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BUG: KASAN: slab-use-after-free in jfs_readdir+0x118f/0x3ae0 fs/jfs/jfs_dtree.c:2881
Read of size 8 at addr ffff8880314fb510 by task syz.0.333/8639

CPU: 1 UID: 0 PID: 8639 Comm: syz.0.333 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xca/0x240 mm/kasan/report.c:482
 kasan_report+0x118/0x150 mm/kasan/report.c:595
 jfs_readdir+0x118f/0x3ae0 fs/jfs/jfs_dtree.c:2881
 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:65
 iterate_dir+0x3a5/0x580 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fefe3c9f749
Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 a8 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007fefe1ee5038 EFLAGS: 00000246 ORIG_RAX: 00000000000000d9
RAX: ffffffffffffffda RBX: 00007fefe3ef6090 RCX: 00007fefe3c9f749
RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000007
RBP: 00007fefe3d23f91 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007fefe3ef6128 R14: 00007fefe3ef6090 R15: 00007ffd7012fca8
 </TASK>

Allocated by task 8628:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 unpoison_slab_object mm/kasan/common.c:339 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:365
 kasan_slab_alloc include/linux/kasan.h:252 [inline]
 slab_post_alloc_hook mm/slub.c:4953 [inline]
 slab_alloc_node mm/slub.c:5263 [inline]
 kmem_cache_alloc_noprof+0x18d/0x6c0 mm/slub.c:5270
 mempool_alloc_noprof+0x1cf/0x2f0 mm/mempool.c:567
 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
 __get_metapage+0x50c/0xde0 fs/jfs/jfs_metapage.c:760
 dtSplitRoot+0x202/0x16c0 fs/jfs/jfs_dtree.c:1910
 dtSplitUp fs/jfs/jfs_dtree.c:993 [inline]
 dtInsert+0xef8/0x5f40 fs/jfs/jfs_dtree.c:871
 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137
 lookup_open fs/namei.c:4440 [inline]
 open_last_lookups fs/namei.c:4540 [inline]
 path_openat+0x18d1/0x3df0 fs/namei.c:4784
 do_filp_open+0x1fa/0x410 fs/namei.c:4814
 do_sys_openat2+0x121/0x200 fs/open.c:1430
 do_sys_open fs/open.c:1436 [inline]
 __do_sys_openat fs/open.c:1452 [inline]
 __se_sys_openat fs/open.c:1447 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1447
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 8639:
 kasan_save_stack mm/kasan/common.c:56 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:77
 kasan_save_free_info+0x46/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:252 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:284
 kasan_slab_free include/linux/kasan.h:234 [inline]
 slab_free_hook mm/slub.c:2540 [inline]
 slab_free mm/slub.c:6668 [inline]
 kmem_cache_free+0x18f/0x8d0 mm/slub.c:6779
 mempool_free+0xf5/0x140 mm/mempool.c:712
 free_metapage fs/jfs/jfs_metapage.c:279 [inline]
 drop_metapage fs/jfs/jfs_metapage.c:316 [inline]
 release_metapage+0x84c/0xab0 fs/jfs/jfs_metapage.c:892
 dtReadNext fs/jfs/jfs_dtree.c:3202 [inline]
 jfs_readdir+0xece/0x3ae0 fs/jfs/jfs_dtree.c:2874
 wrap_directory_iterator+0x99/0xe0 fs/readdir.c:65
 iterate_dir+0x3a5/0x580 fs/readdir.c:108
 __do_sys_getdents64 fs/readdir.c:410 [inline]
 __se_sys_getdents64+0xe4/0x260 fs/readdir.c:396
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xfa/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8880314fb4e0
 which belongs to the cache jfs_mp of size 248
The buggy address is located 48 bytes inside of
 freed 248-byte region [ffff8880314fb4e0, ffff8880314fb5d8)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8880314fb000 pfn:0x314fb
flags: 0x80000000000000(node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000000 ffff88801a375780 dead000000000122 0000000000000000
raw: ffff8880314fb000 00000000800d000a 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 5795, tgid 5795 (syz-executor), ts 271928472639, free_ts 271927985270
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x234/0x290 mm/page_alloc.c:1846
 prep_new_page mm/page_alloc.c:1854 [inline]
 get_page_from_freelist+0x28c0/0x2960 mm/page_alloc.c:3915
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:5210
 alloc_pages_mpol+0xd1/0x380 mm/mempolicy.c:2486
 alloc_slab_page mm/slub.c:3075 [inline]
 allocate_slab+0x86/0x3b0 mm/slub.c:3248
 new_slab mm/slub.c:3302 [inline]
 ___slab_alloc+0xb10/0x1400 mm/slub.c:4656
 __slab_alloc+0xc6/0x1f0 mm/slub.c:4779
 __slab_alloc_node mm/slub.c:4855 [inline]
 slab_alloc_node mm/slub.c:5251 [inline]
 kmem_cache_alloc_noprof+0x101/0x6c0 mm/slub.c:5270
 mempool_alloc_noprof+0x1cf/0x2f0 mm/mempool.c:567
 alloc_metapage fs/jfs/jfs_metapage.c:264 [inline]
 __get_metapage+0x50c/0xde0 fs/jfs/jfs_metapage.c:760
 diWriteSpecial+0x1b4/0x460 fs/jfs/jfs_imap.c:518
 diSync+0x69d/0x8d0 fs/jfs/jfs_imap.c:251
 diUnmount+0xc8/0x130 fs/jfs/jfs_imap.c:185
 jfs_umount+0x1d7/0x3c0 fs/jfs/jfs_umount.c:72
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x135/0x2c0 fs/super.c:643
page last free pid 5795 tgid 5795 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1395 [inline]
 free_unref_folios+0xc28/0x1810 mm/page_alloc.c:3000
 folios_put_refs+0x569/0x670 mm/swap.c:1002
 folio_batch_release include/linux/pagevec.h:101 [inline]
 truncate_inode_pages_range+0x349/0xd90 mm/truncate.c:408
 diUnmount+0xf7/0x130 fs/jfs/jfs_imap.c:190
 jfs_umount+0x191/0x3c0 fs/jfs/jfs_umount.c:63
 jfs_put_super+0x8c/0x190 fs/jfs/super.c:194
 generic_shutdown_super+0x135/0x2c0 fs/super.c:643
 kill_block_super+0x44/0x90 fs/super.c:1722
 deactivate_locked_super+0xbc/0x130 fs/super.c:474
 cleanup_mnt+0x425/0x4c0 fs/namespace.c:1318
 task_work_run+0x1d4/0x260 kernel/task_work.c:233
 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline]
 __exit_to_user_mode_loop kernel/entry/common.c:44 [inline]
 exit_to_user_mode_loop+0xff/0x4f0 kernel/entry/common.c:75
 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:226 [inline]
 syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:256 [inline]
 syscall_exit_to_user_mode_work include/linux/entry-common.h:159 [inline]
 syscall_exit_to_user_mode include/linux/entry-common.h:194 [inline]
 do_syscall_64+0x2d0/0xf80 arch/x86/entry/syscall_64.c:100
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8880314fb400: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff8880314fb480: 00 00 00 00 fc fc fc fc fc fc fc fc fa fb fb fb
>ffff8880314fb500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff8880314fb580: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
 ffff8880314fb600: fc fc fc 00 00 00 00 00 00 00 00 00 00 00 00 00
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