syzbot

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BUG: KASAN: use-after-free in ocfs2_duplicate_inline_data+0x3ae/0x570 fs/ocfs2/refcounttree.c:3946
Read of size 8483 at addr ffff88800bbc56c8 by task syz.0.0/5335

CPU: 0 UID: 0 PID: 5335 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x264/0x2c0 mm/kasan/generic.c:200
 __asan_memcpy+0x29/0x70 mm/kasan/shadow.c:105
 ocfs2_duplicate_inline_data+0x3ae/0x570 fs/ocfs2/refcounttree.c:3946
 ocfs2_reflink_remap_blocks+0xfcf/0x1a30 fs/ocfs2/refcounttree.c:4625
 ocfs2_remap_file_range+0x451/0x6f0 fs/ocfs2/file.c:2747
 vfs_copy_file_range+0xd80/0x1370 fs/read_write.c:1600
 __do_sys_copy_file_range fs/read_write.c:1683 [inline]
 __se_sys_copy_file_range+0x2fb/0x480 fs/read_write.c:1650
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7feeb9d9ce59
Code: ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 e8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007feebacb8fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000146
RAX: ffffffffffffffda RBX: 00007feeba016090 RCX: 00007feeb9d9ce59
RDX: 0000000000000005 RSI: 00002000000001c0 RDI: 0000000000000006
RBP: 00007feeb9e32d6f R08: ffffffffa003e45b R09: 0700000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007feeba016128 R14: 00007feeba016090 R15: 00007ffccb81aac8
 </TASK>

The buggy address belongs to the physical page:
page: refcount:2 mapcount:0 mapping:ffff88801cc25940 index:0x854 pfn:0xbbc5
memcg:ffff888036579480
aops:def_blk_aops ino:700000 dentry name(?):""
flags: 0xfff98000004224(referenced|lru|workingset|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff98000004224 ffff88801c6e5600 ffffea00004a7b48 ffff88801cc25940
raw: 0000000000000854 ffff888046e8c1d0 00000002ffffffff ffff888036579480
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_MOVABLE|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL), pid 5334, tgid 5333 (syz.0.0), ts 85585712597, free_ts 85544039740
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x24ba/0x2540 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
 alloc_pages_mpol+0x235/0x490 mm/mempolicy.c:2490
 alloc_frozen_pages_noprof mm/mempolicy.c:2561 [inline]
 alloc_pages_noprof+0xac/0x2a0 mm/mempolicy.c:2581
 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2591
 filemap_alloc_folio_noprof+0x111/0x470 mm/filemap.c:1014
 __filemap_get_folio_mpol+0x3fc/0xb00 mm/filemap.c:2012
 __filemap_get_folio include/linux/pagemap.h:763 [inline]
 grow_dev_folio fs/buffer.c:954 [inline]
 grow_buffers fs/buffer.c:1020 [inline]
 __getblk_slow fs/buffer.c:1038 [inline]
 bdev_getblk+0x1f6/0x6e0 fs/buffer.c:1358
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 ocfs2_read_blocks+0x56d/0x1530 fs/ocfs2/buffer_head_io.c:236
 ocfs2_read_inode_block_full fs/ocfs2/inode.c:1745 [inline]
 ocfs2_read_inode_block+0xec/0x1d0 fs/ocfs2/inode.c:1759
 ocfs2_assign_bh fs/ocfs2/dlmglue.c:2415 [inline]
 ocfs2_inode_lock_full_nested+0x2ac/0x1bd0 fs/ocfs2/dlmglue.c:2510
 ocfs2_reflink_inodes_lock+0x489/0xc20 fs/ocfs2/refcounttree.c:4743
 ocfs2_remap_file_range+0x236/0x6f0 fs/ocfs2/file.c:2721
 vfs_copy_file_range+0xd80/0x1370 fs/read_write.c:1600
 __do_sys_copy_file_range fs/read_write.c:1683 [inline]
 __se_sys_copy_file_range+0x2fb/0x480 fs/read_write.c:1650
page last free pid 5338 tgid 5333 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 free_unref_folios+0xcec/0x1480 mm/page_alloc.c:3004
 folios_put_refs+0x9ff/0xb40 mm/swap.c:1008
 folio_batch_release include/linux/folio_batch.h:101 [inline]
 mapping_try_invalidate+0x3c2/0x4c0 mm/truncate.c:579
 loop_set_status+0x29b/0xe40 drivers/block/loop.c:1246
 loop_set_status_old drivers/block/loop.c:1362 [inline]
 lo_ioctl+0xce6/0x1fb0 drivers/block/loop.c:1551
 blkdev_ioctl+0x5e3/0x740 block/ioctl.c:797
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88800bbc5f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88800bbc5f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88800bbc6000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff88800bbc6080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88800bbc6100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
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