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BUG: KASAN: slab-use-after-free in jfs_readdir+0x10a8/0x33f0 fs/jfs/jfs_dtree.c:2878
Read of size 8 at addr ffff88807c777030 by task syz.0.576/11517

CPU: 1 UID: 0 PID: 11517 Comm: syz.0.576 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/09/2026
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+0x10a8/0x33f0 fs/jfs/jfs_dtree.c:2878
 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67
 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110
 __do_sys_getdents fs/readdir.c:319 [inline]
 __se_sys_getdents+0xf1/0x270 fs/readdir.c:304
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f42b28ece59
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:00007f42b0b46028 EFLAGS: 00000246 ORIG_RAX: 000000000000004e
RAX: ffffffffffffffda RBX: 00007f42b2b65fa0 RCX: 00007f42b28ece59
RDX: 0000000000000058 RSI: 0000000000000000 RDI: 0000000000000006
RBP: 00007f42b2982d6f R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f42b2b66038 R14: 00007f42b2b65fa0 R15: 00007ffcfd9579d8
 </TASK>

Allocated by task 11517:
 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:4610 [inline]
 slab_alloc_node mm/slub.c:4939 [inline]
 kmem_cache_alloc_noprof+0x337/0x680 mm/slub.c:4946
 mempool_alloc_noprof+0x1c5/0x300 mm/mempool.c:559
 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
 __get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761
 dtSplitRoot+0x216/0x1900 fs/jfs/jfs_dtree.c:1907
 dtSplitUp fs/jfs/jfs_dtree.c:990 [inline]
 dtInsert+0xedd/0x5cb0 fs/jfs/jfs_dtree.c:868
 jfs_mkdir+0x76b/0xb00 fs/jfs/namei.c:271
 vfs_mkdir+0x402/0x620 fs/namei.c:5272
 filename_mkdirat+0x289/0x520 fs/namei.c:5305
 __do_sys_mkdirat fs/namei.c:5326 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5323
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 11517:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 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:2700 [inline]
 slab_free mm/slub.c:6310 [inline]
 kmem_cache_free+0x187/0x6c0 mm/slub.c:6437
 mempool_free+0xf5/0x140 mm/mempool.c:704
 free_metapage fs/jfs/jfs_metapage.c:280 [inline]
 drop_metapage fs/jfs/jfs_metapage.c:317 [inline]
 release_metapage+0x7eb/0xa50 fs/jfs/jfs_metapage.c:893
 dtReadNext fs/jfs/jfs_dtree.c:3199 [inline]
 jfs_readdir+0xe35/0x33f0 fs/jfs/jfs_dtree.c:2871
 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:67
 iterate_dir+0x2f1/0x4e0 fs/readdir.c:110
 __do_sys_getdents fs/readdir.c:319 [inline]
 __se_sys_getdents+0xf1/0x270 fs/readdir.c:304
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88807c777000
 which belongs to the cache jfs_mp of size 248
The buggy address is located 48 bytes inside of
 freed 248-byte region [ffff88807c777000, ffff88807c7770f8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88807c777d68 pfn:0x7c777
flags: 0x80000000000200(workingset|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000200 ffff88801d3badc0 ffffea0000b02650 ffff88801d3b7e88
raw: ffff88807c777d68 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 11121, tgid 11119 (syz.2.537), ts 340487396117, free_ts 340422319999
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x22d/0x280 mm/page_alloc.c:1853
 prep_new_page mm/page_alloc.c:1861 [inline]
 get_page_from_freelist+0x2877/0x28f0 mm/page_alloc.c:3941
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5221
 alloc_slab_page mm/slub.c:3289 [inline]
 allocate_slab+0x74/0x5d0 mm/slub.c:3404
 new_slab mm/slub.c:3447 [inline]
 refill_objects+0x32b/0x3c0 mm/slub.c:7241
 refill_sheaf mm/slub.c:2827 [inline]
 __pcs_replace_empty_main+0x335/0x6a0 mm/slub.c:4692
 alloc_from_pcs mm/slub.c:4790 [inline]
 slab_alloc_node mm/slub.c:4924 [inline]
 kmem_cache_alloc_noprof+0x42f/0x680 mm/slub.c:4946
 mempool_alloc_noprof+0x1c5/0x300 mm/mempool.c:559
 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
 __get_metapage+0x4ed/0xdf0 fs/jfs/jfs_metapage.c:761
 diNewExt+0xa53/0x3020 fs/jfs/jfs_imap.c:2275
 diAllocExt fs/jfs/jfs_imap.c:1952 [inline]
 diAllocAG+0xbed/0x1de0 fs/jfs/jfs_imap.c:1669
 diAlloc+0x1de/0x1690 fs/jfs/jfs_imap.c:1590
 ialloc+0x8c/0x8e0 fs/jfs/jfs_inode.c:56
 jfs_mkdir+0x1e4/0xb00 fs/jfs/namei.c:226
 vfs_mkdir+0x402/0x620 fs/namei.c:5272
 filename_mkdirat+0x289/0x520 fs/namei.c:5305
page last free pid 20 tgid 20 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1397 [inline]
 __free_frozen_pages+0x1019/0x1100 mm/page_alloc.c:2938
 rcu_do_batch kernel/rcu/tree.c:2645 [inline]
 rcu_core kernel/rcu/tree.c:2897 [inline]
 rcu_cpu_kthread+0x950/0x1480 kernel/rcu/tree.c:2985
 smpboot_thread_fn+0x57c/0xa80 kernel/smpboot.c:160
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88807c776f00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
 ffff88807c776f80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff
>ffff88807c777000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                     ^
 ffff88807c777080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fc
 ffff88807c777100: fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb fb
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