<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux-stable.git/net/can, branch v6.5.2</title>
<subtitle>Linux kernel stable tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/'/>
<entry>
<title>can: raw: add missing refcount for memory leak fix</title>
<updated>2023-08-23T00:18:50+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-08-21T14:45:47+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=c275a176e4b69868576e543409927ae75e3a3288'/>
<id>c275a176e4b69868576e543409927ae75e3a3288</id>
<content type='text'>
Commit ee8b94c8510c ("can: raw: fix receiver memory leak") introduced
a new reference to the CAN netdevice that has assigned CAN filters.
But this new ro-&gt;dev reference did not maintain its own refcount which
lead to another KASAN use-after-free splat found by Eric Dumazet.

This patch ensures a proper refcount for the CAN nedevice.

Fixes: ee8b94c8510c ("can: raw: fix receiver memory leak")
Reported-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/r/20230821144547.6658-3-socketcan@hartkopp.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Commit ee8b94c8510c ("can: raw: fix receiver memory leak") introduced
a new reference to the CAN netdevice that has assigned CAN filters.
But this new ro-&gt;dev reference did not maintain its own refcount which
lead to another KASAN use-after-free splat found by Eric Dumazet.

This patch ensures a proper refcount for the CAN nedevice.

Fixes: ee8b94c8510c ("can: raw: fix receiver memory leak")
Reported-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/r/20230821144547.6658-3-socketcan@hartkopp.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: isotp: fix support for transmission of SF without flow control</title>
<updated>2023-08-23T00:18:50+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-08-21T14:45:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=0bfe71159230bab79ee230225ae12ffecbb69f3e'/>
<id>0bfe71159230bab79ee230225ae12ffecbb69f3e</id>
<content type='text'>
The original implementation had a very simple handling for single frame
transmissions as it just sent the single frame without a timeout handling.

With the new echo frame handling the echo frame was also introduced for
single frames but the former exception ('simple without timers') has been
maintained by accident. This leads to a 1 second timeout when closing the
socket and to an -ECOMM error when CAN_ISOTP_WAIT_TX_DONE is selected.

As the echo handling is always active (also for single frames) remove the
wrong extra condition for single frames.

Fixes: 9f39d36530e5 ("can: isotp: add support for transmission without flow control")
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/r/20230821144547.6658-2-socketcan@hartkopp.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The original implementation had a very simple handling for single frame
transmissions as it just sent the single frame without a timeout handling.

With the new echo frame handling the echo frame was also introduced for
single frames but the former exception ('simple without timers') has been
maintained by accident. This leads to a 1 second timeout when closing the
socket and to an -ECOMM error when CAN_ISOTP_WAIT_TX_DONE is selected.

As the echo handling is always active (also for single frames) remove the
wrong extra condition for single frames.

Fixes: 9f39d36530e5 ("can: isotp: add support for transmission without flow control")
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/r/20230821144547.6658-2-socketcan@hartkopp.net
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: annotate data-races around sk-&gt;sk_mark</title>
<updated>2023-07-29T17:13:41+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-07-28T15:03:15+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3c5b4d69c358a9275a8de98f87caf6eda644b086'/>
<id>3c5b4d69c358a9275a8de98f87caf6eda644b086</id>
<content type='text'>
sk-&gt;sk_mark is often read while another thread could change the value.

Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.")
Signed-off-by: Eric Dumazet &lt;edumazet@google.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>
sk-&gt;sk_mark is often read while another thread could change the value.

Fixes: 4a19ec5800fc ("[NET]: Introducing socket mark socket option.")
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: raw: fix lockdep issue in raw_release()</title>
<updated>2023-07-20T11:46:29+00:00</updated>
<author>
<name>Eric Dumazet</name>
<email>edumazet@google.com</email>
</author>
<published>2023-07-20T11:44:38+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=11c9027c983e9e4b408ee5613b6504d24ebd85be'/>
<id>11c9027c983e9e4b408ee5613b6504d24ebd85be</id>
<content type='text'>
syzbot complained about a lockdep issue [1]

Since raw_bind() and raw_setsockopt() first get RTNL
before locking the socket, we must adopt the same order in raw_release()

[1]
WARNING: possible circular locking dependency detected
6.5.0-rc1-syzkaller-00192-g78adb4bcf99e #0 Not tainted
------------------------------------------------------
syz-executor.0/14110 is trying to acquire lock:
ffff88804e4b6130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1708 [inline]
ffff88804e4b6130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: raw_bind+0xb1/0xab0 net/can/raw.c:435

but task is already holding lock:
ffffffff8e3df368 (rtnl_mutex){+.+.}-{3:3}, at: raw_bind+0xa7/0xab0 net/can/raw.c:434

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #1 (rtnl_mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x181/0x1340 kernel/locking/mutex.c:747
raw_release+0x1c6/0x9b0 net/can/raw.c:391
__sock_release+0xcd/0x290 net/socket.c:654
sock_close+0x1c/0x20 net/socket.c:1386
__fput+0x3fd/0xac0 fs/file_table.c:384
task_work_run+0x14d/0x240 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-&gt; #0 (sk_lock-AF_CAN){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5144
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726
lock_sock_nested+0x3a/0xf0 net/core/sock.c:3492
lock_sock include/net/sock.h:1708 [inline]
raw_bind+0xb1/0xab0 net/can/raw.c:435
__sys_bind+0x1ec/0x220 net/socket.c:1792
__do_sys_bind net/socket.c:1803 [inline]
__se_sys_bind net/socket.c:1801 [inline]
__x64_sys_bind+0x72/0xb0 net/socket.c:1801
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(rtnl_mutex);
        lock(sk_lock-AF_CAN);
        lock(rtnl_mutex);
lock(sk_lock-AF_CAN);

*** DEADLOCK ***

1 lock held by syz-executor.0/14110:

stack backtrace:
CPU: 0 PID: 14110 Comm: syz-executor.0 Not tainted 6.5.0-rc1-syzkaller-00192-g78adb4bcf99e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call Trace:
&lt;TASK&gt;
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
check_noncircular+0x311/0x3f0 kernel/locking/lockdep.c:2195
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5144
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726
lock_sock_nested+0x3a/0xf0 net/core/sock.c:3492
lock_sock include/net/sock.h:1708 [inline]
raw_bind+0xb1/0xab0 net/can/raw.c:435
__sys_bind+0x1ec/0x220 net/socket.c:1792
__do_sys_bind net/socket.c:1803 [inline]
__se_sys_bind net/socket.c:1801 [inline]
__x64_sys_bind+0x72/0xb0 net/socket.c:1801
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd89007cb29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd890d2a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00007fd89019bf80 RCX: 00007fd89007cb29
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00007fd8900c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd89019bf80 R15: 00007ffebf8124f8
&lt;/TASK&gt;

Fixes: ee8b94c8510c ("can: raw: fix receiver memory leak")
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Cc: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Cc: stable@vger.kernel.org
Cc: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20230720114438.172434-1-edumazet@google.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
syzbot complained about a lockdep issue [1]

Since raw_bind() and raw_setsockopt() first get RTNL
before locking the socket, we must adopt the same order in raw_release()

[1]
WARNING: possible circular locking dependency detected
6.5.0-rc1-syzkaller-00192-g78adb4bcf99e #0 Not tainted
------------------------------------------------------
syz-executor.0/14110 is trying to acquire lock:
ffff88804e4b6130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: lock_sock include/net/sock.h:1708 [inline]
ffff88804e4b6130 (sk_lock-AF_CAN){+.+.}-{0:0}, at: raw_bind+0xb1/0xab0 net/can/raw.c:435

but task is already holding lock:
ffffffff8e3df368 (rtnl_mutex){+.+.}-{3:3}, at: raw_bind+0xa7/0xab0 net/can/raw.c:434

which lock already depends on the new lock.

the existing dependency chain (in reverse order) is:

-&gt; #1 (rtnl_mutex){+.+.}-{3:3}:
__mutex_lock_common kernel/locking/mutex.c:603 [inline]
__mutex_lock+0x181/0x1340 kernel/locking/mutex.c:747
raw_release+0x1c6/0x9b0 net/can/raw.c:391
__sock_release+0xcd/0x290 net/socket.c:654
sock_close+0x1c/0x20 net/socket.c:1386
__fput+0x3fd/0xac0 fs/file_table.c:384
task_work_run+0x14d/0x240 kernel/task_work.c:179
resume_user_mode_work include/linux/resume_user_mode.h:49 [inline]
exit_to_user_mode_loop kernel/entry/common.c:171 [inline]
exit_to_user_mode_prepare+0x210/0x240 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:297
do_syscall_64+0x44/0xb0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd

-&gt; #0 (sk_lock-AF_CAN){+.+.}-{0:0}:
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5144
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726
lock_sock_nested+0x3a/0xf0 net/core/sock.c:3492
lock_sock include/net/sock.h:1708 [inline]
raw_bind+0xb1/0xab0 net/can/raw.c:435
__sys_bind+0x1ec/0x220 net/socket.c:1792
__do_sys_bind net/socket.c:1803 [inline]
__se_sys_bind net/socket.c:1801 [inline]
__x64_sys_bind+0x72/0xb0 net/socket.c:1801
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

other info that might help us debug this:

Possible unsafe locking scenario:

CPU0 CPU1
---- ----
lock(rtnl_mutex);
        lock(sk_lock-AF_CAN);
        lock(rtnl_mutex);
lock(sk_lock-AF_CAN);

*** DEADLOCK ***

1 lock held by syz-executor.0/14110:

stack backtrace:
CPU: 0 PID: 14110 Comm: syz-executor.0 Not tainted 6.5.0-rc1-syzkaller-00192-g78adb4bcf99e #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/03/2023
Call Trace:
&lt;TASK&gt;
__dump_stack lib/dump_stack.c:88 [inline]
dump_stack_lvl+0xd9/0x1b0 lib/dump_stack.c:106
check_noncircular+0x311/0x3f0 kernel/locking/lockdep.c:2195
check_prev_add kernel/locking/lockdep.c:3142 [inline]
check_prevs_add kernel/locking/lockdep.c:3261 [inline]
validate_chain kernel/locking/lockdep.c:3876 [inline]
__lock_acquire+0x2e3d/0x5de0 kernel/locking/lockdep.c:5144
lock_acquire kernel/locking/lockdep.c:5761 [inline]
lock_acquire+0x1ae/0x510 kernel/locking/lockdep.c:5726
lock_sock_nested+0x3a/0xf0 net/core/sock.c:3492
lock_sock include/net/sock.h:1708 [inline]
raw_bind+0xb1/0xab0 net/can/raw.c:435
__sys_bind+0x1ec/0x220 net/socket.c:1792
__do_sys_bind net/socket.c:1803 [inline]
__se_sys_bind net/socket.c:1801 [inline]
__x64_sys_bind+0x72/0xb0 net/socket.c:1801
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7fd89007cb29
Code: 28 00 00 00 75 05 48 83 c4 28 c3 e8 e1 20 00 00 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 &lt;48&gt; 3d 01 f0 ff ff 73 01 c3 48 c7 c1 b0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fd890d2a0c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
RAX: ffffffffffffffda RBX: 00007fd89019bf80 RCX: 00007fd89007cb29
RDX: 0000000000000010 RSI: 0000000020000040 RDI: 0000000000000003
RBP: 00007fd8900c847a R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 000000000000000b R14: 00007fd89019bf80 R15: 00007ffebf8124f8
&lt;/TASK&gt;

Fixes: ee8b94c8510c ("can: raw: fix receiver memory leak")
Reported-by: syzbot &lt;syzkaller@googlegroups.com&gt;
Signed-off-by: Eric Dumazet &lt;edumazet@google.com&gt;
Cc: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Cc: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Cc: stable@vger.kernel.org
Cc: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
Link: https://lore.kernel.org/all/20230720114438.172434-1-edumazet@google.com
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: bcm: Fix UAF in bcm_proc_show()</title>
<updated>2023-07-17T07:46:26+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=55c3b96074f3f9b0aee19bf93cd71af7516582bb'/>
<id>55c3b96074f3f9b0aee19bf93cd71af7516582bb</id>
<content type='text'>
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;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: raw: fix receiver memory leak</title>
<updated>2023-07-17T07:23:31+00:00</updated>
<author>
<name>Ziyang Xuan</name>
<email>william.xuanziyang@huawei.com</email>
</author>
<published>2023-07-11T01:17:37+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=ee8b94c8510ce64afe0b87ef548d23e00915fb10'/>
<id>ee8b94c8510ce64afe0b87ef548d23e00915fb10</id>
<content type='text'>
Got kmemleak errors with the following ltp can_filter testcase:

for ((i=1; i&lt;=100; i++))
do
        ./can_filter &amp;
        sleep 0.1
done

==============================================================
[&lt;00000000db4a4943&gt;] can_rx_register+0x147/0x360 [can]
[&lt;00000000a289549d&gt;] raw_setsockopt+0x5ef/0x853 [can_raw]
[&lt;000000006d3d9ebd&gt;] __sys_setsockopt+0x173/0x2c0
[&lt;00000000407dbfec&gt;] __x64_sys_setsockopt+0x61/0x70
[&lt;00000000fd468496&gt;] do_syscall_64+0x33/0x40
[&lt;00000000b7e47d51&gt;] entry_SYSCALL_64_after_hwframe+0x61/0xc6

It's a bug in the concurrent scenario of unregister_netdevice_many()
and raw_release() as following:

             cpu0                                        cpu1
unregister_netdevice_many(can_dev)
  unlist_netdevice(can_dev) // dev_get_by_index() return NULL after this
  net_set_todo(can_dev)
						raw_release(can_socket)
						  dev = dev_get_by_index(, ro-&gt;ifindex); // dev == NULL
						  if (dev) { // receivers in dev_rcv_lists not free because dev is NULL
						    raw_disable_allfilters(, dev, );
						    dev_put(dev);
						  }
						  ...
						  ro-&gt;bound = 0;
						  ...

call_netdevice_notifiers(NETDEV_UNREGISTER, )
  raw_notify(, NETDEV_UNREGISTER, )
    if (ro-&gt;bound) // invalid because ro-&gt;bound has been set 0
      raw_disable_allfilters(, dev, ); // receivers in dev_rcv_lists will never be freed

Add a net_device pointer member in struct raw_sock to record bound
can_dev, and use rtnl_lock to serialize raw_socket members between
raw_bind(), raw_release(), raw_setsockopt() and raw_notify(). Use
ro-&gt;dev to decide whether to free receivers in dev_rcv_lists.

Fixes: 8d0caedb7596 ("can: bcm/raw/isotp: use per module netdevice notifier")
Reviewed-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Link: https://lore.kernel.org/all/20230711011737.1969582-1-william.xuanziyang@huawei.com
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Got kmemleak errors with the following ltp can_filter testcase:

for ((i=1; i&lt;=100; i++))
do
        ./can_filter &amp;
        sleep 0.1
done

==============================================================
[&lt;00000000db4a4943&gt;] can_rx_register+0x147/0x360 [can]
[&lt;00000000a289549d&gt;] raw_setsockopt+0x5ef/0x853 [can_raw]
[&lt;000000006d3d9ebd&gt;] __sys_setsockopt+0x173/0x2c0
[&lt;00000000407dbfec&gt;] __x64_sys_setsockopt+0x61/0x70
[&lt;00000000fd468496&gt;] do_syscall_64+0x33/0x40
[&lt;00000000b7e47d51&gt;] entry_SYSCALL_64_after_hwframe+0x61/0xc6

It's a bug in the concurrent scenario of unregister_netdevice_many()
and raw_release() as following:

             cpu0                                        cpu1
unregister_netdevice_many(can_dev)
  unlist_netdevice(can_dev) // dev_get_by_index() return NULL after this
  net_set_todo(can_dev)
						raw_release(can_socket)
						  dev = dev_get_by_index(, ro-&gt;ifindex); // dev == NULL
						  if (dev) { // receivers in dev_rcv_lists not free because dev is NULL
						    raw_disable_allfilters(, dev, );
						    dev_put(dev);
						  }
						  ...
						  ro-&gt;bound = 0;
						  ...

call_netdevice_notifiers(NETDEV_UNREGISTER, )
  raw_notify(, NETDEV_UNREGISTER, )
    if (ro-&gt;bound) // invalid because ro-&gt;bound has been set 0
      raw_disable_allfilters(, dev, ); // receivers in dev_rcv_lists will never be freed

Add a net_device pointer member in struct raw_sock to record bound
can_dev, and use rtnl_lock to serialize raw_socket members between
raw_bind(), raw_release(), raw_setsockopt() and raw_notify(). Use
ro-&gt;dev to decide whether to free receivers in dev_rcv_lists.

Fixes: 8d0caedb7596 ("can: bcm/raw/isotp: use per module netdevice notifier")
Reviewed-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Acked-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Signed-off-by: Ziyang Xuan &lt;william.xuanziyang@huawei.com&gt;
Link: https://lore.kernel.org/all/20230711011737.1969582-1-william.xuanziyang@huawei.com
Cc: stable@vger.kernel.org
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>2023-06-27T16:45:22+00:00</updated>
<author>
<name>Jakub Kicinski</name>
<email>kuba@kernel.org</email>
</author>
<published>2023-06-27T16:45:22+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=3674fbf0451df0395f9fa18df3122927006a3829'/>
<id>3674fbf0451df0395f9fa18df3122927006a3829</id>
<content type='text'>
Merge in late fixes to prepare for the 6.5 net-next PR.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Merge in late fixes to prepare for the 6.5 net-next PR.

Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>sock: Remove -&gt;sendpage*() in favour of sendmsg(MSG_SPLICE_PAGES)</title>
<updated>2023-06-24T22:50:13+00:00</updated>
<author>
<name>David Howells</name>
<email>dhowells@redhat.com</email>
</author>
<published>2023-06-23T22:55:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=dc97391e661009eab46783030d2404c9b6e6f2e7'/>
<id>dc97391e661009eab46783030d2404c9b6e6f2e7</id>
<content type='text'>
Remove -&gt;sendpage() and -&gt;sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt; # for net/can
cc: Jens Axboe &lt;axboe@kernel.dk&gt;
cc: Matthew Wilcox &lt;willy@infradead.org&gt;
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Remove -&gt;sendpage() and -&gt;sendpage_locked().  sendmsg() with
MSG_SPLICE_PAGES should be used instead.  This allows multiple pages and
multipage folios to be passed through.

Signed-off-by: David Howells &lt;dhowells@redhat.com&gt;
Acked-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt; # for net/can
cc: Jens Axboe &lt;axboe@kernel.dk&gt;
cc: Matthew Wilcox &lt;willy@infradead.org&gt;
cc: linux-afs@lists.infradead.org
cc: mptcp@lists.linux.dev
cc: rds-devel@oss.oracle.com
cc: tipc-discussion@lists.sourceforge.net
cc: virtualization@lists.linux-foundation.org
Link: https://lore.kernel.org/r/20230623225513.2732256-16-dhowells@redhat.com
Signed-off-by: Jakub Kicinski &lt;kuba@kernel.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: isotp: isotp_sendmsg(): fix return error fix on TX path</title>
<updated>2023-06-22T08:45:09+00:00</updated>
<author>
<name>Oliver Hartkopp</name>
<email>socketcan@hartkopp.net</email>
</author>
<published>2023-06-07T07:27:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux-stable.git/commit/?id=e38910c0072b541a91954682c8b074a93e57c09b'/>
<id>e38910c0072b541a91954682c8b074a93e57c09b</id>
<content type='text'>
With commit d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return
error on FC timeout on TX path") the missing correct return value in
the case of a protocol error was introduced.

But the way the error value has been read and sent to the user space
does not follow the common scheme to clear the error after reading
which is provided by the sock_error() function. This leads to an error
report at the following write() attempt although everything should be
working.

Fixes: d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return error on FC timeout on TX path")
Reported-by: Carsten Schmidt &lt;carsten.schmidt-achim@t-online.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230607072708.38809-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
With commit d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return
error on FC timeout on TX path") the missing correct return value in
the case of a protocol error was introduced.

But the way the error value has been read and sent to the user space
does not follow the common scheme to clear the error after reading
which is provided by the sock_error() function. This leads to an error
report at the following write() attempt although everything should be
working.

Fixes: d674a8f123b4 ("can: isotp: isotp_sendmsg(): fix return error on FC timeout on TX path")
Reported-by: Carsten Schmidt &lt;carsten.schmidt-achim@t-online.de&gt;
Signed-off-by: Oliver Hartkopp &lt;socketcan@hartkopp.net&gt;
Link: https://lore.kernel.org/all/20230607072708.38809-1-socketcan@hartkopp.net
Cc: stable@vger.kernel.org
Signed-off-by: Marc Kleine-Budde &lt;mkl@pengutronix.de&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>can: j1939: avoid possible use-after-free when j1939_can_rx_register fails</title>
<updated>2023-06-05T06:26:40+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=9f16eb106aa5fce15904625661312623ec783ed3'/>
<id>9f16eb106aa5fce15904625661312623ec783ed3</id>
<content type='text'>
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;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
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;
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