==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x83c/0x15f4 fs/ext4/xattr.c:1710
Read of size 18446744073709551600 at addr ffff0000d4a762b8 by task syz.4.11/4475

CPU: 1 PID: 4475 Comm: syz.4.11 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/07/2026
Call trace:
 dump_backtrace+0x1c4/0x1f0 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+0x83c/0x15f4 fs/ext4/xattr.c:1710
 ext4_xattr_ibody_set+0x208/0x604 fs/ext4/xattr.c:2217
 ext4_destroy_inline_data_nolock+0x1c8/0x4a8 fs/ext4/inline.c:468
 ext4_convert_inline_data_to_extent fs/ext4/inline.c:628 [inline]
 ext4_try_to_write_inline_data+0x5d4/0x11a0 fs/ext4/inline.c:769
 ext4_write_begin+0x234/0x12d4 fs/ext4/inode.c:1206
 generic_perform_write+0x240/0x508 mm/filemap.c:3862
 ext4_buffered_write_iter+0x2c0/0x520 fs/ext4/file.c:285
 ext4_file_write_iter+0x188/0x1500 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+0x3c8/0x7c8 fs/read_write.c:584
 ksys_pwrite64 fs/read_write.c:699 [inline]
 __do_sys_pwrite64 fs/read_write.c:709 [inline]
 __se_sys_pwrite64 fs/read_write.c:706 [inline]
 __arm64_sys_pwrite64+0x178/0x210 fs/read_write.c:706
 __invoke_syscall arch/arm64/kernel/syscall.c:38 [inline]
 invoke_syscall+0x98/0x290 arch/arm64/kernel/syscall.c:52
 el0_svc_common+0x13c/0x258 arch/arm64/kernel/syscall.c:140
 do_el0_svc+0x5c/0x134 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:00000000f4f622fe refcount:3 mapcount:1 mapping:000000004002b741 index:0x2 pfn:0x114a76
memcg:ffff0000d0ce2000
aops:def_blk_aops ino:700004
flags: 0x5ffe6000002205e(referenced|uptodate|dirty|lru|workingset|private|mappedtodisk|node=0|zone=2|lastcpupid=0x7ff)
raw: 05ffe6000002205e fffffc00038865c8 fffffc0003529ac8 ffff0000c567eb18
raw: 0000000000000002 ffff0000e1859740 0000000300000000 ffff0000d0ce2000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff0000d4a76180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d4a76200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff0000d4a76280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffff0000d4a76300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff0000d4a76380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs error (device loop4): ext4_map_blocks:637: inode #2: block 13: comm syz.4.11: lblock 0 mapped to illegal pblock 13 (length 1)
EXT4-fs (loop4): Remounting filesystem read-only