==================================================================
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 ffff888073f7ac18 by task syz-executor/6127

CPU: 0 UID: 0 PID: 6127 Comm: syz-executor 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~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:573
 kasan_check_byte include/linux/kasan.h:401 [inline]
 lock_acquire kernel/locking/lockdep.c:5842 [inline]
 lock_acquire+0xfc/0x330 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: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+0x2cf/0x440 drivers/virtio/virtio_ring.c:2718
 __handle_irq_event_percpu+0x236/0x890 kernel/irq/handle.c:211
 handle_irq_event_percpu kernel/irq/handle.c:248 [inline]
 handle_irq_event+0xab/0x1e0 kernel/irq/handle.c:265
 handle_edge_irq+0x3ca/0x9e0 kernel/irq/chip.c:855
 generic_handle_irq_desc include/linux/irqdesc.h:172 [inline]
 handle_irq arch/x86/kernel/irq.c:255 [inline]
 call_irq_handler arch/x86/kernel/irq.c:311 [inline]
 __common_interrupt+0xd0/0x2f0 arch/x86/kernel/irq.c:326
 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:319
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:688
RIP: 0010:pte_none arch/x86/include/asm/pgtable.h:949 [inline]
RIP: 0010:copy_pte_range mm/memory.c:1275 [inline]
RIP: 0010:copy_pmd_range mm/memory.c:1392 [inline]
RIP: 0010:copy_pud_range mm/memory.c:1429 [inline]
RIP: 0010:copy_p4d_range mm/memory.c:1453 [inline]
RIP: 0010:copy_page_range+0x129a/0x6780 mm/memory.c:1535
Code: 89 b1 ff 48 8b 44 24 18 48 b9 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 08 00 0f 85 3f 47 00 00 48 8b 44 24 18 31 ff 48 8b 18 <48> 89 dd 48 83 e5 9f 48 89 ee e8 67 84 b1 ff 48 85 ed 0f 84 44 12
RSP: 0018:ffffc9000476f650 EFLAGS: 00000246
RAX: ffff888043ca1840 RBX: 8000000062cdd007 RCX: dffffc0000000000
RDX: ffff8880266b4980 RSI: ffffffff820ccef3 RDI: 0000000000000000
RBP: 0000000000001000 R08: 0000000000000005 R09: 000000000000001f
R10: 0000000000000008 R11: ffff8880266b54b0 R12: 0000000000000008
R13: 0000000000000001 R14: 00000000f6600000 R15: ffffea00018b3700
 dup_mmap+0xbea/0x20e0 mm/mmap.c:1827
 dup_mm kernel/fork.c:1529 [inline]
 copy_mm kernel/fork.c:1581 [inline]
 copy_process+0x3b9f/0x7430 kernel/fork.c:2221
 kernel_clone+0xfc/0x910 kernel/fork.c:2651
 __do_compat_sys_ia32_clone+0xcb/0x110 arch/x86/kernel/sys_ia32.c:254
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf7f37579
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:00000000fffc50bc EFLAGS: 00000292 ORIG_RAX: 0000000000000078
RAX: ffffffffffffffda RBX: 0000000001200011 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000578e54a8
RBP: 00000000f73c6ff4 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 31763:
 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:397 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:414
 kmalloc_noprof include/linux/slab.h:957 [inline]
 p9_client_create+0xae/0xe40 net/9p/client.c:862
 v9fs_session_init+0x40/0xd40 fs/9p/v9fs.c:442
 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
 vfs_get_tree+0x8e/0x330 fs/super.c:1751
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount fs/namespace.c:3712 [inline]
 path_mount+0x7bf/0x23a0 fs/namespace.c:4022
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount fs/namespace.c:4201 [inline]
 __ia32_sys_mount+0x291/0x310 fs/namespace.c:4201
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 31763:
 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:584
 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:2540 [inline]
 slab_free mm/slub.c:6668 [inline]
 kfree+0x2f8/0x6e0 mm/slub.c:6876
 p9_client_create+0x6c5/0xe40 net/9p/client.c:941
 v9fs_session_init+0x40/0xd40 fs/9p/v9fs.c:442
 v9fs_get_tree+0xb8/0xb50 fs/9p/vfs_super.c:97
 vfs_get_tree+0x8e/0x330 fs/super.c:1751
 fc_mount fs/namespace.c:1199 [inline]
 do_new_mount_fc fs/namespace.c:3636 [inline]
 do_new_mount fs/namespace.c:3712 [inline]
 path_mount+0x7bf/0x23a0 fs/namespace.c:4022
 do_mount fs/namespace.c:4035 [inline]
 __do_sys_mount fs/namespace.c:4224 [inline]
 __se_sys_mount fs/namespace.c:4201 [inline]
 __ia32_sys_mount+0x291/0x310 fs/namespace.c:4201
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff888073f7ac00
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff888073f7ac00, ffff888073f7ae00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x73f78
head: order:2 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
anon flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000040 ffff88801b442c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 04fff00000000040 ffff88801b442c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 04fff00000000002 ffffea0001cfde01 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 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 28630, tgid 28628 (syz.1.10935), ts 465334332586, free_ts 464597801084
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1af/0x220 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0xd0b/0x31a0 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x25f/0x2430 mm/page_alloc.c:5210
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab mm/slub.c:3248 [inline]
 new_slab+0x2c3/0x430 mm/slub.c:3302
 ___slab_alloc+0xe18/0x1c90 mm/slub.c:4656
 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 __kmalloc_cache_noprof+0x485/0x800 mm/slub.c:5771
 kmalloc_noprof include/linux/slab.h:957 [inline]
 kzalloc_noprof include/linux/slab.h:1094 [inline]
 device_private_init drivers/base/core.c:3534 [inline]
 device_add+0xcf2/0x1980 drivers/base/core.c:3585
 add_one_compat_dev+0x591/0x820 drivers/infiniband/core/device.c:1002
 add_compat_devs drivers/infiniband/core/device.c:1063 [inline]
 enable_device_and_get+0x336/0x3f0 drivers/infiniband/core/device.c:1374
 ib_register_device drivers/infiniband/core/device.c:1487 [inline]
 ib_register_device+0x8de/0xe70 drivers/infiniband/core/device.c:1433
 siw_device_register drivers/infiniband/sw/siw/siw_main.c:71 [inline]
 siw_newlink drivers/infiniband/sw/siw/siw_main.c:430 [inline]
 siw_newlink+0xb71/0xdc0 drivers/infiniband/sw/siw/siw_main.c:412
 nldev_newlink+0x3a6/0x680 drivers/infiniband/core/nldev.c:1797
 rdma_nl_rcv_msg+0x38a/0x6e0 drivers/infiniband/core/netlink.c:195
 rdma_nl_rcv_skb.constprop.0.isra.0+0x2d0/0x430 drivers/infiniband/core/netlink.c:239
page last free pid 6125 tgid 6125 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7df/0x1170 mm/page_alloc.c:2943
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4c/0xf0 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x195/0x1e0 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x69/0x90 mm/kasan/common.c:349
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x25e/0x770 mm/slub.c:5270
 ptlock_alloc+0x1f/0x70 mm/memory.c:7377
 ptlock_init include/linux/mm.h:3280 [inline]
 pagetable_pte_ctor include/linux/mm.h:3334 [inline]
 __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline]
 pte_alloc_one+0x84/0x3d0 arch/x86/mm/pgtable.c:18
 __pte_alloc+0x6d/0x3f0 mm/memory.c:453
 copy_pte_range mm/memory.c:1237 [inline]
 copy_pmd_range mm/memory.c:1392 [inline]
 copy_pud_range mm/memory.c:1429 [inline]
 copy_p4d_range mm/memory.c:1453 [inline]
 copy_page_range+0x3f3e/0x6780 mm/memory.c:1535
 dup_mmap+0xbea/0x20e0 mm/mmap.c:1827
 dup_mm kernel/fork.c:1529 [inline]
 copy_mm kernel/fork.c:1581 [inline]
 copy_process+0x3b9f/0x7430 kernel/fork.c:2221
 kernel_clone+0xfc/0x910 kernel/fork.c:2651
 __do_compat_sys_ia32_clone+0xcb/0x110 arch/x86/kernel/sys_ia32.c:254
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0xe8/0x680 arch/x86/entry/syscall_32.c:307
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:332
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Memory state around the buggy address:
 ffff888073f7ab00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888073f7ab80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff888073f7ac00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff888073f7ac80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888073f7ad00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	89 b1 ff 48 8b 44    	mov    %esi,0x448b48ff(%rcx)
   6:	24 18                	and    $0x18,%al
   8:	48 b9 00 00 00 00 00 	movabs $0xdffffc0000000000,%rcx
   f:	fc ff df
  12:	48 c1 e8 03          	shr    $0x3,%rax
  16:	80 3c 08 00          	cmpb   $0x0,(%rax,%rcx,1)
  1a:	0f 85 3f 47 00 00    	jne    0x475f
  20:	48 8b 44 24 18       	mov    0x18(%rsp),%rax
  25:	31 ff                	xor    %edi,%edi
  27:	48 8b 18             	mov    (%rax),%rbx
* 2a:	48 89 dd             	mov    %rbx,%rbp <-- trapping instruction
  2d:	48 83 e5 9f          	and    $0xffffffffffffff9f,%rbp
  31:	48 89 ee             	mov    %rbp,%rsi
  34:	e8 67 84 b1 ff       	call   0xffb184a0
  39:	48 85 ed             	test   %rbp,%rbp
  3c:	0f                   	.byte 0xf
  3d:	84                   	.byte 0x84
  3e:	44                   	rex.R
  3f:	12                   	.byte 0x12