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BUG: KASAN: slab-use-after-free in jfs_lazycommit+0x74b/0xa90
Read of size 4 at addr ffff888129ff6e94 by task jfsCommit/114

CPU: 0 UID: 0 PID: 114 Comm: jfsCommit 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+0x189/0x250
 print_report+0xca/0x240
 kasan_report+0x118/0x150
 jfs_lazycommit+0x74b/0xa90
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30
 </TASK>

Allocated by task 11988:
 kasan_save_track+0x3e/0x80
 __kasan_kmalloc+0x93/0xb0
 __kmalloc_cache_noprof+0x230/0x3d0
 jfs_fill_super+0xc2/0xd80
 get_tree_bdev_flags+0x40e/0x4d0
 vfs_get_tree+0x92/0x2b0
 do_new_mount+0x2a2/0x9e0
 __se_sys_mount+0x317/0x410
 do_syscall_64+0xfa/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 11446:
 kasan_save_track+0x3e/0x80
 kasan_save_free_info+0x46/0x50
 __kasan_slab_free+0x5b/0x80
 kfree+0x18e/0x440
 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+0xec/0x110
 do_syscall_64+0x2bd/0x3b0
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff888129ff6e00
 which belongs to the cache kmalloc-256 of size 256
The buggy address is located 148 bytes inside of
 freed 256-byte region [ffff888129ff6e00, ffff888129ff6f00)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x129ff6
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x57ff00000000040(head|node=1|zone=2|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 057ff00000000040 ffff88801a441b40 ffffea00009ea080 dead000000000006
raw: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000040 ffff88801a441b40 ffffea00009ea080 dead000000000006
head: 0000000000000000 0000000000100010 00000000f5000000 0000000000000000
head: 057ff00000000001 ffffea0004a7fd81 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 0x52820(GFP_ATOMIC|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 10403, tgid 10403 (kworker/1:8), ts 268226637841, free_ts 256552657572
 post_alloc_hook+0x240/0x2a0
 get_page_from_freelist+0x21e4/0x22c0
 __alloc_frozen_pages_noprof+0x181/0x370
 alloc_pages_mpol+0x232/0x4a0
 allocate_slab+0x8a/0x370
 ___slab_alloc+0xbeb/0x1410
 __kmalloc_cache_noprof+0x296/0x3d0
 batadv_bla_get_backbone_gw+0x147/0xed0
 batadv_bla_tx+0xbdc/0x1390
 batadv_interface_tx+0x572/0x14c0
 dev_hard_start_xmit+0x2d7/0x830
 __dev_queue_xmit+0x1b8d/0x3b50
 ip6_finish_output2+0x11bc/0x16a0
 NF_HOOK+0x9e/0x380
 mld_sendpack+0x800/0xd80
 mld_ifc_work+0x83e/0xd60
page last free pid 15 tgid 15 stack trace:
 __free_frozen_pages+0xbc4/0xd30
 __tlb_remove_table+0x2d2/0x3b0
 tlb_remove_table_rcu+0x85/0x100
 rcu_core+0xcab/0x1770
 handle_softirqs+0x286/0x870
 run_ksoftirqd+0x9b/0x100
 smpboot_thread_fn+0x542/0xa60
 kthread+0x711/0x8a0
 ret_from_fork+0x3fc/0x770
 ret_from_fork_asm+0x1a/0x30

Memory state around the buggy address:
 ffff888129ff6d80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888129ff6e00: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888129ff6e80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                         ^
 ffff888129ff6f00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff888129ff6f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
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