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BUG: KASAN: use-after-free in vhci_hub_control+0x1b6d/0x1be0 drivers/usb/usbip/vhci_hcd.c:441
Read of size 4 at addr ffff8801cdb684bc by task syz-executor4/27453

CPU: 0 PID: 27453 Comm: syz-executor4 Not tainted 4.19.0-rc6-next-20181005+ #88
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d3/0x2c4 lib/dump_stack.c:113
 print_address_description.cold.8+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_error mm/kasan/report.c:354 [inline]
 kasan_report.cold.9+0x242/0x309 mm/kasan/report.c:412
 __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:432
 vhci_hub_control+0x1b6d/0x1be0 drivers/usb/usbip/vhci_hcd.c:441
 rh_call_control drivers/usb/core/hcd.c:679 [inline]
 rh_urb_enqueue drivers/usb/core/hcd.c:838 [inline]
 usb_hcd_submit_urb+0x17bb/0x20a0 drivers/usb/core/hcd.c:1651
 usb_submit_urb+0x893/0x14e0 drivers/usb/core/urb.c:570
 usb_start_wait_urb+0x13d/0x370 drivers/usb/core/message.c:57
 usb_internal_control_msg drivers/usb/core/message.c:101 [inline]
 usb_control_msg+0x332/0x4e0 drivers/usb/core/message.c:152
 proc_control+0x99b/0xef0 drivers/usb/core/devio.c:1106
 usbdev_do_ioctl+0x1eb8/0x3b50 drivers/usb/core/devio.c:2412
 usbdev_ioctl+0x25/0x30 drivers/usb/core/devio.c:2569
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:501 [inline]
 do_vfs_ioctl+0x1de/0x1720 fs/ioctl.c:685
 ksys_ioctl+0xa9/0xd0 fs/ioctl.c:702
 __do_sys_ioctl fs/ioctl.c:709 [inline]
 __se_sys_ioctl fs/ioctl.c:707 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:707
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fdc9965ec78 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000020000000 RSI: 00000000c0185500 RDI: 0000000000000003
RBP: 000000000072bf00 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fdc9965f6d4
R13: 00000000004bf6c0 R14: 00000000004cf598 R15: 00000000ffffffff

Allocated by task 27136:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xc7/0xe0 mm/kasan/kasan.c:553
 __do_kmalloc_node mm/slab.c:3684 [inline]
 __kmalloc_node+0x50/0x70 mm/slab.c:3691
 kmalloc_node include/linux/slab.h:589 [inline]
 kvmalloc_node+0x65/0xf0 mm/util.c:423
 kvmalloc include/linux/mm.h:577 [inline]
 kvmalloc_array include/linux/mm.h:595 [inline]
 alloc_fdtable+0xd9/0x280 fs/file.c:115
 dup_fd+0xa71/0xf50 fs/file.c:310
 copy_files kernel/fork.c:1423 [inline]
 copy_process+0x2734/0x8780 kernel/fork.c:1905
 _do_fork+0x1cb/0x11c0 kernel/fork.c:2216
 __do_sys_clone kernel/fork.c:2323 [inline]
 __se_sys_clone kernel/fork.c:2317 [inline]
 __x64_sys_clone+0xbf/0x150 kernel/fork.c:2317
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 27137:
 save_stack+0x43/0xd0 mm/kasan/kasan.c:448
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/kasan.c:521
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3817
 kvfree+0x61/0x70 mm/util.c:452
 __free_fdtable+0x31/0x70 fs/file.c:31
 put_files_struct+0x31d/0x3c0 fs/file.c:420
 exit_files+0x83/0xb0 fs/file.c:445
 do_exit+0xf40/0x2610 kernel/exit.c:862
 do_group_exit+0x177/0x440 kernel/exit.c:970
 __do_sys_exit_group kernel/exit.c:981 [inline]
 __se_sys_exit_group kernel/exit.c:979 [inline]
 __x64_sys_exit_group+0x3e/0x50 kernel/exit.c:979
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff8801cdb68440
 which belongs to the cache kmalloc-2k of size 2048
The buggy address is located 124 bytes inside of
 2048-byte region [ffff8801cdb68440, ffff8801cdb68c40)
The buggy address belongs to the page:
page:ffffea000736da00 count:1 mapcount:0 mapping:ffff8801da800c40 index:0x0 compound_mapcount: 0
flags: 0x2fffc0000010200(slab|head)
raw: 02fffc0000010200 ffffea00075fb508 ffffea000747d908 ffff8801da800c40
raw: 0000000000000000 ffff8801cdb68440 0000000100000003 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8801cdb68380: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
 ffff8801cdb68400: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb
>ffff8801cdb68480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                        ^
 ffff8801cdb68500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff8801cdb68580: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
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