RAX: ffffffffffffffda RBX: 00007f65e1c2ac90 RCX: 00000000004578a9
RDX: 0000000020000080 RSI: 0000000000005423 RDI: 0000000000000003
RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f65e1c2b6d4
R13: 00000000004c59b1 R14: 00000000004da4f8 R15: 00000000ffffffff
BUG: unable to handle kernel paging request at fffffbfffffffffe
IP: slhc_free+0x1e/0x80 drivers/net/slip/slhc.c:159
PGD 21fff4067 
P4D 21fff4067 
PUD 21fff3067 
PMD 21fff2067 
PTE 0

Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 8316 Comm: syz-executor4 Not tainted 4.12.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
task: ffff8801b8926280 task.stack: ffff8801bc830000
RIP: 0010:slhc_free+0x1e/0x80 drivers/net/slip/slhc.c:159
RSP: 0018:ffff8801bc8379d0 EFLAGS: 00010a03
RAX: dffffc0000000000 RBX: fffffffffffffff4 RCX: 1ffff10037124d6a
RDX: 1ffffffffffffffe RSI: ffff8801b8926b30 RDI: fffffffffffffff4
RBP: ffff8801bc8379d8 R08: ffff8801b8926b50 R09: 0000000000000006
R10: 0000000000000000 R11: ffff8801b8926280 R12: fffffffffffffff4
R13: ffff8801b89515c0 R14: ffff8801b89515c8 R15: ffff8801b8950b00
FS:  00007f65e1c2b700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffffbfffffffffe CR3: 00000001c0b82000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 sl_alloc_bufs drivers/net/slip/slip.c:197 [inline]
 slip_open+0xd22/0x1097 drivers/net/slip/slip.c:826
 tty_ldisc_open.isra.1+0x60/0xa0 drivers/tty/tty_ldisc.c:466
 tty_set_ldisc+0x25a/0x750 drivers/tty/tty_ldisc.c:594
 tiocsetd drivers/tty/tty_io.c:2220 [inline]
 tty_ioctl+0xd92/0x1320 drivers/tty/tty_io.c:2464
 vfs_ioctl fs/ioctl.c:45 [inline]
 file_ioctl fs/ioctl.c:499 [inline]
 do_vfs_ioctl+0x183/0x15a0 fs/ioctl.c:683
 SYSC_ioctl fs/ioctl.c:700 [inline]
 SyS_ioctl+0x74/0x80 fs/ioctl.c:691
 entry_SYSCALL_64_fastpath+0x23/0xc2
RIP: 0033:0x4578a9
RSP: 002b:00007f65e1c2ac78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f65e1c2ac90 RCX: 00000000004578a9
RDX: 0000000020000080 RSI: 0000000000005423 RDI: 0000000000000003
RBP: 0000000000000082 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f65e1c2b6d4
R13: 00000000004c59b1 R14: 00000000004da4f8 R15: 00000000ffffffff
Code: 55 fd eb ed 66 0f 1f 84 00 00 00 00 00 48 85 ff 74 60 48 b8 00 00 00 00 00 fc ff df 48 89 fa 55 48 c1 ea 03 48 89 e5 53 48 89 fb <80> 3c 02 00 75 42 48 8b 3b 48 85 ff 74 05 e8 6f fa 54 fd 48 8d 
RIP: slhc_free+0x1e/0x80 drivers/net/slip/slhc.c:159 RSP: ffff8801bc8379d0
CR2: fffffbfffffffffe
---[ end trace 305830fe9e66b546 ]---