Re: [syzbot] BUG: unable to handle kernel paging request in ath9k_htc_rxep

[syzbot]

syzbot has found a reproducer for the following issue on:

HEAD commit:    97db1b081e12 dt-bindings: usb: dwc3: Update dwc3 TX fifo p..
git tree:       https://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb.git usb-testing
console output: https://syzkaller.appspot.com/x/log.txt?x=13b7fd02300000
kernel config:  https://syzkaller.appspot.com/x/.config?x=db8b503c237253ee
dashboard link: https://syzkaller.appspot.com/bug?extid=dc6c749aec286992cea2
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10431e54300000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=13d2dc32300000

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+dc6c749aec286992cea2@xxxxxxxxxxxxxxxxxxxxxxxxx

BUG: unable to handle page fault for address: ffffffffffffffc8
#PF: supervisor read access in kernel mode
#PF: error_code(0x0000) - not-present page
PGD 7426067 P4D 7426067 PUD 7428067 PMD 0 
Oops: 0000 [#1] SMP KASAN
CPU: 1 PID: 0 Comm: swapper/1 Tainted: G        W         5.14.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:ath9k_htc_rxep+0xb5/0x210 drivers/net/wireless/ath/ath9k/htc_drv_txrx.c:1135
Code: 8b 43 38 48 8d 58 c8 49 39 c4 0f 84 ee 00 00 00 e8 f0 64 37 fe 48 89 d8 48 c1 e8 03 0f b6 04 28 84 c0 74 06 0f 8e 0a 01 00 00 <44> 0f b6 3b 31 ff 44 89 fe e8 fd 6b 37 fe 45 84 ff 75 a8 e8 c3 64
RSP: 0018:ffffc900001489b8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffffffffffc8 RCX: 0000000000000100
RDX: ffff8881002c0000 RSI: ffffffff830a0050 RDI: ffffc90000148928
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000029125 R11: 0000000000000000 R12: ffff888119a9b678
R13: ffff888119a9b240 R14: ffff888119a9b688 R15: ffff8881088974a8
FS:  0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffc8 CR3: 000000010719b000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 <IRQ>
 ath9k_htc_rx_msg+0x2e4/0xb70 drivers/net/wireless/ath/ath9k/htc_hst.c:461
 ath9k_hif_usb_reg_in_cb+0x1ac/0x630 drivers/net/wireless/ath/ath9k/hif_usb.c:733
 __usb_hcd_giveback_urb+0x2b0/0x5c0 drivers/usb/core/hcd.c:1656
 usb_hcd_giveback_urb+0x367/0x410 drivers/usb/core/hcd.c:1726
 dummy_timer+0x11f9/0x32b0 drivers/usb/gadget/udc/dummy_hcd.c:1987
 call_timer_fn+0x1a5/0x630 kernel/time/timer.c:1417
 expire_timers kernel/time/timer.c:1462 [inline]
 __run_timers.part.0+0x675/0xa10 kernel/time/timer.c:1731
 __run_timers kernel/time/timer.c:1712 [inline]
 run_timer_softirq+0x80/0x120 kernel/time/timer.c:1744
 __do_softirq+0x1b0/0x910 kernel/softirq.c:558
 invoke_softirq kernel/softirq.c:432 [inline]
 __irq_exit_rcu+0x117/0x160 kernel/softirq.c:636
 irq_exit_rcu+0x5/0x10 kernel/softirq.c:648
 sysvec_apic_timer_interrupt+0x6a/0x90 arch/x86/kernel/apic/apic.c:1100
 </IRQ>
 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:638
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:29 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline]
RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:132 [inline]
RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:110 [inline]
RIP: 0010:acpi_idle_do_entry+0x1c6/0x250 drivers/acpi/processor_idle.c:553
Code: 89 de e8 cd ed 80 fb 84 db 75 ac e8 94 e6 80 fb e8 5f f2 86 fb eb 0c e8 88 e6 80 fb 0f 00 2d 81 b0 88 00 e8 7c e6 80 fb fb f4 <9c> 5b 81 e3 00 02 00 00 fa 31 ff 48 89 de e8 07 ef 80 fb 48 85 db
RSP: 0018:ffffc900000dfd18 EFLAGS: 00000293
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: ffff8881002c0000 RSI: ffffffff85c07ec4 RDI: ffffffff85c07eb1
RBP: ffff888109b93064 R08: 0000000000000000 R09: 0000000000000000
R10: ffffffff81477148 R11: 0000000000000000 R12: 0000000000000001
R13: ffff888109b93000 R14: ffff888109b93064 R15: ffff88810cf00004
 acpi_idle_enter+0x355/0x4f0 drivers/acpi/processor_idle.c:688
 cpuidle_enter_state+0x1b1/0xc80 drivers/cpuidle/cpuidle.c:237
 cpuidle_enter+0x4a/0xa0 drivers/cpuidle/cpuidle.c:351
 call_cpuidle kernel/sched/idle.c:158 [inline]
 cpuidle_idle_call kernel/sched/idle.c:239 [inline]
 do_idle+0x3dd/0x580 kernel/sched/idle.c:306
 cpu_startup_entry+0x14/0x20 kernel/sched/idle.c:403
 start_secondary+0x267/0x340 arch/x86/kernel/smpboot.c:270
 secondary_startup_64_no_verify+0xb0/0xbb
Modules linked in:
CR2: ffffffffffffffc8
---[ end trace c812365639e6eb14 ]---
RIP: 0010:ath9k_htc_rxep+0xb5/0x210 drivers/net/wireless/ath/ath9k/htc_drv_txrx.c:1135
Code: 8b 43 38 48 8d 58 c8 49 39 c4 0f 84 ee 00 00 00 e8 f0 64 37 fe 48 89 d8 48 c1 e8 03 0f b6 04 28 84 c0 74 06 0f 8e 0a 01 00 00 <44> 0f b6 3b 31 ff 44 89 fe e8 fd 6b 37 fe 45 84 ff 75 a8 e8 c3 64
RSP: 0018:ffffc900001489b8 EFLAGS: 00010046
RAX: 0000000000000000 RBX: ffffffffffffffc8 RCX: 0000000000000100
RDX: ffff8881002c0000 RSI: ffffffff830a0050 RDI: ffffc90000148928
RBP: dffffc0000000000 R08: 0000000000000001 R09: 0000000000000003
R10: fffff52000029125 R11: 0000000000000000 R12: ffff888119a9b678
R13: ffff888119a9b240 R14: ffff888119a9b688 R15: ffff8881088974a8
FS:  0000000000000000(0000) GS:ffff8881f6900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: ffffffffffffffc8 CR3: 000000010719b000 CR4: 00000000001506e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400