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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:301 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xc1/0xd0 fs/buffer.c:161
Write of size 4 at addr ffffc9000c96f660 by task ksoftirqd/1/23

CPU: 1 UID: 0 PID: 23 Comm: ksoftirqd/1 Not tainted 6.14.0-next-20250404-syzkaller #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0x16e/0x5b0 mm/kasan/report.c:521
 kasan_report+0x143/0x180 mm/kasan/report.c:634
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x28f/0x2a0 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:301 [inline]
 end_buffer_read_sync+0xc1/0xd0 fs/buffer.c:161
 end_bio_bh_io_sync+0xbf/0x120 fs/buffer.c:2748
 blk_update_request+0x5e5/0x1160 block/blk-mq.c:983
 blk_mq_end_request+0x3e/0x70 block/blk-mq.c:1145
 blk_complete_reqs block/blk-mq.c:1220 [inline]
 blk_done_softirq+0x100/0x150 block/blk-mq.c:1225
 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579
 run_ksoftirqd+0xcf/0x130 kernel/softirq.c:968
 smpboot_thread_fn+0x576/0xaa0 kernel/smpboot.c:164
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>

The buggy address belongs to the virtual mapping at
 [ffffc9000c968000, ffffc9000c971000) created by:
 copy_process+0x5dc/0x3d10 kernel/fork.c:2259

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x5 pfn:0x6df91
memcg:ffff888029473902
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000005 0000000000000000 00000001ffffffff ffff888029473902
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 6709, tgid 6709 (syz.3.332), ts 149941804509, free_ts 149806798993
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1f4/0x240 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x356d/0x3700 mm/page_alloc.c:3655
 __alloc_frozen_pages_noprof+0x211/0x5b0 mm/page_alloc.c:4937
 alloc_pages_mpol+0x339/0x690 mm/mempolicy.c:2302
 alloc_frozen_pages_noprof mm/mempolicy.c:2373 [inline]
 alloc_pages_noprof+0x121/0x190 mm/mempolicy.c:2393
 vm_area_alloc_pages mm/vmalloc.c:3591 [inline]
 __vmalloc_area_node mm/vmalloc.c:3669 [inline]
 __vmalloc_node_range_noprof+0x9cb/0x1390 mm/vmalloc.c:3844
 __vmalloc_node_noprof+0x80/0xa0 mm/vmalloc.c:3907
 alloc_thread_stack_node kernel/fork.c:314 [inline]
 dup_task_struct+0x3f7/0x870 kernel/fork.c:1136
 copy_process+0x5dc/0x3d10 kernel/fork.c:2259
 kernel_clone+0x242/0x930 kernel/fork.c:2844
 __do_sys_clone3 kernel/fork.c:3148 [inline]
 __se_sys_clone3+0x348/0x380 kernel/fork.c:3127
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf3/0x230 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 68 tgid 68 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0xde8/0x10a0 mm/page_alloc.c:2682
 pagetable_free include/linux/mm.h:3032 [inline]
 pagetable_dtor_free include/linux/mm.h:3130 [inline]
 __tlb_remove_table+0x36b/0x460 include/asm-generic/tlb.h:215
 __tlb_remove_table_free mm/mmu_gather.c:227 [inline]
 tlb_remove_table_rcu+0x79/0xf0 mm/mmu_gather.c:290
 rcu_do_batch kernel/rcu/tree.c:2568 [inline]
 rcu_core+0xaac/0x17a0 kernel/rcu/tree.c:2824
 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:579
 do_softirq+0x11f/0x1e0 kernel/softirq.c:480
 __local_bh_enable_ip+0x1be/0x200 kernel/softirq.c:407
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x312/0x3b0 net/batman-adv/network-coding.c:471
 batadv_nc_worker+0x328/0x610 net/batman-adv/network-coding.c:720
 process_one_work kernel/workqueue.c:3238 [inline]
 process_scheduled_works+0xac3/0x18e0 kernel/workqueue.c:3319
 worker_thread+0x870/0xd50 kernel/workqueue.c:3400
 kthread+0x7b7/0x940 kernel/kthread.c:464
 ret_from_fork+0x4b/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:
 ffffc9000c96f500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc9000c96f580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc9000c96f600: 00 00 00 00 00 00 00 00 f1 f1 f1 f1 00 00 00 00
                                                          ^
 ffffc9000c96f680: 00 00 00 f2 f2 f2 f2 f2 00 f2 f2 f2 01 f3 f3 f3
 ffffc9000c96f700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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