Re: [syzbot] general protection fault in i2c_setup_smbus_alert

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    ef6b35306dd8 Add linux-next specific files for 20220204
git tree:       linux-next
console output: https://syzkaller.appspot.com/x/log.txt?x=15e40d84700000
kernel config:  https://syzkaller.appspot.com/x/.config?x=e0431e0b00810b4f
dashboard link: https://syzkaller.appspot.com/bug?extid=0591ccf54ee05344e4eb
compiler:       gcc (Debian 10.2.1-6) 10.2.1 20210110, GNU ld (GNU Binutils for Debian) 2.35.2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=1105f472700000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=16492aa4700000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+0591ccf54ee05344e4eb@xxxxxxxxxxxxxxxxxxxxxxxxx

usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3
usb 1-1: Product: syz
usb 1-1: Manufacturer: syz
usb 1-1: SerialNumber: syz
usb 1-1: config 0 descriptor??
general protection fault, probably for non-canonical address 0xdffffc000000008a: 0000 [#1] PREEMPT SMP KASAN
KASAN: null-ptr-deref in range [0x0000000000000450-0x0000000000000457]
CPU: 1 PID: 35 Comm: kworker/1:1 Not tainted 5.17.0-rc2-next-20220204-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: usb_hub_wq hub_event
RIP: 0010:dev_fwnode drivers/base/property.c:22 [inline]
RIP: 0010:device_property_match_string+0x2c/0xa0 drivers/base/property.c:224
Code: 49 89 d5 41 54 49 89 f4 55 53 48 89 fb e8 bc 01 fa fc 48 8d bb 50 04 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <80> 3c 02 00 75 5a 48 8b ab 50 04 00 00 48 85 ed 74 22 e8 8d 01 fa
RSP: 0018:ffffc900010befd8 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 000000000000008a RSI: ffffffff847ea734 RDI: 0000000000000450
RBP: ffff8880127ec038 R08: 0000000000000000 R09: ffff8880127ec1a3
R10: ffffffff85ea3a99 R11: 0000000000000000 R12: ffffffff8a658720
R13: ffffffff8a6586e0 R14: ffff8880127ec660 R15: ffff8880127ec664
FS:  0000000000000000(0000) GS:ffff8880b9d00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007ffd0b1f0910 CR3: 000000007f0f9000 CR4: 00000000003506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <TASK>
 i2c_setup_smbus_alert+0x9c/0x1a0 drivers/i2c/i2c-core-smbus.c:710
 i2c_register_adapter+0x32f/0x1150 drivers/i2c/i2c-core-base.c:1482
 i2c_add_adapter+0x11a/0x1c0 drivers/i2c/i2c-core-base.c:1587
 osif_probe+0x2ae/0x500 drivers/i2c/busses/i2c-robotfuzz-osif.c:164
 usb_probe_interface+0x315/0x7f0 drivers/usb/core/driver.c:396
 call_driver_probe drivers/base/dd.c:517 [inline]
 really_probe+0x245/0xcc0 drivers/base/dd.c:596
 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:752
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:782
 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:899
 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
 __device_attach+0x228/0x4a0 drivers/base/dd.c:970
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
 device_add+0xc17/0x1ee0 drivers/base/core.c:3405
 usb_set_configuration+0x101e/0x1900 drivers/usb/core/message.c:2170
 usb_generic_driver_probe+0xba/0x100 drivers/usb/core/generic.c:238
 usb_probe_device+0xd9/0x2c0 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:517 [inline]
 really_probe+0x245/0xcc0 drivers/base/dd.c:596
 __driver_probe_device+0x338/0x4d0 drivers/base/dd.c:752
 driver_probe_device+0x4c/0x1a0 drivers/base/dd.c:782
 __device_attach_driver+0x20b/0x2f0 drivers/base/dd.c:899
 bus_for_each_drv+0x15f/0x1e0 drivers/base/bus.c:427
 __device_attach+0x228/0x4a0 drivers/base/dd.c:970
 bus_probe_device+0x1e4/0x290 drivers/base/bus.c:487
 device_add+0xc17/0x1ee0 drivers/base/core.c:3405
 usb_new_device.cold+0x63f/0x108e drivers/usb/core/hub.c:2566
 hub_port_connect drivers/usb/core/hub.c:5362 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5506 [inline]
 port_event drivers/usb/core/hub.c:5664 [inline]
 hub_event+0x25c6/0x4680 drivers/usb/core/hub.c:5746
 process_one_work+0x996/0x1610 kernel/workqueue.c:2289
 worker_thread+0x665/0x1080 kernel/workqueue.c:2436
 kthread+0x2e9/0x3a0 kernel/kthread.c:377
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295
 </TASK>
Modules linked in:
----------------
Code disassembly (best guess):
   0:	49 89 d5             	mov    %rdx,%r13
   3:	41 54                	push   %r12
   5:	49 89 f4             	mov    %rsi,%r12
   8:	55                   	push   %rbp
   9:	53                   	push   %rbx
   a:	48 89 fb             	mov    %rdi,%rbx
   d:	e8 bc 01 fa fc       	callq  0xfcfa01ce
  12:	48 8d bb 50 04 00 00 	lea    0x450(%rbx),%rdi
  19:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  20:	fc ff df
  23:	48 89 fa             	mov    %rdi,%rdx
  26:	48 c1 ea 03          	shr    $0x3,%rdx
* 2a:	80 3c 02 00          	cmpb   $0x0,(%rdx,%rax,1) <-- trapping instruction
  2e:	75 5a                	jne    0x8a
  30:	48 8b ab 50 04 00 00 	mov    0x450(%rbx),%rbp
  37:	48 85 ed             	test   %rbp,%rbp
  3a:	74 22                	je     0x5e
  3c:	e8                   	.byte 0xe8
  3d:	8d 01                	lea    (%rcx),%eax
  3f:	fa                   	cli