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BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x1326/0x3860 fs/ext4/xattr.c:1729
Read of size 18446744073709551600 at addr ffff8881351422b8 by task kworker/u4:4/358

CPU: 1 PID: 358 Comm: kworker/u4:4 Tainted: G        W         syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Workqueue: writeback wb_workfn (flush-7:4)
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_destroy_inline_data+0x84/0xe0 fs/ext4/inline.c:1896
 ext4_writepages+0x766/0x2eb0 fs/ext4/inode.c:2779
 do_writepages+0x128/0x280 mm/page-writeback.c:2380
 __writeback_single_inode+0xd5/0xa20 fs/fs-writeback.c:1470
 writeback_sb_inodes+0x8ca/0x1480 fs/fs-writeback.c:1733
 wb_writeback+0x403/0xbe0 fs/fs-writeback.c:1908
 wb_do_writeback fs/fs-writeback.c:2053 [inline]
 wb_workfn+0x3ac/0xf30 fs/fs-writeback.c:2094
 process_one_work+0x6e1/0xba0 kernel/workqueue.c:2301
 worker_thread+0xa6a/0x13c0 kernel/workqueue.c:2447
 kthread+0x346/0x3d0 kernel/kthread.c:313
 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:298

The buggy address belongs to the page:
page:ffffea0004d45080 refcount:2 mapcount:0 mapping:ffff8881107039d0 index:0x2 pfn:0x135142
aops:def_blk_aops ino:0
flags: 0x400000000002203e(referenced|uptodate|dirty|lru|active|private|mappedtodisk)
raw: 400000000002203e ffffea000498d0c8 ffffea00045d7a08 ffff8881107039d0
raw: 0000000000000002 ffff88812ba597e0 00000002ffffffff ffff88810e8ba000
page dumped because: kasan: bad access detected
page->mem_cgroup:ffff88810e8ba000
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x108c48(GFP_NOFS|__GFP_NOFAIL|__GFP_HARDWALL|__GFP_MOVABLE), pid 989, ts 41809081694, free_ts 41808366925
 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]
 pagecache_get_page+0x63e/0x930 mm/filemap.c:1848
 find_or_create_page include/linux/pagemap.h:402 [inline]
 grow_dev_page fs/buffer.c:976 [inline]
 grow_buffers fs/buffer.c:1045 [inline]
 __getblk_slow fs/buffer.c:1072 [inline]
 __getblk_gfp+0x212/0x780 fs/buffer.c:1370
 sb_getblk include/linux/buffer_head.h:361 [inline]
 __ext4_get_inode_loc+0x467/0xc30 fs/ext4/inode.c:4449
 __ext4_get_inode_loc_noinmem fs/ext4/inode.c:4559 [inline]
 __ext4_iget+0x495/0x44c0 fs/ext4/inode.c:4809
 ext4_orphan_get+0x1e3/0x630 fs/ext4/ialloc.c:1395
 ext4_orphan_cleanup+0x663/0xd30 fs/ext4/super.c:3083
 ext4_fill_super+0x865f/0x8d70 fs/ext4/super.c:5074
 mount_bdev+0x28b/0x3a0 fs/super.c:1442
 ext4_mount+0x34/0x40 fs/ext4/super.c:6661
 legacy_get_tree+0xed/0x190 fs/fs_context.c:593
 vfs_get_tree+0x89/0x260 fs/super.c:1572
 do_new_mount+0x25a/0xa20 fs/namespace.c:3006
 path_mount+0x585/0xc90 fs/namespace.c:3336
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_list+0x129/0x9c0 mm/page_alloc.c:3443
 release_pages+0xe52/0xea0 mm/swap.c:1103
 __pagevec_release+0x71/0xe0 mm/swap.c:1123
 pagevec_release include/linux/pagevec.h:88 [inline]
 shmem_undo_range+0x74a/0x1810 mm/shmem.c:969
 shmem_truncate_range mm/shmem.c:1073 [inline]
 shmem_evict_inode+0x210/0xa00 mm/shmem.c:1173
 evict+0x4ae/0x930 fs/inode.c:612
 iput_final fs/inode.c:1736 [inline]
 iput+0x638/0x7c0 fs/inode.c:1762
 dentry_unlink_inode+0x2cf/0x380 fs/dcache.c:378
 __dentry_kill+0x44f/0x650 fs/dcache.c:583
 dentry_kill+0xc0/0x2a0 fs/dcache.c:-1
 dput+0x42/0x80 fs/dcache.c:883
 do_renameat2+0x7bd/0xe50 fs/namei.c:4631
 __do_sys_rename fs/namei.c:4678 [inline]
 __se_sys_rename fs/namei.c:4676 [inline]
 __x64_sys_rename+0x86/0x90 fs/namei.c:4676
 do_syscall_64+0x31/0x40 arch/x86/entry/common.c:46
 entry_SYSCALL_64_after_hwframe+0x61/0xcb

Memory state around the buggy address:
 ffff888135142180: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888135142200: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888135142280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                        ^
 ffff888135142300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888135142380: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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