==================================================================
BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166
Read of size 1 at addr ffff88802af4c818 by task dhcpcd-run-hook/15570

CPU: 0 UID: 0 PID: 15570 Comm: dhcpcd-run-hook Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <IRQ>
 __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/0x1c0 mm/kasan/report.c:595
 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:574
 kasan_check_byte include/linux/kasan.h:402 [inline]
 lock_acquire kernel/locking/lockdep.c:5842 [inline]
 lock_acquire+0x132/0x370 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:132 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:166
 p9_tag_remove net/9p/client.c:274 [inline]
 p9_req_put net/9p/client.c:282 [inline]
 p9_req_put+0xaf/0x250 net/9p/client.c:279
 req_done+0x1dc/0x2e0 net/9p/trans_virtio.c:147
 vring_interrupt+0x2ef/0x660 drivers/virtio/virtio_ring.c:3297
 __handle_irq_event_percpu+0x232/0x880 kernel/irq/handle.c:209
 handle_irq_event_percpu kernel/irq/handle.c:246 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:263
 handle_edge_irq+0x34c/0x950 kernel/irq/chip.c:859
 generic_handle_irq_desc include/linux/irqdesc.h:188 [inline]
 handle_irq arch/x86/kernel/irq.c:209 [inline]
 call_irq_handler arch/x86/kernel/irq.c:265 [inline]
 __common_interrupt+0xd8/0x2f0 arch/x86/kernel/irq.c:280
 common_interrupt+0xb9/0xe0 arch/x86/kernel/irq.c:273
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665
RIP: 0010:memcpy+0xe/0x30 arch/x86/lib/memcpy_64.S:39
Code: 1f 84 00 00 00 00 00 0f 1f 44 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 48 89 f8 48 89 d1 f3 a4 <e9> cd 1e 03 00 66 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90
RSP: 0018:ffffc90004f3f840 EFLAGS: 00000202
RAX: ffff88805892f4b0 RBX: ffff88805892f400 RCX: 0000000000000000
RDX: 0000000000000020 RSI: ffff888013b38fd0 RDI: ffff88805892f4d0
RBP: ffff888013b38f00 R08: 0000000000000001 R09: ffffed100b125e99
R10: ffff88805892f4cf R11: ffff88801d2e6780 R12: 0000000008100073
R13: 0000000000000001 R14: dffffc0000000000 R15: ffff888013b38f00
 vm_area_init_from mm/vma_init.c:59 [inline]
 vm_area_dup+0x2cf/0x8e0 mm/vma_init.c:130
 dup_mmap+0x6f6/0x21b0 mm/mmap.c:1786
 dup_mm kernel/fork.c:1538 [inline]
 copy_mm kernel/fork.c:1590 [inline]
 copy_process+0x4588/0x8030 kernel/fork.c:2288
 kernel_clone+0x176/0x9d0 kernel/fork.c:2747
 __do_sys_clone+0xd9/0x120 kernel/fork.c:2888
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x115/0x840 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7ff629e90636
Code: 89 df e8 6d e8 f6 ff 45 31 c0 31 d2 31 f6 64 48 8b 04 25 10 00 00 00 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 52 89 c5 85 c0 75 31 64 48 8b 04 25 10 00 00
RSP: 002b:00007fffb77df080 EFLAGS: 00000246 ORIG_RAX: 0000000000000038
RAX: ffffffffffffffda RBX: 00007fffb77df088 RCX: 00007ff629e90636
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011
RBP: 00005584abb6fe60 R08: 0000000000000000 R09: 3c00000040001201
R10: 00007ff629cf6f50 R11: 0000000000000246 R12: 00005584abb733a8
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 15571:
 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+0xaa/0xb0 mm/kasan/common.c:415
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_noprof+0x2e5/0x6c0 mm/slub.c:5515
 _kmalloc_noprof include/linux/slab.h:969 [inline]
 p9_client_create+0xaf/0xd40 net/9p/client.c:864
 v9fs_session_init+0x3c/0xdd0 fs/9p/v9fs.c:471
 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
 vfs_get_tree+0x92/0x320 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount fs/namespace.c:3841 [inline]
 path_mount+0x7d0/0x23d0 fs/namespace.c:4161
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount fs/namespace.c:4367 [inline]
 __ia32_sys_mount+0x292/0x310 fs/namespace.c:4367
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 15571:
 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+0x5f/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2705 [inline]
 slab_free mm/slub.c:6405 [inline]
 kfree+0x22b/0x6c0 mm/slub.c:6720
 p9_client_create+0x72d/0xd40 net/9p/client.c:943
 v9fs_session_init+0x3c/0xdd0 fs/9p/v9fs.c:471
 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
 vfs_get_tree+0x92/0x320 fs/super.c:1694
 fc_mount fs/namespace.c:1198 [inline]
 do_new_mount_fc fs/namespace.c:3765 [inline]
 do_new_mount fs/namespace.c:3841 [inline]
 path_mount+0x7d0/0x23d0 fs/namespace.c:4161
 do_mount fs/namespace.c:4174 [inline]
 __do_sys_mount fs/namespace.c:4390 [inline]
 __se_sys_mount fs/namespace.c:4367 [inline]
 __ia32_sys_mount+0x292/0x310 fs/namespace.c:4367
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe7/0x970 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x70 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff88802af4c800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802af4c800, ffff88802af4ca00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2af4c
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 ffff88801b842c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b842c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000800100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffffffffffff01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 837, tgid 837 (kworker/u33:6), ts 57210489211, free_ts 55906552156
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0xfd/0x120 mm/page_alloc.c:1859
 prep_new_page mm/page_alloc.c:1867 [inline]
 get_page_from_freelist+0xf48/0x3530 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x299/0x2dc0 mm/page_alloc.c:5304
 alloc_slab_page mm/slub.c:3294 [inline]
 allocate_slab mm/slub.c:3408 [inline]
 new_slab+0xa2/0x650 mm/slub.c:3454
 refill_objects+0xe3/0x410 mm/slub.c:7338
 refill_sheaf mm/slub.c:2832 [inline]
 __pcs_replace_empty_main+0x376/0x680 mm/slub.c:4703
 alloc_from_pcs mm/slub.c:4801 [inline]
 slab_alloc_node mm/slub.c:4933 [inline]
 __do_kmalloc_node mm/slub.c:5361 [inline]
 __kmalloc_noprof+0x66d/0x820 mm/slub.c:5387
 _kmalloc_noprof include/linux/slab.h:973 [inline]
 _kzalloc_noprof include/linux/slab.h:1290 [inline]
 fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x14c/0xad0 net/ipv6/route.c:3833
 ip6_route_add+0x4b/0x1d0 net/ipv6/route.c:3962
 addrconf_prefix_route+0x2fb/0x510 net/ipv6/addrconf.c:2504
 addrconf_add_linklocal+0x329/0x500 net/ipv6/addrconf.c:3336
 addrconf_addr_gen+0x364/0x3b0 net/ipv6/addrconf.c:3470
 addrconf_dev_config net/ipv6/addrconf.c:3517 [inline]
 addrconf_init_auto_addrs+0x1cb/0x780 net/ipv6/addrconf.c:3595
 addrconf_notify+0xa10/0x1ba0 net/ipv6/addrconf.c:3775
 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
page last free pid 5737 tgid 5737 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1406 [inline]
 __free_frozen_pages+0x79f/0x1090 mm/page_alloc.c:2950
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x47/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x1a0/0x1f0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4612 [inline]
 slab_alloc_node mm/slub.c:4945 [inline]
 kmem_cache_alloc_node_noprof+0x27d/0x6b0 mm/slub.c:5017
 __alloc_skb+0x140/0x710 net/core/skbuff.c:704
 alloc_skb include/linux/skbuff.h:1384 [inline]
 nlmsg_new include/net/netlink.h:1055 [inline]
 rtmsg_ifinfo_build_skb+0x81/0x260 net/core/rtnetlink.c:4524
 rtmsg_ifinfo_event net/core/rtnetlink.c:4566 [inline]
 rtmsg_ifinfo_event net/core/rtnetlink.c:4556 [inline]
 rtnetlink_event+0x137/0x1f0 net/core/rtnetlink.c:7136
 notifier_call_chain+0x99/0x3f0 kernel/notifier.c:85
 call_netdevice_notifiers_info+0xbe/0x110 net/core/dev.c:2250
 call_netdevice_notifiers_extack net/core/dev.c:2288 [inline]
 call_netdevice_notifiers net/core/dev.c:2302 [inline]
 netdev_features_change net/core/dev.c:1590 [inline]
 netdev_change_features net/core/dev.c:11119 [inline]
 netdev_compute_master_upper_features+0x7d4/0xa50 net/core/dev.c:12887
 br_add_if+0x126a/0x1c80 net/bridge/br_if.c:686
 do_set_master+0x40f/0x730 net/core/rtnetlink.c:3020
 do_setlink.isra.0+0xb2b/0x3e60 net/core/rtnetlink.c:3222
 rtnl_changelink net/core/rtnetlink.c:3849 [inline]
 __rtnl_newlink net/core/rtnetlink.c:4022 [inline]
 rtnl_newlink+0x11c2/0x2380 net/core/rtnetlink.c:4159
 rtnetlink_rcv_msg+0x95e/0xe90 net/core/rtnetlink.c:7076

Memory state around the buggy address:
 ffff88802af4c700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802af4c780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802af4c800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802af4c880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802af4c900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess), 1 bytes skipped:
   0:	84 00                	test   %al,(%rax)
   2:	00 00                	add    %al,(%rax)
   4:	00 00                	add    %al,(%rax)
   6:	0f 1f 44 00 00       	nopl   0x0(%rax,%rax,1)
   b:	90                   	nop
   c:	90                   	nop
   d:	90                   	nop
   e:	90                   	nop
   f:	90                   	nop
  10:	90                   	nop
  11:	90                   	nop
  12:	90                   	nop
  13:	90                   	nop
  14:	90                   	nop
  15:	90                   	nop
  16:	90                   	nop
  17:	90                   	nop
  18:	90                   	nop
  19:	90                   	nop
  1a:	90                   	nop
  1b:	f3 0f 1e fa          	endbr64
  1f:	66 90                	xchg   %ax,%ax
  21:	48 89 f8             	mov    %rdi,%rax
  24:	48 89 d1             	mov    %rdx,%rcx
  27:	f3 a4                	rep movsb %ds:(%rsi),%es:(%rdi)
* 29:	e9 cd 1e 03 00       	jmp    0x31efb <-- trapping instruction
  2e:	66 66 2e 0f 1f 84 00 	data16 cs nopw 0x0(%rax,%rax,1)
  35:	00 00 00 00
  39:	66 90                	xchg   %ax,%ax
  3b:	90                   	nop
  3c:	90                   	nop
  3d:	90                   	nop
  3e:	90                   	nop