==================================================================
BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x1248/0x37c0 fs/jfs/jfs_dtree.c:-1
Read of size 1 at addr ffff88805c243065 by task syz.9.241/7645

CPU: 1 UID: 0 PID: 7645 Comm: syz.9.241 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 03/18/2026
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:378 [inline]
 print_report+0xba/0x230 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 dtSplitPage+0x1248/0x37c0 fs/jfs/jfs_dtree.c:-1
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x10a4/0x5f10 fs/jfs/jfs_dtree.c:871
 jfs_mkdir+0x783/0xb00 fs/jfs/namei.c:271
 vfs_mkdir+0x40b/0x630 fs/namei.c:5239
 filename_mkdirat+0x289/0x520 fs/namei.c:5272
 __do_sys_mkdirat fs/namei.c:5293 [inline]
 __se_sys_mkdirat+0x35/0x150 fs/namei.c:5290
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f99f150b687
Code: 00 66 90 48 89 f2 b9 00 01 00 00 48 89 fe bf 9c ff ff ff e9 db f7 ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 b8 02 01 00 00 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:00007f99ef73ce58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007f99ef73cee0 RCX: 00007f99f150b687
RDX: 00000000000001ff RSI: 0000200000000040 RDI: 00000000ffffff9c
RBP: 0000200000000000 R08: 0000000000000000 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000200000000040
R13: 00007f99ef73cea0 R14: 0000000000000000 R15: 0000200000000380
 </TASK>

Allocated by task 7642:
 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:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_lru_noprof+0x33c/0x680 mm/slub.c:4885
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x6a/0x1b0 fs/inode.c:347
 iget_locked+0x131/0x6a0 fs/inode.c:1480
 jfs_iget+0x24/0x470 fs/jfs/inode.c:29
 jfs_lookup+0x220/0x420 fs/jfs/namei.c:1472
 __lookup_slow+0x2d2/0x440 fs/namei.c:1916
 lookup_slow+0x53/0x70 fs/namei.c:1933
 walk_component fs/namei.c:2279 [inline]
 lookup_last fs/namei.c:2786 [inline]
 path_lookupat+0x3f5/0x8c0 fs/namei.c:2810
 filename_lookup+0x256/0x5d0 fs/namei.c:2839
 __do_sys_chdir fs/open.c:559 [inline]
 __se_sys_chdir+0xa8/0x2a0 fs/open.c:552
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88805c242700
 which belongs to the cache jfs_ip of size 2368
The buggy address is located 37 bytes to the right of
 allocated 2368-byte region [ffff88805c242700, ffff88805c243040)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff88805c244e00 pfn:0x5c240
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff88805c247ec1
flags: 0x80000000000240(workingset|head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000240 ffff88801c757dc0 ffff88801c74ec88 ffffea00014c6410
raw: ffff88805c244e00 00000008000d000a 00000000f5000000 ffff88805c247ec1
head: 0080000000000240 ffff88801c757dc0 ffff88801c74ec88 ffffea00014c6410
head: ffff88805c244e00 00000008000d000a 00000000f5000000 ffff88805c247ec1
head: 0080000000000003 ffffea0001709001 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000008
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 3, migratetype Reclaimable, gfp_mask 0xd2050(__GFP_RECLAIMABLE|__GFP_IO|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6030, tgid 6026 (syz.0.24), ts 111658171081, free_ts 110479605803
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x231/0x280 mm/page_alloc.c:1889
 prep_new_page mm/page_alloc.c:1897 [inline]
 get_page_from_freelist+0x28bb/0x2950 mm/page_alloc.c:3962
 __alloc_frozen_pages_noprof+0x18d/0x380 mm/page_alloc.c:5250
 alloc_slab_page mm/slub.c:3292 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3481
 new_slab mm/slub.c:3539 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7175
 refill_sheaf mm/slub.c:2812 [inline]
 alloc_full_sheaf mm/slub.c:2834 [inline]
 __pcs_replace_empty_main+0x480/0x710 mm/slub.c:4626
 alloc_from_pcs mm/slub.c:4717 [inline]
 slab_alloc_node mm/slub.c:4851 [inline]
 kmem_cache_alloc_lru_noprof+0x433/0x680 mm/slub.c:4885
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x6a/0x1b0 fs/inode.c:347
 new_inode+0x22/0x170 fs/inode.c:1185
 jfs_fill_super+0x569/0xd80 fs/jfs/super.c:511
 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:3763 [inline]
 do_new_mount+0x341/0xd30 fs/namespace.c:3839
 do_mount fs/namespace.c:4172 [inline]
 __do_sys_mount fs/namespace.c:4361 [inline]
 __se_sys_mount+0x31d/0x420 fs/namespace.c:4338
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0x14d/0xf80 arch/x86/entry/syscall_64.c:94
page last free pid 5855 tgid 5855 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 __free_pages_prepare mm/page_alloc.c:1433 [inline]
 __free_frozen_pages+0xfe3/0x1170 mm/page_alloc.c:2978
 __slab_free+0x24f/0x2a0 mm/slub.c:5573
 qlink_free mm/kasan/quarantine.c:163 [inline]
 qlist_free_all+0x97/0x100 mm/kasan/quarantine.c:179
 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286
 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350
 kasan_slab_alloc include/linux/kasan.h:253 [inline]
 slab_post_alloc_hook mm/slub.c:4538 [inline]
 slab_alloc_node mm/slub.c:4866 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4873
 anon_vma_chain_alloc mm/rmap.c:142 [inline]
 __anon_vma_prepare+0xcb/0x4a0 mm/rmap.c:194
 __vmf_anon_prepare mm/memory.c:3734 [inline]
 vmf_anon_prepare mm/internal.h:502 [inline]
 do_anonymous_page mm/memory.c:5262 [inline]
 do_pte_missing+0x1d20/0x29e0 mm/memory.c:4475
 handle_pte_fault mm/memory.c:6317 [inline]
 __handle_mm_fault mm/memory.c:6455 [inline]
 handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6624
 do_user_addr_fault+0x75b/0x1340 arch/x86/mm/fault.c:1385
 handle_page_fault arch/x86/mm/fault.c:1474 [inline]
 exc_page_fault+0x6a/0xc0 arch/x86/mm/fault.c:1527
 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618

Memory state around the buggy address:
 ffff88805c242f00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805c242f80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805c243000: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                                       ^
 ffff88805c243080: fc fc fc fc fc fc fc fc 00 00 00 00 00 00 00 00
 ffff88805c243100: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
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