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BUG: KASAN: slab-out-of-bounds in dtSplitPage+0x1248/0x37c0 fs/jfs/jfs_dtree.c:-1
Read of size 1 at addr ffff888040f2c3e5 by task syz.1.736/11083

CPU: 0 UID: 0 PID: 11083 Comm: syz.1.736 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026
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_symlink+0x8b5/0xfd0 fs/jfs/namei.c:1021
 vfs_symlink+0x195/0x340 fs/namei.c:5615
 filename_symlinkat+0x1cd/0x420 fs/namei.c:5640
 __do_sys_symlink fs/namei.c:5667 [inline]
 __se_sys_symlink+0x4d/0x2b0 fs/namei.c:5663
 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: 0033:0x7efc4c65c629
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:00007efc4a895028 EFLAGS: 00000246 ORIG_RAX: 0000000000000058
RAX: ffffffffffffffda RBX: 00007efc4c8d6090 RCX: 00007efc4c65c629
RDX: 0000000000000000 RSI: 00002000000002c0 RDI: 0000200000000100
RBP: 00007efc4c6f2b39 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007efc4c8d6128 R14: 00007efc4c8d6090 R15: 00007ffd6f6c6d38
 </TASK>

Allocated by task 11056:
 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:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 kmem_cache_alloc_lru_noprof+0x33c/0x680 mm/slub.c:4849
 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:2780 [inline]
 path_lookupat+0x3f5/0x8c0 fs/namei.c:2804
 filename_lookup+0x256/0x5d0 fs/namei.c:2833
 __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 ffff888040f2ba80
 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 [ffff888040f2ba80, ffff888040f2c3c0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888040f2a700 pfn:0x40f28
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff888040f2fec1
flags: 0x80000000000240(workingset|head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000240 ffff888140aa1dc0 ffffea0001038a10 ffffea000103b610
raw: ffff888040f2a700 00000008000d0008 00000000f5000000 ffff888040f2fec1
head: 0080000000000240 ffff888140aa1dc0 ffffea0001038a10 ffffea000103b610
head: ffff888040f2a700 00000008000d0008 00000000f5000000 ffff888040f2fec1
head: 0080000000000003 ffffea000103ca01 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 5978, tgid 5963 (syz.4.17), ts 113508981137, free_ts 113088218014
 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:3255 [inline]
 allocate_slab+0x77/0x660 mm/slub.c:3444
 new_slab mm/slub.c:3502 [inline]
 refill_objects+0x334/0x3c0 mm/slub.c:7134
 refill_sheaf+0x29/0x50 mm/slub.c:2804
 alloc_full_sheaf mm/slub.c:2825 [inline]
 __pcs_replace_empty_main+0x3ab/0x5f0 mm/slub.c:4588
 alloc_from_pcs mm/slub.c:4681 [inline]
 slab_alloc_node mm/slub.c:4815 [inline]
 kmem_cache_alloc_lru_noprof+0x433/0x680 mm/slub.c:4849
 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_one_qstr_excl+0x131/0x360 fs/namei.c:1805
 __start_renaming+0x186/0x410 fs/namei.c:3856
 filename_renameat2+0x38c/0x9c0 fs/namei.c:6119
page last free pid 5919 tgid 5919 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:5532
 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:4501 [inline]
 slab_alloc_node mm/slub.c:4830 [inline]
 kmem_cache_alloc_noprof+0x33b/0x680 mm/slub.c:4837
 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:5261 [inline]
 do_pte_missing+0x1fe2/0x2d30 mm/memory.c:4475
 handle_pte_fault mm/memory.c:6316 [inline]
 __handle_mm_fault mm/memory.c:6454 [inline]
 handle_mm_fault+0xd0a/0x13c0 mm/memory.c:6623
 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:
 ffff888040f2c280: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff888040f2c300: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff888040f2c380: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
                                                       ^
 ffff888040f2c400: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
 ffff888040f2c480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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