================================================================== BUG: KASAN: use-after-free in mcp2221_raw_event+0x1070/0x10a0 drivers/hid/hid-mcp2221.c:948 Read of size 1 at addr ffff888127d7ffff by task syz.1.6130/31083 CPU: 0 UID: 0 PID: 31083 Comm: syz.1.6130 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0xcd/0x630 mm/kasan/report.c:482 kasan_report+0xe0/0x110 mm/kasan/report.c:595 mcp2221_raw_event+0x1070/0x10a0 drivers/hid/hid-mcp2221.c:948 __hid_input_report.constprop.0+0x314/0x470 drivers/hid/hid-core.c:2139 hid_irq_in+0x35e/0x870 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x38b/0x610 drivers/usb/core/hcd.c:1661 usb_hcd_giveback_urb+0x39b/0x450 drivers/usb/core/hcd.c:1745 dummy_timer+0x1809/0x3ad0 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xc40 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x208/0x940 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xfa/0x160 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1056 [inline] sysvec_apic_timer_interrupt+0x90/0xb0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:stack_trace_consume_entry+0x73/0x170 kernel/stacktrace.c:89 Code: 03 0f b6 04 02 84 c0 74 08 3c 03 0f 8e ad 00 00 00 31 c0 3b 6b 08 0f 83 81 00 00 00 48 b8 00 00 00 00 00 fc ff df 48 8d 7b 0c <48> 89 fa 48 c1 ea 03 0f b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 RSP: 0018:ffffc9000d3b79d0 EFLAGS: 00000283 RAX: dffffc0000000000 RBX: ffffc9000d3b7ab0 RCX: ffffc9000d3b7944 RDX: 1ffff92001a76f57 RSI: ffffffff81e18464 RDI: ffffc9000d3b7abc RBP: 0000000000000001 R08: 0000000000000001 R09: 00000000ffffffff R10: 0000000000000002 R11: 000000000000e183 R12: ffffffff816b1980 R13: ffffc9000d3b7ab0 R14: 0000000000000000 R15: ffff888112771d40 arch_stack_walk+0x88/0x100 arch/x86/kernel/stacktrace.c:27 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x43/0x70 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2540 [inline] slab_free mm/slub.c:6668 [inline] kfree+0x2c8/0x680 mm/slub.c:6876 raw_ioctl_ep_write drivers/usb/gadget/legacy/raw_gadget.c:1154 [inline] raw_ioctl+0xab6/0x2e60 drivers/usb/gadget/legacy/raw_gadget.c:1325 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7fb754b4f34b Code: 00 48 89 44 24 18 31 c0 48 8d 44 24 60 c7 04 24 10 00 00 00 48 89 44 24 08 48 8d 44 24 20 48 89 44 24 10 b8 10 00 00 00 0f 05 <89> c2 3d 00 f0 ff ff 77 1c 48 8b 44 24 18 64 48 2b 04 25 28 00 00 RSP: 002b:00007fb7535adf70 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fb754b4f34b RDX: 00007fb7535adff0 RSI: 0000000040085507 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007fb754ed0320 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000200000000040 R13: 0000000000000000 R14: 00007fb754da5fa0 R15: 00007fff0d5790d8 The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x127d7f flags: 0x200000000000000(node=0|zone=2) raw: 0200000000000000 dead000000000100 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as freed page last allocated via order 0, migratetype Unmovable, gfp_mask 0x29c2(GFP_NOWAIT|__GFP_HIGHMEM|__GFP_IO|__GFP_FS|__GFP_ZERO), pid 2968, tgid 2968 (syz-executor), ts 45478868673, free_ts 1497852865483 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846 prep_new_page mm/page_alloc.c:1854 [inline] get_page_from_freelist+0x1058/0x3cb0 mm/page_alloc.c:3915 __alloc_frozen_pages_noprof+0x259/0x21c0 mm/page_alloc.c:5210 alloc_pages_mpol+0xe4/0x410 mm/mempolicy.c:2486 alloc_frozen_pages_noprof mm/mempolicy.c:2557 [inline] alloc_pages_noprof+0x131/0x390 mm/mempolicy.c:2577 vm_area_alloc_pages mm/vmalloc.c:3649 [inline] __vmalloc_area_node mm/vmalloc.c:3863 [inline] __vmalloc_node_range_noprof+0xe6c/0x16b0 mm/vmalloc.c:4051 vmalloc_user_noprof+0x9e/0xe0 mm/vmalloc.c:4205 kcov_ioctl+0x4c/0x6e0 kernel/kcov.c:716 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 2979 tgid 2979 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1395 [inline] __free_frozen_pages+0x795/0x1010 mm/page_alloc.c:2943 vfree+0x1fd/0xb50 mm/vmalloc.c:3466 kcov_put kernel/kcov.c:439 [inline] kcov_put kernel/kcov.c:435 [inline] kcov_close+0x34/0x60 kernel/kcov.c:535 __fput+0x402/0xb70 fs/file_table.c:468 task_work_run+0x150/0x240 kernel/task_work.c:233 exit_task_work include/linux/task_work.h:40 [inline] do_exit+0x87f/0x2bd0 kernel/exit.c:971 do_group_exit+0xd3/0x2a0 kernel/exit.c:1112 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7e0 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:41 [inline] exit_to_user_mode_loop+0x80/0x4f0 kernel/entry/common.c:75 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline] do_syscall_64+0x4bb/0x570 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f Memory state around the buggy address: ffff888127d7fe80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff888127d7ff00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff888127d7ff80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff888127d80000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888127d80080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 03 0f add (%rdi),%ecx 2: b6 04 mov $0x4,%dh 4: 02 84 c0 74 08 3c 03 add 0x33c0874(%rax,%rax,8),%al b: 0f 8e ad 00 00 00 jle 0xbe 11: 31 c0 xor %eax,%eax 13: 3b 6b 08 cmp 0x8(%rbx),%ebp 16: 0f 83 81 00 00 00 jae 0x9d 1c: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 23: fc ff df 26: 48 8d 7b 0c lea 0xc(%rbx),%rdi * 2a: 48 89 fa mov %rdi,%rdx <-- trapping instruction 2d: 48 c1 ea 03 shr $0x3,%rdx 31: 0f b6 14 02 movzbl (%rdx,%rax,1),%edx 35: 48 89 f8 mov %rdi,%rax 38: 83 e0 07 and $0x7,%eax 3b: 83 c0 03 add $0x3,%eax 3e: 38 d0 cmp %dl,%al