================================================================== BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x1070/0x10a0 drivers/hid/hid-mcp2221.c:948 Read of size 1 at addr ffff88805226ffff by task syz.3.494/7790 CPU: 1 UID: 0 PID: 7790 Comm: syz.3.494 Not tainted syzkaller #0 PREEMPT(full) 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+0x314/0x450 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+0x1809/0x3a00 drivers/usb/gadget/udc/dummy_hcd.c:1995 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 kernel/time/hrtimer.c:1841 hrtimer_run_softirq+0x17d/0x350 kernel/time/hrtimer.c:1858 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 __do_softirq kernel/softirq.c:656 [inline] invoke_softirq kernel/softirq.c:496 [inline] __irq_exit_rcu+0x109/0x170 kernel/softirq.c:723 irq_exit_rcu+0x9/0x30 kernel/softirq.c:739 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa4/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:finish_task_switch.isra.0+0x22a/0xc10 kernel/sched/core.c:5193 Code: fb 09 00 00 44 8b 05 49 36 f8 0e 45 85 c0 0f 85 be 01 00 00 4c 89 e7 e8 a4 f6 ff ff e8 bf d3 3a 00 fb 65 48 8b 1d ee 99 17 12 <48> 8d bb 58 16 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 RSP: 0018:ffffc9001b7ef4a8 EFLAGS: 00000206 RAX: 000000000000b70f RBX: ffff888073d3a480 RCX: ffffffff81c4e8df RDX: 0000000000000000 RSI: ffffffff8da2c9e6 RDI: ffffffff8bf073c0 RBP: ffffc9001b7ef4f0 R08: 0000000000000001 R09: 0000000000000001 R10: ffffffff90821bd7 R11: 0000000000000001 R12: ffff8880b853a380 R13: ffff88802784a480 R14: ffff8880b843a380 R15: ffff8880b853b1b0 context_switch kernel/sched/core.c:5328 [inline] __schedule+0x1198/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x257/0x290 kernel/time/sleep_timeout.c:75 unix_wait_for_peer+0x24e/0x280 net/unix/af_unix.c:1639 unix_dgram_sendmsg+0x1419/0x17f0 net/unix/af_unix.c:2273 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa98/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmmsg+0x200/0x420 net/socket.c:2773 __do_sys_sendmmsg net/socket.c:2800 [inline] __se_sys_sendmmsg net/socket.c:2797 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2797 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f732bd8f749 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f732cb75038 EFLAGS: 00000246 ORIG_RAX: 0000000000000133 RAX: ffffffffffffffda RBX: 00007f732bfe5fa0 RCX: 00007f732bd8f749 RDX: 0000000000000651 RSI: 0000200000000000 RDI: 0000000000000008 RBP: 00007f732be13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f732bfe6038 R14: 00007f732bfe5fa0 R15: 00007fff4090db58 Allocated by task 7582: kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x89/0x90 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4978 [inline] slab_alloc_node mm/slub.c:5288 [inline] kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5340 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:579 __alloc_skb+0x166/0x380 net/core/skbuff.c:670 alloc_skb include/linux/skbuff.h:1383 [inline] __ip_append_data+0x30b3/0x41a0 net/ipv4/ip_output.c:1133 ip_append_data net/ipv4/ip_output.c:1378 [inline] ip_append_data+0x10f/0x1a0 net/ipv4/ip_output.c:1357 raw_sendmsg+0xeee/0x38b0 net/ipv4/raw.c:651 inet_sendmsg+0x11c/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x973/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmmsg+0x200/0x420 net/socket.c:2773 __do_sys_sendmmsg net/socket.c:2800 [inline] __se_sys_sendmmsg net/socket.c:2797 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2797 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 7582: 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:587 kasan_save_free_info mm/kasan/kasan.h:406 [inline] poison_slab_object mm/kasan/common.c:252 [inline] __kasan_slab_free+0x5f/0x80 mm/kasan/common.c:284 kasan_slab_free include/linux/kasan.h:234 [inline] slab_free_hook mm/slub.c:2543 [inline] slab_free mm/slub.c:6642 [inline] kmem_cache_free+0x2d4/0x6c0 mm/slub.c:6752 skb_kfree_head net/core/skbuff.c:1046 [inline] skb_kfree_head net/core/skbuff.c:1043 [inline] skb_free_head+0x1b7/0x210 net/core/skbuff.c:1060 skb_release_data+0x795/0x9e0 net/core/skbuff.c:1087 skb_release_all net/core/skbuff.c:1152 [inline] __kfree_skb net/core/skbuff.c:1166 [inline] sk_skb_reason_drop+0x129/0x1a0 net/core/skbuff.c:1204 kfree_skb_reason include/linux/skbuff.h:1322 [inline] ip_protocol_deliver_rcu+0x213/0x4c0 net/ipv4/ip_input.c:219 ip_local_deliver_finish+0x3f2/0x720 net/ipv4/ip_input.c:239 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_local_deliver+0x18e/0x1f0 net/ipv4/ip_input.c:260 dst_input include/net/dst.h:474 [inline] ip_rcv_finish net/ipv4/ip_input.c:453 [inline] NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] ip_rcv+0x2e0/0x600 net/ipv4/ip_input.c:573 __netif_receive_skb_one_core+0x197/0x1e0 net/core/dev.c:6079 __netif_receive_skb+0x1d/0x160 net/core/dev.c:6192 process_backlog+0x439/0x15e0 net/core/dev.c:6544 __napi_poll.constprop.0+0xba/0x550 net/core/dev.c:7594 napi_poll net/core/dev.c:7657 [inline] net_rx_action+0x97f/0xef0 net/core/dev.c:7784 handle_softirqs+0x219/0x8e0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xb2/0xf0 kernel/softirq.c:510 __local_bh_enable_ip+0x100/0x120 kernel/softirq.c:450 local_bh_enable include/linux/bottom_half.h:33 [inline] rcu_read_unlock_bh include/linux/rcupdate.h:936 [inline] __dev_queue_xmit+0xb06/0x4490 net/core/dev.c:4790 dev_queue_xmit include/linux/netdevice.h:3365 [inline] neigh_hh_output include/net/neighbour.h:531 [inline] neigh_output include/net/neighbour.h:545 [inline] ip_finish_output2+0xc38/0x21a0 net/ipv4/ip_output.c:237 __ip_finish_output.part.0+0x1b4/0x350 net/ipv4/ip_output.c:315 __ip_finish_output net/ipv4/ip_output.c:303 [inline] ip_finish_output net/ipv4/ip_output.c:325 [inline] NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x35f/0xa90 net/ipv4/ip_output.c:438 dst_output include/net/dst.h:464 [inline] ip_local_out net/ipv4/ip_output.c:131 [inline] ip_send_skb net/ipv4/ip_output.c:1508 [inline] ip_push_pending_frames+0x30e/0x5d0 net/ipv4/ip_output.c:1528 raw_sendmsg+0x144e/0x38b0 net/ipv4/raw.c:657 inet_sendmsg+0x11c/0x140 net/ipv4/af_inet.c:853 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0x973/0xc70 net/socket.c:2630 ___sys_sendmsg+0x134/0x1d0 net/socket.c:2684 __sys_sendmmsg+0x200/0x420 net/socket.c:2773 __do_sys_sendmmsg net/socket.c:2800 [inline] __se_sys_sendmmsg net/socket.c:2797 [inline] __x64_sys_sendmmsg+0x9c/0x100 net/socket.c:2797 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f The buggy address belongs to the object at ffff88805226fa80 which belongs to the cache skbuff_small_head of size 704 The buggy address is located 703 bytes to the right of allocated 704-byte region [ffff88805226fa80, ffff88805226fd40) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5226c head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 00fff00000000040 ffff88801e6c9b40 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000 head: 00fff00000000040 ffff88801e6c9b40 dead000000000122 0000000000000000 head: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000 head: 00fff00000000002 ffffea0001489b01 00000000ffffffff 00000000ffffffff head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000004 ---------------- Code disassembly (best guess), 2 bytes skipped: 0: 00 00 add %al,(%rax) 2: 44 8b 05 49 36 f8 0e mov 0xef83649(%rip),%r8d # 0xef83652 9: 45 85 c0 test %r8d,%r8d c: 0f 85 be 01 00 00 jne 0x1d0 12: 4c 89 e7 mov %r12,%rdi 15: e8 a4 f6 ff ff call 0xfffff6be 1a: e8 bf d3 3a 00 call 0x3ad3de 1f: fb sti 20: 65 48 8b 1d ee 99 17 mov %gs:0x121799ee(%rip),%rbx # 0x12179a16 27: 12 * 28: 48 8d bb 58 16 00 00 lea 0x1658(%rbx),%rdi <-- trapping instruction 2f: 48 b8 00 00 00 00 00 movabs $0xdffffc0000000000,%rax 36: fc ff df 39: 48 89 fa mov %rdi,%rdx 3c: 48 rex.W 3d: c1 .byte 0xc1