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BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x86c/0x164c fs/ext4/xattr.c:1767
Read of size 18446744073709551600 at addr ffff000100d496b8 by task syz.3.602/7609

CPU: 0 UID: 0 PID: 7609 Comm: syz.3.602 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/14/2026
Call trace:
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:499 (C)
 __dump_stack+0x30/0x40 lib/dump_stack.c:94
 dump_stack_lvl+0xd8/0x12c lib/dump_stack.c:120
 print_address_description+0xb0/0x238 mm/kasan/report.c:378
 print_report+0x68/0x84 mm/kasan/report.c:482
 kasan_report+0x8c/0xc4 mm/kasan/report.c:595
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x17c/0x1ac mm/kasan/generic.c:200
 __asan_memmove+0x3c/0x84 mm/kasan/shadow.c:94
 ext4_xattr_set_entry+0x86c/0x164c fs/ext4/xattr.c:1767
 ext4_xattr_ibody_set+0x20c/0x4b4 fs/ext4/xattr.c:2277
 ext4_destroy_inline_data_nolock+0x1c8/0x4a8 fs/ext4/inline.c:471
 ext4_convert_inline_data_to_extent+0x424/0xc34 fs/ext4/inline.c:630
 ext4_try_to_write_inline_data+0x68/0xa8 fs/ext4/inline.c:788
 ext4_write_begin+0x2f8/0x1370 fs/ext4/inode.c:1306
 generic_perform_write+0x23c/0x7a4 mm/filemap.c:4374
 ext4_buffered_write_iter+0xd8/0x2f4 fs/ext4/file.c:354
 ext4_file_write_iter+0x1f4/0x1478 fs/ext4/file.c:-1
 new_sync_write fs/read_write.c:595 [inline]
 vfs_write+0x51c/0xa0c fs/read_write.c:687
 ksys_write+0x12c/0x228 fs/read_write.c:739
 __do_sys_write fs/read_write.c:750 [inline]
 __se_sys_write fs/read_write.c:747 [inline]
 __arm64_sys_write+0x84/0x98 fs/read_write.c:747
 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline]
 invoke_syscall+0x98/0x244 arch/arm64/kernel/syscall.c:49
 el0_svc_common+0xec/0x23c arch/arm64/kernel/syscall.c:121
 do_el0_svc+0x4c/0x5c arch/arm64/kernel/syscall.c:140
 el0_svc+0x60/0x1d8 arch/arm64/kernel/entry-common.c:796
 el0t_64_sync_handler+0x44/0x104 arch/arm64/kernel/entry-common.c:815
 el0t_64_sync+0x198/0x19c arch/arm64/kernel/entry.S:606

The buggy address belongs to the physical page:
page: refcount:2 mapcount:0 mapping:000000003197d81f index:0xc pfn:0x140d49
memcg:ffff0000d8f87580
aops:def_blk_aops ino:700003 dentry name(?):""
flags: 0x5ffc00000004134(referenced|dirty|lru|active|private|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffc00000004134 fffffdffc40361c8 fffffdffc374b388 ffff0000c14936d0
raw: 000000000000000c ffff0000d0168b60 00000002ffffffff ffff0000d8f87580
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff000100d49580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000100d49600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff000100d49680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffff000100d49700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff000100d49780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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