==================================================================
BUG: KASAN: out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: out-of-bounds in atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
BUG: KASAN: out-of-bounds in put_bh include/linux/buffer_head.h:304 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
Write of size 4 at addr ffffc9000c9cf700 by task ksoftirqd/1/23

CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Not tainted 6.16.0-rc1-syzkaller-00005-g488ef3560196 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xd2/0x2b0 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:189
 instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
 put_bh include/linux/buffer_head.h:304 [inline]
 end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
 end_bio_bh_io_sync+0xbd/0x120 fs/buffer.c:2783
 blk_update_request+0x5eb/0xe70 block/blk-mq.c:987
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1149
 blk_complete_reqs block/blk-mq.c:1224 [inline]
 blk_done_softirq+0x10a/0x160 block/blk-mq.c:1229
 handle_softirqs+0x286/0x870 kernel/softirq.c:579
 run_ksoftirqd+0x9b/0x100 kernel/softirq.c:968
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:164
 kthread+0x711/0x8a0 kernel/kthread.c:464
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the virtual mapping at
 [ffffc9000c9c8000, ffffc9000c9d1000) created by:
 copy_process+0x54b/0x3c00 kernel/fork.c:1999

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88805b9cb000 pfn:0x5b9cb
memcg:ffff888033223b82
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff88805b9cb000 0000000000000000 00000001ffffffff ffff888033223b82
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x2dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_ZERO|__GFP_NOWARN), pid 10103, tgid 10103 (syz.2.1180), ts 278798177629, free_ts 277868378791
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1704
 prep_new_page mm/page_alloc.c:1712 [inline]
 get_page_from_freelist+0x21e4/0x22c0 mm/page_alloc.c:3669
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4959
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2419
 alloc_frozen_pages_noprof mm/mempolicy.c:2490 [inline]
 alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2510
 vm_area_alloc_pages mm/vmalloc.c:3634 [inline]
 __vmalloc_area_node mm/vmalloc.c:3712 [inline]
 __vmalloc_node_range_noprof+0x97d/0x12f0 mm/vmalloc.c:3885
 __vmalloc_node_noprof+0xc2/0x110 mm/vmalloc.c:3948
 alloc_thread_stack_node kernel/fork.c:317 [inline]
 dup_task_struct+0x3e7/0x860 kernel/fork.c:877
 copy_process+0x54b/0x3c00 kernel/fork.c:1999
 kernel_clone+0x21e/0x870 kernel/fork.c:2599
 __do_sys_clone3 kernel/fork.c:2903 [inline]
 __se_sys_clone3+0x256/0x2d0 kernel/fork.c:2882
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 10083 tgid 10077 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1248 [inline]
 __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706
 tlb_batch_list_free mm/mmu_gather.c:159 [inline]
 tlb_finish_mmu+0x112/0x1d0 mm/mmu_gather.c:500
 exit_mmap+0x44c/0xb50 mm/mmap.c:1297
 __mmput+0x118/0x420 kernel/fork.c:1121
 exit_mm+0x1da/0x2c0 kernel/exit.c:581
 do_exit+0x640/0x22e0 kernel/exit.c:943
 do_group_exit+0x21c/0x2d0 kernel/exit.c:1104
 get_signal+0x1286/0x1340 kernel/signal.c:3034
 arch_do_signal_or_restart+0x9a/0x750 arch/x86/kernel/signal.c:337
 exit_to_user_mode_loop+0x75/0x110 kernel/entry/common.c:111
 exit_to_user_mode_prepare include/linux/entry-common.h:330 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:414 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:449 [inline]
 do_syscall_64+0x2bd/0x3b0 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffffc9000c9cf600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000c9cf680: 00 00 00 00 00 00 00 00 00 00 00 00 f1 f1 f1 f1
>ffffc9000c9cf700: 00 00 00 00 00 00 00 f2 f2 f2 f2 f2 00 f2 f2 f2
                      ^
 ffffc9000c9cf780: 01 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000c9cf800: 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3 00 00 00 00
==================================================================
vkms_vblank_simulate: vblank timer overrun