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BUG: KASAN: slab-out-of-bounds in dtInsertEntry+0xe9a/0x1430 fs/jfs/jfs_dtree.c:3753
Read of size 4 at addr ffff88805880b6e4 by task syz.4.41/6189

CPU: 0 UID: 0 PID: 6189 Comm: syz.4.41 Not tainted 6.15.0-rc5-syzkaller-00300-g3ce9925823c7 #0 PREEMPT(full) 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025
Call Trace:
 <TASK>
 dump_stack_lvl+0x189/0x250 lib/dump_stack.c:120
 print_address_description mm/kasan/report.c:408 [inline]
 print_report+0xb4/0x290 mm/kasan/report.c:521
 kasan_report+0x118/0x150 mm/kasan/report.c:634
 dtInsertEntry+0xe9a/0x1430 fs/jfs/jfs_dtree.c:3753
 dtSplitPage+0x2a83/0x3b20 fs/jfs/jfs_dtree.c:1596
 dtSplitUp fs/jfs/jfs_dtree.c:1092 [inline]
 dtInsert+0x109b/0x5f40 fs/jfs/jfs_dtree.c:871
 jfs_create+0x6c8/0xa80 fs/jfs/namei.c:137
 lookup_open fs/namei.c:3701 [inline]
 open_last_lookups fs/namei.c:3800 [inline]
 path_openat+0x14f1/0x3830 fs/namei.c:4036
 do_filp_open+0x1fa/0x410 fs/namei.c:4066
 do_sys_openat2+0x121/0x1c0 fs/open.c:1429
 do_sys_open fs/open.c:1444 [inline]
 __do_sys_openat fs/open.c:1460 [inline]
 __se_sys_openat fs/open.c:1455 [inline]
 __x64_sys_openat+0x138/0x170 fs/open.c:1455
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f852478e969
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:00007f85255ba038 EFLAGS: 00000246 ORIG_RAX: 0000000000000101
RAX: ffffffffffffffda RBX: 00007f85249b6080 RCX: 00007f852478e969
RDX: 000000000000275a RSI: 0000200000000100 RDI: ffffffffffffff9c
RBP: 00007f8524810ab1 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 0000000000000000 R14: 00007f85249b6080 R15: 00007ffed5ccc108
 </TASK>

Allocated by task 6185:
 kasan_save_stack mm/kasan/common.c:47 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:68
 unpoison_slab_object mm/kasan/common.c:319 [inline]
 __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:345
 kasan_slab_alloc include/linux/kasan.h:250 [inline]
 slab_post_alloc_hook mm/slub.c:4147 [inline]
 slab_alloc_node mm/slub.c:4196 [inline]
 kmem_cache_alloc_lru_noprof+0x1c6/0x3d0 mm/slub.c:4215
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x67/0x1b0 fs/inode.c:346
 iget_locked+0xf0/0x570 fs/inode.c:1439
 jfs_iget+0x24/0x3e0 fs/jfs/inode.c:29
 jfs_lookup+0x1c5/0x380 fs/jfs/namei.c:1469
 __lookup_slow+0x294/0x3d0 fs/namei.c:1817
 lookup_slow+0x53/0x70 fs/namei.c:1834
 walk_component+0x2d2/0x400 fs/namei.c:2138
 lookup_last fs/namei.c:2636 [inline]
 path_lookupat+0x163/0x430 fs/namei.c:2660
 filename_lookup+0x212/0x570 fs/namei.c:2689
 user_path_at+0x3a/0x60 fs/namei.c:3120
 __do_sys_chdir fs/open.c:557 [inline]
 __se_sys_chdir+0x91/0x280 fs/open.c:551
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88805880ae18
 which belongs to the cache jfs_ip of size 2232
The buggy address is located 20 bytes to the right of
 allocated 2232-byte region [ffff88805880ae18, ffff88805880b6d0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x58808
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8880316f9f01
flags: 0xfff00000000040(head|node=0|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 00fff00000000040 ffff8881432d1b40 dead000000000122 0000000000000000
raw: 0000000000000000 00000000000d000d 00000000f5000000 ffff8880316f9f01
head: 00fff00000000040 ffff8881432d1b40 dead000000000122 0000000000000000
head: 0000000000000000 00000000000d000d 00000000f5000000 ffff8880316f9f01
head: 00fff00000000003 ffffea0001620201 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 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 5940, tgid 5938 (syz.2.3), ts 98484851754, free_ts 27868725986
 set_page_owner include/linux/page_owner.h:32 [inline]
 post_alloc_hook+0x1d8/0x230 mm/page_alloc.c:1718
 prep_new_page mm/page_alloc.c:1726 [inline]
 get_page_from_freelist+0x21c7/0x22a0 mm/page_alloc.c:3688
 __alloc_frozen_pages_noprof+0x181/0x370 mm/page_alloc.c:4970
 alloc_pages_mpol+0x232/0x4a0 mm/mempolicy.c:2301
 alloc_slab_page mm/slub.c:2450 [inline]
 allocate_slab+0x8a/0x3b0 mm/slub.c:2618
 new_slab mm/slub.c:2672 [inline]
 ___slab_alloc+0xbfc/0x1480 mm/slub.c:3858
 __slab_alloc mm/slub.c:3948 [inline]
 __slab_alloc_node mm/slub.c:4023 [inline]
 slab_alloc_node mm/slub.c:4184 [inline]
 kmem_cache_alloc_lru_noprof+0x288/0x3d0 mm/slub.c:4215
 jfs_alloc_inode+0x28/0x70 fs/jfs/super.c:105
 alloc_inode+0x67/0x1b0 fs/inode.c:346
 new_inode+0x22/0x170 fs/inode.c:1145
 jfs_fill_super+0x569/0xd90 fs/jfs/super.c:511
 get_tree_bdev_flags+0x40b/0x4d0 fs/super.c:1636
 vfs_get_tree+0x8f/0x2b0 fs/super.c:1759
 do_new_mount+0x24a/0xa40 fs/namespace.c:3881
 do_mount fs/namespace.c:4221 [inline]
 __do_sys_mount fs/namespace.c:4432 [inline]
 __se_sys_mount+0x317/0x410 fs/namespace.c:4409
 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline]
 do_syscall_64+0xf6/0x210 arch/x86/entry/syscall_64.c:94
page last free pid 1 tgid 1 stack trace:
 reset_page_owner include/linux/page_owner.h:25 [inline]
 free_pages_prepare mm/page_alloc.c:1262 [inline]
 __free_frozen_pages+0xb05/0xcd0 mm/page_alloc.c:2725
 __free_pages mm/page_alloc.c:5080 [inline]
 free_contig_range+0x159/0x440 mm/page_alloc.c:6936
 destroy_args+0x86/0x460 mm/debug_vm_pgtable.c:1017
 debug_vm_pgtable+0x3cf/0x410 mm/debug_vm_pgtable.c:1397
 do_one_initcall+0x233/0x820 init/main.c:1257
 do_initcall_level+0x137/0x1f0 init/main.c:1319
 do_initcalls+0x69/0xd0 init/main.c:1335
 kernel_init_freeable+0x3d9/0x570 init/main.c:1567
 kernel_init+0x1d/0x1d0 init/main.c:1457
 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88805880b580: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
 ffff88805880b600: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
>ffff88805880b680: 00 00 00 00 00 00 00 00 00 00 fc fc fc fc fc fc
                                                       ^
 ffff88805880b700: fc fc fc fc fc fc fc fc fc fc fa fb fb fb fb fb
 ffff88805880b780: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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