==================================================================
BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x1326/0x3860 fs/ext4/xattr.c:1729
Read of size 18446744073709551600 at addr ffff8881165112b8 by task syz.9.315/1535

CPU: 0 PID: 1535 Comm: syz.9.315 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 __dump_stack+0x21/0x24 lib/dump_stack.c:77
 dump_stack_lvl+0x1a7/0x208 lib/dump_stack.c:118
 print_address_description+0x7f/0x2c0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:435 [inline]
 kasan_report+0xe2/0x130 mm/kasan/report.c:452
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x249/0x2a0 mm/kasan/generic.c:189
 memmove+0x2d/0x70 mm/kasan/shadow.c:54
 ext4_xattr_set_entry+0x1326/0x3860 fs/ext4/xattr.c:1729
 ext4_xattr_ibody_set+0x122/0x360 fs/ext4/xattr.c:2229
 ext4_destroy_inline_data_nolock+0x20f/0x5e0 fs/ext4/inline.c:464
 ext4_convert_inline_data_to_extent fs/ext4/inline.c:629 [inline]
 ext4_try_to_write_inline_data+0x6d0/0x11f0 fs/ext4/inline.c:769
 ext4_write_begin+0x246/0x1690 fs/ext4/inode.c:1192
 ext4_da_write_begin+0x478/0xf10 fs/ext4/inode.c:3033
 generic_perform_write+0x2ce/0x540 mm/filemap.c:3509
 ext4_buffered_write_iter+0x4b8/0x640 fs/ext4/file.c:271
 ext4_file_write_iter+0x53f/0x1980 fs/ext4/file.c:-1
 call_write_iter include/linux/fs.h:2066 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x758/0xdc0 fs/read_write.c:605
 ksys_pwrite64 fs/read_write.c:712 [inline]
 __do_sys_pwrite64 fs/read_write.c:722 [inline]
 __se_sys_pwrite64 fs/read_write.c:719 [inline]
 __x64_sys_pwrite64+0x197/0x220 fs/read_write.c:719
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
RIP: 0033:0x7fe536513799
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:00007fe534f6e028 EFLAGS: 00000246 ORIG_RAX: 0000000000000012
RAX: ffffffffffffffda RBX: 00007fe53678cfa0 RCX: 00007fe536513799
RDX: 0000000000000002 RSI: 0000200000000800 RDI: 0000000000000008
RBP: 00007fe5365a9c99 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000008080c61 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fe53678d038 R14: 00007fe53678cfa0 R15: 00007ffc403b5818

The buggy address belongs to the page:
page:ffffea0004594440 refcount:3 mapcount:1 mapping:ffff888110750290 index:0x2 pfn:0x116511
aops:def_blk_aops ino:0
flags: 0x400000000002203e(referenced|uptodate|dirty|lru|active|private|mappedtodisk)
raw: 400000000002203e ffffea0004d97ac8 ffff888127140030 ffff888110750290
raw: 0000000000000002 ffff88812b151f18 0000000300000000 ffff8881069aa000
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff8881069aa000
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x112cc0(GFP_USER|__GFP_NOWARN|__GFP_NORETRY), pid 1535, ts 74444142055, free_ts 74443755143
 set_page_owner include/linux/page_owner.h:35 [inline]
 post_alloc_hook mm/page_alloc.c:2456 [inline]
 prep_new_page+0x179/0x180 mm/page_alloc.c:2462
 get_page_from_freelist+0x223b/0x23d0 mm/page_alloc.c:4254
 __alloc_pages_nodemask+0x290/0x620 mm/page_alloc.c:5384
 __alloc_pages include/linux/gfp.h:544 [inline]
 __alloc_pages_node include/linux/gfp.h:557 [inline]
 alloc_pages_node include/linux/gfp.h:571 [inline]
 alloc_pages include/linux/gfp.h:590 [inline]
 __page_cache_alloc include/linux/pagemap.h:290 [inline]
 page_cache_ra_unbounded+0x2dc/0x7e0 mm/readahead.c:226
 do_page_cache_ra+0xf2/0x110 mm/readahead.c:277
 do_sync_mmap_readahead mm/filemap.c:2668 [inline]
 filemap_fault+0x1211/0x20d0 mm/filemap.c:2811
 __do_fault mm/memory.c:4064 [inline]
 do_read_fault mm/memory.c:4399 [inline]
 do_fault mm/memory.c:4527 [inline]
 handle_pte_fault+0x1fa5/0x3750 mm/memory.c:4791
 __handle_mm_fault mm/memory.c:4944 [inline]
 handle_mm_fault+0xf81/0x1710 mm/memory.c:5358
 faultin_page mm/gup.c:902 [inline]
 __get_user_pages+0xbf8/0x1400 mm/gup.c:1121
 populate_vma_page_range mm/gup.c:1454 [inline]
 __mm_populate+0x34f/0x440 mm/gup.c:1502
 mm_populate include/linux/mm.h:2793 [inline]
 vm_mmap_pgoff+0x254/0x370 mm/util.c:548
 ksys_mmap_pgoff+0x16f/0x1e0 mm/mmap.c:1712
 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:95 [inline]
 __se_sys_mmap arch/x86/kernel/sys_x86_64.c:86 [inline]
 __x64_sys_mmap+0xfa/0x110 arch/x86/kernel/sys_x86_64.c:86
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:28 [inline]
 free_pages_prepare mm/page_alloc.c:1349 [inline]
 free_pcp_prepare mm/page_alloc.c:1421 [inline]
 free_unref_page_prepare+0x2b7/0x2d0 mm/page_alloc.c:3336
 free_unref_page+0x7f/0x190 mm/page_alloc.c:3391
 __put_single_page mm/swap.c:104 [inline]
 __put_page+0xae/0xe0 mm/swap.c:135
 put_page include/linux/mm.h:1268 [inline]
 __skb_frag_unref include/linux/skbuff.h:3124 [inline]
 skb_release_data+0x21f/0x670 net/core/skbuff.c:620
 skb_release_all net/core/skbuff.c:680 [inline]
 __kfree_skb net/core/skbuff.c:694 [inline]
 kfree_skb+0xb9/0x2f0 net/core/skbuff.c:713
 llc_rcv+0x5de/0xb60 net/llc/llc_input.c:-1
 __netif_receive_skb_one_core net/core/dev.c:5415 [inline]
 __netif_receive_skb+0xc8/0x280 net/core/dev.c:5529
 netif_receive_skb_internal net/core/dev.c:5634 [inline]
 netif_receive_skb+0x9b/0x3f0 net/core/dev.c:5693
 tun_rx_batched+0x5f6/0x730 drivers/net/tun.c:-1
 tun_get_user+0x277a/0x3270 drivers/net/tun.c:2026
 tun_chr_write_iter+0x1bf/0x270 drivers/net/tun.c:2059
 call_write_iter include/linux/fs.h:2066 [inline]
 new_sync_write fs/read_write.c:518 [inline]
 vfs_write+0x758/0xdc0 fs/read_write.c:605
 ksys_write+0x149/0x250 fs/read_write.c:658
 __do_sys_write fs/read_write.c:670 [inline]
 __se_sys_write fs/read_write.c:667 [inline]
 __x64_sys_write+0x7b/0x90 fs/read_write.c:667
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff888116511180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888116511200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888116511280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffff888116511300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888116511380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================
EXT4-fs error (device loop9): ext4_read_block_bitmap_nowait:476: comm syz.9.315: Invalid block bitmap block 48142 in block_group 0