==================================================================
BUG: KASAN: slab-use-after-free in __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
BUG: KASAN: slab-use-after-free in _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
Read of size 1 at addr ffff8880285b7018 by task syz.2.198/6701

CPU: 3 UID: 0 PID: 6701 Comm: syz.2.198 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014
Call Trace:
 <IRQ>
 __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
 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:580
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire kernel/locking/lockdep.c:5842 [inline]
 lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5825
 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
 _raw_spin_lock_irqsave+0x3a/0x60 kernel/locking/spinlock.c:162
 p9_tag_remove net/9p/client.c:397 [inline]
 p9_req_put net/9p/client.c:405 [inline]
 p9_req_put+0xaf/0x250 net/9p/client.c:402
 req_done+0x1dc/0x2e0 net/9p/trans_virtio.c:147
 vring_interrupt drivers/virtio/virtio_ring.c:2719 [inline]
 vring_interrupt+0x31e/0x400 drivers/virtio/virtio_ring.c:2694
 __handle_irq_event_percpu+0x236/0x920 kernel/irq/handle.c:203
 handle_irq_event_percpu kernel/irq/handle.c:240 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:257
 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:254 [inline]
 call_irq_handler arch/x86/kernel/irq.c:310 [inline]
 __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:325
 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:318
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:__kasan_check_write+0x8/0x20 mm/kasan/shadow.c:37
Code: f0 ff ff 66 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <89> f6 ba 01 00 00 00 e9 2c f0 ff ff 66 66 2e 0f 1f 84 00 00 00 00
RSP: 0000:ffffc90006cfee48 EFLAGS: 00000293
RAX: 0000000000000000 RBX: ffffea0001650780 RCX: ffffffff8205afb0
RDX: ffff88802989a480 RSI: 0000000000000004 RDI: ffffea00016507b4
RBP: 000000000000000e R08: 0000000000000005 R09: 0000000000000000
R10: 0000000000000002 R11: 0000000000000000 R12: ffffea00016507b4
R13: 0000000000000001 R14: 0000000000000002 R15: 1ffff92000d9fdd7
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_add include/linux/atomic/atomic-instrumented.h:104 [inline]
 page_ref_add include/linux/page_ref.h:120 [inline]
 folio_ref_add include/linux/page_ref.h:127 [inline]
 try_grab_folio+0x220/0x2c0 mm/gup.c:150
 follow_page_pte+0x4dc/0x1390 mm/gup.c:858
 follow_pmd_mask mm/gup.c:928 [inline]
 follow_pud_mask mm/gup.c:967 [inline]
 follow_p4d_mask mm/gup.c:984 [inline]
 follow_page_mask mm/gup.c:1023 [inline]
 __get_user_pages+0x918/0x3530 mm/gup.c:1426
 __get_user_pages_locked mm/gup.c:1692 [inline]
 get_dump_page+0x257/0x3d0 mm/gup.c:2192
 dump_user_range+0x195/0xb70 fs/coredump.c:1366
 elf_core_dump+0x29c3/0x3c00 fs/binfmt_elf.c:2111
 coredump_write fs/coredump.c:1049 [inline]
 vfs_coredump+0x2b9f/0x5670 fs/coredump.c:1170
 get_signal+0x22e1/0x26d0 kernel/signal.c:3019
 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:40 [inline]
 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline]
 irqentry_exit_to_user_mode+0x141/0x2b0 kernel/entry/common.c:73
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:623
RIP: 0033:0x7fa8bc84f987
Code: 88 15 72 5d ec 00 88 05 6f 5d ec 00 c3 50 48 8d 35 19 26 1c 00 48 8d 3d 1f 26 1c 00 31 c0 e8 20 f7 ff ff 53 89 fb 48 83 ec 10 <64> 8b 04 25 94 ff ff ff 85 c0 74 2a 89 fe 31 c0 bf 3c 00 00 00 e8
RSP: 002b:00007fa8bd7c71a0 EFLAGS: 00010206
RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007fa8bc98eec9
RDX: 00007fa8bd7c71c0 RSI: 00007fa8bd7c72f0 RDI: 000000000000000b
RBP: 00007fa8bca11f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000
R13: 00007fa8bcbe6038 R14: 00007fa8bcbe5fa0 R15: 00007ffcba904988
 </TASK>

Allocated by task 6712:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56
 kasan_save_track+0x14/0x30 mm/kasan/common.c:77
 poison_kmalloc_redzone mm/kasan/common.c:400 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417
 kmalloc_noprof include/linux/slab.h:957 [inline]
 p9_client_create+0xc7/0x11d0 net/9p/client.c:985
 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122
 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663
 vfs_get_tree+0x8e/0x340 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount fs/namespace.c:3727 [inline]
 path_mount+0x7b9/0x23a0 fs/namespace.c:4037
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount fs/namespace.c:4215 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6712:
 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:2514 [inline]
 slab_free mm/slub.c:6566 [inline]
 kfree+0x2b8/0x6d0 mm/slub.c:6773
 p9_client_create+0xa28/0x11d0 net/9p/client.c:1064
 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc5/0xa90 fs/9p/vfs_super.c:122
 legacy_get_tree+0x10c/0x220 fs/fs_context.c:663
 vfs_get_tree+0x8e/0x340 fs/super.c:1751
 fc_mount fs/namespace.c:1208 [inline]
 do_new_mount_fc fs/namespace.c:3651 [inline]
 do_new_mount fs/namespace.c:3727 [inline]
 path_mount+0x7b9/0x23a0 fs/namespace.c:4037
 do_mount fs/namespace.c:4050 [inline]
 __do_sys_mount fs/namespace.c:4238 [inline]
 __se_sys_mount fs/namespace.c:4215 [inline]
 __x64_sys_mount+0x293/0x310 fs/namespace.c:4215
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880285b7000
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff8880285b7000, ffff8880285b7200)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x285b4
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 ffff88801b042c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b042c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000a16d01 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 5956, tgid 5956 (syz-executor), ts 55026267320, free_ts 54901554836
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1850
 prep_new_page mm/page_alloc.c:1858 [inline]
 get_page_from_freelist+0x10a3/0x3a30 mm/page_alloc.c:3884
 __alloc_frozen_pages_noprof+0x25f/0x2470 mm/page_alloc.c:5183
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:3030 [inline]
 allocate_slab mm/slub.c:3203 [inline]
 new_slab+0x24a/0x360 mm/slub.c:3257
 ___slab_alloc+0xdc4/0x1ae0 mm/slub.c:4627
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4746
 __slab_alloc_node mm/slub.c:4822 [inline]
 slab_alloc_node mm/slub.c:5233 [inline]
 __do_kmalloc_node mm/slub.c:5602 [inline]
 __kmalloc_noprof+0x501/0x880 mm/slub.c:5615
 kmalloc_noprof include/linux/slab.h:961 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x14c/0x870 net/ipv6/route.c:3809
 ip6_route_add.part.0+0x22/0x1d0 net/ipv6/route.c:3938
 ip6_route_add+0x45/0x60 net/ipv6/route.c:3935
 addrconf_prefix_route+0x2fd/0x510 net/ipv6/addrconf.c:2488
 addrconf_add_linklocal+0x329/0x500 net/ipv6/addrconf.c:3313
 addrconf_addr_gen+0x364/0x3b0 net/ipv6/addrconf.c:3442
 addrconf_dev_config net/ipv6/addrconf.c:3489 [inline]
 addrconf_init_auto_addrs+0x2ba/0x810 net/ipv6/addrconf.c:3567
page last free pid 5346 tgid 5346 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 __free_frozen_pages+0x7df/0x1160 mm/page_alloc.c:2906
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4d/0x120 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:352
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4946 [inline]
 slab_alloc_node mm/slub.c:5245 [inline]
 kmem_cache_alloc_node_noprof+0x28a/0x770 mm/slub.c:5297
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:660
 alloc_skb include/linux/skbuff.h:1383 [inline]
 alloc_skb_with_frags+0xe0/0x860 net/core/skbuff.c:6671
 sock_alloc_send_pskb+0x7f9/0x980 net/core/sock.c:2965
 unix_dgram_sendmsg+0x3e9/0x17f0 net/unix/af_unix.c:2153
 sock_sendmsg_nosec net/socket.c:727 [inline]
 __sock_sendmsg net/socket.c:742 [inline]
 __sys_sendto+0x4a3/0x520 net/socket.c:2244
 __do_sys_sendto net/socket.c:2251 [inline]
 __se_sys_sendto net/socket.c:2247 [inline]
 __x64_sys_sendto+0xe0/0x1c0 net/socket.c:2247
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x4e0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880285b6f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8880285b6f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff8880285b7000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff8880285b7080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8880285b7100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	f0 ff                	lock (bad)
   2:	ff 66 66             	jmp    *0x66(%rsi)
   5:	2e 0f 1f 84 00 00 00 	cs nopl 0x0(%rax,%rax,1)
   c:	00 00
   e:	0f 1f 40 00          	nopl   0x0(%rax)
  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:	90                   	nop
  1c:	90                   	nop
  1d:	90                   	nop
  1e:	90                   	nop
  1f:	90                   	nop
  20:	90                   	nop
  21:	90                   	nop
  22:	f3 0f 1e fa          	endbr64
  26:	48 8b 0c 24          	mov    (%rsp),%rcx
* 2a:	89 f6                	mov    %esi,%esi <-- trapping instruction
  2c:	ba 01 00 00 00       	mov    $0x1,%edx
  31:	e9 2c f0 ff ff       	jmp    0xfffff062
  36:	66                   	data16
  37:	66                   	data16
  38:	2e                   	cs
  39:	0f                   	.byte 0xf
  3a:	1f                   	(bad)
  3b:	84 00                	test   %al,(%rax)
  3d:	00 00                	add    %al,(%rax)