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BUG: KASAN: slab-use-after-free in snapshot_ctr+0x5cb/0x1340 drivers/md/dm-snap.c:1284
Read of size 8 at addr ffff88804004d398 by task syz.0.0/5357

CPU: 0 UID: 0 PID: 5357 Comm: syz.0.0 Not tainted syzkaller #0 PREEMPT(full) 
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0xe8/0x150 lib/dump_stack.c:120
 print_address_description+0x55/0x1e0 mm/kasan/report.c:378
 print_report+0x58/0x70 mm/kasan/report.c:482
 kasan_report+0x117/0x150 mm/kasan/report.c:595
 snapshot_ctr+0x5cb/0x1340 drivers/md/dm-snap.c:1284
 dm_table_add_target+0x58d/0xc70 drivers/md/dm-table.c:749
 populate_table drivers/md/dm-ioctl.c:1602 [inline]
 table_load+0x325/0x8a0 drivers/md/dm-ioctl.c:1645
 ctl_ioctl drivers/md/dm-ioctl.c:2221 [inline]
 dm_ctl_ioctl+0x9ec/0xe10 drivers/md/dm-ioctl.c:2243
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7f36ac39f559
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:00007f36ad349fe8 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 00007f36ac625fa0 RCX: 00007f36ac39f559
RDX: 0000200000000000 RSI: 00000000c138fd09 RDI: 0000000000000003
RBP: 00007f36ac436b20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000
R13: 00007f36ac626038 R14: 00007f36ac625fa0 R15: 00007ffe6e9165b8
 </TASK>

Allocated by task 5357:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 poison_kmalloc_redzone mm/kasan/common.c:409 [inline]
 __kasan_kmalloc+0x93/0xb0 mm/kasan/common.c:426
 kasan_kmalloc include/linux/kasan.h:263 [inline]
 __kmalloc_cache_node_noprof+0x3cc/0x620 mm/slub.c:5699
 _kmalloc_node_noprof include/linux/slab.h:1196 [inline]
 open_table_device drivers/md/dm.c:733 [inline]
 dm_get_table_device+0x23e/0x730 drivers/md/dm.c:821
 dm_get_device+0x327/0x760 drivers/md/dm-table.c:388
 snapshot_ctr+0x2b2/0x1340 drivers/md/dm-snap.c:1269
 dm_table_add_target+0x58d/0xc70 drivers/md/dm-table.c:749
 populate_table drivers/md/dm-ioctl.c:1602 [inline]
 table_load+0x325/0x8a0 drivers/md/dm-ioctl.c:1645
 ctl_ioctl drivers/md/dm-ioctl.c:2221 [inline]
 dm_ctl_ioctl+0x9ec/0xe10 drivers/md/dm-ioctl.c:2243
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

Freed by task 5357:
 kasan_save_stack mm/kasan/common.c:57 [inline]
 kasan_save_track+0x3e/0x80 mm/kasan/common.c:78
 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:584
 poison_slab_object mm/kasan/common.c:264 [inline]
 __kasan_slab_free+0x5c/0x80 mm/kasan/common.c:296
 kasan_slab_free include/linux/kasan.h:235 [inline]
 slab_free_hook mm/slub.c:2780 [inline]
 slab_free mm/slub.c:6630 [inline]
 kfree+0x1c5/0x650 mm/slub.c:6923
 close_table_device drivers/md/dm.c:798 [inline]
 dm_put_table_device+0x255/0x2a0 drivers/md/dm.c:841
 upgrade_mode drivers/md/dm-table.c:326 [inline]
 dm_get_device+0x56f/0x760 drivers/md/dm-table.c:399
 snapshot_ctr+0x471/0x1340 drivers/md/dm-snap.c:1279
 dm_table_add_target+0x58d/0xc70 drivers/md/dm-table.c:749
 populate_table drivers/md/dm-ioctl.c:1602 [inline]
 table_load+0x325/0x8a0 drivers/md/dm-ioctl.c:1645
 ctl_ioctl drivers/md/dm-ioctl.c:2221 [inline]
 dm_ctl_ioctl+0x9ec/0xe10 drivers/md/dm-ioctl.c:2243
 vfs_ioctl fs/ioctl.c:51 [inline]
 __do_sys_ioctl fs/ioctl.c:597 [inline]
 __se_sys_ioctl+0xfc/0x170 fs/ioctl.c:583
 do_syscall_x64 arch/x86/entry/syscall_64.c:61 [inline]
 do_syscall_64+0x166/0x520 arch/x86/entry/syscall_64.c:84
 entry_SYSCALL_64_after_hwframe+0x77/0x7f

The buggy address belongs to the object at ffff88804004d380
 which belongs to the cache kmalloc-96 of size 96
The buggy address is located 24 bytes inside of
 freed 96-byte region [ffff88804004d380, ffff88804004d3e0)

The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x4004d
flags: 0x4fff00000000000(node=1|zone=1|lastcpupid=0x7ff)
page_type: f5(slab)
raw: 04fff00000000000 ffff88801c441280 dead000000000100 dead000000000122
raw: 0000000000000000 0000000000200020 00000000f5000000 0000000000000000
page dumped because: kasan: bad access detected
page_owner tracks the page as allocated
page last allocated via order 0, migratetype Unmovable, gfp_mask 0x52cc0(GFP_KERNEL|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP), pid 1, tgid 1 (swapper/0), ts 25597448691
 set_page_owner include/linux/page_owner.h:33 [inline]
 post_alloc_hook+0x1f9/0x250 mm/page_alloc.c:1854
 prep_new_page mm/page_alloc.c:1862 [inline]
 get_page_from_freelist+0x220f/0x2280 mm/page_alloc.c:3933
 __alloc_frozen_pages_noprof+0x1fc/0x400 mm/page_alloc.c:5429
 alloc_slab_page mm/slub.c:3384 [inline]
 allocate_slab+0x7d/0x5e0 mm/slub.c:3499
 new_slab mm/slub.c:3550 [inline]
 ___slab_alloc+0x16a/0x960 mm/slub.c:4605
 slab_alloc_node mm/slub.c:5024 [inline]
 __kmalloc_cache_node_noprof+0x1d6/0x620 mm/slub.c:5695
 _kmalloc_node_noprof include/linux/slab.h:1196 [inline]
 alloc_flush_pnodes kernel/workqueue.c:5275 [inline]
 __alloc_workqueue+0x7dc/0x21d0 kernel/workqueue.c:6189
 alloc_workqueue_va kernel/workqueue.c:6253 [inline]
 alloc_workqueue_noprof+0xe3/0x210 kernel/workqueue.c:6269
 mlx4_ib_init+0x1b/0x90 drivers/infiniband/hw/mlx4/main.c:3349
 do_one_initcall+0x250/0x870 init/main.c:1423
 do_initcall_level+0x10a/0x1a0 init/main.c:1485
 do_initcalls+0x59/0xa0 init/main.c:1501
 kernel_init_freeable+0x29d/0x3e0 init/main.c:1736
 kernel_init+0x22/0x1d0 init/main.c:1626
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
page last free pid 44 tgid 44 ts 25596861804 stack trace:
 reset_page_owner include/linux/page_owner.h:26 [inline]
 __free_pages_prepare mm/page_alloc.c:1401 [inline]
 __free_frozen_pages+0xc97/0xd90 mm/page_alloc.c:2952
 __kasan_populate_vmalloc_do mm/kasan/shadow.c:393 [inline]
 __kasan_populate_vmalloc+0x1a8/0x1c0 mm/kasan/shadow.c:424
 kasan_populate_vmalloc include/linux/kasan.h:580 [inline]
 alloc_vmap_area+0xd10/0x1410 mm/vmalloc.c:2145
 __get_vm_area_node+0x200/0x2f0 mm/vmalloc.c:3248
 __vmalloc_node_range_noprof+0x36e/0x16f0 mm/vmalloc.c:4079
 __vmalloc_node_noprof+0xc2/0x100 mm/vmalloc.c:4180
 alloc_thread_stack_node kernel/fork.c:359 [inline]
 dup_task_struct+0x2c6/0xa00 kernel/fork.c:930
 copy_process+0x7ea/0x44b0 kernel/fork.c:2141
 kernel_clone+0x2d7/0x940 kernel/fork.c:2783
 user_mode_thread+0x115/0x180 kernel/fork.c:2860
 call_usermodehelper_exec_work+0x5c/0x230 kernel/umh.c:169
 process_one_work kernel/workqueue.c:3495 [inline]
 process_scheduled_works+0xc3d/0x1630 kernel/workqueue.c:3578
 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3659
 kthread+0x38b/0x480 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245

Memory state around the buggy address:
 ffff88804004d280: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88804004d300: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
>ffff88804004d380: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                            ^
 ffff88804004d400: fa fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
 ffff88804004d480: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
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