netbsd boot error: panic: UBSan: Undefined Behavior in /syzkaller/managers/netbsd-kubsan/kernel/sys/kern/vfs_subr.c:LINE, member access wit

[syzbot]

Hello,

syzbot found the following crash on:

HEAD commit: e55c7118 Belatedly update several entries that move from y..
git tree: netbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=15053852e00000
kernel config: https://syzkaller.appspot.com/x/.config?x=824b23e1f4b6c76b
dashboard link: https://syzkaller.appspot.com/bug?extid=d27bc1be926b3641c0ad

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+d27bc1...@syzkaller.appspotmail.com

[ 1.5079810] panic: UBSan: Undefined Behavior in
/syzkaller/managers/netbsd-kubsan/kernel/sys/kern/vfs_subr.c:793:14, member
access within null pointer of type 'struct vnode_impl'

[ 1.5217763] cpu0: Begin traceback...
[ 1.5217763] init: copying out path `/sbin/init' 11
[ 1.5217763] vpanic() at netbsd:vpanic+0x2aa sys/kern/subr_prf.c:336
[ 1.5439859] isAlreadyReported() at netbsd:isAlreadyReported
[ 1.5662425] HandleTypeMismatch.part.1() at
netbsd:HandleTypeMismatch.part.1+0x15b
[ 1.5885008] HandleTypeMismatch() at netbsd:HandleTypeMismatch+0x7b
sys/../common/lib/libc/misc/ubsan.c:408
[ 1.6107583] sched_sync() at netbsd:sched_sync+0x50a
sys/kern/vfs_subr.c:793
[ 1.6230693] cpu0: End traceback...
[ 1.6230693] fatal breakpoint trap in supervisor mode
[ 1.6344692] trap type 1 code 0 rip 0xffffffff8021dddd cs 0x8 rflags
0x286 cr2 0 ilevel 0 rsp 0xffffd300a69169e0
[ 1.6344692] curlwp 0xffff91d6c6833660 pid 0.55 lowest kstack
0xffffd300a69132c0
Stopped in pid 0.55 (system) at netbsd:breakpoint+0x5: leave
db{0}>


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