================================================================== BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948 Read of size 1 at addr ffff88811d2dffff by task kworker/1:8/19292 CPU: 1 UID: 0 PID: 19292 Comm: kworker/1:8 Not tainted syzkaller #0 PREEMPT(voluntary) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: events legacy_dvb_usb_read_remote_control 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+0x156/0x4c9 mm/kasan/report.c:482 kasan_report+0xdf/0x1a0 mm/kasan/report.c:595 mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948 __hid_input_report.constprop.0+0x314/0x460 drivers/hid/hid-core.c:2139 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+0xd85/0x3670 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x516/0x990 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x1dd/0x8f0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0xed/0x150 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+0x8f/0xb0 arch/x86/kernel/apic/apic.c:1056 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:console_flush_one_record+0xac3/0xe50 kernel/printk/printk.c:3216 Code: 00 e8 11 59 28 00 9c 5d 81 e5 00 02 00 00 31 ff 48 89 ee e8 5f 76 20 00 48 85 ed 0f 85 d7 01 00 00 e8 71 7b 20 00 fb 4c 89 e8 <48> c1 e8 03 42 80 3c 38 00 0f 85 64 03 00 00 48 8b 0c 24 48 8b 6b RSP: 0018:ffffc900153df778 EFLAGS: 00000293 RAX: ffffffff89a50638 RBX: ffffffff89a505e0 RCX: ffffffff8190c081 RDX: ffff88811d34d7c0 RSI: ffffffff8190c08f RDI: ffff88811d34d7c0 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 000000000001f484 R13: ffffffff89a50638 R14: ffffc900153df7f8 R15: dffffc0000000000 console_flush_all kernel/printk/printk.c:3289 [inline] __console_flush_and_unlock kernel/printk/printk.c:3319 [inline] console_unlock+0x103/0x260 kernel/printk/printk.c:3359 vprintk_emit+0x407/0x6b0 kernel/printk/printk.c:2426 _printk+0xcf/0x110 kernel/printk/printk.c:2451 m920x_read drivers/media/usb/dvb-usb/m920x.c:40 [inline] m920x_rc_query.cold+0x2b/0x30 drivers/media/usb/dvb-usb/m920x.c:188 legacy_dvb_usb_read_remote_control+0x10c/0x4f0 drivers/media/usb/dvb-usb/dvb-usb-remote.c:123 process_one_work+0x9c2/0x1840 kernel/workqueue.c:3257 process_scheduled_works kernel/workqueue.c:3340 [inline] worker_thread+0x5da/0xe40 kernel/workqueue.c:3421 kthread+0x3b3/0x730 kernel/kthread.c:463 ret_from_fork+0x6c3/0xa20 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246 Allocated by task 5214: 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:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [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:6149 do_readlinkat+0x24b/0x390 fs/stat.c:590 __do_sys_readlink fs/stat.c:613 [inline] __se_sys_readlink fs/stat.c:610 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:610 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 5214: 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:2540 [inline] slab_free mm/slub.c:6670 [inline] kfree+0x1ad/0x630 mm/slub.c:6878 do_delayed_call include/linux/delayed_call.h:28 [inline] vfs_readlink+0x175/0x440 fs/namei.c:6154 do_readlinkat+0x24b/0x390 fs/stat.c:590 __do_sys_readlink fs/stat.c:613 [inline] __se_sys_readlink fs/stat.c:610 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:610 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88811d2de000 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 [ffff88811d2de000, ffff88811d2df000) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x11d2d8 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 0000000000040004 00000000f5000000 0000000000000000 head: 0200000000000040 ffff888100042140 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000000f5000000 0000000000000000 head: 0200000000000003 ffffea000474b601 00000000ffffffff 00000000ffffffff head: 0000000000000000 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 5243, tgid 5243 (udevd), ts 173432765900, free_ts 173346474586 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1e1/0x250 mm/page_alloc.c:1884 prep_new_page mm/page_alloc.c:1892 [inline] get_page_from_freelist+0xd57/0x3b20 mm/page_alloc.c:3945 __alloc_frozen_pages_noprof+0x269/0x2230 mm/page_alloc.c:5240 alloc_pages_mpol+0xe8/0x410 mm/mempolicy.c:2486 alloc_slab_page mm/slub.c:3075 [inline] allocate_slab mm/slub.c:3248 [inline] new_slab+0x2c4/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __kmalloc_cache_noprof+0x4ee/0x7e0 mm/slub.c:5771 kmalloc_noprof include/linux/slab.h:957 [inline] kzalloc_noprof include/linux/slab.h:1094 [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:6149 do_readlinkat+0x24b/0x390 fs/stat.c:590 __do_sys_readlink fs/stat.c:613 [inline] __se_sys_readlink fs/stat.c:610 [inline] __x64_sys_readlink+0x78/0xc0 fs/stat.c:610 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f page last free pid 5243 tgid 5243 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1433 [inline] __free_frozen_pages+0x7d1/0x1010 mm/page_alloc.c:2973 discard_slab mm/slub.c:3346 [inline] __put_partials+0x127/0x160 mm/slub.c:3886 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x47/0xe0 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x4e/0x70 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4953 [inline] slab_alloc_node mm/slub.c:5263 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kmalloc_node_noprof+0x309/0x9a0 mm/slub.c:5663 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline] alloc_slab_obj_exts+0x46/0x110 mm/slub.c:2123 account_slab mm/slub.c:3202 [inline] allocate_slab mm/slub.c:3267 [inline] new_slab+0x354/0x440 mm/slub.c:3302 ___slab_alloc+0xda3/0x1ca0 mm/slub.c:4656 __slab_alloc.isra.0+0x63/0x110 mm/slub.c:4779 __slab_alloc_node mm/slub.c:4855 [inline] slab_alloc_node mm/slub.c:5251 [inline] __do_kmalloc_node mm/slub.c:5656 [inline] __kvmalloc_node_noprof+0x5d7/0xa80 mm/slub.c:7136 seq_buf_alloc fs/seq_file.c:38 [inline] seq_read_iter+0x819/0x1270 fs/seq_file.c:210 kernfs_fop_read_iter+0x46c/0x610 fs/kernfs/file.c:297 new_sync_read fs/read_write.c:491 [inline] vfs_read+0x825/0xb30 fs/read_write.c:572 ksys_read+0x12a/0x250 fs/read_write.c:715 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xc9/0x570 arch/x86/entry/syscall_64.c:94 Memory state around the buggy address: ffff88811d2dfe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88811d2dff00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff88811d2dff80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88811d2e0000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88811d2e0080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ================================================================== ---------------- Code disassembly (best guess): 0: 00 e8 add %ch,%al 2: 11 59 28 adc %ebx,0x28(%rcx) 5: 00 9c 5d 81 e5 00 02 add %bl,0x200e581(%rbp,%rbx,2) c: 00 00 add %al,(%rax) e: 31 ff xor %edi,%edi 10: 48 89 ee mov %rbp,%rsi 13: e8 5f 76 20 00 call 0x207677 18: 48 85 ed test %rbp,%rbp 1b: 0f 85 d7 01 00 00 jne 0x1f8 21: e8 71 7b 20 00 call 0x207b97 26: fb sti 27: 4c 89 e8 mov %r13,%rax * 2a: 48 c1 e8 03 shr $0x3,%rax <-- trapping instruction 2e: 42 80 3c 38 00 cmpb $0x0,(%rax,%r15,1) 33: 0f 85 64 03 00 00 jne 0x39d 39: 48 8b 0c 24 mov (%rsp),%rcx 3d: 48 rex.W 3e: 8b .byte 0x8b 3f: 6b .byte 0x6b