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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:304 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xc3/0xe0 fs/buffer.c:161
Write of size 4 at addr ffffc90004f2f720 by task kworker/u8:0/12

CPU: 0 UID: 0 PID: 12 Comm: kworker/u8:0 Not tainted 6.15.0-rc4-syzkaller-00011-gf15d97df5afa #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Workqueue: bat_events batadv_nc_worker
Call Trace:
 <IRQ>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xb4/0x290 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+0x29a/0x2b0 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+0xba/0x120 fs/buffer.c:2783
 blk_update_request+0x5ee/0xe80 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+0x107/0x160 block/blk-mq.c:1225
 handle_softirqs+0x283/0x870 kernel/softirq.c:579
 do_softirq+0xec/0x180 kernel/softirq.c:480
 </IRQ>
 <TASK>
 __local_bh_enable_ip+0x17d/0x1c0 kernel/softirq.c:407
 spin_unlock_bh include/linux/spinlock.h:396 [inline]
 batadv_nc_purge_paths+0x318/0x3b0 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+0xadb/0x17a0 kernel/workqueue.c:3319
 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400
 kthread+0x70e/0x8a0 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
 [ffffc90004f28000, ffffc90004f31000) created by:
 copy_process+0x544/0x3b80 kernel/fork.c:2259

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x1ab pfn:0x2ec85
flags: 0xfff00000000000(node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 00000000000001ab 0000000000000000 00000001ffffffff 0000000000000000
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 8507, tgid 8507 (syz.4.1203), ts 348509195200, free_ts 348508058191
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_frozen_pages_noprof mm/mempolicy.c:2372 [inline]
 alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2392
 vm_area_alloc_pages mm/vmalloc.c:3591 [inline]
 __vmalloc_area_node mm/vmalloc.c:3669 [inline]
 __vmalloc_node_range_noprof+0x8fe/0x12c0 mm/vmalloc.c:3844
 __vmalloc_node_noprof+0x7d/0x90 mm/vmalloc.c:3907
 alloc_thread_stack_node kernel/fork.c:314 [inline]
 dup_task_struct+0x3e7/0x860 kernel/fork.c:1136
 copy_process+0x544/0x3b80 kernel/fork.c:2259
 kernel_clone+0x224/0x7f0 kernel/fork.c:2844
 __do_sys_clone3 kernel/fork.c:3148 [inline]
 __se_sys_clone3+0x256/0x2d0 kernel/fork.c:3127
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 7896 tgid 7896 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 free_unref_folios+0xb70/0x1490 mm/page_alloc.c:2782
 folios_put_refs+0x559/0x640 mm/swap.c:992
 folio_batch_release include/linux/pagevec.h:101 [inline]
 truncate_inode_pages_range+0x346/0xda0 mm/truncate.c:379
 kill_bdev block/bdev.c:91 [inline]
 blkdev_flush_mapping+0x108/0x270 block/bdev.c:712
 blkdev_put_whole block/bdev.c:719 [inline]
 bdev_release+0x417/0x650 block/bdev.c:1144
 blkdev_release+0x15/0x20 block/fops.c:660
 __fput+0x449/0xa70 fs/file_table.c:465
 fput_close_sync+0x119/0x200 fs/file_table.c:570
 __do_sys_close fs/open.c:1581 [inline]
 __se_sys_close fs/open.c:1566 [inline]
 __x64_sys_close+0x7f/0x110 fs/open.c:1566
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffffc90004f2f600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004f2f680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffffc90004f2f700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                  ^
 ffffc90004f2f780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffffc90004f2f800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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