Re: [PATCH] nss: Get rid of alloca usage in db-XXX

[Joe Simmons-Talbott <josimmon@redhat.com>]

On Wed, Sep 27, 2023 at 05:55:05PM +0200, Andreas Schwab wrote:
> On Sep 27 2023, Joe Simmons-Talbott wrote:
> 
> > Replace alloca usage with a scratch_buffer.
> > ---
> >  nss/nss_db/db-XXX.c | 12 +++++++++++-
> >  1 file changed, 11 insertions(+), 1 deletion(-)
> >
> > diff --git a/nss/nss_db/db-XXX.c b/nss/nss_db/db-XXX.c
> > index 0ce730db5a..2df31a8077 100644
> > --- a/nss/nss_db/db-XXX.c
> > +++ b/nss/nss_db/db-XXX.c
> > @@ -18,6 +18,7 @@
> >  
> >  #include <dlfcn.h>
> >  #include <fcntl.h>
> > +#include <scratch_buffer.h>
> >  #include <stdint.h>
> >  #include <sys/mman.h>
> >  #include <libc-lock.h>
> > @@ -126,6 +127,8 @@ enum nss_status								      \
> >  			char *buffer, size_t buflen, int *errnop H_ERRNO_PROTO)\
> >  {									      \
> >    struct parser_data *data = (void *) buffer;				      \
> > +  struct scratch_buffer sbuf;						      \
> > +  scratch_buffer_init (&sbuf);						      \
> >  									      \
> >    if (buflen < sizeof *data)						      \
> >      {									      \
> > @@ -160,7 +163,13 @@ enum nss_status								      \
> >    else									      \
> >      {									      \
> >        const size_t size = (keysize) + 1;				      \
> > -      key = alloca (size);						      \
> > +      if (!scratch_buffer_set_array_size (&sbuf, 1, size))		      \
> > +	{								      \
> > +	  H_ERRNO_SET (NETDB_INTERNAL);					      \
> > +	  status = NSS_STATUS_TRYAGAIN;					      \
> > +	  return status;						      \
> 
> That needs to set *errnop and goto out.
> 

Thanks.  Fixed in v2.  I left the H_ERRNO_SET call in there as I wasn't
sure if I needed it or not.

Thanks,
Joe