syzbot

loop2: detected capacity change from 0 to 2048
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BUG: KASAN: use-after-free in check_igot_inode fs/ext4/inode.c:-1 [inline]
BUG: KASAN: use-after-free in __ext4_iget+0x2b5/0x3cc0 fs/ext4/inode.c:4673
Read of size 8 at addr ffff888067e91320 by task syz.2.6664/20098

CPU: 1 PID: 20098 Comm: syz.2.6664 Not tainted 5.15.181-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/19/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x168/0x230 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_igot_inode fs/ext4/inode.c:-1 [inline]
 __ext4_iget+0x2b5/0x3cc0 fs/ext4/inode.c:4673
 ext4_fill_super+0x77d5/0x9a00 fs/ext4/super.c:4841
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3013
 do_mount fs/namespace.c:3356 [inline]
 __do_sys_mount fs/namespace.c:3564 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3541
 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: 0033:0x7f9e4163810a
Code: d8 64 89 02 48 c7 c0 ff ff ff ff eb a6 e8 de 1a 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 49 89 ca b8 a5 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007f9e3f49de68 EFLAGS: 00000246 ORIG_RAX: 00000000000000a5
RAX: ffffffffffffffda RBX: 00007f9e3f49def0 RCX: 00007f9e4163810a
RDX: 0000200000000780 RSI: 00002000000007c0 RDI: 00007f9e3f49deb0
RBP: 0000200000000780 R08: 00007f9e3f49def0 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00002000000007c0
R13: 00007f9e3f49deb0 R14: 0000000000000749 R15: 0000200000000800
 </TASK>

Allocated by task 6686:
 kasan_save_stack mm/kasan/common.c:38 [inline]
 kasan_set_track mm/kasan/common.c:46 [inline]
 set_alloc_info mm/kasan/common.c:434 [inline]
 __kasan_slab_alloc+0x9c/0xd0 mm/kasan/common.c:467
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3233
 reiserfs_alloc_inode+0x19/0xb0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 new_inode_pseudo+0x5f/0x210 fs/inode.c:1001
 new_inode+0x25/0x1c0 fs/inode.c:1030
 reiserfs_mkdir+0x185/0x970 fs/reiserfs/namei.c:815
 xattr_mkdir fs/reiserfs/xattr.c:76 [inline]
 create_privroot fs/reiserfs/xattr.c:889 [inline]
 reiserfs_xattr_init+0x331/0x720 fs/reiserfs/xattr.c:1012
 reiserfs_fill_super+0x1fa6/0x23e0 fs/reiserfs/super.c:2179
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3013
 do_mount fs/namespace.c:3356 [inline]
 __do_sys_mount fs/namespace.c:3564 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3541
 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

Last potentially related work creation:
 kasan_save_stack+0x35/0x60 mm/kasan/common.c:38
 kasan_record_aux_stack+0xb8/0x100 mm/kasan/generic.c:348
 __call_rcu kernel/rcu/tree.c:3007 [inline]
 call_rcu+0x179/0x920 kernel/rcu/tree.c:3087
 destroy_inode fs/inode.c:316 [inline]
 evict+0x7da/0x870 fs/inode.c:662
 dispose_list fs/inode.c:680 [inline]
 evict_inodes+0x604/0x690 fs/inode.c:734
 generic_shutdown_super+0x93/0x300 fs/super.c:454
 kill_block_super+0x7c/0xe0 fs/super.c:1427
 deactivate_locked_super+0x93/0xf0 fs/super.c:335
 cleanup_mnt+0x418/0x4d0 fs/namespace.c:1143
 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+0xb1/0x140 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
 entry_SYSCALL_64_after_hwframe+0x66/0xd0

The buggy address belongs to the object at ffff888067e90d40
 which belongs to the cache reiser_inode_cache of size 1568
The buggy address is located 1504 bytes inside of
 1568-byte region [ffff888067e90d40, ffff888067e91360)
The buggy address belongs to the page:
page:ffffea00019fa400 refcount:1 mapcount:0 mapping:0000000000000000 index:0xffff888067e970a0 pfn:0x67e90
head:ffffea00019fa400 order:3 compound_mapcount:0 compound_pincount:0
memcg:ffff888026005601
flags: 0xfff00000010200(slab|head|node=0|zone=1|lastcpupid=0x7ff)
raw: 00fff00000010200 0000000000000000 dead000000000122 ffff888146646dc0
raw: ffff888067e970a0 0000000080130003 00000001ffffffff ffff888026005601
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0x1d20d0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC|__GFP_HARDWALL|__GFP_RECLAIMABLE), pid 5209, ts 115649794661, free_ts 81032927799
 prep_new_page mm/page_alloc.c:2426 [inline]
 get_page_from_freelist+0x1b77/0x1c60 mm/page_alloc.c:4192
 __alloc_pages+0x1e1/0x470 mm/page_alloc.c:5466
 alloc_slab_page mm/slub.c:1775 [inline]
 allocate_slab mm/slub.c:1912 [inline]
 new_slab+0xc0/0x4b0 mm/slub.c:1975
 ___slab_alloc+0x81e/0xdf0 mm/slub.c:3008
 __slab_alloc mm/slub.c:3095 [inline]
 slab_alloc_node mm/slub.c:3186 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x195/0x290 mm/slub.c:3233
 reiserfs_alloc_inode+0x19/0xb0 fs/reiserfs/super.c:642
 alloc_inode fs/inode.c:261 [inline]
 iget5_locked+0x9e/0x250 fs/inode.c:1263
 reiserfs_fill_super+0x11c5/0x23e0 fs/reiserfs/super.c:2057
 mount_bdev+0x287/0x3c0 fs/super.c:1400
 legacy_get_tree+0xe6/0x180 fs/fs_context.c:611
 vfs_get_tree+0x88/0x270 fs/super.c:1530
 do_new_mount+0x24a/0xa40 fs/namespace.c:3013
 do_mount fs/namespace.c:3356 [inline]
 __do_sys_mount fs/namespace.c:3564 [inline]
 __se_sys_mount+0x2d6/0x3c0 fs/namespace.c:3541
 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+0x94/0x280 mm/page_alloc.c:3396
 free_slab mm/slub.c:2015 [inline]
 discard_slab mm/slub.c:2021 [inline]
 __unfreeze_partials+0x1a5/0x200 mm/slub.c:2507
 put_cpu_partial+0x12d/0x190 mm/slub.c:2587
 qlist_free_all+0x35/0x90 mm/kasan/quarantine.c:176
 kasan_quarantine_reduce+0x150/0x160 mm/kasan/quarantine.c:283
 __kasan_slab_alloc+0x2f/0xd0 mm/kasan/common.c:444
 kasan_slab_alloc include/linux/kasan.h:254 [inline]
 slab_post_alloc_hook+0x4c/0x380 mm/slab.h:519
 slab_alloc_node mm/slub.c:3220 [inline]
 slab_alloc mm/slub.c:3228 [inline]
 kmem_cache_alloc+0x100/0x290 mm/slub.c:3233
 getname_flags+0xb5/0x500 fs/namei.c:138
 user_path_at_empty+0x2a/0x190 fs/namei.c:2882
 user_path_at include/linux/namei.h:57 [inline]
 vfs_statx+0x102/0x4d0 fs/stat.c:221
 vfs_fstatat fs/stat.c:243 [inline]
 __do_sys_newfstatat fs/stat.c:411 [inline]
 __se_sys_newfstatat fs/stat.c:405 [inline]
 __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405
 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

Memory state around the buggy address:
 ffff888067e91200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff888067e91280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888067e91300: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                               ^
 ffff888067e91380: fc fc fc fc fc fc fc fc fc fc fc fc 00 00 00 00
 ffff888067e91400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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