vkms_vblank_simulate: vblank timer overrun
==================================================================
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 ffff88802b130418 by task syz.0.34/6146

CPU: 3 UID: 0 PID: 6146 Comm: syz.0.34 Not tainted 6.15.0-rc1-syzkaller-00065-g3b07108ada81 #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:408 [inline]
 print_report+0xc3/0x670 mm/kasan/report.c:521
 kasan_report+0xe0/0x110 mm/kasan/report.c:634
 __kasan_check_byte+0x36/0x50 mm/kasan/common.c:557
 kasan_check_byte include/linux/kasan.h:399 [inline]
 lock_acquire kernel/locking/lockdep.c:5840 [inline]
 lock_acquire+0xfc/0x350 kernel/locking/lockdep.c:5823
 __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:2715 [inline]
 vring_interrupt+0x31b/0x400 drivers/virtio/virtio_ring.c:2690
 __handle_irq_event_percpu+0x229/0x7d0 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+0x263/0xd10 kernel/irq/chip.c:831
 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:266 [inline]
 __common_interrupt+0xdf/0x250 arch/x86/kernel/irq.c:292
 common_interrupt+0xba/0xe0 arch/x86/kernel/irq.c:285
 </IRQ>
 <TASK>
 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:693
RIP: 0010:memory_is_nonzero mm/kasan/generic.c:103 [inline]
RIP: 0010:memory_is_poisoned_n mm/kasan/generic.c:129 [inline]
RIP: 0010:memory_is_poisoned mm/kasan/generic.c:161 [inline]
RIP: 0010:check_region_inline mm/kasan/generic.c:180 [inline]
RIP: 0010:kasan_check_range+0x64/0x1a0 mm/kasan/generic.c:189
Code: 89 fd 48 b8 00 00 00 00 00 fc ff df 4d 89 d1 48 c1 ed 03 49 c1 e9 03 48 01 c5 49 01 c1 48 89 e8 49 8d 59 01 48 89 da 48 29 ea <48> 83 fa 10 0f 8e 8d 00 00 00 41 89 eb 41 83 e3 07 0f 85 9a 00 00
RSP: 0018:ffffc900032af0e8 EFLAGS: 00000202
RAX: fffff940002a9790 RBX: fffff940002a9791 RCX: ffffffff81fd17bc
RDX: 0000000000000001 RSI: 0000000000000008 RDI: ffffea000154bc80
RBP: fffff940002a9790 R08: 0000000000000000 R09: fffff940002a9790
R10: ffffea000154bc87 R11: 0000000000000000 R12: 0000000000001000
R13: ffff888036318808 R14: 0000000000001000 R15: ffff888036318858
 instrument_atomic_read include/linux/instrumented.h:68 [inline]
 _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline]
 folio_test_uptodate include/linux/page-flags.h:801 [inline]
 shmem_write_end+0xcc/0x4d0 mm/shmem.c:3313
 generic_perform_write+0x26e/0x930 mm/filemap.c:4123
 shmem_file_write_iter+0x10e/0x140 mm/shmem.c:3464
 __kernel_write_iter+0x317/0xa90 fs/read_write.c:617
 dump_emit_page fs/coredump.c:885 [inline]
 dump_user_range+0x418/0xb30 fs/coredump.c:959
 elf_core_dump+0x288a/0x3a90 fs/binfmt_elf.c:2128
 do_coredump+0x3183/0x4480 fs/coredump.c:759
 get_signal+0x22e3/0x26d0 kernel/signal.c:3019
 arch_do_signal_or_restart+0x8f/0x7d0 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop kernel/entry/common.c:111 [inline]
 exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline]
 irqentry_exit_to_user_mode+0x13f/0x280 kernel/entry/common.c:231
 asm_exc_general_protection+0x26/0x30 arch/x86/include/asm/idtentry.h:617
RIP: 00fb:0x0
Code: Unable to access opcode bytes at 0xffffffffffffffd6.
RSP: 002b:0000000000000000 EFLAGS: 00000202
RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000
RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 6181:
 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:377 [inline]
 __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:394
 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+0xc5/0xa30 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8b/0x340 fs/super.c:1759
 do_new_mount fs/namespace.c:3879 [inline]
 path_mount+0x14d4/0x1f30 fs/namespace.c:4206
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount fs/namespace.c:4407 [inline]
 __x64_sys_mount+0x28d/0x310 fs/namespace.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6181:
 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:247 [inline]
 __kasan_slab_free+0x51/0x70 mm/kasan/common.c:264
 kasan_slab_free include/linux/kasan.h:233 [inline]
 slab_free_hook mm/slub.c:2389 [inline]
 slab_free mm/slub.c:4646 [inline]
 kfree+0x2b6/0x4d0 mm/slub.c:4845
 p9_client_create+0xa28/0x11c0 net/9p/client.c:1064
 v9fs_session_init+0x1f7/0x1a80 fs/9p/v9fs.c:410
 v9fs_mount+0xc5/0xa30 fs/9p/vfs_super.c:122
 legacy_get_tree+0x109/0x220 fs/fs_context.c:662
 vfs_get_tree+0x8b/0x340 fs/super.c:1759
 do_new_mount fs/namespace.c:3879 [inline]
 path_mount+0x14d4/0x1f30 fs/namespace.c:4206
 do_mount fs/namespace.c:4219 [inline]
 __do_sys_mount fs/namespace.c:4430 [inline]
 __se_sys_mount fs/namespace.c:4407 [inline]
 __x64_sys_mount+0x28d/0x310 fs/namespace.c:4407
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xcd/0x260 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88802b130400
 which belongs to the cache kmalloc-512 of size 512
The buggy address is located 24 bytes inside of
 freed 512-byte region [ffff88802b130400, ffff88802b130600)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x2b130
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 ffff88801b442c80 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000040 ffff88801b442c80 dead000000000100 dead000000000122
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 00fff00000000002 ffffea0000ac4c01 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 5939, tgid 5939 (syz-executor), ts 70007830198, free_ts 69837464301
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x181/0x1b0 mm/page_alloc.c:1717
 prep_new_page mm/page_alloc.c:1725 [inline]
 get_page_from_freelist+0x1193/0x39b0 mm/page_alloc.c:3652
 __alloc_frozen_pages_noprof+0x263/0x23a0 mm/page_alloc.c:4934
 alloc_pages_mpol+0x1fb/0x550 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2459 [inline]
 allocate_slab mm/slub.c:2623 [inline]
 new_slab+0x23c/0x330 mm/slub.c:2676
 ___slab_alloc+0xd9c/0x1940 mm/slub.c:3862
 __slab_alloc.constprop.0+0x56/0xb0 mm/slub.c:3952
 __slab_alloc_node mm/slub.c:4027 [inline]
 slab_alloc_node mm/slub.c:4188 [inline]
 __do_kmalloc_node mm/slub.c:4330 [inline]
 __kmalloc_noprof+0x2f2/0x510 mm/slub.c:4343
 kmalloc_noprof include/linux/slab.h:909 [inline]
 kzalloc_noprof include/linux/slab.h:1039 [inline]
 fib6_info_alloc+0x40/0x160 net/ipv6/ip6_fib.c:155
 ip6_route_info_create+0x33f/0x18e0 net/ipv6/route.c:3801
 addrconf_f6i_alloc+0x391/0x670 net/ipv6/route.c:4630
 ipv6_add_addr+0x531/0x1fe0 net/ipv6/addrconf.c:1121
 inet6_addr_add+0x256/0x960 net/ipv6/addrconf.c:3049
 inet6_rtm_newaddr+0x1619/0x1c70 net/ipv6/addrconf.c:5059
 rtnetlink_rcv_msg+0x95b/0xe90 net/core/rtnetlink.c:6955
 netlink_rcv_skb+0x16a/0x440 net/netlink/af_netlink.c:2534
page last free pid 58 tgid 58 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0x69d/0xff0 mm/page_alloc.c:2680
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x4e/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:329
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4151 [inline]
 slab_alloc_node mm/slub.c:4200 [inline]
 kmem_cache_alloc_node_noprof+0x1d5/0x3b0 mm/slub.c:4252
 __alloc_skb+0x2b2/0x380 net/core/skbuff.c:658
 alloc_skb include/linux/skbuff.h:1340 [inline]
 mld_newpack.isra.0+0x18e/0xa20 net/ipv6/mcast.c:1788
 add_grhead+0x299/0x340 net/ipv6/mcast.c:1899
 add_grec+0x112a/0x1680 net/ipv6/mcast.c:2037
 mld_send_cr net/ipv6/mcast.c:2163 [inline]
 mld_ifc_work+0x41f/0xca0 net/ipv6/mcast.c:2702
 process_one_work+0x9cc/0x1b70 kernel/workqueue.c:3238
 process_scheduled_works kernel/workqueue.c:3319 [inline]
 worker_thread+0x6c8/0xf10 kernel/workqueue.c:3400
 kthread+0x3c2/0x780 kernel/kthread.c:464
 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88802b130300: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff88802b130380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
>ffff88802b130400: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                            ^
 ffff88802b130480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88802b130500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
==================================================================
----------------
Code disassembly (best guess):
   0:	89 fd                	mov    %edi,%ebp
   2:	48 b8 00 00 00 00 00 	movabs $0xdffffc0000000000,%rax
   9:	fc ff df
   c:	4d 89 d1             	mov    %r10,%r9
   f:	48 c1 ed 03          	shr    $0x3,%rbp
  13:	49 c1 e9 03          	shr    $0x3,%r9
  17:	48 01 c5             	add    %rax,%rbp
  1a:	49 01 c1             	add    %rax,%r9
  1d:	48 89 e8             	mov    %rbp,%rax
  20:	49 8d 59 01          	lea    0x1(%r9),%rbx
  24:	48 89 da             	mov    %rbx,%rdx
  27:	48 29 ea             	sub    %rbp,%rdx
* 2a:	48 83 fa 10          	cmp    $0x10,%rdx <-- trapping instruction
  2e:	0f 8e 8d 00 00 00    	jle    0xc1
  34:	41 89 eb             	mov    %ebp,%r11d
  37:	41 83 e3 07          	and    $0x7,%r11d
  3b:	0f                   	.byte 0xf
  3c:	85                   	.byte 0x85
  3d:	9a                   	(bad)