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BUG: KASAN: slab-use-after-free in dtSplitPage+0x1248/0x37c0
Read of size 1 at addr ffff8881b6521b85 by task syz.3.447/8080

CPU: 1 UID: 0 PID: 8080 Comm: syz.3.447 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.2-debian-1.16.2-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150
 print_report+0xba/0x230
 kasan_report+0x117/0x150
 dtSplitPage+0x1248/0x37c0
 dtInsert+0x10a4/0x5f10
 jfs_mkdir+0x783/0xb00
 vfs_mkdir+0x413/0x630
 filename_mkdirat+0x285/0x510
 __se_sys_mkdirat+0x35/0x150
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fb2c919b607
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:00007fb2ca126e58 EFLAGS: 00000246 ORIG_RAX: 0000000000000102
RAX: ffffffffffffffda RBX: 00007fb2ca126ee0 RCX: 00007fb2c919b607
RDX: 00000000000001ff RSI: 0000200000000680 RDI: 00000000ffffff9c
RBP: 0000200000000000 R08: 0000200000000040 R09: 0000000000000000
R10: 0000200000000000 R11: 0000000000000246 R12: 0000200000000680
R13: 00007fb2ca126ea0 R14: 0000000000000000 R15: 0000000000000000
 </TASK>

Allocated by task 8080:
 kasan_save_track+0x3e/0x80
 __kasan_slab_alloc+0x6c/0x80
 kmem_cache_alloc_lru_noprof+0x2b8/0x640
 jfs_alloc_inode+0x28/0x70
 alloc_inode+0x6a/0x1b0
 new_inode+0x22/0x170
 ialloc+0x4c/0x8f0
 jfs_create+0x1da/0xb10
 vfs_create+0x2d1/0x460
 filename_mknodat+0x3e8/0x660
 __se_sys_mknod+0x3a/0x150
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 8080:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kmem_cache_free+0x187/0x630
 rcu_core+0x7cd/0x1070
 handle_softirqs+0x22a/0x870
 __irq_exit_rcu+0x5f/0x150
 irq_exit_rcu+0x9/0x30
 sysvec_apic_timer_interrupt+0x57/0xc0
 asm_sysvec_apic_timer_interrupt+0x1a/0x20

Last potentially related work creation:
 kasan_save_stack+0x3e/0x60
 kasan_record_aux_stack+0xbd/0xd0
 call_rcu+0xee/0x890
 evict+0x95b/0xb10
 jfs_create+0x503/0xb10
 vfs_create+0x2d1/0x460
 filename_mknodat+0x3e8/0x660
 __se_sys_mknod+0x3a/0x150
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff8881b6521b78
 which belongs to the cache jfs_ip of size 2216
The buggy address is located 13 bytes inside of
 freed 2216-byte region [ffff8881b6521b78, ffff8881b6522420)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff8881b6520000 pfn:0x1b6520
head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
memcg:ffff8881b6527709
flags: 0x57ff00000000240(workingset|head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000240 ffff888103363140 ffff888168771b88 ffffea0006c4ac10
raw: ffff8881b6520000 00000008000d000c 00000000f5000000 ffff8881b6527709
head: 057ff00000000240 ffff888103363140 ffff888168771b88 ffffea0006c4ac10
head: ffff8881b6520000 00000008000d000c 00000000f5000000 ffff8881b6527709
head: 057ff00000000003 ffffea0006d94801 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 6039, tgid 6038 (syz.2.44), ts 73445476163, free_ts 72196813237
 post_alloc_hook+0x231/0x280
 get_page_from_freelist+0x24dc/0x2580
 __alloc_frozen_pages_noprof+0x18d/0x380
 allocate_slab+0x77/0x660
 refill_objects+0x331/0x3c0
 __pcs_replace_empty_main+0x40a/0x730
 kmem_cache_alloc_lru_noprof+0x37c/0x640
 jfs_alloc_inode+0x28/0x70
 alloc_inode+0x6a/0x1b0
 new_inode+0x22/0x170
 jfs_fill_super+0x569/0xd80
 get_tree_bdev_flags+0x431/0x4f0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x341/0xd30
 __se_sys_mount+0x31d/0x420
 do_syscall_64+0x14d/0xf80
page last free pid 5816 tgid 5816 stack trace:
 __free_frozen_pages+0xc2b/0xdb0
 __slab_free+0x263/0x2b0
 qlist_free_all+0x97/0x100
 kasan_quarantine_reduce+0x148/0x160
 __kasan_slab_alloc+0x22/0x80
 kmem_cache_alloc_noprof+0x2bc/0x650
 do_getname+0x2e/0x250
 user_path_at+0x2a/0x160
 __x64_sys_umount+0xf6/0x170
 do_syscall_64+0x14d/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Memory state around the buggy address:
 ffff8881b6521a80: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 fc
 ffff8881b6521b00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fa
>ffff8881b6521b80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                   ^
 ffff8881b6521c00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8881b6521c80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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