

In the j1939_tp_tx_dat_new() function, an out-of-bounds memory access
could occur during the memcpy() operation if the size of skb-&gt;cb is
larger than the size of struct j1939_sk_buff_cb. This is because the
memcpy() operation uses the size of skb-&gt;cb, leading to a read beyond
the struct j1939_sk_buff_cb.

Updated the memcpy() operation to use the size of struct
j1939_sk_buff_cb instead of the size of skb-&gt;cb. This ensures that the
memcpy() operation only reads the memory within the bounds of struct
j1939_sk_buff_cb, preventing out-of-bounds memory access.

Additionally, add a BUILD_BUG_ON() to check that the size of skb-&gt;cb
is greater than or equal to the size of struct j1939_sk_buff_cb. This
ensures that the skb-&gt;cb buffer is large enough to hold the
j1939_sk_buff_cb structure.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: Shuangpeng Bai &lt;sjb7183@psu.edu&gt;
Tested-by: Shuangpeng Bai &lt;sjb7183@psu.edu&gt;
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://groups.google.com/g/syzkaller/c/G_LL-C3plRs/m/-8xCi6dCAgAJ
Link: https://lore.kernel.org/all/20230404073128.3173900-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
[mkl: rephrase commit message]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 b45193cb4df556fe6251b285a5ce44046dd36b4a upstream.

In the j1939_tp_tx_dat_new() function, an out-of-bounds memory access
could occur during the memcpy() operation if the size of skb-&gt;cb is
larger than the size of struct j1939_sk_buff_cb. This is because the
memcpy() operation uses the size of skb-&gt;cb, leading to a read beyond
the struct j1939_sk_buff_cb.

Updated the memcpy() operation to use the size of struct
j1939_sk_buff_cb instead of the size of skb-&gt;cb. This ensures that the
memcpy() operation only reads the memory within the bounds of struct
j1939_sk_buff_cb, preventing out-of-bounds memory access.

Additionally, add a BUILD_BUG_ON() to check that the size of skb-&gt;cb
is greater than or equal to the size of struct j1939_sk_buff_cb. This
ensures that the skb-&gt;cb buffer is large enough to hold the
j1939_sk_buff_cb structure.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Reported-by: Shuangpeng Bai &lt;sjb7183@psu.edu&gt;
Tested-by: Shuangpeng Bai &lt;sjb7183@psu.edu&gt;
Signed-off-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://groups.google.com/g/syzkaller/c/G_LL-C3plRs/m/-8xCi6dCAgAJ
Link: https://lore.kernel.org/all/20230404073128.3173900-1-o.rempel@pengutronix.de
Cc: stable@vger.kernel.org
[mkl: rephrase commit message]
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: bcm: bcm_tx_setup(): fix KMSAN uninit-value in vfs_write</title>
<updated>2023-04-05T09:16:44+00:00</updated>
<author>
<name>Ivan Orlov</name>
<email>ivan.orlov0322@gmail.com</email>
</author>
<published>2023-03-14T12:04:45+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=78bc7f0ab99458221224d3ab97199c0f8e6861f1'/>
<id>78bc7f0ab99458221224d3ab97199c0f8e6861f1</id>
<content type='text'>
[ Upstream commit 2b4c99f7d9a57ecd644eda9b1fb0a1072414959f ]

Syzkaller reported the following issue:

=====================================================
BUG: KMSAN: uninit-value in aio_rw_done fs/aio.c:1520 [inline]
BUG: KMSAN: uninit-value in aio_write+0x899/0x950 fs/aio.c:1600
 aio_rw_done fs/aio.c:1520 [inline]
 aio_write+0x899/0x950 fs/aio.c:1600
 io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019
 __do_sys_io_submit fs/aio.c:2078 [inline]
 __se_sys_io_submit+0x293/0x770 fs/aio.c:2048
 __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:766 [inline]
 slab_alloc_node mm/slub.c:3452 [inline]
 __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:967 [inline]
 __kmalloc+0x11d/0x3b0 mm/slab_common.c:981
 kmalloc_array include/linux/slab.h:636 [inline]
 bcm_tx_setup+0x80e/0x29d0 net/can/bcm.c:930
 bcm_sendmsg+0x3a2/0xce0 net/can/bcm.c:1351
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 sock_write_iter+0x495/0x5e0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2189 [inline]
 aio_write+0x63a/0x950 fs/aio.c:1600
 io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019
 __do_sys_io_submit fs/aio.c:2078 [inline]
 __se_sys_io_submit+0x293/0x770 fs/aio.c:2048
 __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CPU: 1 PID: 5034 Comm: syz-executor350 Not tainted 6.2.0-rc6-syzkaller-80422-geda666ff2276 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
=====================================================

We can follow the call chain and find that 'bcm_tx_setup' function
calls 'memcpy_from_msg' to copy some content to the newly allocated
frame of 'op-&gt;frames'. After that the 'len' field of copied structure
being compared with some constant value (64 or 8). However, if
'memcpy_from_msg' returns an error, we will compare some uninitialized
memory. This triggers 'uninit-value' issue.

This patch will add 'memcpy_from_msg' possible errors processing to
avoid uninit-value issue.

Tested via syzkaller

Reported-by: syzbot+c9bfd85eca611ebf5db1@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=47f897f8ad958bbde5790ebf389b5e7e0a345089
Signed-off-by: Ivan Orlov &lt;ivan.orlov0322@gmail.com&gt;
Fixes: 6f3b911d5f29b ("can: bcm: add support for CAN FD frames")
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230314120445.12407-1-ivan.orlov0322@gmail.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit 2b4c99f7d9a57ecd644eda9b1fb0a1072414959f ]

Syzkaller reported the following issue:

=====================================================
BUG: KMSAN: uninit-value in aio_rw_done fs/aio.c:1520 [inline]
BUG: KMSAN: uninit-value in aio_write+0x899/0x950 fs/aio.c:1600
 aio_rw_done fs/aio.c:1520 [inline]
 aio_write+0x899/0x950 fs/aio.c:1600
 io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019
 __do_sys_io_submit fs/aio.c:2078 [inline]
 __se_sys_io_submit+0x293/0x770 fs/aio.c:2048
 __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Uninit was created at:
 slab_post_alloc_hook mm/slab.h:766 [inline]
 slab_alloc_node mm/slub.c:3452 [inline]
 __kmem_cache_alloc_node+0x71f/0xce0 mm/slub.c:3491
 __do_kmalloc_node mm/slab_common.c:967 [inline]
 __kmalloc+0x11d/0x3b0 mm/slab_common.c:981
 kmalloc_array include/linux/slab.h:636 [inline]
 bcm_tx_setup+0x80e/0x29d0 net/can/bcm.c:930
 bcm_sendmsg+0x3a2/0xce0 net/can/bcm.c:1351
 sock_sendmsg_nosec net/socket.c:714 [inline]
 sock_sendmsg net/socket.c:734 [inline]
 sock_write_iter+0x495/0x5e0 net/socket.c:1108
 call_write_iter include/linux/fs.h:2189 [inline]
 aio_write+0x63a/0x950 fs/aio.c:1600
 io_submit_one+0x1d1c/0x3bf0 fs/aio.c:2019
 __do_sys_io_submit fs/aio.c:2078 [inline]
 __se_sys_io_submit+0x293/0x770 fs/aio.c:2048
 __x64_sys_io_submit+0x92/0xd0 fs/aio.c:2048
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x3d/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

CPU: 1 PID: 5034 Comm: syz-executor350 Not tainted 6.2.0-rc6-syzkaller-80422-geda666ff2276 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/12/2023
=====================================================

We can follow the call chain and find that 'bcm_tx_setup' function
calls 'memcpy_from_msg' to copy some content to the newly allocated
frame of 'op-&gt;frames'. After that the 'len' field of copied structure
being compared with some constant value (64 or 8). However, if
'memcpy_from_msg' returns an error, we will compare some uninitialized
memory. This triggers 'uninit-value' issue.

This patch will add 'memcpy_from_msg' possible errors processing to
avoid uninit-value issue.

Tested via syzkaller

Reported-by: syzbot+c9bfd85eca611ebf5db1@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=47f897f8ad958bbde5790ebf389b5e7e0a345089
Signed-off-by: Ivan Orlov &lt;ivan.orlov0322@gmail.com&gt;
Fixes: 6f3b911d5f29b ("can: bcm: add support for CAN FD frames")
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230314120445.12407-1-ivan.orlov0322@gmail.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: do not wait 250 ms if the same addr was already claimed</title>
<updated>2023-02-22T11:50:30+00:00</updated>
<author>
<name>Devid Antonio Filoni</name>
<email>devid.filoni@egluetechnologies.com</email>
</author>
<published>2022-11-25T17:04:18+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ae774f480da32fea60bb454555c3a1bc347778c7'/>
<id>ae774f480da32fea60bb454555c3a1bc347778c7</id>
<content type='text'>
commit 4ae5e1e97c44f4654516c1d41591a462ed62fa7b upstream.

The ISO 11783-5 standard, in "4.5.2 - Address claim requirements", states:
  d) No CF shall begin, or resume, transmission on the network until 250
     ms after it has successfully claimed an address except when
     responding to a request for address-claimed.

But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
prioritization" show that the CF begins the transmission after 250 ms
from the first AC (address-claimed) message even if it sends another AC
message during that time window to resolve the address contention with
another CF.

As stated in "4.4.2.3 - Address-claimed message":
  In order to successfully claim an address, the CF sending an address
  claimed message shall not receive a contending claim from another CF
  for at least 250 ms.

As stated in "4.4.3.2 - NAME management (NM) message":
  1) A commanding CF can
     d) request that a CF with a specified NAME transmit the address-
        claimed message with its current NAME.
  2) A target CF shall
     d) send an address-claimed message in response to a request for a
        matching NAME

Taking the above arguments into account, the 250 ms wait is requested
only during network initialization.

Do not restart the timer on AC message if both the NAME and the address
match and so if the address has already been claimed (timer has expired)
or the AC message has been sent to resolve the contention with another
CF (timer is still running).

Signed-off-by: Devid Antonio Filoni &lt;devid.filoni@egluetechnologies.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20221125170418.34575-1-devid.filoni@egluetechnologies.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 4ae5e1e97c44f4654516c1d41591a462ed62fa7b upstream.

The ISO 11783-5 standard, in "4.5.2 - Address claim requirements", states:
  d) No CF shall begin, or resume, transmission on the network until 250
     ms after it has successfully claimed an address except when
     responding to a request for address-claimed.

But "Figure 6" and "Figure 7" in "4.5.4.2 - Address-claim
prioritization" show that the CF begins the transmission after 250 ms
from the first AC (address-claimed) message even if it sends another AC
message during that time window to resolve the address contention with
another CF.

As stated in "4.4.2.3 - Address-claimed message":
  In order to successfully claim an address, the CF sending an address
  claimed message shall not receive a contending claim from another CF
  for at least 250 ms.

As stated in "4.4.3.2 - NAME management (NM) message":
  1) A commanding CF can
     d) request that a CF with a specified NAME transmit the address-
        claimed message with its current NAME.
  2) A target CF shall
     d) send an address-claimed message in response to a request for a
        matching NAME

Taking the above arguments into account, the 250 ms wait is requested
only during network initialization.

Do not restart the timer on AC message if both the NAME and the address
match and so if the address has already been claimed (timer has expired)
or the AC message has been sent to resolve the contention with another
CF (timer is still running).

Signed-off-by: Devid Antonio Filoni &lt;devid.filoni@egluetechnologies.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20221125170418.34575-1-devid.filoni@egluetechnologies.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: fix errant WARN_ON_ONCE in j1939_session_deactivate</title>
<updated>2023-02-22T11:50:24+00:00</updated>
<author>
<name>Ziyang Xuan</name>
<email>william.xuanziyang@huawei.com</email>
</author>
<published>2021-09-06T09:42:00+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=6950df42a03c9ac9290503ced3f371199cb68fa9'/>
<id>6950df42a03c9ac9290503ced3f371199cb68fa9</id>
<content type='text'>
[ Upstream commit d0553680f94c49bbe0e39eb50d033ba563b4212d ]

The conclusion "j1939_session_deactivate() should be called with a
session ref-count of at least 2" is incorrect. In some concurrent
scenarios, j1939_session_deactivate can be called with the session
ref-count less than 2. But there is not any problem because it
will check the session active state before session putting in
j1939_session_deactivate_locked().

Here is the concurrent scenario of the problem reported by syzbot
and my reproduction log.

        cpu0                            cpu1
                                j1939_xtp_rx_eoma
j1939_xtp_rx_abort_one
                                j1939_session_get_by_addr [kref == 2]
j1939_session_get_by_addr [kref == 3]
j1939_session_deactivate [kref == 2]
j1939_session_put [kref == 1]
				j1939_session_completed
				j1939_session_deactivate
				WARN_ON_ONCE(kref &lt; 2)

=====================================================
WARNING: CPU: 1 PID: 21 at net/can/j1939/transport.c:1088 j1939_session_deactivate+0x5f/0x70
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7+ #32
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:j1939_session_deactivate+0x5f/0x70
Call Trace:
 j1939_session_deactivate_activate_next+0x11/0x28
 j1939_xtp_rx_eoma+0x12a/0x180
 j1939_tp_recv+0x4a2/0x510
 j1939_can_recv+0x226/0x380
 can_rcv_filter+0xf8/0x220
 can_receive+0x102/0x220
 ? process_backlog+0xf0/0x2c0
 can_rcv+0x53/0xf0
 __netif_receive_skb_one_core+0x67/0x90
 ? process_backlog+0x97/0x2c0
 __netif_receive_skb+0x22/0x80

Fixes: 0c71437dd50d ("can: j1939: j1939_session_deactivate(): clarify lifetime of session object")
Reported-by: syzbot+9981a614060dcee6eeca@syzkaller.appspotmail.com
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20210906094200.95868-1-william.xuanziyang@huawei.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
[ Upstream commit d0553680f94c49bbe0e39eb50d033ba563b4212d ]

The conclusion "j1939_session_deactivate() should be called with a
session ref-count of at least 2" is incorrect. In some concurrent
scenarios, j1939_session_deactivate can be called with the session
ref-count less than 2. But there is not any problem because it
will check the session active state before session putting in
j1939_session_deactivate_locked().

Here is the concurrent scenario of the problem reported by syzbot
and my reproduction log.

        cpu0                            cpu1
                                j1939_xtp_rx_eoma
j1939_xtp_rx_abort_one
                                j1939_session_get_by_addr [kref == 2]
j1939_session_get_by_addr [kref == 3]
j1939_session_deactivate [kref == 2]
j1939_session_put [kref == 1]
				j1939_session_completed
				j1939_session_deactivate
				WARN_ON_ONCE(kref &lt; 2)

=====================================================
WARNING: CPU: 1 PID: 21 at net/can/j1939/transport.c:1088 j1939_session_deactivate+0x5f/0x70
CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 5.14.0-rc7+ #32
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.13.0-1ubuntu1 04/01/2014
RIP: 0010:j1939_session_deactivate+0x5f/0x70
Call Trace:
 j1939_session_deactivate_activate_next+0x11/0x28
 j1939_xtp_rx_eoma+0x12a/0x180
 j1939_tp_recv+0x4a2/0x510
 j1939_can_recv+0x226/0x380
 can_rcv_filter+0xf8/0x220
 can_receive+0x102/0x220
 ? process_backlog+0xf0/0x2c0
 can_rcv+0x53/0xf0
 __netif_receive_skb_one_core+0x67/0x90
 ? process_backlog+0x97/0x2c0
 __netif_receive_skb+0x22/0x80

Fixes: 0c71437dd50d ("can: j1939: j1939_session_deactivate(): clarify lifetime of session object")
Reported-by: syzbot+9981a614060dcee6eeca@syzkaller.appspotmail.com
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Acked-by: Oleksij Rempel &lt;o.rempel@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20210906094200.95868-1-william.xuanziyang@huawei.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Sasha Levin &lt;sashal@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: af_can: fix NULL pointer dereference in can_rcv_filter</title>
<updated>2022-12-14T10:30:44+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2022-12-06T20:12:59+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3982652957e8d79ac32efcb725450580650a8644'/>
<id>3982652957e8d79ac32efcb725450580650a8644</id>
<content type='text'>
commit 0acc442309a0a1b01bcdaa135e56e6398a49439c upstream.

Analogue to commit 8aa59e355949 ("can: af_can: fix NULL pointer
dereference in can_rx_register()") we need to check for a missing
initialization of ml_priv in the receive path of CAN frames.

Since commit 4e096a18867a ("net: introduce CAN specific pointer in the
struct net_device") the check for dev-&gt;type to be ARPHRD_CAN is not
sufficient anymore since bonding or tun netdevices claim to be CAN
devices but do not initialize ml_priv accordingly.

Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device")
Reported-by: syzbot+2d7f58292cb5b29eb5ad@syzkaller.appspotmail.com
Reported-by: Wei Chen &lt;harperchen1110@gmail.com&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20221206201259.3028-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&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 0acc442309a0a1b01bcdaa135e56e6398a49439c upstream.

Analogue to commit 8aa59e355949 ("can: af_can: fix NULL pointer
dereference in can_rx_register()") we need to check for a missing
initialization of ml_priv in the receive path of CAN frames.

Since commit 4e096a18867a ("net: introduce CAN specific pointer in the
struct net_device") the check for dev-&gt;type to be ARPHRD_CAN is not
sufficient anymore since bonding or tun netdevices claim to be CAN
devices but do not initialize ml_priv accordingly.

Fixes: 4e096a18867a ("net: introduce CAN specific pointer in the struct net_device")
Reported-by: syzbot+2d7f58292cb5b29eb5ad@syzkaller.appspotmail.com
Reported-by: Wei Chen &lt;harperchen1110@gmail.com&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20221206201259.3028-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Signed-off-by: Greg Kroah-Hartman &lt;gregkh@linuxfoundation.org&gt;
</pre>
</div>
</content>
</entry>
</feed>
