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BUG: KASAN: slab-use-after-free in jfs_readdir+0x1152/0x3420 fs/jfs/jfs_dtree.c:2878
Read of size 8 at addr ffff88803cf7b648 by task syz.9.397/9163

CPU: 0 UID: 0 PID: 9163 Comm: syz.9.397 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 04/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 jfs_readdir+0x1152/0x3420 fs/jfs/jfs_dtree.c:2878
 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67
 iterate_dir+0x3a5/0x580 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:399 [inline]
 __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f300bffce59
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:00007f300a24e028 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007f300c275fa0 RCX: 00007f300bffce59
RDX: 0000000000000022 RSI: 0000000000000000 RDI: 0000000000000004
RBP: 00007f300c092d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f300c276038 R14: 00007f300c275fa0 R15: 00007ffc978e2dc8
 </TASK>

Allocated by task 9163:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 unpoison_slab_object mm/kasan/common.c:340 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:366
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4569 [inline]
 slab_alloc_node mm/slub.c:4898 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4905
 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:566
 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
 __get_metapage+0x50c/0xe20 fs/jfs/jfs_metapage.c:761
 dtSplitRoot+0x202/0x16c0 fs/jfs/jfs_dtree.c:1907
 dtSplitUp fs/jfs/jfs_dtree.c:990 [inline]
 dtInsert+0xeea/0x5cd0 fs/jfs/jfs_dtree.c:868
 jfs_mkdir+0x783/0xb00 fs/jfs/namei.c:271
 vfs_mkdir+0x40b/0x630 fs/namei.c:5261
 filename_mkdirat+0x289/0x520 fs/namei.c:5294
 __do_sys_mkdirat fs/namei.c:5315 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5312
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 9163:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:253 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:285
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2689 [inline]
 slab_free mm/slub.c:6250 [inline]
 kmem_cache_free+0x187/0x6c0 mm/slub.c:6377
 mempool_free+0xf5/0x140 mm/mempool.c:711
 free_metapage fs/jfs/jfs_metapage.c:280 [inline]
 drop_metapage fs/jfs/jfs_metapage.c:317 [inline]
 release_metapage+0x827/0xa90 fs/jfs/jfs_metapage.c:893
 dtReadNext fs/jfs/jfs_dtree.c:3199 [inline]
 jfs_readdir+0xee3/0x3420 fs/jfs/jfs_dtree.c:2871
 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67
 iterate_dir+0x3a5/0x580 fs/readdir.c:110
 __do_sys_getdents64 fs/readdir.c:399 [inline]
 __se_sys_getdents64+0xf1/0x280 fs/readdir.c:384
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88803cf7b618
 which belongs to the cache jfs_mp of size 248
The buggy address is located 48 bytes inside of
 freed 248-byte region [ffff88803cf7b618, ffff88803cf7b710)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88803cf7bc30 pfn:0x3cf7b
flags: 0x80000000000200(workingset|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000200 ffff88801ef3cdc0 ffffea000079f950 ffffea00016a1490
raw: ffff88803cf7bc30 00000008000d0009 00000000f5000000 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 0xd2800(GFP_NOWAIT|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6034, tgid 6028 (syz.1.50), ts 125425213120, free_ts 125418309787
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1858
 prep_new_page mm/page_alloc.c:1866 [inline]
 get_page_from_freelist+0x27c8/0x2840 mm/page_alloc.c:3946
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5226
 alloc_slab_page mm/slub.c:3278 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3467
 new_slab mm/slub.c:3525 [inline]
 refill_objects+0x33c/0x3d0 mm/slub.c:7255
 refill_sheaf mm/slub.c:2816 [inline]
 __pcs_replace_empty_main+0x373/0x720 mm/slub.c:4651
 alloc_from_pcs mm/slub.c:4749 [inline]
 slab_alloc_node mm/slub.c:4883 [inline]
 kmem_cache_alloc_noprof+0x433/0x680 mm/slub.c:4905
 mempool_alloc_noprof+0x1d4/0x300 mm/mempool.c:566
 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
 __get_metapage+0x50c/0xe20 fs/jfs/jfs_metapage.c:761
 diReadSpecial+0x25b/0x710 fs/jfs/jfs_imap.c:447
 jfs_mount+0x73/0x870 fs/jfs/jfs_mount.c:87
 jfs_fill_super+0x6bc/0xd80 fs/jfs/super.c:523
 get_tree_bdev_flags+0x431/0x4f0 fs/super.c:1694
 vfs_get_tree+0x92/0x2a0 fs/super.c:1754
 fc_mount fs/namespace.c:1193 [inline]
 do_new_mount_fc fs/namespace.c:3758 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3834
 do_mount fs/namespace.c:4167 [inline]
 __do_sys_mount fs/namespace.c:4383 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4360
page last free pid 6051 tgid 6051 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1402 [inline]
 __free_frozen_pages+0xfa6/0x10f0 mm/page_alloc.c:2943
 ___free_pages_bulk mm/kasan/shadow.c:333 [inline]
 __kasan_populate_vmalloc_do mm/kasan/shadow.c:385 [inline]
 __kasan_populate_vmalloc+0x137/0x1d0 mm/kasan/shadow.c:424
 kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
 alloc_vmap_area+0xd47/0x1480 mm/vmalloc.c:2123
 __get_vm_area_node+0x226/0x350 mm/vmalloc.c:3226
 __vmalloc_node_range_noprof+0x36a/0x1750 mm/vmalloc.c:4024
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4124
 alloc_thread_stack_node kernel/fork.c:357 [inline]
 dup_task_struct+0x298/0x840 kernel/fork.c:926
 copy_process+0x89b/0x4450 kernel/fork.c:2090
 kernel_clone+0x283/0x870 kernel/fork.c:2721
 __do_sys_clone3 kernel/fork.c:3025 [inline]
 __se_sys_clone3+0x33c/0x360 kernel/fork.c:3004
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x15f/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff88803cf7b500: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88803cf7b580: 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc
>ffff88803cf7b600: fc fc fc fa fb fb fb fb fb fb fb fb fb fb fb fb
                                              ^
 ffff88803cf7b680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88803cf7b700: fb fb fc fc fc fc fc fc fc fc fa fb fb fb fb fb
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