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BUG: KASAN: out-of-bounds in instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
BUG: KASAN: out-of-bounds in atomic_dec include/linux/atomic/atomic-instrumented.h:257 [inline]
BUG: KASAN: out-of-bounds in put_bh include/linux/buffer_head.h:323 [inline]
BUG: KASAN: out-of-bounds in end_buffer_read_sync+0xe4/0x190 fs/buffer.c:161
Write of size 4 at addr ffff800020fd74e0 by task ksoftirqd/1/21

CPU: 1 PID: 21 Comm: ksoftirqd/1 Not tainted 6.3.0-rc7-syzkaller-00084-g14f8db1c0f9a #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/14/2023
Call trace:
 dump_backtrace+0x1b8/0x1e4 arch/arm64/kernel/stacktrace.c:233
 show_stack+0x2c/0x44 arch/arm64/kernel/stacktrace.c:240
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd0/0x124 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:319 [inline]
 print_report+0x174/0x514 mm/kasan/report.c:430
 kasan_report+0xd4/0x130 mm/kasan/report.c:536
 kasan_check_range+0x264/0x2a4 mm/kasan/generic.c:187
 __kasan_check_write+0x20/0x30 mm/kasan/shadow.c:37
 instrument_atomic_read_write include/linux/instrumented.h:102 [inline]
 atomic_dec include/linux/atomic/atomic-instrumented.h:257 [inline]
 put_bh include/linux/buffer_head.h:323 [inline]
 end_buffer_read_sync+0xe4/0x190 fs/buffer.c:161
 end_bio_bh_io_sync+0xb0/0x194 fs/buffer.c:2703
 bio_endio+0x740/0x784 block/bio.c:1607
 req_bio_endio block/blk-mq.c:795 [inline]
 blk_update_request+0x4e0/0x1074 block/blk-mq.c:927
 blk_mq_end_request+0x54/0x88 block/blk-mq.c:1054
 lo_complete_rq+0x140/0x258 drivers/block/loop.c:370
 blk_complete_reqs block/blk-mq.c:1132 [inline]
 blk_done_softirq+0x11c/0x168 block/blk-mq.c:1137
 __do_softirq+0x2d0/0xd54 kernel/softirq.c:571
 run_ksoftirqd+0x6c/0x148 kernel/softirq.c:934
 smpboot_thread_fn+0x4b0/0x920 kernel/smpboot.c:164
 kthread+0x250/0x2d8 kernel/kthread.c:376
 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:870

The buggy address belongs to the virtual mapping at
 [ffff800020fd0000, ffff800020fd9000) created by:
 copy_process+0x4b8/0x3808 kernel/fork.c:2098

The buggy address belongs to the physical page:
page:0000000077cb5dc0 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x12e716
memcg:ffff0000ca377202
flags: 0x5ffc00000000000(node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000000000 0000000000000000 dead000000000122 0000000000000000
raw: 0000000000000000 0000000000000000 00000001ffffffff ffff0000ca377202
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff800020fd7380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff800020fd7400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff800020fd7480: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                          ^
 ffff800020fd7500: 00 00 00 00 f1 f1 f1 f1 00 00 00 00 00 00 00 f2
 ffff800020fd7580: f2 f2 f2 f2 00 f3 f3 f3 00 00 00 00 00 00 00 00
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