==================================================================
BUG: KASAN: slab-use-after-free in __lock_acquire+0x2de0/0x3cb0 kernel/locking/lockdep.c:5007
Read of size 8 at addr ffff888054db4818 by task syz-executor/5601

CPU: 0 UID: 0 PID: 5601 Comm: syz-executor Not tainted 6.11.0-rc6-syzkaller #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:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5727
Code: c1 05 9a 37 99 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24
RSP: 0018:ffffc900041f7560 EFLAGS: 00000206
RAX: dffffc0000000000 RBX: 1ffff9200083eeae RCX: 0000000000000001
RDX: 0000000000000001 RSI: ffffffff8b4cd2c0 RDI: ffffffff8bb07d60
RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff2d120e0
R10: ffffffff96890707 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: ffffffff8ddb93e0 R15: 0000000000000000
 rcu_lock_acquire include/linux/rcupdate.h:326 [inline]
 rcu_read_lock_sched include/linux/rcupdate.h:930 [inline]
 pfn_valid include/linux/mmzone.h:2022 [inline]
 page_table_check_set+0x11a/0x9d0 mm/page_table_check.c:110
 __page_table_check_ptes_set+0x2d0/0x3e0 mm/page_table_check.c:225
 page_table_check_ptes_set include/linux/page_table_check.h:74 [inline]
 set_ptes include/linux/pgtable.h:267 [inline]
 __copy_present_ptes mm/memory.c:967 [inline]
 copy_present_ptes mm/memory.c:1050 [inline]
 copy_pte_range mm/memory.c:1165 [inline]
 copy_pmd_range mm/memory.c:1252 [inline]
 copy_pud_range mm/memory.c:1289 [inline]
 copy_p4d_range mm/memory.c:1313 [inline]
 copy_page_range+0x1e16/0x57b0 mm/memory.c:1411
 dup_mmap kernel/fork.c:749 [inline]
 dup_mm kernel/fork.c:1672 [inline]
 copy_mm+0x1340/0x2550 kernel/fork.c:1721
 copy_process+0x3ea8/0x6f50 kernel/fork.c:2374
 kernel_clone+0xfd/0x960 kernel/fork.c:2781
 __do_compat_sys_ia32_clone+0xb7/0x100 arch/x86/kernel/sys_ia32.c:254
 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
RIP: 0023:0xf73ce579
Code: b8 01 10 06 03 74 b4 01 10 07 03 74 b0 01 10 08 03 74 d8 01 00 00 00 00 00 00 00 00 00 00 00 00 00 51 52 55 89 e5 0f 34 cd 80 <5d> 5a 59 c3 90 90 90 90 8d b4 26 00 00 00 00 8d b4 26 00 00 00 00
RSP: 002b:00000000ffdb37bc EFLAGS: 00000292 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000005785c4a8
RBP: 00000000f73c0ff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 7860:
 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 7860:
 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:2252 [inline]
 slab_free mm/slub.c:4473 [inline]
 kfree+0x12a/0x3b0 mm/slub.c:4594
 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 ffff888054db4800
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888054db4800, ffff888054db4a00)

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x54db4
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: 0xfdffffff(slab)
raw: 04fff00000000040 ffff88801ac42c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
head: 04fff00000000040 ffff88801ac42c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000080100010 00000001fdffffff 0000000000000000
head: 04fff00000000002 ffffea0001536d01 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 0x1d20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL), pid 5592, tgid 5592 (syz-executor), ts 85638190950, free_ts 84432025276
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x2d1/0x350 mm/page_alloc.c:1493
 prep_new_page mm/page_alloc.c:1501 [inline]
 get_page_from_freelist+0x1351/0x2e50 mm/page_alloc.c:3439
 __alloc_pages_noprof+0x22b/0x2460 mm/page_alloc.c:4695
 __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:2321
 allocate_slab mm/slub.c:2484 [inline]
 new_slab+0x84/0x260 mm/slub.c:2537
 ___slab_alloc+0xdac/0x1870 mm/slub.c:3723
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3813
 __slab_alloc_node mm/slub.c:3866 [inline]
 slab_alloc_node mm/slub.c:4025 [inline]
 __do_kmalloc_node mm/slub.c:4157 [inline]
 __kmalloc_noprof+0x379/0x410 mm/slub.c:4170
 kmalloc_noprof include/linux/slab.h:685 [inline]
 kzalloc_noprof include/linux/slab.h:807 [inline]
 fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x337/0x1aa0 net/ipv6/route.c:3761
 addrconf_f6i_alloc+0x393/0x670 net/ipv6/route.c:4588
 ipv6_add_addr+0x538/0x2060 net/ipv6/addrconf.c:1120
 inet6_addr_add+0x3bb/0xbc0 net/ipv6/addrconf.c:3060
 inet6_rtm_newaddr+0x11d4/0x1aa0 net/ipv6/addrconf.c:5048
 rtnetlink_rcv_msg+0x3c7/0xea0 net/core/rtnetlink.c:6647
 netlink_rcv_skb+0x165/0x410 net/netlink/af_netlink.c:2550
page last free pid 5592 tgid 5592 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1094 [inline]
 free_unref_page+0x64a/0xe40 mm/page_alloc.c:2612
 __put_partials+0x14c/0x170 mm/slub.c:3051
 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:3988 [inline]
 slab_alloc_node mm/slub.c:4037 [inline]
 kmem_cache_alloc_node_noprof+0x153/0x310 mm/slub.c:4080
 __alloc_skb+0x2b3/0x380 net/core/skbuff.c:664
 alloc_skb include/linux/skbuff.h:1320 [inline]
 nlmsg_new include/net/netlink.h:1015 [inline]
 netlink_ack+0x164/0xb20 net/netlink/af_netlink.c:2487
 netlink_rcv_skb+0x327/0x410 net/netlink/af_netlink.c:2556
 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
 sock_sendmsg_nosec net/socket.c:730 [inline]
 __sock_sendmsg net/socket.c:745 [inline]
 __sys_sendto+0x47f/0x4e0 net/socket.c:2204
 __do_compat_sys_socketcall+0x5e2/0x700 net/compat.c:475
 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

Memory state around the buggy address:
 ffff888054db4700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888054db4780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888054db4800: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888054db4880: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888054db4900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	c1 05 9a 37 99 7e 83 	roll   $0x83,0x7e99379a(%rip)        # 0x7e9937a1
   7:	f8                   	clc
   8:	01 0f                	add    %ecx,(%rdi)
   a:	85 ea                	test   %ebp,%edx
   c:	02 00                	add    (%rax),%al
   e:	00 9c 58 f6 c4 02 0f 	add    %bl,0xf02c4f6(%rax,%rbx,2)
  15:	85 d5                	test   %edx,%ebp
  17:	02 00                	add    (%rax),%al
  19:	00 48 85             	add    %cl,-0x7b(%rax)
  1c:	ed                   	in     (%dx),%eax
  1d:	74 01                	je     0x20
  1f:	fb                   	sti
  20:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
  27:	fc ff df
* 2a:	48 01 c3             	add    %rax,%rbx <-- trapping instruction
  2d:	48 c7 03 00 00 00 00 	movq   $0x0,(%rbx)
  34:	48 c7 43 08 00 00 00 	movq   $0x0,0x8(%rbx)
  3b:	00
  3c:	48                   	rex.W
  3d:	8b                   	.byte 0x8b
  3e:	84                   	.byte 0x84
  3f:	24                   	.byte 0x24