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BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x74b/0xa90
Read of size 4 at addr ffff888102eec694 by task jfsCommit/118

CPU: 0 UID: 0 PID: 118 Comm: jfsCommit Tainted: G             L      syzkaller #0 PREEMPT(full) 
Tainted: [L]=SOFTLOCKUP
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+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 jfs_lazycommit+0x74b/0xa90
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 6724:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x3e2/0x700
 jfs_fill_super+0xc2/0xd80
 get_tree_bdev_flags+0x40e/0x4d0
 vfs_get_tree+0x92/0x2a0
 do_new_mount+0x302/0xa10
 __se_sys_mount+0x313/0x410
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 6470:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5c/0x80
 kfree+0x1c0/0x660
 generic_shutdown_super+0x135/0x2c0
 kill_block_super+0x44/0x90
 deactivate_locked_super+0xbc/0x130
 cleanup_mnt+0x425/0x4c0
 task_work_run+0x1d4/0x260
 exit_to_user_mode_loop+0xff/0x4f0
 do_syscall_64+0x2d0/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888102eec600
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 148 bytes inside of
 freed 256-byte region [ffff888102eec600, ffff888102eec700)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0xffff888102eed800 pfn:0x102eec
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
ksm flags: 0x17ff00000000040(head|node=0|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 017ff00000000040 ffff888100041b40 ffffea0005b7ff00 0000000000000003
raw: ffff888102eed800 000000000010000c 00000000f5000000 0000000000000000
head: 017ff00000000040 ffff888100041b40 ffffea0005b7ff00 0000000000000003
head: ffff888102eed800 000000000010000c 00000000f5000000 0000000000000000
head: 017ff00000000001 ffffea00040bbb01 00000000ffffffff 00000000ffffffff
head: ffffffffffffffff 0000000000000000 00000000ffffffff 0000000000000002
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 1, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 6653, tgid 6651 (syz.2.179), ts 101862534682, free_ts 99227071601
 post_alloc_hook+0x23d/0x2a0
 get_page_from_freelist+0x22f6/0x23d0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x86/0x3b0
 ___slab_alloc+0xf2b/0x1960
 __slab_alloc+0x65/0x100
 __kmalloc_noprof+0x47d/0x800
 iter_file_splice_write+0x1c8/0x10b0
 direct_splice_actor+0x101/0x160
 splice_direct_to_actor+0x5a8/0xcc0
 do_splice_direct+0x181/0x270
 do_sendfile+0x4da/0x7e0
 __se_sys_sendfile64+0x13e/0x190
 do_syscall_64+0xfa/0xf80
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
page last free pid 15 tgid 15 stack trace:
 __free_frozen_pages+0xb99/0xd10
 rcu_core+0xd70/0x1870
 handle_softirqs+0x27d/0x850
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x599/0xb30
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff888102eec580: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888102eec600: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888102eec680: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888102eec700: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888102eec780: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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