==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x860/0x15a0 fs/ext4/xattr.c:1710
Read of size 18446744073709551600 at addr ffff0000d0cbaab8 by task syz.3.10/4437

CPU: 0 PID: 4437 Comm: syz.3.10 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call trace:
 dump_backtrace+0x1c0/0x1ec arch/arm64/kernel/stacktrace.c:158
 show_stack+0x2c/0x3c arch/arm64/kernel/stacktrace.c:165
 __dump_stack+0x30/0x40 lib/dump_stack.c:88
 dump_stack_lvl+0xf4/0x15c lib/dump_stack.c:106
 print_address_description+0x88/0x218 mm/kasan/report.c:316
 print_report+0x50/0x68 mm/kasan/report.c:420
 kasan_report+0xa8/0xfc mm/kasan/report.c:524
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x258/0x290 mm/kasan/generic.c:189
 memmove+0x48/0x90 mm/kasan/shadow.c:54
 ext4_xattr_set_entry+0x860/0x15a0 fs/ext4/xattr.c:1710
 ext4_xattr_ibody_set+0x204/0x5f8 fs/ext4/xattr.c:2217
 ext4_destroy_inline_data_nolock+0x1d8/0x4b4 fs/ext4/inline.c:468
 ext4_convert_inline_data_to_extent fs/ext4/inline.c:620 [inline]
 ext4_try_to_write_inline_data+0x5e4/0x11ac fs/ext4/inline.c:761
 ext4_write_begin+0x230/0x131c fs/ext4/inode.c:1206
 ext4_da_write_begin+0x348/0x990 fs/ext4/inode.c:3002
 generic_perform_write+0x234/0x4f4 mm/filemap.c:3862
 ext4_buffered_write_iter+0x2c4/0x528 fs/ext4/file.c:285
 ext4_file_write_iter+0x18c/0x1574 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2265 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x3ec/0x7f0 fs/read_write.c:584
 ksys_write+0x12c/0x224 fs/read_write.c:637
 __do_sys_write fs/read_write.c:649 [inline]
 __se_sys_write fs/read_write.c:646 [inline]
 __arm64_sys_write+0x7c/0x90 fs/read_write.c:646
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x138/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x58/0x130 arch/arm64/kernel/syscall.c:204
 el0_svc+0x58/0x128 arch/arm64/kernel/entry-common.c:637
 el0t_64_sync_handler+0x84/0xf0 arch/arm64/kernel/entry-common.c:655
 el0t_64_sync+0x18c/0x190 arch/arm64/kernel/entry.S:585

The buggy address belongs to the physical page:
page:00000000806e07d6 refcount:3 mapcount:1 mapping:000000007e4a7dc0 index:0x1 pfn:0x110cba
memcg:ffff0000c0940000
aops:def_blk_aops ino:700003
flags: 0x5ffd6000002205e(referenced|uptodate|dirty|lru|workingset|private|mappedtodisk|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffd6000002205e fffffc0003651648 fffffc0003404548 ffff0000c049eb18
raw: 0000000000000001 ffff0000e023a2b8 0000000300000000 ffff0000c0940000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d0cba980: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d0cbaa00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000d0cbaa80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffff0000d0cbab00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d0cbab80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs error (device loop3): ext4_ind_map_blocks:604: inode #15: comm syz.3.10: Can't allocate blocks for non-extent mapped inodes with bigalloc
syz.3.10: attempt to access beyond end of device
loop3: rw=145409, sector=2, nr_sectors = 2 limit=1
Buffer I/O error on dev loop3, logical block 1, lost sync page write
EXT4-fs (loop3): I/O error while writing superblock
EXT4-fs error (device loop3): ext4_check_bdev_write_error:218: comm syz.3.10: Error while async write back metadata
syz.3.10: attempt to access beyond end of device
loop3: rw=145409, sector=2, nr_sectors = 2 limit=1
Buffer I/O error on dev loop3, logical block 1, lost sync page write
EXT4-fs (loop3): I/O error while writing superblock