loop7: detected capacity change from 0 to 1024
EXT4-fs (loop7): mounted filesystem without journal. Quota mode: none.
==================================================================
BUG: KASAN: use-after-free in ext4_xattr_set_entry+0x1a71/0x21d0 fs/ext4/xattr.c:1703
Read of size 12404 at addr ffff8881201f5800 by task syz.7.135/863

CPU: 0 PID: 863 Comm: syz.7.135 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
Call Trace:
 <TASK>
 __dump_stack+0x21/0x24 lib/dump_stack.c:88
 dump_stack_lvl+0x110/0x170 lib/dump_stack.c:106
 print_address_description+0x71/0x200 mm/kasan/report.c:316
 print_report+0x4a/0x60 mm/kasan/report.c:420
 kasan_report+0x122/0x150 mm/kasan/report.c:524
 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+0x1a71/0x21d0 fs/ext4/xattr.c:1703
 ext4_xattr_block_set+0x69d/0x3260 fs/ext4/xattr.c:1924
 ext4_xattr_set_handle+0xbc4/0x12c0 fs/ext4/xattr.c:2418
 ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2520
 ext4_xattr_trusted_set+0x3c/0x50 fs/ext4/xattr_trusted.c:38
 __vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 __vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
 vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
 do_setxattr fs/xattr.c:594 [inline]
 setxattr+0x346/0x360 fs/xattr.c:617
 path_setxattr+0x147/0x290 fs/xattr.c:636
 __do_sys_lsetxattr fs/xattr.c:659 [inline]
 __se_sys_lsetxattr fs/xattr.c:655 [inline]
 __x64_sys_lsetxattr+0xc2/0xe0 fs/xattr.c:655
 x64_sys_call+0x8b7/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:190
 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: 0033:0x7fda0259bf79
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:00007fda034a5028 EFLAGS: 00000246 ORIG_RAX: 00000000000000bd
RAX: ffffffffffffffda RBX: 00007fda02815fa0 RCX: 00007fda0259bf79
RDX: 0000200000000000 RSI: 00002000000000c0 RDI: 0000200000000100
RBP: 00007fda026327e0 R08: 0000000000000000 R09: 0000000000000000
R10: 000000000000fe37 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fda02816038 R14: 00007fda02815fa0 R15: 00007fff042fcaf8
 </TASK>

The buggy address belongs to the physical page:
page:ffffea0004807d40 refcount:2 mapcount:0 mapping:ffff88810b3132d0 index:0x1c pfn:0x1201f5
memcg:ffff888100238000
aops:def_blk_aops ino:700007
flags: 0x560000000000205a(referenced|dirty|lru|workingset|private|zone=1)
raw: 560000000000205a ffffea0004e4f848 ffffea0004807d08 ffff88810b3132d0
raw: 000000000000001c ffff888132d1b5e8 00000002ffffffff ffff888100238000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Movable, gfp_mask 0x148c48(GFP_NOFS|__GFP_NOFAIL|__GFP_COMP|__GFP_HARDWALL|__GFP_MOVABLE), pid 863, tgid 862 (syz.7.135), ts 37926288076, free_ts 37906178756
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2643
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2650
 get_page_from_freelist+0x2d12/0x2d80 mm/page_alloc.c:4554
 __alloc_pages+0x1d9/0x480 mm/page_alloc.c:5868
 __folio_alloc+0x12/0x40 mm/page_alloc.c:5900
 __folio_alloc_node include/linux/gfp.h:245 [inline]
 folio_alloc include/linux/gfp.h:274 [inline]
 filemap_alloc_folio include/linux/pagemap.h:515 [inline]
 __filemap_get_folio+0x721/0x9b0 mm/filemap.c:2018
 pagecache_get_page+0x2b/0x110 mm/folio-compat.c:110
 find_or_create_page include/linux/pagemap.h:656 [inline]
 grow_dev_page fs/buffer.c:989 [inline]
 grow_buffers fs/buffer.c:1054 [inline]
 __getblk_slow fs/buffer.c:1081 [inline]
 __getblk_gfp+0x217/0x7d0 fs/buffer.c:1376
 sb_getblk include/linux/buffer_head.h:356 [inline]
 ext4_xattr_block_set+0x1e07/0x3260 fs/ext4/xattr.c:2089
 ext4_xattr_set_handle+0xbc4/0x12c0 fs/ext4/xattr.c:2418
 ext4_xattr_set+0x242/0x320 fs/ext4/xattr.c:2520
 ext4_xattr_user_set+0xc4/0xf0 fs/ext4/xattr_user.c:41
 __vfs_setxattr+0x3f2/0x440 fs/xattr.c:182
 __vfs_setxattr_noperm+0x12a/0x5e0 fs/xattr.c:216
 __vfs_setxattr_locked+0x212/0x230 fs/xattr.c:277
 vfs_setxattr+0x167/0x2e0 fs/xattr.c:309
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1551 [inline]
 free_pcp_prepare mm/page_alloc.c:1625 [inline]
 free_unref_page_prepare+0x742/0x750 mm/page_alloc.c:3589
 free_unref_page_list+0x117/0x8c0 mm/page_alloc.c:3740
 release_pages+0xaf2/0xb50 mm/swap.c:1048
 free_pages_and_swap_cache+0x86/0xa0 mm/swap_state.c:315
 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline]
 tlb_flush_mmu_free mm/mmu_gather.c:254 [inline]
 tlb_flush_mmu mm/mmu_gather.c:261 [inline]
 tlb_finish_mmu+0x1aa/0x370 mm/mmu_gather.c:361
 unmap_region+0x2b7/0x320 mm/mmap.c:2419
 do_mas_align_munmap+0xbed/0x1320 mm/mmap.c:2693
 do_mas_munmap+0x241/0x2b0 mm/mmap.c:2751
 __vm_munmap+0x1bd/0x330 mm/mmap.c:3050
 __do_sys_munmap mm/mmap.c:3076 [inline]
 __se_sys_munmap mm/mmap.c:3072 [inline]
 __x64_sys_munmap+0x6b/0x80 mm/mmap.c:3072
 x64_sys_call+0x8a/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:12
 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:
 ffff8881201f6f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8881201f6f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff8881201f7000: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
                   ^
 ffff8881201f7080: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff8881201f7100: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
==================================================================