[moderation/CI] Re: gs_usb: fixes

[syzbot ci <syzbot+cie8e5fbe72e8f515f@syzkaller.appspotmail.com>]

syzbot ci has tested the following series

[v3] gs_usb: fixes
https://lore.kernel.org/all/20261026-gs_usb-fixes-v3-0-3a68f1f62813@pengutronix.de
* [PATCH v3 1/4] can: gs_usb: gs_can_start_xmit(): don't leak uninitialized memory over USB
* [PATCH v3 2/4] can: gs_usb: gs_usb_probe(): init netdev completely before register_candev()
* [PATCH v3 3/4] can: gs_usb: gs_usb_receive_bulk_callback(): check for overflow flag if SKB allocation fails
* [PATCH v3 4/4] can: gs_usb: gs_usb_receive_bulk_callback(): add missing call to can_rx_offload_irq_finish

and found the following issue:
general protection fault in can_rx_offload_del

Full report is available here:
https://ci.syzbot.org/series/0c1fc4c5-6a50-43da-a45c-fbc3a8685c3d

***

general protection fault in can_rx_offload_del

tree:      axboe
URL:       https://kernel.googlesource.com/pub/scm/linux/kernel/git/axboe/linux.git
base:      734bef548a96e8774d6eef5dfa2026c6edc4e80b
arch:      amd64
compiler:  Debian clang version 22.1.8 (1~deb13u4), Debian LLD 22.1.8
config:    https://ci.syzbot.org/builds/03f4b948-ccf7-4d18-8177-b9847267246c/config
syz repro: https://ci.syzbot.org/findings/e4142ca3-3d98-40ef-95df-e6f3ad59fd4e/syz_repro

gs_usb 1-1:0.0: Couldn't get bit timing const for channel 0 (-EPROTO)
Oops: general protection fault, probably for non-canonical address 0xdffffc000000005f: 0000 [#1] SMP KASAN PTI
KASAN: null-ptr-deref in range [0x00000000000002f8-0x00000000000002ff]
CPU: 1 UID: 0 PID: 5651 Comm: kworker/1:4 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Workqueue: usb_hub_wq hub_event
RIP: 0010:__netif_napi_del include/linux/netdevice.h:3007 [inline]
RIP: 0010:netif_napi_del include/linux/netdevice.h:3026 [inline]
RIP: 0010:can_rx_offload_del+0x3c/0x1e0 drivers/net/can/dev/rx-offload.c:423
Code: 48 89 fb 48 bd 00 00 00 00 00 fc ff df e8 9c 5f fc fa 4c 8d a3 d0 00 00 00 49 89 dd 4c 8d b3 00 01 00 00 4c 89 f3 48 c1 eb 03 <80> 3c 2b 00 74 08 4c 89 f7 e8 26 57 6d fb 41 bf 38 0e 00 00 49 8b
RSP: 0018:ffffc90006a4eb30 EFLAGS: 00010206
RAX: ffffffff86cbe694 RBX: 000000000000005f RCX: ffff8881ba5cbc00
RDX: 0000000000000000 RSI: 000000000000009e RDI: 00000000000001f9
RBP: dffffc0000000000 R08: ffffc90006a4e6c7 R09: 1ffff92000d49cd8
R10: dffffc0000000000 R11: fffff52000d49cd9 R12: 00000000000002c9
R13: 00000000000001f9 R14: 00000000000002f9 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a7ca4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fd875c71220 CR3: 0000000115016000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 gs_destroy_candev drivers/net/can/usb/gs_usb.c:1510 [inline]
 gs_usb_probe+0x2201/0x2730 drivers/net/can/usb/gs_usb.c:1639
 usb_probe_interface+0x788/0xe50 drivers/usb/core/driver.c:399
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:503
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:623
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_set_configuration+0x1bb5/0x2260 drivers/usb/core/message.c:2274
 usb_generic_driver_probe+0x8d/0x150 drivers/usb/core/generic.c:250
 usb_probe_device+0x1c3/0x3b0 drivers/usb/core/driver.c:293
 call_driver_probe drivers/base/dd.c:-1 [inline]
 really_probe+0x254/0xae0 drivers/base/dd.c:706
 __driver_probe_device+0x1e8/0x360 drivers/base/dd.c:868
 driver_probe_device+0x4f/0x240 drivers/base/dd.c:898
 __device_attach_driver+0x270/0x410 drivers/base/dd.c:1026
 bus_for_each_drv+0x258/0x2f0 drivers/base/bus.c:503
 __device_attach+0x2c4/0x450 drivers/base/dd.c:1098
 device_initial_probe+0xa1/0xd0 drivers/base/dd.c:1153
 bus_probe_device+0x12a/0x220 drivers/base/bus.c:623
 device_add+0x7d7/0xb80 drivers/base/core.c:3776
 usb_new_device+0x9aa/0x1690 drivers/usb/core/hub.c:2713
 hub_port_connect drivers/usb/core/hub.c:5585 [inline]
 hub_port_connect_change drivers/usb/core/hub.c:5725 [inline]
 port_event drivers/usb/core/hub.c:5889 [inline]
 hub_event+0x28e8/0x4d30 drivers/usb/core/hub.c:5971
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
Modules linked in:
---[ end trace 0000000000000000 ]---
RIP: 0010:__netif_napi_del include/linux/netdevice.h:3007 [inline]
RIP: 0010:netif_napi_del include/linux/netdevice.h:3026 [inline]
RIP: 0010:can_rx_offload_del+0x3c/0x1e0 drivers/net/can/dev/rx-offload.c:423
Code: 48 89 fb 48 bd 00 00 00 00 00 fc ff df e8 9c 5f fc fa 4c 8d a3 d0 00 00 00 49 89 dd 4c 8d b3 00 01 00 00 4c 89 f3 48 c1 eb 03 <80> 3c 2b 00 74 08 4c 89 f7 e8 26 57 6d fb 41 bf 38 0e 00 00 49 8b
RSP: 0018:ffffc90006a4eb30 EFLAGS: 00010206
RAX: ffffffff86cbe694 RBX: 000000000000005f RCX: ffff8881ba5cbc00
RDX: 0000000000000000 RSI: 000000000000009e RDI: 00000000000001f9
RBP: dffffc0000000000 R08: ffffc90006a4e6c7 R09: 1ffff92000d49cd8
R10: dffffc0000000000 R11: fffff52000d49cd9 R12: 00000000000002c9
R13: 00000000000001f9 R14: 00000000000002f9 R15: 0000000000000000
FS:  0000000000000000(0000) GS:ffff8882a7ca4000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f58953fcfe0 CR3: 000000000fb48000 CR4: 00000000000006f0
----------------
Code disassembly (best guess):
   0:	48 89 fb             	mov    %rdi,%rbx
   3:	48 bd 00 00 00 00 00 	movabs $0xdffffc0000000000,%rbp
   a:	fc ff df
   d:	e8 9c 5f fc fa       	call   0xfafc5fae
  12:	4c 8d a3 d0 00 00 00 	lea    0xd0(%rbx),%r12
  19:	49 89 dd             	mov    %rbx,%r13
  1c:	4c 8d b3 00 01 00 00 	lea    0x100(%rbx),%r14
  23:	4c 89 f3             	mov    %r14,%rbx
  26:	48 c1 eb 03          	shr    $0x3,%rbx
* 2a:	80 3c 2b 00          	cmpb   $0x0,(%rbx,%rbp,1) <-- trapping instruction
  2e:	74 08                	je     0x38
  30:	4c 89 f7             	mov    %r14,%rdi
  33:	e8 26 57 6d fb       	call   0xfb6d575e
  38:	41 bf 38 0e 00 00    	mov    $0xe38,%r15d
  3e:	49                   	rex.WB
  3f:	8b                   	.byte 0x8b


***

If these findings have caused you to resend the series or submit a
separate fix, please add the following tag to your commit message:
  Tested-by: syzbot@syzkaller.appspotmail.com

---
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