panic: runtime error: invalid memory address or nil pointer dereference [recovered]

[syzbot]

Hello,

syzbot found the following issue on:

HEAD commit: b20edd337af0 Recent OpenSBI versions implement shutdown an..
git tree: openbsd
console output: https://syzkaller.appspot.com/x/log.txt?x=162360dc980000
kernel config: https://syzkaller.appspot.com/x/.config?x=7058272de1526588
dashboard link: https://syzkaller.appspot.com/bug?extid=75be278bccb4e6f11abe

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

Downloadable assets:
disk image: https://storage.googleapis.com/syzbot-assets/d10d5e73f943/disk-b20edd33.raw.xz
bsd.gdb: https://storage.googleapis.com/syzbot-assets/83ce40a92db6/bsd-b20edd33.gdb.xz
kernel image: https://storage.googleapis.com/syzbot-assets/b689f1d30e65/kernel-b20edd33.xz

IMPORTANT: if you fix the issue, please add the following tag to the commit:
Reported-by: syzbot+75be27...@syzkaller.appspotmail.com

panic: runtime error: invalid memory address or nil pointer dereference [recovered]
panic: runtime error: invalid memory address or nil pointer dereference
[signal SIGSEGV: segmentation violation code=0x1 addr=0x0 pc=0x0]

goroutine 59 [running]:
encoding/gob.catchError(0xc00061d710)
/usr/local/go/src/encoding/gob/error.go:38 +0x6d
panic({0xb02080?, 0x12d08d0?})
/usr/local/go/src/runtime/panic.go:770 +0x132
encoding/gob.(*Encoder).encodeArray(0xc0000e12c0?, 0xc0002c7290?, {0xaa1fc0?, 0xc000857460?, 0xc000479790?}, 0xc000646900, 0x0, 0x5, 0x0)
/usr/local/go/src/encoding/gob/encode.go:342 +0x4d4
encoding/gob.encOpFor.func1(0xba63e0?, 0xc0000e12c0, {0xaa1fc0?, 0xc000857460?, 0xc000479818?})
/usr/local/go/src/encoding/gob/encode.go:516 +0x139
encoding/gob.(*Encoder).encodeStruct(0xc00061d680, 0xc00061d6b8, 0xc0000a3050, {0xba63e0?, 0xc000857440?, 0x407ecb?})
/usr/local/go/src/encoding/gob/encode.go:328 +0x2de
encoding/gob.(*Encoder).encode(0xc00061d680, 0xc00061d6b8, {0xa931c0?, 0xc000857440?, 0xc000857480?}, 0xc000857480)
/usr/local/go/src/encoding/gob/encode.go:666 +0x1b0
encoding/gob.(*Encoder).EncodeValue(0xc00061d680, {0xa931c0?, 0xc000857440?, 0xc0004799f0?})
/usr/local/go/src/encoding/gob/encoder.go:251 +0x405
encoding/gob.(*Encoder).Encode(0x55c848d09f5f30d0?, {0xa931c0?, 0xc000857440?})
/usr/local/go/src/encoding/gob/encoder.go:176 +0x75
net/rpc.(*gobClientCodec).WriteRequest(0xc00057c900, 0xc00057c960?, {0xa931c0, 0xc000857440})
/usr/local/go/src/net/rpc/client.go:221 +0x53
net/rpc.(*Client).send(0xc0002f0ae0, 0xc000614cd0)
/usr/local/go/src/net/rpc/client.go:91 +0x224
net/rpc.(*Client).Go(0xc0002f0ae0, {0xc26e69, 0x14}, {0xa931c0, 0xc000857440}, {0xa93200, 0xc000614c80}, 0xc0002f0d80)
/usr/local/go/src/net/rpc/client.go:315 +0x13a
net/rpc.(*Client).Call(...)
/usr/local/go/src/net/rpc/client.go:321
github.com/google/syzkaller/pkg/rpctype.(*RPCClient).Call(0xc0000103d8, {0xc26e69, 0x14}, {0xa931c0, 0xc000857440}, {0xa93200, 0xc000614c80})
/syzkaller/gopath/src/github.com/google/syzkaller/pkg/rpctype/rpc.go:88 +0x145
main.(*FuzzerTool).exchangeDataCall(0xc00022b930, {0xc0006b0008, 0x5, 0x8}, 0x183717)
/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:264 +0x21c
main.(*FuzzerTool).exchangeDataWorker(0xc00022b930)
/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:304 +0x76
created by main.main in goroutine 1
/syzkaller/gopath/src/github.com/google/syzkaller/syz-fuzzer/fuzzer.go:202 +0x1168


OpenBSD/amd64 (Amnesiac) (tty00)

login:


---
This report is generated by a bot. It may contain errors.
See https://goo.gl/tpsmEJ for more information about syzbot.
syzbot engineers can be reached at syzk...@googlegroups.com.

syzbot will keep track of this issue. See:
https://goo.gl/tpsmEJ#status for how to communicate with syzbot.

If the report is already addressed, let syzbot know by replying with:
#syz fix: exact-commit-title

If you want to overwrite report's subsystems, reply with:
#syz set subsystems: new-subsystem
(See the list of subsystem names on the web dashboard)

If the report is a duplicate of another one, reply with:
#syz dup: exact-subject-of-another-report

If you want to undo deduplication, reply with:
#syz undup