cmd/asm: nil deref (3)

[dvyukov]

asm crashes on the following input (in hex):

00000000  47 4c 4f 42 4c 20 61 2c  00 30 24 53 42 0a        |GLOBL a,.0$SB.|

panic: runtime error: invalid memory address or nil pointer dereference
[signal 0xb code=0x1 addr=0x0 pc=0x4b0501]

goroutine 1 [running]:
cmd/internal/obj.Mconv(0xc82007d8d0, 0x0, 0x0)
    src/cmd/internal/obj/util.go:460 +0x661
cmd/internal/obj.Dconv(0x70fce0, 0xc82007d8d0, 0x0, 0x0)
    src/cmd/internal/obj/util.go:384 +0xc0c
cmd/asm/internal/asm.(*Parser).validateImmediate(0xc82007de70, 0x6083c0, 0x5, 0xc82007d8d0)
    src/cmd/asm/internal/asm/asm.go:88 +0x87
cmd/asm/internal/asm.(*Parser).asmGlobl(0xc82007de70, 0xc82010a0a0, 0x5, 0xc82007db28, 0x2, 0x3)
    src/cmd/asm/internal/asm/asm.go:249 +0x21f
cmd/asm/internal/asm.(*Parser).pseudo(0xc82007de70, 0x8, 0xc82010a0a0, 0x5, 0xc82007db28, 0x2, 0x3)
    src/cmd/asm/internal/asm/parse.go:221 +0x1c4
cmd/asm/internal/asm.(*Parser).line(0xc82007de70, 0xc820112060)
    src/cmd/asm/internal/asm/parse.go:185 +0x990
cmd/asm/internal/asm.(*Parser).Parse(0xc82007de70, 0xc820112060, 0xc820102120)
    src/cmd/asm/internal/asm/parse.go:85 +0x21
main.main()
    src/cmd/asm/main.go:59 +0xb85

go version devel +b9dbb03 Mon Sep 14 04:51:46 2015 +0000 linux/amd64

[gopherbot]

CL https://golang.org/cl/14563 mentions this issue.