================================================================== BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:957 Read of size 1 at addr ffff88814340ffff by task syz.2.3723/21435 CPU: 1 UID: 0 PID: 21435 Comm: syz.2.3723 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x100/0x190 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x13d/0x4b0 mm/kasan/report.c:482 kasan_report+0xdf/0x1d0 mm/kasan/report.c:595 mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:957 __hid_input_report.constprop.0+0x314/0x460 drivers/hid/hid-core.c:2147 hid_irq_in+0x52e/0x6b0 drivers/hid/usbhid/hid-core.c:286 __usb_hcd_giveback_urb+0x38d/0x610 drivers/usb/core/hcd.c:1657 usb_hcd_giveback_urb+0x3ca/0x4a0 drivers/usb/core/hcd.c:1741 dummy_timer+0xda1/0x36c0 drivers/usb/gadget/udc/dummy_hcd.c:2005 __run_hrtimer kernel/time/hrtimer.c:1930 [inline] __hrtimer_run_queues+0x470/0xa00 kernel/time/hrtimer.c:1994 hrtimer_run_softirq+0x17d/0x2c0 kernel/time/hrtimer.c:2011 handle_softirqs+0x1dd/0x9e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x160/0x210 kernel/softirq.c:735 irq_exit_rcu+0x9/0x30 kernel/softirq.c:752 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1061 [inline] sysvec_apic_timer_interrupt+0x42/0xb0 arch/x86/kernel/apic/apic.c:1061 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0033:0x7f4f585fca6d Code: 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 00 75 RSP: 002b:00007f4f57055f60 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000001 RCX: 00007f4f585fca6b RDX: 0000000000000001 RSI: 0000000040085507 RDI: 0000000000000003 RBP: 0000000000000003 R08: 00007f4f589a0320 R09: 0000000000000000 R10: 0000000000000003 R11: 0000000000000246 R12: 0000200000000140 R13: 0000000000000000 R14: 00007f4f58875fa0 R15: 00007fff878f7f18 Allocated by task 8391: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 poison_kmalloc_redzone mm/kasan/common.c:398 [inline] __kasan_kmalloc+0x8f/0xa0 mm/kasan/common.c:415 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] kernfs_iop_get_link fs/kernfs/symlink.c:137 [inline] kernfs_iop_get_link+0x65/0x16a0 fs/kernfs/symlink.c:128 vfs_readlink+0x213/0x440 fs/namei.c:6265 do_readlinkat+0x250/0x370 fs/stat.c:583 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 8391: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 kasan_save_free_info+0x3b/0x70 mm/kasan/generic.c:584 poison_slab_object mm/kasan/common.c:253 [inline] __kasan_slab_free+0x43/0x70 mm/kasan/common.c:285 kasan_slab_free include/linux/kasan.h:235 [inline] slab_free_hook mm/slub.c:2689 [inline] slab_free mm/slub.c:6246 [inline] kfree+0x204/0x650 mm/slub.c:6561 do_delayed_call include/linux/delayed_call.h:28 [inline] vfs_readlink+0x175/0x440 fs/namei.c:6270 do_readlinkat+0x250/0x370 fs/stat.c:583 __do_sys_readlink fs/stat.c:605 [inline] __se_sys_readlink fs/stat.c:602 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:602 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x10b/0x7f0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88814340e000 which belongs to the cache kmalloc-4k of size 4096 The buggy address is located 4095 bytes to the right of allocated 4096-byte region [ffff88814340e000, ffff88814340f000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x143408 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff888100042140 dead000000000100 dead000000000122 raw: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888100042140 dead000000000100 dead000000000122 head: 0000000000000000 0000000800040004 00000000f5000000 0000000000000000 head: 0200000000000003 fffffffffffffe01 00000000ffffffff 00000000ffffffff head: 0000000200000935 0000000000000000 00000000ffffffff 0000000000000008 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 12956, tgid 12955 (syz.1.2101), ts 1095317023710, free_ts 1086849283617 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x153/0x170 mm/page_alloc.c:1858 prep_new_page mm/page_alloc.c:1866 [inline] get_page_from_freelist+0xf34/0x3a90 mm/page_alloc.c:3946 __alloc_frozen_pages_noprof+0x273/0x28a0 mm/page_alloc.c:5226 alloc_slab_page mm/slub.c:3278 [inline] allocate_slab mm/slub.c:3467 [inline] new_slab+0xa6/0x6b0 mm/slub.c:3525 refill_objects+0x277/0x420 mm/slub.c:7251 refill_sheaf mm/slub.c:2816 [inline] __pcs_replace_empty_main+0x375/0x650 mm/slub.c:4651 alloc_from_pcs mm/slub.c:4749 [inline] slab_alloc_node mm/slub.c:4883 [inline] __kmalloc_cache_noprof+0x52c/0x6b0 mm/slub.c:5410 kmalloc_noprof include/linux/slab.h:950 [inline] kzalloc_noprof include/linux/slab.h:1188 [inline] kobject_uevent_env+0x263/0x18b0 lib/kobject_uevent.c:543 gadget_bind_driver+0x773/0xbf0 drivers/usb/gadget/udc/core.c:1653 call_driver_probe drivers/base/dd.c:631 [inline] really_probe+0x241/0xa60 drivers/base/dd.c:709 __driver_probe_device+0x22e/0x480 drivers/base/dd.c:871 driver_probe_device+0x4c/0x1b0 drivers/base/dd.c:901 __driver_attach+0x21f/0x5d0 drivers/base/dd.c:1295 bus_for_each_dev+0x13e/0x1d0 drivers/base/bus.c:383 bus_add_driver+0x305/0x5b0 drivers/base/bus.c:756 driver_register+0x1e2/0x360 drivers/base/driver.c:249 page last free pid 23 tgid 23 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1402 [inline] __free_pages_ok+0x607/0xdf0 mm/page_alloc.c:1583 v4l2_device_release drivers/media/v4l2-core/v4l2-device.c:51 [inline] kref_put include/linux/kref.h:65 [inline] v4l2_device_put+0xa3/0xd0 drivers/media/v4l2-core/v4l2-device.c:56 usb_unbind_interface+0x1dd/0x9e0 drivers/usb/core/driver.c:458 device_remove drivers/base/dd.c:621 [inline] device_remove+0x12a/0x180 drivers/base/dd.c:613 __device_release_driver drivers/base/dd.c:1352 [inline] device_release_driver_internal+0x44e/0x620 drivers/base/dd.c:1375 bus_remove_device+0x2bc/0x560 drivers/base/bus.c:657 device_del+0x376/0x9b0 drivers/base/core.c:3895 usb_disable_device+0x367/0x810 drivers/usb/core/message.c:1478 usb_disconnect+0x2e2/0x9a0 drivers/usb/core/hub.c:2345 hub_port_connect drivers/usb/core/hub.c:5407 [inline] hub_port_connect_change drivers/usb/core/hub.c:5707 [inline] port_event drivers/usb/core/hub.c:5871 [inline] hub_event+0x1d0c/0x4af0 drivers/usb/core/hub.c:5953 process_one_work+0xa0e/0x1980 kernel/workqueue.c:3302 process_scheduled_works kernel/workqueue.c:3385 [inline] worker_thread+0x5ef/0xe50 kernel/workqueue.c:3466 kthread+0x370/0x450 kernel/kthread.c:436 ret_from_fork+0x69a/0xc80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 Memory state around the buggy address: ffff88814340fe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88814340ff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88814340ff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888143410000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888143410080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================