================================================================== BUG: KASAN: slab-out-of-bounds in mcp2221_raw_event+0x103c/0x10a0 drivers/hid/hid-mcp2221.c:948 Read of size 1 at addr ffff888138dcbfff by task ksoftirqd/1/22 CPU: 1 UID: 0 PID: 22 Comm: ksoftirqd/1 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+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 run_ksoftirqd kernel/softirq.c:1063 [inline] run_ksoftirqd+0x38/0x60 kernel/softirq.c:1055 smpboot_thread_fn+0x3d3/0xaa0 kernel/smpboot.c:160 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 2862: kasan_save_stack+0x30/0x50 mm/kasan/common.c:57 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6e/0x70 mm/kasan/common.c:366 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] kmem_cache_alloc_node_noprof+0x292/0x7d0 mm/slub.c:5315 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:586 __alloc_skb+0x186/0x410 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] netlink_alloc_large_skb+0x69/0x150 net/netlink/af_netlink.c:1184 netlink_sendmsg+0x680/0xda0 net/netlink/af_netlink.c:1869 sock_sendmsg_nosec net/socket.c:727 [inline] __sock_sendmsg net/socket.c:742 [inline] ____sys_sendmsg+0xa54/0xc30 net/socket.c:2592 ___sys_sendmsg+0x190/0x1e0 net/socket.c:2646 __sys_sendmsg+0x170/0x220 net/socket.c:2678 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 5234: 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] kmem_cache_free+0x124/0x6d0 mm/slub.c:6781 skb_kfree_head net/core/skbuff.c:1066 [inline] skb_kfree_head net/core/skbuff.c:1063 [inline] skb_free_head+0x1c6/0x220 net/core/skbuff.c:1080 skb_release_data+0x540/0x700 net/core/skbuff.c:1107 skb_release_all net/core/skbuff.c:1182 [inline] __kfree_skb net/core/skbuff.c:1196 [inline] consume_skb net/core/skbuff.c:1428 [inline] consume_skb+0xc4/0x110 net/core/skbuff.c:1422 netlink_recvmsg+0x51b/0x9c0 net/netlink/af_netlink.c:1972 sock_recvmsg_nosec net/socket.c:1078 [inline] sock_recvmsg+0x1f9/0x250 net/socket.c:1100 ____sys_recvmsg+0x218/0x6b0 net/socket.c:2812 ___sys_recvmsg+0x16a/0x1a0 net/socket.c:2854 __sys_recvmsg+0x16d/0x220 net/socket.c:2887 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 ffff888138dcba80 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 [ffff888138dcba80, ffff888138dcbd40) The buggy address belongs to the physical page: page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x138dc8 head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 anon flags: 0x200000000000040(head|node=0|zone=2) page_type: f5(slab) raw: 0200000000000040 ffff8881026bcc80 ffffea00046b9800 dead000000000005 raw: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000 head: 0200000000000040 ffff8881026bcc80 ffffea00046b9800 dead000000000005 head: 0000000000000000 0000000000130013 00000000f5000000 0000000000000000 head: 0200000000000002 ffffea0004e37201 00000000ffffffff 00000000ffffffff head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000004 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd2820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6433, tgid 6432 (syz.2.316), ts 236562984447, free_ts 236285714953 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] kmem_cache_alloc_node_noprof+0x4a9/0x7d0 mm/slub.c:5315 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:586 __alloc_skb+0x186/0x410 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] __tcp_send_ack.part.0+0x66/0x730 net/ipv4/tcp_output.c:4437 __tcp_send_ack net/ipv4/tcp_output.c:4470 [inline] tcp_send_ack+0x84/0xa0 net/ipv4/tcp_output.c:4470 __tcp_ack_snd_check+0x1fe/0x9f0 net/ipv4/tcp_input.c:5932 tcp_ack_snd_check net/ipv4/tcp_input.c:5986 [inline] tcp_ack_snd_check net/ipv4/tcp_input.c:5980 [inline] tcp_rcv_established+0xc26/0x36b0 net/ipv4/tcp_input.c:6477 tcp_v4_do_rcv+0x5dc/0xaa0 net/ipv4/tcp_ipv4.c:1881 tcp_v4_rcv+0x304c/0x46a0 net/ipv4/tcp_ipv4.c:2324 page last free pid 6429 tgid 6429 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 stack_depot_save_flags+0x412/0x9c0 lib/stackdepot.c:727 kasan_save_stack+0x3f/0x50 mm/kasan/common.c:58 kasan_save_track+0x14/0x30 mm/kasan/common.c:78 unpoison_slab_object mm/kasan/common.c:340 [inline] __kasan_slab_alloc+0x6e/0x70 mm/kasan/common.c:366 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] kmem_cache_alloc_node_noprof+0x292/0x7d0 mm/slub.c:5315 kmalloc_reserve+0x18b/0x2c0 net/core/skbuff.c:586 __alloc_skb+0x186/0x410 net/core/skbuff.c:690 alloc_skb include/linux/skbuff.h:1383 [inline] arp_create+0x18c/0x8b0 net/ipv4/arp.c:561 arp_send_dst net/ipv4/arp.c:314 [inline] arp_send_dst+0xa4/0x280 net/ipv4/arp.c:301 arp_process+0x1c17/0x2330 net/ipv4/arp.c:855 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] arp_rcv+0x350/0x640 net/ipv4/arp.c:996 __netif_receive_skb_list_ptype net/core/dev.c:6200 [inline] __netif_receive_skb_list_ptype net/core/dev.c:6184 [inline] __netif_receive_skb_list_core+0x6da/0x940 net/core/dev.c:6242 __netif_receive_skb_list net/core/dev.c:6294 [inline] netif_receive_skb_list_internal+0x722/0xd40 net/core/dev.c:6385 gro_normal_list include/net/gro.h:524 [inline] gro_normal_list include/net/gro.h:520 [inline] gro_flush_normal include/net/gro.h:532 [inline] napi_complete_done+0x221/0x940 net/core/dev.c:6754 virtqueue_napi_complete drivers/net/virtio_net.c:749 [inline] virtnet_poll+0x1713/0x2790 drivers/net/virtio_net.c:3091 Memory state around the buggy address: ffff888138dcbe80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff888138dcbf00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc >ffff888138dcbf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff888138dcc000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff888138dcc080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ==================================================================