==================================================================
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:302 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xe4/0x190 fs/buffer.c:161
Write of size 4 at addr ffff80009f1a7340 by task ksoftirqd/0/16

CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc4-syzkaller-g7678c1b2735a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:484 (C)
 __dump_stack lib/dump_stack.c:94 [inline]
 dump_stack_lvl+0xe4/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:377 [inline]
 print_report+0x198/0x538 mm/kasan/report.c:488
 kasan_report+0xd8/0x138 mm/kasan/report.c:601
 kasan_check_range+0x268/0x2a8 mm/kasan/generic.c:189
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 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+0xe4/0x190 fs/buffer.c:161
 end_bio_bh_io_sync+0xb0/0x184 fs/buffer.c:2771
 bio_endio+0x82c/0x868 block/bio.c:1708
 blk_update_request+0x4ac/0xda0 block/blk-mq.c:923
 blk_mq_end_request+0x54/0x88 block/blk-mq.c:1051
 lo_complete_rq+0x188/0x2f4 drivers/block/loop.c:386
 blk_complete_reqs block/blk-mq.c:1126 [inline]
 blk_done_softirq+0x11c/0x168 block/blk-mq.c:1131
 handle_softirqs+0x2e0/0xbf8 kernel/softirq.c:554
 run_ksoftirqd+0x70/0x158 kernel/softirq.c:927
 smpboot_thread_fn+0x4b0/0x90c kernel/smpboot.c:164
 kthread+0x288/0x310 kernel/kthread.c:389
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862

The buggy address belongs to the virtual mapping at
 [ffff80009f1a0000, ffff80009f1a9000) created by:
 copy_process+0x490/0x3250 kernel/fork.c:2203

The buggy address belongs to the physical page:
page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x1ce pfn:0x116596
memcg:ffff0000cc77ea82
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 00000000000001ce 0000000000000000 00000001ffffffff ffff0000cc77ea82
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff80009f1a7200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff80009f1a7280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff80009f1a7300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                              ^
 ffff80009f1a7380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff80009f1a7400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================