Re: [Qemu-devel] [PATCH] hw/s390x/ipl: Fix crash that occurs when -kernel is used with small images

[Christian Borntraeger <borntraeger@de.ibm.com>]

On 06/10/2018 03:12 PM, Thomas Huth wrote:
> Add a sanity check to fix the following crash:
> 
> $ echo "Insane in the mainframe" > /tmp/test.txt
> $ s390x-softmmu/qemu-system-s390x -nographic -kernel /tmp/test.txt
> Segmentation fault (core dumped)
> 
> Signed-off-by: Thomas Huth <thuth@redhat.com>

Reviewed-by: Christian Borntraeger <borntraeger@de.ibm.com>

I think a similar problem exists for INITRD_PARM_START and INITRD_PARM_SIZE. No?


> ---
>  hw/s390x/ipl.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/hw/s390x/ipl.c b/hw/s390x/ipl.c
> index 04245b5..9bb9b50 100644
> --- a/hw/s390x/ipl.c
> +++ b/hw/s390x/ipl.c
> @@ -168,7 +168,8 @@ static void s390_ipl_realize(DeviceState *dev, Error **errp)
>           * we can not rely on the ELF entry point - it was 0x800 (the SALIPL
>           * loader) and it won't work. For this case we force it to 0x10000, too.
>           */
> -        if (pentry == KERN_IMAGE_START || pentry == 0x800) {
> +        if ((pentry == KERN_IMAGE_START || pentry == 0x800) &&
> +            kernel_size > KERN_PARM_AREA + strlen(ipl->cmdline)) {
>              ipl->start_addr = KERN_IMAGE_START;
>              /* Overwrite parameters in the kernel image, which are "rom" */
>              strcpy(rom_ptr(KERN_PARM_AREA), ipl->cmdline);
>