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BUG: KASAN: out-of-bounds in ext4_xattr_set_entry+0x1bf6/0x3ea0 fs/ext4/xattr.c:1715
Read of size 18446744073709550766 at addr ffff88805e0f27e0 by task syz.5.107/4808

CPU: 1 PID: 4808 Comm: syz.5.107 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x250 lib/dump_stack.c:106
 print_address_description+0x60/0x2d0 mm/kasan/report.c:248
 __kasan_report mm/kasan/report.c:434 [inline]
 kasan_report+0xdf/0x130 mm/kasan/report.c:451
 check_region_inline mm/kasan/generic.c:-1 [inline]
 kasan_check_range+0x235/0x290 mm/kasan/generic.c:189
 memmove+0x25/0x60 mm/kasan/shadow.c:54
 ext4_xattr_set_entry+0x1bf6/0x3ea0 fs/ext4/xattr.c:1715
 ext4_xattr_block_set+0x4fd/0x2d20 fs/ext4/xattr.c:1924
 ext4_xattr_set_handle+0xbc4/0x12b0 fs/ext4/xattr.c:2407
 ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2508
 __vfs_setxattr+0x3e0/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x129/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x167/0x2e0 fs/xattr.c:303
 do_setxattr fs/xattr.c:588 [inline]
 setxattr+0x36c/0x390 fs/xattr.c:611
 path_setxattr+0x147/0x290 fs/xattr.c:630
 __do_sys_lsetxattr fs/xattr.c:653 [inline]
 __se_sys_lsetxattr fs/xattr.c:649 [inline]
 __x64_sys_lsetxattr+0xb4/0xd0 fs/xattr.c:649
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
RIP: 0033:0x7f2dc9be2799
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:00007f2dc79d7028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007f2dc9e5c270 RCX: 00007f2dc9be2799
RDX: 0000200000000440 RSI: 00002000000000c0 RDI: 0000200000000100
RBP: 00007f2dc9c78bd9 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f2dc9e5c308 R14: 00007f2dc9e5c270 R15: 00007ffdad8a1ea8
 </TASK>

The buggy address belongs to the page:
page:ffffea0001783c80 refcount:6 mapcount:0 mapping:ffff888140899470 index:0x1c pfn:0x5e0f2
memcg:ffff88807b094000
aops:def_blk_aops ino:700005
flags: 0xfff00000002018(dirty|lru|private|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000002018 ffff88807b5c3020 ffffea0001783cc8 ffff888140899470
raw: 000000000000001c ffff8880751be1d0 00000006ffffffff ffff88807b094000
page dumped because: kasan: bad access detected
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 4790, ts 93488406785, free_ts 93449006334
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1bbd/0x1ca0 mm/page_alloc.c:4192
 __alloc_pages+0x1ee/0x480 mm/page_alloc.c:5487
 __page_cache_alloc+0xce/0x440 mm/filemap.c:1022
 pagecache_get_page+0x9b6/0xf10 mm/filemap.c:1940
 find_or_create_page include/linux/pagemap.h:420 [inline]
 grow_dev_page fs/buffer.c:949 [inline]
 grow_buffers fs/buffer.c:1014 [inline]
 __getblk_slow fs/buffer.c:1041 [inline]
 __getblk_gfp+0x247/0xb60 fs/buffer.c:1336
 sb_getblk include/linux/buffer_head.h:361 [inline]
 ext4_xattr_block_set+0x1d85/0x2d20 fs/ext4/xattr.c:2105
 ext4_xattr_set_handle+0xbc4/0x12b0 fs/ext4/xattr.c:2407
 ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2508
 __vfs_setxattr+0x3e0/0x420 fs/xattr.c:182
 __vfs_setxattr_noperm+0x129/0x5e0 fs/xattr.c:216
 vfs_setxattr+0x167/0x2e0 fs/xattr.c:303
 do_setxattr fs/xattr.c:588 [inline]
 setxattr+0x36c/0x390 fs/xattr.c:611
 path_setxattr+0x147/0x290 fs/xattr.c:630
 __do_sys_setxattr fs/xattr.c:646 [inline]
 __se_sys_setxattr fs/xattr.c:642 [inline]
 __x64_sys_setxattr+0xb7/0xd0 fs/xattr.c:642
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x66/0xd0
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1340 [inline]
 free_pcp_prepare mm/page_alloc.c:1391 [inline]
 free_unref_page_prepare+0x637/0x6c0 mm/page_alloc.c:3317
 free_unref_page_list+0x119/0x820 mm/page_alloc.c:3433
 release_pages+0x186c/0x1be0 mm/swap.c:963
 __pagevec_release+0x6d/0xe0 mm/swap.c:983
 pagevec_release include/linux/pagevec.h:81 [inline]
 shmem_undo_range+0x62b/0x1930 mm/shmem.c:964
 shmem_truncate_range mm/shmem.c:1063 [inline]
 shmem_evict_inode+0x220/0xa40 mm/shmem.c:1145
 evict+0x4c9/0x8d0 fs/inode.c:647
 __dentry_kill+0x431/0x650 fs/dcache.c:586
 dentry_kill+0xb8/0x290 fs/dcache.c:-1
 dput+0xd8/0x1a0 fs/dcache.c:893
 __fput+0x5ee/0x930 fs/file_table.c:319
 task_work_run+0x125/0x1a0 kernel/task_work.c:188
 tracehook_notify_resume include/linux/tracehook.h:189 [inline]
 exit_to_user_mode_loop+0x10f/0x130 kernel/entry/common.c:181
 exit_to_user_mode_prepare+0xee/0x180 kernel/entry/common.c:214
 __syscall_exit_to_user_mode_work kernel/entry/common.c:296 [inline]
 syscall_exit_to_user_mode+0x16/0x40 kernel/entry/common.c:307
 do_syscall_64+0x58/0xa0 arch/x86/entry/common.c:86

Memory state around the buggy address:
 ffff88805e0f2680: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805e0f2700: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805e0f2780: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                                       ^
 ffff88805e0f2800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805e0f2880: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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