assertion failed: kref_refcnt(kref) > 0 (2)

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: 8ce32bf0 Unmap pages mapped during a failed fill_vmr()
git tree: akaros
console output: https://syzkaller.appspot.com/x/log.txt?x=14325552e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=9b018fab5edd31b3
dashboard link: https://syzkaller.appspot.com/bug?extid=6c8cc372aee901326a5f

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+6c8cc3...@syzkaller.appspotmail.com

kernel panic at /syzkaller/managers/main/kernel/kern/include/kref.h:68,
from core 0: assertion failed: kref_refcnt(kref) > 0
Stack Backtrace on Core 0:
#01 [<0xffffffffc200a7fc>] in backtrace at src/kdebug.c:235
#02 [<0xffffffffc2009f95>] in _panic at src/init.c:275
#03 [<0xffffffffc20496db>] in kref_put at include/kref.h:68
#04 [< [inline] >] in proc_decref at src/process.c:587
#04 [< [inline] >] in proc_disown_children at src/process.c:853
#04 [<0xffffffffc204d520>] in proc_destroy at src/process.c:932
#05 [<0xffffffffc2058c36>] in sys_proc_destroy at src/syscall.c:852
#06 [<0xffffffffc2059f49>] in syscall at src/syscall.c:2582
#07 [<0xffffffffc205aad8>] in run_local_syscall at src/syscall.c:2619
#08 [<0xffffffffc205b019>] in prep_syscalls at src/syscall.c:2639
#09 [<0xffffffffc20b6282>] in sysenter_callwrapper at arch/x86/trap.c:926


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[syzbot]

Auto-closing this bug as obsolete.
Crashes did not happen for a while, no reproducer and no activity.