[PATCH] kexec/fs2dt: Check for NULL pointer in dt_copy_old_root_param()

[Simon Horman]

On Fri, Sep 23, 2016 at 03:20:46PM +0530, Pratyush Anand wrote:
> On 23/09/2016:12:47:39 PM, Madhavan Srinivasan wrote:
> > In dt_copy_old_root_param(), FILE * returned
> > from fopen is not checked for NULL pointer
> > before passinig to fclose(). This could trigger
> > a segfault. Patch adds a check.
> > 
> > Signed-off-by: Madhavan Srinivasan <maddy at linux.vnet.ibm.com>
> > ---
> >  kexec/fs2dt.c | 3 ++-
> >  1 file changed, 2 insertions(+), 1 deletion(-)
> > 
> > diff --git a/kexec/fs2dt.c b/kexec/fs2dt.c
> > index 6ed2399759cf..2c1ebdf525f4 100644
> > --- a/kexec/fs2dt.c
> > +++ b/kexec/fs2dt.c
> > @@ -540,7 +540,8 @@ static void dt_copy_old_root_param(void)
> >  	if (last_cmdline)
> >  		free(last_cmdline);
> >  
> > -	fclose(fp);
> > +	if (fp)
> > +		fclose(fp);
> 
> Looks fine, however a better practise could be to return just after fopen() if
> fp was null.

That sounds like it would be somewhat cleaner.
Madhavan, could you see about making it so?