==================================================================
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 ffff88802adb2418 by task syz.2.3379/23269

CPU: 0 UID: 0 PID: 23269 Comm: syz.2.3379 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:568
 kasan_check_byte include/linux/kasan.h:399 [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+0x31b/0x400 drivers/virtio/virtio_ring.c:2694
 __handle_irq_event_percpu+0x22c/0x7d0 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+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+0xcd/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:__sanitizer_cov_trace_pc+0x0/0x70 kernel/kcov.c:210
Code: 36 e1 54 00 48 89 df 5b e9 1d 68 5a 00 be 03 00 00 00 5b e9 92 15 26 03 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 <f3> 0f 1e fa 48 8b 34 24 65 48 8b 15 e8 55 1b 12 65 8b 05 f9 55 1b
RSP: 0018:ffffc90002f5f9b8 EFLAGS: 00000246
RAX: 000000008004a204 RBX: 0000000080000002 RCX: ffffc9000c803000
RDX: 0000000000080000 RSI: ffffffff8960b5ee RDI: 0000000000000005
RBP: ffffc90002f5fd58 R08: 0000000000000005 R09: 0000000000000000
R10: 0000000080000002 R11: 0000000000000000 R12: ffff88805407bc00
R13: 000000008004a200 R14: ffffc90002f5fd58 R15: 0000000080000002
 ____sys_recvmsg+0xab/0x6b0 net/socket.c:2816
 ___sys_recvmsg+0x114/0x1a0 net/socket.c:2876
 do_recvmmsg+0x55d/0x750 net/socket.c:2963
 __sys_recvmmsg+0x21c/0x280 net/socket.c:3045
 __do_compat_sys_recvmmsg_time32 net/compat.c:418 [inline]
 __se_compat_sys_recvmmsg_time32 net/compat.c:414 [inline]
 __ia32_compat_sys_recvmmsg_time32+0xc4/0x160 net/compat.c:414
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
RIP: 0023:0xf709e579
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:00000000f546d55c EFLAGS: 00000296 ORIG_RAX: 0000000000000151
RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 0000000080000040
RDX: 00000000080002c1 RSI: 0000000000000002 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000296 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 23270:
 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:388 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:405
 kmalloc_noprof include/linux/slab.h:905 [inline]
 p9_client_create+0xc7/0x11c0 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:666
 vfs_get_tree+0x8e/0x340 fs/super.c:1815
 do_new_mount fs/namespace.c:3808 [inline]
 path_mount+0x1513/0x2000 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount fs/namespace.c:4324 [inline]
 __ia32_sys_mount+0x28b/0x310 fs/namespace.c:4324
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

Freed by task 23270:
 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:576
 poison_slab_object mm/kasan/common.c:243 [inline]
 __kasan_slab_free+0x60/0x70 mm/kasan/common.c:275
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2422 [inline]
 slab_free mm/slub.c:4695 [inline]
 kfree+0x2b4/0x4d0 mm/slub.c:4894
 p9_client_create+0xa28/0x11c0 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:666
 vfs_get_tree+0x8e/0x340 fs/super.c:1815
 do_new_mount fs/namespace.c:3808 [inline]
 path_mount+0x1513/0x2000 fs/namespace.c:4123
 do_mount fs/namespace.c:4136 [inline]
 __do_sys_mount fs/namespace.c:4347 [inline]
 __se_sys_mount fs/namespace.c:4324 [inline]
 __ia32_sys_mount+0x28b/0x310 fs/namespace.c:4324
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e

The buggy address belongs to the object at ffff88802adb2400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802adb2400, ffff88802adb2600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2adb0
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: f5(slab)
raw: 00fff00000000040 ffff88801b842c80 0000000000000000 dead000000000001
raw: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b842c80 0000000000000000 dead000000000001
head: 0000000000000000 0000000080100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000ab6c01 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 9360, tgid 9357 (syz.1.602), ts 199384344112, free_ts 190525924855
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1c0/0x230 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x132b/0x38e0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x261/0x23f0 mm/page_alloc.c:5148
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2416
 alloc_slab_page mm/slub.c:2492 [inline]
 allocate_slab mm/slub.c:2660 [inline]
 new_slab+0x247/0x330 mm/slub.c:2714
 ___slab_alloc+0xcf2/0x1750 mm/slub.c:3901
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3992
 __slab_alloc_node mm/slub.c:4067 [inline]
 slab_alloc_node mm/slub.c:4228 [inline]
 __do_kmalloc_node mm/slub.c:4375 [inline]
 __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4388
 kmalloc_noprof include/linux/slab.h:909 [inline]
 io_cache_alloc_new+0x45/0xf0 io_uring/alloc_cache.c:40
 io_cache_alloc io_uring/alloc_cache.h:59 [inline]
 io_uring_alloc_async_data io_uring/io_uring.h:246 [inline]
 io_msg_alloc_async+0x1c3/0x3a0 io_uring/net.c:192
 io_sendmsg_prep+0x37d/0x550 io_uring/net.c:443
 io_init_req io_uring/io_uring.c:2197 [inline]
 io_submit_sqe io_uring/io_uring.c:2244 [inline]
 io_submit_sqes+0x853/0x25c0 io_uring/io_uring.c:2396
 __do_sys_io_uring_enter+0xd6a/0x1630 io_uring/io_uring.c:3463
 do_syscall_32_irqs_on arch/x86/entry/syscall_32.c:83 [inline]
 __do_fast_syscall_32+0x7c/0x300 arch/x86/entry/syscall_32.c:306
 do_fast_syscall_32+0x32/0x80 arch/x86/entry/syscall_32.c:331
 entry_SYSENTER_compat_after_hwframe+0x84/0x8e
page last free pid 9207 tgid 9199 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0x7d5/0x10f0 mm/page_alloc.c:2895
 discard_slab mm/slub.c:2758 [inline]
 __put_partials+0x165/0x1c0 mm/slub.c:3223
 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:340
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4191 [inline]
 slab_alloc_node mm/slub.c:4240 [inline]
 kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4292
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:659
 alloc_skb_fclone include/linux/skbuff.h:1386 [inline]
 tipc_buf_acquire+0x26/0xe0 net/tipc/msg.c:72
 tipc_msg_build+0x59c/0x1150 net/tipc/msg.c:422
 tipc_sendmcast+0x79a/0xba0 net/tipc/socket.c:879
 __tipc_sendmsg+0x1360/0x19a0 net/tipc/socket.c:1465
 tipc_sendmsg+0x4f/0x70 net/tipc/socket.c:1399
 sock_sendmsg_nosec net/socket.c:714 [inline]
 __sock_sendmsg net/socket.c:729 [inline]
 sock_sendmsg+0x3c9/0x470 net/socket.c:752
 splice_to_socket+0xaf6/0x1110 fs/splice.c:886
 do_splice_from fs/splice.c:938 [inline]
 direct_splice_actor+0x192/0x6c0 fs/splice.c:1161
 splice_direct_to_actor+0x342/0xa30 fs/splice.c:1105

Memory state around the buggy address:
 ffff88802adb2300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802adb2380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802adb2400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802adb2480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802adb2500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	36 e1 54             	ss loope 0x57
   3:	00 48 89             	add    %cl,-0x77(%rax)
   6:	df 5b e9             	fistps -0x17(%rbx)
   9:	1d 68 5a 00 be       	sbb    $0xbe005a68,%eax
   e:	03 00                	add    (%rax),%eax
  10:	00 00                	add    %al,(%rax)
  12:	5b                   	pop    %rbx
  13:	e9 92 15 26 03       	jmp    0x32615aa
  18:	66 90                	xchg   %ax,%ax
  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:	90                   	nop
  23:	90                   	nop
  24:	90                   	nop
  25:	90                   	nop
  26:	90                   	nop
  27:	90                   	nop
  28:	90                   	nop
  29:	90                   	nop
* 2a:	f3 0f 1e fa          	endbr64 <-- trapping instruction
  2e:	48 8b 34 24          	mov    (%rsp),%rsi
  32:	65 48 8b 15 e8 55 1b 	mov    %gs:0x121b55e8(%rip),%rdx        # 0x121b5622
  39:	12
  3a:	65                   	gs
  3b:	8b                   	.byte 0x8b
  3c:	05                   	.byte 0x5
  3d:	f9                   	stc
  3e:	55                   	push   %rbp
  3f:	1b                   	.byte 0x1b