general protection fault, probably for non-canonical address 0xdffffc0000000009: 0000 [#1] PREEMPT SMP KASAN KASAN: null-ptr-deref in range [0x0000000000000048-0x000000000000004f] CPU: 1 PID: 4381 Comm: syz.8.1124 Not tainted syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026 RIP: 0010:dummy_queue+0x1b7/0x870 drivers/usb/gadget/udc/dummy_hcd.c:712 Code: fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 42 39 92 fe 4d 8b 24 24 49 83 c4 48 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 80 05 00 00 45 8b 24 24 44 89 e6 83 e6 02 RSP: 0018:ffffc90000170c50 EFLAGS: 00010206 RAX: 0000000000000009 RBX: ffff88810b9f8e10 RCX: dffffc0000000000 RDX: ffff88811488bb40 RSI: 0000000000000003 RDI: 0000000000000005 RBP: ffffc90000170cc8 R08: ffff88812a168173 R09: ffff88812a168170 R10: dffffc0000000000 R11: ffffed102542d02f R12: 0000000000000048 R13: ffff88810b9f8e00 R14: 1ffff1102173f1c0 R15: ffff888103f84c90 FS: 00007f5bed0cd6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000d6030 CR3: 000000011fe3c000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: usb_ep_queue+0xce/0x210 drivers/usb/gadget/udc/core.c:290 eth_start_xmit+0x811/0xd40 drivers/usb/gadget/function/u_ether.c:588 ncm_tx_timeout+0xec/0x160 drivers/usb/gadget/function/f_ncm.c:1171 __run_hrtimer kernel/time/hrtimer.c:1587 [inline] __hrtimer_run_queues+0x33a/0x7d0 kernel/time/hrtimer.c:1651 hrtimer_run_softirq+0x1ac/0x220 kernel/time/hrtimer.c:1668 __do_softirq+0x255/0x563 kernel/softirq.c:309 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0x60/0x80 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:405 [inline] __irq_exit_rcu+0x128/0x150 kernel/softirq.c:435 irq_exit_rcu+0x9/0x10 kernel/softirq.c:447 sysvec_apic_timer_interrupt+0xbf/0xe0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:635 RIP: 0010:preempt_count_add+0x32/0x1b0 kernel/sched/core.c:4456 Code: 53 49 bf 00 00 00 00 00 fc ff df 48 c7 c0 c0 08 e8 86 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 01 01 00 00 83 3d ee 39 a3 05 00 <75> 07 65 8b 05 b1 9e bd 7e 65 01 3d aa 9e bd 7e 48 c7 c0 c0 08 e8 RSP: 0018:ffffc90001857c90 EFLAGS: 00000246 RAX: 0000000000000004 RBX: ffff88811488ca80 RCX: ffffffff86e80803 RDX: ffffc9000b2d3000 RSI: 000000000004e669 RDI: 0000000000000200 RBP: ffffc90001857ca8 R08: 0000000000000000 R09: 1ffff9200030afc9 R10: dffffc0000000000 R11: fffff5200030afca R12: 0000000000000000 R13: dffffc0000000000 R14: 0000000000000001 R15: dffffc0000000000 __local_bh_disable_ip include/linux/bottom_half.h:12 [inline] local_bh_disable include/linux/bottom_half.h:19 [inline] fpregs_lock arch/x86/include/asm/fpu/api.h:47 [inline] fpu__clear+0x50/0x2d0 arch/x86/kernel/fpu/core.c:357 fpu__clear_user_states+0x1a/0x20 arch/x86/kernel/fpu/core.c:375 handle_signal arch/x86/kernel/signal.c:778 [inline] arch_do_signal_or_restart+0xd2a/0x11b0 arch/x86/kernel/signal.c:807 handle_signal_work kernel/entry/common.c:145 [inline] exit_to_user_mode_loop+0xa2/0xe0 kernel/entry/common.c:169 exit_to_user_mode_prepare+0x76/0xa0 kernel/entry/common.c:199 syscall_exit_to_user_mode+0x1d/0x40 kernel/entry/common.c:274 do_syscall_64+0x3d/0x40 arch/x86/entry/common.c:56 entry_SYSCALL_64_after_hwframe+0x61/0xcb RIP: 0033:0x7f5bee6b4590 Code: 83 c0 16 83 e0 f7 74 12 50 48 8d 3d 72 2d 07 00 e8 65 65 f9 ff 0f 1f 44 00 00 c3 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 <83> ff 21 74 0b c3 66 2e 0f 1f 84 00 00 00 00 00 55 53 48 89 f3 48 RSP: 002b:00007f5bed0ccb38 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 00007f5bee91d098 RCX: 00007f5bee695019 RDX: 00007f5bed0ccb40 RSI: 00007f5bed0ccc70 RDI: 0000000000000021 RBP: 00007f5bee91d090 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f5bee91d128 R14: 00007ffd9ce12730 R15: 00007ffd9ce12818 Modules linked in: ---[ end trace bab9fbce205bcb9b ]--- RIP: 0010:dummy_queue+0x1b7/0x870 drivers/usb/gadget/udc/dummy_hcd.c:712 Code: fc ff df 80 3c 08 00 74 08 4c 89 e7 e8 42 39 92 fe 4d 8b 24 24 49 83 c4 48 4c 89 e0 48 c1 e8 03 48 b9 00 00 00 00 00 fc ff df <0f> b6 04 08 84 c0 0f 85 80 05 00 00 45 8b 24 24 44 89 e6 83 e6 02 RSP: 0018:ffffc90000170c50 EFLAGS: 00010206 RAX: 0000000000000009 RBX: ffff88810b9f8e10 RCX: dffffc0000000000 RDX: ffff88811488bb40 RSI: 0000000000000003 RDI: 0000000000000005 RBP: ffffc90000170cc8 R08: ffff88812a168173 R09: ffff88812a168170 R10: dffffc0000000000 R11: ffffed102542d02f R12: 0000000000000048 R13: ffff88810b9f8e00 R14: 1ffff1102173f1c0 R15: ffff888103f84c90 FS: 00007f5bed0cd6c0(0000) GS:ffff8881f7100000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000000d6030 CR3: 000000011fe3c000 CR4: 00000000003506a0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 ---------------- Code disassembly (best guess): 0: fc cld 1: ff lcall (bad) 2: df 80 3c 08 00 74 filds 0x7400083c(%rax) 8: 08 4c 89 e7 or %cl,-0x19(%rcx,%rcx,4) c: e8 42 39 92 fe call 0xfe923953 11: 4d 8b 24 24 mov (%r12),%r12 15: 49 83 c4 48 add $0x48,%r12 19: 4c 89 e0 mov %r12,%rax 1c: 48 c1 e8 03 shr $0x3,%rax 20: 48 b9 00 00 00 00 00 movabs $0xdffffc0000000000,%rcx 27: fc ff df * 2a: 0f b6 04 08 movzbl (%rax,%rcx,1),%eax <-- trapping instruction 2e: 84 c0 test %al,%al 30: 0f 85 80 05 00 00 jne 0x5b6 36: 45 8b 24 24 mov (%r12),%r12d 3a: 44 89 e6 mov %r12d,%esi 3d: 83 e6 02 and $0x2,%esi