loop4: detected capacity change from 0 to 1024
EXT4-fs (loop4): mounted filesystem without journal. Quota mode: none.
==================================================================
BUG: KASAN: use-after-free in ext4_xattr_list_entries+0x2c8/0x380 fs/ext4/xattr.c:670
Read of size 4 at addr ffff888053620028 by task syz.4.270/5139

CPU: 0 PID: 5139 Comm: syz.4.270 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/24/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0x188/0x24e lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:316 [inline]
 print_report+0xa8/0x210 mm/kasan/report.c:420
 kasan_report+0x10b/0x140 mm/kasan/report.c:524
 ext4_xattr_list_entries+0x2c8/0x380 fs/ext4/xattr.c:670
 ext4_xattr_ibody_list fs/ext4/xattr.c:740 [inline]
 ext4_listxattr+0x208/0x5f0 fs/ext4/xattr.c:765
 vfs_listxattr fs/xattr.c:457 [inline]
 listxattr+0x283/0x2e0 fs/xattr.c:804
 path_listxattr+0xe1/0x1b0 fs/xattr.c:828
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
RIP: 0033:0x7f0e12d9af79
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:00007f0e13c35028 EFLAGS: 00000246 ORIG_RAX: 00000000000000c2
RAX: ffffffffffffffda RBX: 00007f0e13015fa0 RCX: 00007f0e12d9af79
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000200000000000
RBP: 00007f0e12e316e0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f0e13016038 R14: 00007f0e13015fa0 R15: 00007ffe1b11b7b8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea00014d8800 refcount:2 mapcount:1 mapping:ffff888077f1fb58 index:0x68e pfn:0x53620
memcg:ffff888079b50000
aops:shmem_aops ino:434 dentry name(?):"dev/zero"
flags: 0xfff80000080016(referenced|uptodate|lru|swapbacked|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff80000080016 ffffea00014d9bc8 ffffea00014d8848 ffff888077f1fb58
raw: 000000000000068e 0000000000000000 0000000200000000 ffff888079b50000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x140cca(GFP_HIGHUSER_MOVABLE|__GFP_COMP), pid 5149, tgid 5148 (syz.0.273), ts 132985626082, free_ts 80593153363
 set_page_owner include/linux/page_owner.h:31 [inline]
 post_alloc_hook+0x173/0x1a0 mm/page_alloc.c:2559
 prep_new_page mm/page_alloc.c:2566 [inline]
 get_page_from_freelist+0x1a1e/0x1ab0 mm/page_alloc.c:4357
 __alloc_pages+0x1ec/0x4f0 mm/page_alloc.c:5643
 __folio_alloc+0xe/0x30 mm/page_alloc.c:5675
 vma_alloc_folio+0x4a3/0x900 mm/mempolicy.c:2243
 shmem_alloc_folio mm/shmem.c:1589 [inline]
 shmem_alloc_and_acct_folio+0x463/0xbc0 mm/shmem.c:1613
 shmem_get_folio_gfp+0x1361/0x3400 mm/shmem.c:1941
 shmem_fault+0x1b6/0x780 mm/shmem.c:2156
 __do_fault+0x13b/0x4e0 mm/memory.c:4278
 do_read_fault mm/memory.c:4629 [inline]
 do_fault mm/memory.c:4758 [inline]
 handle_pte_fault mm/memory.c:5029 [inline]
 __handle_mm_fault mm/memory.c:5171 [inline]
 handle_mm_fault+0x2407/0x3ee0 mm/memory.c:5292
 faultin_page mm/gup.c:1026 [inline]
 __get_user_pages+0x40d/0xec0 mm/gup.c:1250
 populate_vma_page_range+0x214/0x2b0 mm/gup.c:1607
 __mm_populate+0x25c/0x380 mm/gup.c:1721
 mm_populate include/linux/mm.h:2891 [inline]
 vm_mmap_pgoff+0x212/0x2d0 mm/util.c:525
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:24 [inline]
 free_pages_prepare mm/page_alloc.c:1486 [inline]
 free_pcp_prepare mm/page_alloc.c:1536 [inline]
 free_unref_page_prepare+0x8b4/0x9a0 mm/page_alloc.c:3413
 free_unref_page_list+0xbb/0x8e0 mm/page_alloc.c:3554
 release_pages+0x1fa6/0x2220 mm/swap.c:1035
 __pagevec_release+0x6d/0xe0 mm/swap.c:1055
 pagevec_release include/linux/pagevec.h:71 [inline]
 folio_batch_release include/linux/pagevec.h:135 [inline]
 shmem_undo_range+0x7c2/0x20c0 mm/shmem.c:946
 shmem_truncate_range mm/shmem.c:1062 [inline]
 shmem_evict_inode+0x25b/0xa80 mm/shmem.c:1171
 evict+0x4c9/0x8d0 fs/inode.c:705
 do_unlinkat+0x388/0x580 fs/namei.c:4405
 __do_sys_unlink fs/namei.c:4446 [inline]
 __se_sys_unlink fs/namei.c:4444 [inline]
 __x64_sys_unlink+0x45/0x50 fs/namei.c:4444
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76
 entry_SYSCALL_64_after_hwframe+0x68/0xd2

Memory state around the buggy address:
 ffff88805361ff00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805361ff80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888053620000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
                                  ^
 ffff888053620080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888053620100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
==================================================================