general protection fault in hci_uart_write_work

general protection fault in hci_uart_write_work

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    6b529fb0a3ea Merge tag 'for-5.0-rc1-tag' of git://git.kern..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1366fa30c00000
kernel config:  https://syzkaller.appspot.com/x/.config?x=b05cfdb4ee8ab9b2
dashboard link: https://syzkaller.appspot.com/bug?extid=257790c15bcdef6fe00c
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=134d5107400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=15760b4f400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+257790c15bcdef6fe00c@syzkaller.appspotmail.com

R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000004
R13: ffffffffffffffff R14: 0000000000000000 R15: 0000000000000000
kasan: CONFIG_KASAN_INLINE enabled
Bluetooth: Invalid header checksum
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
Bluetooth: Can't allocate HCI device
CPU: 1 PID: 22 Comm: kworker/1:1 Not tainted 5.0.0-rc1+ #24
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: events hci_uart_write_work
RIP: 0010:hci_uart_write_work+0x1b6/0x710 drivers/bluetooth/hci_ldisc.c:180
Code: 0f 85 6a 04 00 00 49 8b b4 24 c8 00 00 00 4c 89 ef e8 3e a8 96 02 89  
c6 48 8b 45 d0 48 8d b8 5c 10 00 00 48 89 f8 48 c1 e8 03 <0f> b6 14 18 48  
89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1d
RSP: 0018:ffff8880a95c7960 EFLAGS: 00010203
RAX: 000000000000020b RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000105c
RBP: ffff8880a95c79e0 R08: 0000000000000006 R09: ffff8880a95b8e88
R10: ffff8880a95b85c0 R11: 0000000000000000 R12: ffff888087c2b5c0
R13: ffff88808e0775c0 R14: ffff888096c7b868 R15: ffff888087c2b630
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000100 CR3: 00000000978b1000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
  process_one_work+0xd0c/0x1ce0 kernel/workqueue.c:2153
  worker_thread+0x143/0x14a0 kernel/workqueue.c:2296
  kthread+0x357/0x430 kernel/kthread.c:246
  ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Modules linked in:
---[ end trace 5bffc9ea5ce29536 ]---
RIP: 0010:hci_uart_write_work+0x1b6/0x710 drivers/bluetooth/hci_ldisc.c:180
Code: 0f 85 6a 04 00 00 49 8b b4 24 c8 00 00 00 4c 89 ef e8 3e a8 96 02 89  
c6 48 8b 45 d0 48 8d b8 5c 10 00 00 48 89 f8 48 c1 e8 03 <0f> b6 14 18 48  
89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 1d
RSP: 0018:ffff8880a95c7960 EFLAGS: 00010203
RAX: 000000000000020b RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000008 RDI: 000000000000105c
RBP: ffff8880a95c79e0 R08: 0000000000000006 R09: ffff8880a95b8e88
R10: ffff8880a95b85c0 R11: 0000000000000000 R12: ffff888087c2b5c0
R13: ffff88808e0775c0 R14: ffff888096c7b868 R15: ffff888087c2b630
FS:  0000000000000000(0000) GS:ffff8880ae700000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000020000100 CR3: 0000000009871000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400


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