general protection fault in j1939_netdev_notify

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: a99d8080 Linux 5.4-rc6
git tree: upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=14303cdce00000
kernel config: https://syzkaller.appspot.com/x/.config?x=896c87b73c6fcda6
dashboard link: https://syzkaller.appspot.com/bug?extid=95c8e0d9dffde15b6c5c
compiler: clang version 9.0.0 (/home/glider/llvm/clang
80fee25776c2fb61e74c1ecb1a523375c2500b69)
syz repro: https://syzkaller.appspot.com/x/repro.syz?x=12a4e444e00000

The bug was bisected to:

commit 9d71dd0c70099914fcd063135da3c580865e924c
Author: The j1939 authors <linu...@vger.kernel.org>
Date: Mon Oct 8 09:48:36 2018 +0000

can: add support of SAE J1939 protocol

bisection log: https://syzkaller.appspot.com/x/bisect.txt?x=14f90314e00000
final crash: https://syzkaller.appspot.com/x/report.txt?x=16f90314e00000
console output: https://syzkaller.appspot.com/x/log.txt?x=12f90314e00000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+95c8e0...@syzkaller.appspotmail.com
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 1 PID: 8092 Comm: syz-executor.0 Not tainted 5.4.0-rc6 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS
Google 01/01/2011
RIP: 0010:j1939_ndev_to_priv net/can/j1939/main.c:210 [inline]
RIP: 0010:j1939_priv_get_by_ndev_locked net/can/j1939/main.c:222 [inline]
RIP: 0010:j1939_priv_get_by_ndev net/can/j1939/main.c:234 [inline]
RIP: 0010:j1939_netdev_notify+0x10a/0x2c0 net/can/j1939/main.c:344
Code: 88 05 00 00 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 36
95 fc fa bb 28 60 00 00 49 03 1c 24 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00
74 08 48 89 df e8 17 95 fc fa 4c 8b 2b 4d 85 ed 0f
RSP: 0018:ffff8880a58579d0 EFLAGS: 00010206
RAX: 0000000000000c05 RBX: 0000000000006028 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000118 RDI: 0000000000000118
RBP: ffff8880a5857a00 R08: ffffffff86afeeb1 R09: ffffed1014b0af2f
R10: ffffed1014b0af2f R11: 0000000000000000 R12: ffff8880a5a90588
R13: dffffc0000000000 R14: ffff8880a5a9023c R15: 1ffff11014b52047
FS: 0000000001356940(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1d28a0616b CR3: 0000000099ed7000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
notifier_call_chain kernel/notifier.c:95 [inline]
__raw_notifier_call_chain kernel/notifier.c:396 [inline]
raw_notifier_call_chain+0xec/0x190 kernel/notifier.c:403
call_netdevice_notifiers_info net/core/dev.c:1668 [inline]
call_netdevice_notifiers_extack net/core/dev.c:1680 [inline]
call_netdevice_notifiers net/core/dev.c:1694 [inline]
rollback_registered_many+0xbd6/0x11c0 net/core/dev.c:8522
rollback_registered net/core/dev.c:8564 [inline]
unregister_netdevice_queue+0x2ce/0x480 net/core/dev.c:9656
unregister_netdevice include/linux/netdevice.h:2637 [inline]
unregister_netdev+0x1c/0x30 net/core/dev.c:9697
slip_close+0x160/0x190 drivers/net/slip/slip.c:895
tty_ldisc_close+0x126/0x180 drivers/tty/tty_ldisc.c:494
tty_ldisc_kill drivers/tty/tty_ldisc.c:642 [inline]
tty_ldisc_release+0x248/0x5a0 drivers/tty/tty_ldisc.c:814
tty_release_struct+0x2a/0xe0 drivers/tty/tty_io.c:1612
tty_release+0xce9/0xfa0 drivers/tty/tty_io.c:1785
__fput+0x2e4/0x740 fs/file_table.c:280
____fput+0x15/0x20 fs/file_table.c:313
task_work_run+0x17e/0x1b0 kernel/task_work.c:113
tracehook_notify_resume include/linux/tracehook.h:188 [inline]
exit_to_usermode_loop arch/x86/entry/common.c:163 [inline]
prepare_exit_to_usermode+0x459/0x580 arch/x86/entry/common.c:194
syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:274
do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:300
entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x413d90
Code: 01 f0 ff ff 0f 83 30 1b 00 00 c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f
44 00 00 83 3d 7d 42 66 00 00 75 14 b8 03 00 00 00 0f 05 <48> 3d 01 f0 ff
ff 0f 83 04 1b 00 00 c3 48 83 ec 08 e8 0a fc ff ff
RSP: 002b:00007ffec2dd6688 EFLAGS: 00000246 ORIG_RAX: 0000000000000003
RAX: 0000000000000000 RBX: 0000000000000004 RCX: 0000000000413d90
RDX: 0000001b33020000 RSI: 0000000000000000 RDI: 0000000000000003
RBP: 0000000000000001 R08: 0000000000000000 R09: ffffffffffffffff
R10: 0000000000000000 R11: 0000000000000246 R12: 000000000075bf20
R13: 0000000000000003 R14: 00000000007601c8 R15: 000000000075bf2c
Modules linked in:
---[ end trace 8207e28d10fcf54c ]---
RIP: 0010:j1939_ndev_to_priv net/can/j1939/main.c:210 [inline]
RIP: 0010:j1939_priv_get_by_ndev_locked net/can/j1939/main.c:222 [inline]
RIP: 0010:j1939_priv_get_by_ndev net/can/j1939/main.c:234 [inline]
RIP: 0010:j1939_netdev_notify+0x10a/0x2c0 net/can/j1939/main.c:344
Code: 88 05 00 00 4c 89 e0 48 c1 e8 03 42 80 3c 28 00 74 08 4c 89 e7 e8 36
95 fc fa bb 28 60 00 00 49 03 1c 24 48 89 d8 48 c1 e8 03 <42> 80 3c 28 00
74 08 48 89 df e8 17 95 fc fa 4c 8b 2b 4d 85 ed 0f
RSP: 0018:ffff8880a58579d0 EFLAGS: 00010206
RAX: 0000000000000c05 RBX: 0000000000006028 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000118 RDI: 0000000000000118
RBP: ffff8880a5857a00 R08: ffffffff86afeeb1 R09: ffffed1014b0af2f
R10: ffffed1014b0af2f R11: 0000000000000000 R12: ffff8880a5a90588
R13: dffffc0000000000 R14: ffff8880a5a9023c R15: 1ffff11014b52047
FS: 0000000001356940(0000) GS:ffff8880aeb00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f1d28a0616b CR3: 0000000099ed7000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


---
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