KASAN: invalid-free in hub_event

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    d6d460b89378 Merge tag 'dma-mapping-4.20-3' of git://git.i..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=17bd99eb400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=73e2bc0cb6463446
dashboard link: https://syzkaller.appspot.com/bug?extid=98881958e1410ec7e53c
compiler:       gcc (GCC) 8.0.1 20180413 (experimental)

Unfortunately, I don't have any reproducer for this crash yet.

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+98881958e1410ec7e53c@xxxxxxxxxxxxxxxxxxxxxxxxx

erofs: read_super, device -> /dev/loop5
erofs: options ->  
nouser_xattr,fault_injection=0x00000000000007ff,fowner>00000000000000000000,uid<00000000000000000000,subj_type=ntfs
erofs: cannot find valid erofs superblock
vhci_hcd: default hub control req: 0080 v0400 i0000 l0
==================================================================
BUG: KASAN: double-free or invalid-free in port_over_current_notify  
drivers/usb/core/hub.c:5192 [inline]
BUG: KASAN: double-free or invalid-free in port_event  
drivers/usb/core/hub.c:5241 [inline]
BUG: KASAN: double-free or invalid-free in hub_event+0xd97/0x4140  
drivers/usb/core/hub.c:5384

CPU: 1 PID: 32710 Comm: kworker/1:3 Not tainted 4.20.0-rc3+ #129
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Workqueue: usb_hub_wq hub_event
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x244/0x39d lib/dump_stack.c:113
 print_address_description.cold.7+0x9/0x1ff mm/kasan/report.c:256
 kasan_report_invalid_free+0x64/0xa0 mm/kasan/report.c:336
 __kasan_slab_free+0x13a/0x150 mm/kasan/kasan.c:501
 kasan_slab_free+0xe/0x10 mm/kasan/kasan.c:528
 __cache_free mm/slab.c:3498 [inline]
 kfree+0xcf/0x230 mm/slab.c:3817
 port_over_current_notify drivers/usb/core/hub.c:5192 [inline]
 port_event drivers/usb/core/hub.c:5241 [inline]
 hub_event+0xd97/0x4140 drivers/usb/core/hub.c:5384
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Allocated by task 32710:
 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 mm/slab.c:3722 [inline]
 __kmalloc_track_caller+0x157/0x760 mm/slab.c:3737
 kvasprintf+0xb5/0x150 lib/kasprintf.c:25
 kasprintf+0xab/0xe0 lib/kasprintf.c:59
 port_over_current_notify drivers/usb/core/hub.c:5185 [inline]
 port_event drivers/usb/core/hub.c:5241 [inline]
 hub_event+0xd5e/0x4140 drivers/usb/core/hub.c:5384
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

Freed by task 32580:
 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
 port_over_current_notify drivers/usb/core/hub.c:5192 [inline]
 port_event drivers/usb/core/hub.c:5241 [inline]
 hub_event+0xd97/0x4140 drivers/usb/core/hub.c:5384
 process_one_work+0xc90/0x1c40 kernel/workqueue.c:2153
 worker_thread+0x17f/0x1390 kernel/workqueue.c:2296
 kthread+0x35a/0x440 kernel/kthread.c:246
 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352

The buggy address belongs to the object at ffff8881bf0d01c0
 which belongs to the cache kmalloc-32 of size 32
The buggy address is located 0 bytes inside of
 32-byte region [ffff8881bf0d01c0, ffff8881bf0d01e0)
The buggy address belongs to the page:
page:ffffea0006fc3400 count:1 mapcount:0 mapping:ffff8881da8001c0  
index:0xffff8881bf0d0fc1
flags: 0x2fffc0000000200(slab)
raw: 02fffc0000000200 ffffea00074d4b88 ffffea0007528bc8 ffff8881da8001c0
raw: ffff8881bf0d0fc1 ffff8881bf0d0000 000000010000003d 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff8881bf0d0080: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8881bf0d0100: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
> ffff8881bf0d0180: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
                                           ^
 ffff8881bf0d0200: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
 ffff8881bf0d0280: fb fb fb fb fc fc fc fc fb fb fb fb fc fc fc fc
==================================================================


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