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BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x9c1/0x1e20 fs/ext4/xattr.c:1756
Read of size 18446744073709551600 at addr ffff88804c6d52b8 by task syz.0.0/5319

CPU: 0 UID: 0 PID: 5319 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~bpo12+1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x2b0/0x2c0 mm/kasan/generic.c:200
 __asan_memmove+0x29/0x70 mm/kasan/shadow.c:94
 ext4_xattr_set_entry+0x9c1/0x1e20 fs/ext4/xattr.c:1756
 ext4_xattr_ibody_set+0x254/0x6a0 fs/ext4/xattr.c:2268
 ext4_destroy_inline_data_nolock+0x214/0x5b0 fs/ext4/inline.c:463
 ext4_convert_inline_data_to_extent+0x540/0xdd0 fs/ext4/inline.c:613
 ext4_write_begin+0x382/0x19a0 fs/ext4/inode.c:1302
 generic_perform_write+0x2c5/0x900 mm/filemap.c:4254
 ext4_buffered_write_iter+0xce/0x3a0 fs/ext4/file.c:299
 ext4_file_write_iter+0x298/0x1bc0 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:593 [inline]
 vfs_write+0x5c9/0xb30 fs/read_write.c:686
 ksys_pwrite64 fs/read_write.c:793 [inline]
 __do_sys_pwrite64 fs/read_write.c:801 [inline]
 __se_sys_pwrite64 fs/read_write.c:798 [inline]
 __x64_sys_pwrite64+0x193/0x220 fs/read_write.c:798
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f53d178f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f53d2655038 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007f53d19e6090 RCX: 00007f53d178f749
RDX: 0000000000000001 RSI: 0000200000000140 RDI: 0000000000000006
RBP: 00007f53d1813f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008000c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f53d19e6128 R14: 00007f53d19e6090 R15: 00007ffc67772768
 </TASK>

The buggy address belongs to the physical page:
page: refcount:2 mapcount:0 mapping:ffff888032034d80 index:0x2 pfn:0x4c6d5
memcg:ffff888030a90d00
aops:def_blk_aops ino:700000 dentry name(?):""
flags: 0x4fff58000004234(referenced|dirty|lru|workingset|private|node=1|zone=1|lastcpupid=0x7ff)
raw: 04fff58000004234 ffffea000106fd48 ffffea00014cfec8 ffff888032034d80
raw: 0000000000000002 ffff8880518f9658 00000002ffffffff ffff888030a90d00
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 5318, tgid 5317 (syz.0.0), ts 77409764080, free_ts 77377668277
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1845
 prep_new_page mm/page_alloc.c:1853 [inline]
 get_page_from_freelist+0x2365/0x2440 mm/page_alloc.c:3879
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5178
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2416
 alloc_frozen_pages_noprof mm/mempolicy.c:2487 [inline]
 alloc_pages_noprof+0xa9/0x190 mm/mempolicy.c:2507
 folio_alloc_noprof+0x1e/0x30 mm/mempolicy.c:2517
 filemap_alloc_folio_noprof+0xdf/0x470 mm/filemap.c:1020
 __filemap_get_folio+0x3f2/0xaf0 mm/filemap.c:2012
 grow_dev_folio fs/buffer.c:1050 [inline]
 grow_buffers fs/buffer.c:1116 [inline]
 __getblk_slow fs/buffer.c:1134 [inline]
 bdev_getblk+0x1ad/0x660 fs/buffer.c:1461
 __getblk include/linux/buffer_head.h:380 [inline]
 sb_getblk include/linux/buffer_head.h:386 [inline]
 __ext4_get_inode_loc+0x561/0x1040 fs/ext4/inode.c:4837
 ext4_get_inode_loc fs/ext4/inode.c:4965 [inline]
 ext4_reserve_inode_write+0x18b/0x360 fs/ext4/inode.c:6302
 __ext4_mark_inode_dirty+0x15b/0x700 fs/ext4/inode.c:6480
 ext4_dirty_inode+0xd0/0x110 fs/ext4/inode.c:6517
 __mark_inode_dirty+0x2ec/0xe10 fs/fs-writeback.c:2566
 generic_update_time fs/inode.c:2117 [inline]
 inode_update_time fs/inode.c:2130 [inline]
 __file_update_time fs/inode.c:2357 [inline]
 file_modified_flags+0x4b0/0x560 fs/inode.c:2428
 ext4_write_checks+0x240/0x2c0 fs/ext4/file.c:279
page last free pid 5318 tgid 5317 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1394 [inline]
 free_unref_folios+0xdb3/0x14f0 mm/page_alloc.c:2958
 folios_put_refs+0x584/0x670 mm/swap.c:1002
 folio_batch_release include/linux/pagevec.h:101 [inline]
 mapping_try_invalidate+0x324/0x410 mm/truncate.c:579
 loop_set_status+0x26e/0xd60 drivers/block/loop.c:1248
 lo_ioctl+0x9ef/0x1c50 drivers/block/loop.c:-1
 blkdev_ioctl+0x5af/0x6d0 block/ioctl.c:705
 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+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88804c6d5180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804c6d5200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88804c6d5280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffff88804c6d5300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88804c6d5380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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