loop2: detected capacity change from 0 to 1024
EXT4-fs (loop2): mounted filesystem without journal. Quota mode: writeback.
==================================================================
BUG: KASAN: use-after-free in xattr_find_entry+0x2f5/0x300 fs/ext4/xattr.c:294
Read of size 4 at addr ffff88811202b004 by task syz.2.17/375

CPU: 1 PID: 375 Comm: syz.2.17 Not tainted syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report_generic.c:350
 xattr_find_entry+0x2f5/0x300 fs/ext4/xattr.c:294
 ext4_xattr_ibody_get+0x245/0x4d0 fs/ext4/xattr.c:601
 ext4_xattr_get+0x122/0x650 fs/ext4/xattr.c:655
 ext4_get_acl+0x85/0x6c0 fs/ext4/acl.c:165
 get_acl+0x16f/0x280 fs/posix_acl.c:153
 posix_acl_chmod+0xe9/0x260 fs/posix_acl.c:602
 ext4_setattr+0xd4e/0x1c80 fs/ext4/inode.c:5693
 notify_change+0xd33/0x1030 fs/attr.c:499
 chmod_common+0x21a/0x3c0 fs/open.c:607
 do_fchmodat+0xd4/0x1a0 fs/open.c:646
 __do_sys_chmod fs/open.c:664 [inline]
 __se_sys_chmod fs/open.c:662 [inline]
 __x64_sys_chmod+0x60/0x70 fs/open.c:662
 x64_sys_call+0x760/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:91
 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: 0033:0x7f52db99de99
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:00007ffc3d337a08 EFLAGS: 00000246 ORIG_RAX: 000000000000005a
RAX: ffffffffffffffda RBX: 00007f52dbc25fa0 RCX: 00007f52db99de99
RDX: 0000000000000000 RSI: 000000000000023f RDI: 0000200000000180
RBP: 00007f52dba33eaf R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f52dbc25fac R14: 00007f52dbc25fa0 R15: 00007f52dbc25fa0
 </TASK>

Allocated by task 104:
 kasan_save_stack mm/kasan/common.c:46 [inline]
 kasan_set_track+0x4b/0x70 mm/kasan/common.c:53
 kasan_save_alloc_info+0x1f/0x30 mm/kasan/generic.c:505
 __kasan_slab_alloc+0x72/0x80 mm/kasan/common.c:334
 kasan_slab_alloc include/linux/kasan.h:202 [inline]
 slab_post_alloc_hook+0x4f/0x2d0 mm/slab.h:768
 slab_alloc_node mm/slub.c:3382 [inline]
 slab_alloc mm/slub.c:3392 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3399 [inline]
 kmem_cache_alloc+0x166/0x320 mm/slub.c:3408
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 seq_open+0x61/0x130 fs/seq_file.c:63
 kernfs_fop_open+0x4de/0xb80 fs/kernfs/file.c:-1
 do_dentry_open+0x885/0x11f0 fs/open.c:884
 vfs_open+0x73/0x80 fs/open.c:1017
 do_open fs/namei.c:3633 [inline]
 path_openat+0x2699/0x2f30 fs/namei.c:3790
 do_filp_open+0x1ee/0x420 fs/namei.c:3817
 do_sys_openat2+0x15e/0x820 fs/open.c:1343
 do_sys_open fs/open.c:1359 [inline]
 __do_sys_openat fs/open.c:1375 [inline]
 __se_sys_openat fs/open.c:1370 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1370
 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 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

The buggy address belongs to the object at ffff88811202b000
 which belongs to the cache seq_file of size 136
The buggy address is located 4 bytes inside of
 136-byte region [ffff88811202b000, ffff88811202b088)

The buggy address belongs to the physical page:
page:ffffea0004480ac0 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff88811202baf0 pfn:0x11202b
flags: 0x4000000000000200(slab|zone=1)
raw: 4000000000000200 ffffea0004480948 ffffea0004480d48 ffff8881001ec480
raw: ffff88811202baf0 0000000000140000 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x12cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY), pid 104, tgid 104 (udevadm), ts 3816911862, free_ts 3816889904
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f5/0x210 mm/page_alloc.c:2672
 prep_new_page+0x1c/0x110 mm/page_alloc.c:2679
 get_page_from_freelist+0x2ca9/0x2d20 mm/page_alloc.c:4586
 __alloc_pages+0x1fa/0x610 mm/page_alloc.c:5930
 alloc_slab_page+0x6e/0xf0 include/linux/gfp.h:-1
 allocate_slab mm/slub.c:1967 [inline]
 new_slab+0x98/0x3e0 mm/slub.c:2020
 ___slab_alloc+0x70f/0xb70 mm/slub.c:3177
 __slab_alloc+0x5e/0xa0 mm/slub.c:3263
 slab_alloc_node mm/slub.c:3348 [inline]
 slab_alloc mm/slub.c:3392 [inline]
 __kmem_cache_alloc_lru mm/slub.c:3399 [inline]
 kmem_cache_alloc+0x1a8/0x320 mm/slub.c:3408
 kmem_cache_zalloc include/linux/slab.h:689 [inline]
 seq_open+0x61/0x130 fs/seq_file.c:63
 kernfs_fop_open+0x4de/0xb80 fs/kernfs/file.c:-1
 do_dentry_open+0x885/0x11f0 fs/open.c:884
 vfs_open+0x73/0x80 fs/open.c:1017
 do_open fs/namei.c:3633 [inline]
 path_openat+0x2699/0x2f30 fs/namei.c:3790
 do_filp_open+0x1ee/0x420 fs/namei.c:3817
 do_sys_openat2+0x15e/0x820 fs/open.c:1343
page last free stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 free_pages_prepare mm/page_alloc.c:1580 [inline]
 free_pcp_prepare mm/page_alloc.c:1654 [inline]
 free_unref_page_prepare+0x80c/0x820 mm/page_alloc.c:3621
 free_unref_page+0x93/0x530 mm/page_alloc.c:3719
 free_the_page mm/page_alloc.c:863 [inline]
 __free_pages+0x67/0x100 mm/page_alloc.c:6020
 free_pages+0x82/0x90 mm/page_alloc.c:6031
 selinux_genfs_get_sid+0x20b/0x250 security/selinux/hooks.c:1309
 inode_doinit_with_dentry+0x884/0xd90 security/selinux/hooks.c:1504
 selinux_d_instantiate+0x27/0x40 security/selinux/hooks.c:6396
 security_d_instantiate+0xb3/0x110 security/security.c:2097
 d_splice_alias+0x6d/0x390 fs/dcache.c:3155
 kernfs_iop_lookup+0x2c2/0x310 fs/kernfs/dir.c:1204
 lookup_open fs/namei.c:3467 [inline]
 open_last_lookups fs/namei.c:3557 [inline]
 path_openat+0x13fe/0x2f30 fs/namei.c:3787
 do_filp_open+0x1ee/0x420 fs/namei.c:3817
 do_sys_openat2+0x15e/0x820 fs/open.c:1343
 do_sys_open fs/open.c:1359 [inline]
 __do_sys_openat fs/open.c:1375 [inline]
 __se_sys_openat fs/open.c:1370 [inline]
 __x64_sys_openat+0x136/0x160 fs/open.c:1370
 x64_sys_call+0x783/0x9a0 arch/x86/include/generated/asm/syscalls_64.h:258
 do_syscall_x64 arch/x86/entry/common.c:46 [inline]
 do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:76

Memory state around the buggy address:
 ffff88811202af00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88811202af80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88811202b000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff88811202b080: fb fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb
 ffff88811202b100: fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc fc
==================================================================
EXT4-fs error (device loop2): xattr_find_entry:297: inode #12: comm syz.2.17: corrupted xattr entries