==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007
Read of size 8 at addr ffff88802a8ac818 by task kswapd0/112

CPU: 0 UID: 0 PID: 112 Comm: kswapd0 Not tainted 6.11.0-rc6-syzkaller-00075-gad618736883b #0
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:93 [inline]
 dump_stack_lvl+0x116/0x1f0 lib/dump_stack.c:119
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0xc3/0x620 mm/kasan/report.c:488
 kasan_report+0xd9/0x110 mm/kasan/report.c:601
 __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007
 lock_acquire kernel/locking/lockdep.c:5759 [inline]
 lock_acquire+0x1b1/0x560 kernel/locking/lockdep.c:5724
 __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+0x1e7/0x2f0 net/9p/trans_virtio.c:147
 vring_interrupt drivers/virtio/virtio_ring.c:2595 [inline]
 vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2570
 __handle_irq_event_percpu+0x229/0x7c0 kernel/irq/handle.c:158
 handle_irq_event_percpu kernel/irq/handle.c:193 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:210
 handle_edge_irq+0x263/0xd10 kernel/irq/chip.c:831
 generic_handle_irq_desc include/linux/irqdesc.h:173 [inline]
 handle_irq arch/x86/kernel/irq.c:247 [inline]
 call_irq_handler arch/x86/kernel/irq.c:259 [inline]
 __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:285
 common_interrupt+0xab/0xd0 arch/x86/kernel/irq.c:278
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:26 [inline]
RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:87 [inline]
RIP: 0010:arch_local_irq_save arch/x86/include/asm/irqflags.h:123 [inline]
RIP: 0010:lock_acquire kernel/locking/lockdep.c:5755 [inline]
RIP: 0010:lock_acquire+0x160/0x560 kernel/locking/lockdep.c:5724
Code: 0c 01 48 89 f8 83 e0 07 83 c0 03 38 c8 7c 08 84 c9 0f 85 b3 03 00 00 8b 92 dc 0a 00 00 85 d2 0f 85 d6 00 00 00 9c 8f 44 24 08 <48> 8b 6c 24 08 fa 48 c7 c7 20 d3 4c 8b e8 0e e5 9e 09 48 89 e8 45
RSP: 0018:ffffc90000e1f6c8 EFLAGS: 00000246
RAX: 0000000000000007 RBX: 1ffff920001c3edb RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff8bb07de0 RDI: ffff888020c38adc
RBP: 0000000000000000 R08: 0000000000000000 R09: fffffbfff2023bcb
R10: ffffffff9011de5f R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8ddb94a0 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 shrink_slab+0x37f/0x12c0 mm/shrinker.c:667
 shrink_one+0x47e/0x7b0 mm/vmscan.c:4795
 shrink_many mm/vmscan.c:4856 [inline]
 lru_gen_shrink_node mm/vmscan.c:4934 [inline]
 shrink_node+0x2452/0x39d0 mm/vmscan.c:5914
 kswapd_shrink_node mm/vmscan.c:6742 [inline]
 balance_pgdat+0xc19/0x18f0 mm/vmscan.c:6934
 kswapd+0x5ea/0xbf0 mm/vmscan.c:7203
 kthread+0x2c1/0x3a0 kernel/kthread.c:389
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244
 </TASK>

Allocated by task 6877:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 poison_kmalloc_redzone mm/kasan/common.c:370 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:387
 kmalloc_noprof include/linux/slab.h:681 [inline]
 p9_client_create+0xcf/0x11b0 net/9p/client.c:983
 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8f/0x380 fs/super.c:1800
 do_new_mount fs/namespace.c:3472 [inline]
 path_mount+0x6e1/0x1f10 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount fs/namespace.c:3997 [inline]
 __ia32_sys_mount+0x292/0x310 fs/namespace.c:3997
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 6877:
 kasan_save_stack+0x33/0x60 mm/kasan/common.c:47
 kasan_save_track+0x14/0x30 mm/kasan/common.c:68
 kasan_save_free_info+0x3b/0x60 mm/kasan/generic.c:579
 poison_slab_object+0xf7/0x160 mm/kasan/common.c:240
 __kasan_slab_free+0x32/0x50 mm/kasan/common.c:256
 kasan_slab_free include/linux/kasan.h:184 [inline]
 slab_free_hook mm/slub.c:2256 [inline]
 slab_free mm/slub.c:4477 [inline]
 kfree+0x12a/0x3b0 mm/slub.c:4598
 p9_client_create+0x9ca/0x11b0 net/9p/client.c:1054
 v9fs_session_init+0x1f8/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc6/0xa50 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8f/0x380 fs/super.c:1800
 do_new_mount fs/namespace.c:3472 [inline]
 path_mount+0x6e1/0x1f10 fs/namespace.c:3799
 do_mount fs/namespace.c:3812 [inline]
 __do_sys_mount fs/namespace.c:4020 [inline]
 __se_sys_mount fs/namespace.c:3997 [inline]
 __ia32_sys_mount+0x292/0x310 fs/namespace.c:3997
 do_syscall_32_irqs_on arch/x86/entry/common.c:165 [inline]
 __do_fast_syscall_32+0x73/0x120 arch/x86/entry/common.c:386
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/common.c:411
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff88802a8ac800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802a8ac800, ffff88802a8aca00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2a8ac
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
head: 00fff00000000040 ffff88801ac42c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
head: 00fff00000000002 ffffea0000aa2b01 ffffffffffffffff 0000000000000000
head: 0000000000000004 0000000000000000 00000000ffffffff 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 0x252800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_THISNODE), pid 5367, tgid 5367 (syz-executor), ts 73105931481, free_ts 68458169649
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1500
 prep_new_page mm/page_alloc.c:1508 [inline]
 get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3446
 __alloc_pages_slowpath mm/page_alloc.c:4235 [inline]
 __alloc_pages_noprof+0x6ad/0x2460 mm/page_alloc.c:4715
 __alloc_pages_node_noprof include/linux/gfp.h:269 [inline]
 alloc_pages_node_noprof include/linux/gfp.h:296 [inline]
 alloc_slab_page+0x4e/0xf0 mm/slub.c:2325
 allocate_slab mm/slub.c:2488 [inline]
 new_slab+0x84/0x260 mm/slub.c:2541
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3727
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3817
 __slab_alloc_node mm/slub.c:3870 [inline]
 slab_alloc_node mm/slub.c:4029 [inline]
 __do_kmalloc_node mm/slub.c:4161 [inline]
 __kmalloc_node_noprof+0x367/0x440 mm/slub.c:4168
 kmalloc_array_node_noprof include/linux/slab.h:788 [inline]
 alloc_slab_obj_exts+0x41/0xa0 mm/slub.c:1976
 __memcg_slab_post_alloc_hook+0x2bc/0x9c0 mm/memcontrol.c:3019
 memcg_slab_post_alloc_hook mm/slub.c:2164 [inline]
 slab_post_alloc_hook mm/slub.c:4002 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 kmem_cache_alloc_noprof+0x2cd/0x2f0 mm/slub.c:4048
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 anon_vma_clone+0xe1/0x5e0 mm/rmap.c:288
 anon_vma_fork+0x7a/0x620 mm/rmap.c:351
 dup_mmap kernel/fork.c:712 [inline]
 dup_mm kernel/fork.c:1672 [inline]
 copy_mm+0x192b/0x2550 kernel/fork.c:1721
 copy_process+0x3ea8/0x6f50 kernel/fork.c:2374
 kernel_clone+0xfd/0x960 kernel/fork.c:2781
page last free pid 5357 tgid 5357 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1101 [inline]
 free_unref_page+0x64a/0xe40 mm/page_alloc.c:2619
 __put_partials+0x14c/0x170 mm/slub.c:3055
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/0x140 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x192/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:322
 kasan_slab_alloc include/linux/kasan.h:201 [inline]
 slab_post_alloc_hook mm/slub.c:3992 [inline]
 slab_alloc_node mm/slub.c:4041 [inline]
 __kmalloc_cache_noprof+0x11e/0x310 mm/slub.c:4188
 kmalloc_noprof include/linux/slab.h:681 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 nbp_vlan_init+0x164/0x500 net/bridge/br_vlan.c:1259
 br_add_if+0xfdf/0x1b80 net/bridge/br_if.c:676
 do_set_master+0x1bc/0x230 net/core/rtnetlink.c:2701
 do_setlink+0xa82/0x3ec0 net/core/rtnetlink.c:2907
 __rtnl_newlink+0xc3a/0x1920 net/core/rtnetlink.c:3696
 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3743
 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6647
 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2550
 netlink_unicast_kernel net/netlink/af_netlink.c:1331 [inline]
 netlink_unicast+0x53c/0x7f0 net/netlink/af_netlink.c:1357
 netlink_sendmsg+0x8b8/0xd70 net/netlink/af_netlink.c:1901

Memory state around the buggy address:
 ffff88802a8ac700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802a8ac780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802a8ac800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802a8ac880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802a8ac900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	0c 01                	or     $0x1,%al
   2:	48 89 f8             	mov    %rdi,%rax
   5:	83 e0 07             	and    $0x7,%eax
   8:	83 c0 03             	add    $0x3,%eax
   b:	38 c8                	cmp    %cl,%al
   d:	7c 08                	jl     0x17
   f:	84 c9                	test   %cl,%cl
  11:	0f 85 b3 03 00 00    	jne    0x3ca
  17:	8b 92 dc 0a 00 00    	mov    0xadc(%rdx),%edx
  1d:	85 d2                	test   %edx,%edx
  1f:	0f 85 d6 00 00 00    	jne    0xfb
  25:	9c                   	pushf
  26:	8f 44 24 08          	pop    0x8(%rsp)
* 2a:	48 8b 6c 24 08       	mov    0x8(%rsp),%rbp <-- trapping instruction
  2f:	fa                   	cli
  30:	48 c7 c7 20 d3 4c 8b 	mov    $0xffffffff8b4cd320,%rdi
  37:	e8 0e e5 9e 09       	call   0x99ee54a
  3c:	48 89 e8             	mov    %rbp,%rax
  3f:	45                   	rex.RB