KASAN: use-after-scope Read in corrupted

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit:    1bdbe2274920 Merge tag 'vfio-v5.0-rc2' of git://github.com..
git tree:       upstream
console output: https://syzkaller.appspot.com/x/log.txt?x=1519d39f400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=edf1c3031097c304
dashboard link: https://syzkaller.appspot.com/bug?extid=bd36b7dd9330f67037ab
compiler:       gcc (GCC) 9.0.0 20181231 (experimental)
syz repro:      https://syzkaller.appspot.com/x/repro.syz?x=10fce14f400000
C reproducer:   https://syzkaller.appspot.com/x/repro.c?x=110b2017400000

IMPORTANT: if you fix the bug, please add the following tag to the commit:
Reported-by: syzbot+bd36b7dd9330f67037ab@xxxxxxxxxxxxxxxxxxxxxxxxx

==================================================================
BUG: KASAN: use-after-scope in debug_lockdep_rcu_enabled.part.0+0x50/0x60  
kernel/rcu/update.c:249
Read of size 4 at addr ffff8880a945eabc by task  
`9ïïïïïï#ï(ïïïïï<ïïïïïkïïïïïïïEïïïïï>9hïïïïïïïïA/-2122188634

CPU: 0 PID: -2122188634 Comm: ïïEïïïïïïïïïïïïïO2ï Not tainted 5.0.0-rc1+  
#19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
------------[ cut here ]------------
Bad or missing usercopy whitelist? Kernel memory overwrite attempt detected  
to SLAB object 'task_struct' (offset 1344, size 8)!
WARNING: CPU: 0 PID: -1455036288 at mm/usercopy.c:78  
usercopy_warn+0xeb/0x110 mm/usercopy.c:78
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: -1455036288 Comm: ïïEïïïïïïïïïïïïïO2ï Not tainted 5.0.0-rc1+  
#19
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS  
Google 01/01/2011
Call Trace:
Kernel Offset: disabled
Rebooting in 86400 seconds..


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