==================================================================
BUG: KASAN: stack-out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:96 [inline]
BUG: KASAN: stack-out-of-bounds in atomic_dec include/linux/atomic/atomic-instrumented.h:592 [inline]
BUG: KASAN: stack-out-of-bounds in put_bh include/linux/buffer_head.h:302 [inline]
BUG: KASAN: stack-out-of-bounds in end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
Write of size 4 at addr ffffc90005007620 by task ksoftirqd/1/30

CPU: 1 UID: 0 PID: 30 Comm: ksoftirqd/1 Tainted: G        W           6.16.0-syzkaller-11322-g352af6a011d5 #0 PREEMPT_{RT,(full)} 
Tainted: [W]=WARN
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 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:302 [inline]
 end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
 end_bio_bh_io_sync+0xba/0x120 fs/buffer.c:2776
 blk_update_request+0x57e/0xe60 block/blk-mq.c:989
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1151
 blk_complete_reqs block/blk-mq.c:1226 [inline]
 blk_done_softirq+0x107/0x160 block/blk-mq.c:1231
 handle_softirqs+0x22c/0x710 kernel/softirq.c:579
 run_ksoftirqd+0xac/0x210 kernel/softirq.c:968
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
 kthread+0x70e/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 a 8-page vmalloc region starting at 0xffffc90005000000 allocated at copy_process+0x545/0x3ae0 kernel/fork.c:2002
The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88804fa34000 pfn:0x4fa34
memcg:ffff888032eb1682
flags: 0x80000000000000(node=0|zone=1)
raw: 0080000000000000 0000000000000000 dead000000000122 0000000000000000
raw: ffff88804fa34000 0000000000000000 00000001ffffffff ffff888032eb1682
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 2, tgid 2 (kthreadd), ts 543733466091, free_ts 543665434225
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x240/0x2a0 mm/page_alloc.c:1851
 prep_new_page mm/page_alloc.c:1859 [inline]
 get_page_from_freelist+0x2119/0x21b0 mm/page_alloc.c:3858
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5148
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0xcf/0x1e0 mm/mempolicy.c:2507
 vm_area_alloc_pages mm/vmalloc.c:3642 [inline]
 __vmalloc_area_node mm/vmalloc.c:3720 [inline]
 __vmalloc_node_range_noprof+0x97d/0x12f0 mm/vmalloc.c:3893
 __vmalloc_node_noprof+0xc2/0x110 mm/vmalloc.c:3956
 alloc_thread_stack_node kernel/fork.c:318 [inline]
 dup_task_struct+0x3e7/0x860 kernel/fork.c:879
 copy_process+0x545/0x3ae0 kernel/fork.c:2002
 kernel_clone+0x224/0x7c0 kernel/fork.c:2603
 kernel_thread+0x10c/0x160 kernel/fork.c:2665
 create_kthread kernel/kthread.c:487 [inline]
 kthreadd+0x575/0x770 kernel/kthread.c:847
 ret_from_fork+0x3fc/0x770 arch/x86/kernel/process.c:148
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 20 tgid 20 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 __free_frozen_pages+0xb59/0xce0 mm/page_alloc.c:2895
 pagetable_free include/linux/mm.h:2896 [inline]
 pagetable_dtor_free include/linux/mm.h:2994 [inline]
 __tlb_remove_table+0x2d2/0x3b0 include/asm-generic/tlb.h:220
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x85/0x100 mm/mmu_gather.c:290
 rcu_do_batch kernel/rcu/tree.c:2605 [inline]
 rcu_core kernel/rcu/tree.c:2861 [inline]
 rcu_cpu_kthread+0xbf3/0x1b50 kernel/rcu/tree.c:2949
 smpboot_thread_fn+0x53f/0xa60 kernel/smpboot.c:160
 kthread+0x70e/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

Memory state around the buggy address:
 ffffc90005007500: 04 f2 00 00 00 f2 f2 f2 f2 f2 00 f2 f2 f2 00 00
 ffffc90005007580: f3 f3 f3 f3 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90005007600: 00 00 00 00 f1 f1 f1 f1 00 f3 f3 f3 00 00 00 00
                               ^
 ffffc90005007680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90005007700: f1 f1 f1 f1 00 f3 f3 f3 00 00 00 00 00 00 00 00
==================================================================