==================================================================
BUG: KASAN: slab-out-of-bounds in hex_dump_to_buffer+0x3b2/0xd60 lib/hexdump.c:193
Read of size 1 at addr ffff88805dec9e00 by task dhcpcd-run-hook/9206

CPU: 1 PID: 9206 Comm: dhcpcd-run-hook Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/24/2026
Call Trace:
 <IRQ>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 hex_dump_to_buffer+0x3b2/0xd60 lib/hexdump.c:193
 print_hex_dump+0x168/0x2b0 lib/hexdump.c:276
 pn533_recv_frame+0x593/0x5f0 drivers/nfc/pn533/pn533.c:2206
 __usb_hcd_giveback_urb+0x35d/0x520 drivers/usb/core/hcd.c:1674
 dummy_timer+0xa47/0x34a0 drivers/usb/gadget/udc/dummy_hcd.c:2012
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676
RIP: 0010:lock_acquire+0x209/0x400 kernel/locking/lockdep.c:5741
Code: f7 84 24 80 00 00 00 00 02 00 00 43 c6 44 3c 04 f8 0f 85 f0 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 04 3c 00 00 00 00 43 c7 44 3c 08 00 00 00 00 65 48 8b 04 25
RSP: 0018:ffffc9000341f9c0 EFLAGS: 00000206
RAX: 0000000000000001 RBX: 0000000000000000 RCX: 74beea6e4a8e0f00
RDX: 0000000000000000 RSI: ffffffff8a2b3e80 RDI: ffffffff8a7a4c00
RBP: ffffc9000341fad0 R08: dffffc0000000000 R09: 1ffffffff2202a18
R10: dffffc0000000000 R11: fffffbfff2202a19 R12: 1ffff92000683f44
R13: ffff88807af5a390 R14: 0000000000000246 R15: dffffc0000000000
 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline]
 _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:154
 spin_lock include/linux/spinlock.h:364 [inline]
 browse_rb mm/mmap.c:356 [inline]
 validate_mm+0x360/0xa50 mm/mmap.c:423
 __vma_adjust+0x1da9/0x1e30 mm/mmap.c:1029
 vma_adjust include/linux/mm.h:2567 [inline]
 __split_vma+0x346/0x410 mm/mmap.c:-1
 mprotect_fixup+0x5bb/0x800 mm/mprotect.c:483
 do_mprotect_pkey+0x658/0x910 mm/mprotect.c:636
 __do_sys_mprotect mm/mprotect.c:662 [inline]
 __se_sys_mprotect mm/mprotect.c:659 [inline]
 __x64_sys_mprotect+0x7c/0x90 mm/mprotect.c:659
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f0f64abf2c7
Code: 89 3d fd 3f 01 00 eb 90 0f 1f 00 f7 d8 89 05 f0 3f 01 00 48 c7 c0 ff ff ff ff eb 91 0f 1f 80 00 00 00 00 b8 0a 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8d 0d c9 3f 01 00 f7 d8 89 01 48 83
RSP: 002b:00007fff45f460f8 EFLAGS: 00000206
 ORIG_RAX: 000000000000000a
RAX: ffffffffffffffda RBX: 00007f0f64a9b0c0 RCX: 00007f0f64abf2c7
RDX: 0000000000000001 RSI: 0000000000003000 RDI: 00007f0f64a97000
RBP: 00007fff45f463c0 R08: 0000000000000000 R09: 00007f0f64a18bf7
R10: 00007f0f64a9b0c0 R11: 0000000000000206 R12: 0000000000000008
R13: 000000720b60d165 R14: 0000000000000000 R15: 00007f0f64ad3310
 </TASK>

Allocated by task 9206:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 ____kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc+0xaf/0xe0 mm/kasan/common.c:522
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 pn533_recv_response+0xbc/0x230 drivers/nfc/pn533/usb.c:65
 __usb_hcd_giveback_urb+0x35d/0x520 drivers/usb/core/hcd.c:1674
 dummy_timer+0xa47/0x34a0 drivers/usb/gadget/udc/dummy_hcd.c:2012
 call_timer_fn+0x17b/0x540 kernel/time/timer.c:1648
 expire_timers kernel/time/timer.c:1699 [inline]
 __run_timers+0x56c/0x810 kernel/time/timer.c:1970
 run_timer_softirq+0x63/0xf0 kernel/time/timer.c:1983
 handle_softirqs+0x336/0x830 kernel/softirq.c:576
 __do_softirq kernel/softirq.c:610 [inline]
 invoke_softirq kernel/softirq.c:450 [inline]
 __irq_exit_rcu+0x13b/0x230 kernel/softirq.c:659
 irq_exit_rcu+0x5/0x20 kernel/softirq.c:671
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1108 [inline]
 sysvec_apic_timer_interrupt+0xa0/0xc0 arch/x86/kernel/apic/apic.c:1108
 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 kvfree_call_rcu+0x105/0x7f0 kernel/rcu/tree.c:3600
 __ipv6_dev_mc_dec+0x2df/0x340 net/ipv6/mcast.c:988
 ipv6_mc_destroy_dev+0x32c/0x590 net/ipv6/mcast.c:2839
 addrconf_ifdown+0x1505/0x19f0 net/ipv6/addrconf.c:3936
 addrconf_notify+0x445/0xf20 net/ipv6/addrconf.c:-1
 notifier_call_chain kernel/notifier.c:83 [inline]
 raw_notifier_call_chain+0xcb/0x160 kernel/notifier.c:391
 call_netdevice_notifiers_extack net/core/dev.c:2074 [inline]
 call_netdevice_notifiers net/core/dev.c:2088 [inline]
 unregister_netdevice_many+0x109b/0x1a40 net/core/dev.c:11160
 ip6_tnl_exit_batch_net+0x5d6/0x620 net/ipv6/ip6_tunnel.c:2293
 ops_exit_list net/core/net_namespace.c:177 [inline]
 cleanup_net+0x78e/0xba0 net/core/net_namespace.c:635
 process_one_work+0x867/0xff0 kernel/workqueue.c:2310
 worker_thread+0xad7/0x12a0 kernel/workqueue.c:2457
 kthread+0x42e/0x520 kernel/kthread.c:334
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

The buggy address belongs to the object at ffff88805dec9c00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 0 bytes to the right of
 512-byte region [ffff88805dec9c00, ffff88805dec9e00)
The buggy address belongs to the page:
page:ffffea000177b200 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x5dec8
head:ffffea000177b200 order:2 compound_mapcount:0 compound_pincount:0
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 dead000000000100 dead000000000122 ffff888017841c80
raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 2, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 4187, ts 57907073275, free_ts 17190039464
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x24f6/0x2670 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5501
 alloc_slab_page mm/slub.c:1780 [inline]
 allocate_slab mm/slub.c:1917 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1980
 ___slab_alloc+0x807/0xdd0 mm/slub.c:3013
 __slab_alloc mm/slub.c:3100 [inline]
 slab_alloc_node mm/slub.c:3191 [inline]
 __kmalloc_node_track_caller+0x13d/0x3a0 mm/slub.c:4963
 kmalloc_reserve net/core/skbuff.c:356 [inline]
 __alloc_skb+0x22c/0x750 net/core/skbuff.c:427
 alloc_skb include/linux/skbuff.h:1162 [inline]
 netlink_alloc_large_skb net/netlink/af_netlink.c:1178 [inline]
 netlink_sendmsg+0x654/0xbe0 net/netlink/af_netlink.c:1894
 sock_sendmsg_nosec net/socket.c:706 [inline]
 __sock_sendmsg net/socket.c:718 [inline]
 __sys_sendto+0x46d/0x620 net/socket.c:2073
 __do_sys_sendto net/socket.c:2085 [inline]
 __se_sys_sendto net/socket.c:2081 [inline]
 __x64_sys_sendto+0xda/0xf0 net/socket.c:2081
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page+0x8f/0x2a0 mm/page_alloc.c:3396
 free_contig_range+0x96/0xf0 mm/page_alloc.c:9428
 destroy_args+0xef/0xa00 mm/debug_vm_pgtable.c:1018
 debug_vm_pgtable+0x321/0x380 mm/debug_vm_pgtable.c:1336
 do_one_initcall+0x272/0x730 init/main.c:1276
 do_initcall_level+0x13d/0x1f0 init/main.c:1349
 do_initcalls+0x4b/0x90 init/main.c:1365
 kernel_init_freeable+0x3d5/0x560 init/main.c:1589
 kernel_init+0x19/0x1b0 init/main.c:1480
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287

Memory state around the buggy address:
 ffff88805dec9d00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805dec9d80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805dec9e00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
                   ^
 ffff88805dec9e80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88805dec9f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
==================================================================
----------------
Code disassembly (best guess):
   0:	f7 84 24 80 00 00 00 	testl  $0x200,0x80(%rsp)
   7:	00 02 00 00
   b:	43 c6 44 3c 04 f8    	movb   $0xf8,0x4(%r12,%r15,1)
  11:	0f 85 f0 00 00 00    	jne    0x107
  17:	41 f7 c6 00 02 00 00 	test   $0x200,%r14d
  1e:	74 01                	je     0x21
  20:	fb                   	sti
  21:	48 c7 44 24 60 0e 36 	movq   $0x45e0360e,0x60(%rsp)
  28:	e0 45
* 2a:	4b c7 04 3c 00 00 00 	movq   $0x0,(%r12,%r15,1) <-- trapping instruction
  31:	00
  32:	43 c7 44 3c 08 00 00 	movl   $0x0,0x8(%r12,%r15,1)
  39:	00 00
  3b:	65                   	gs
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	04 25                	add    $0x25,%al