2020-08-29 15:37:46

by J. Bruce Fields

Subject: Re: [PATCH] gss_krb5: Fix memleak in krb5_make_rc4_seq_num

This code is rarely if ever used, and there are pending patches to
remove it completely, so I don't think it's worth trying to fix a rare
memory leak at this point.

--b.

On Thu, Aug 27, 2020 at 04:02:50PM +0800, Dinghao Liu wrote:
> When kmalloc() fails, cipher should be freed
> just like when krb5_rc4_setup_seq_key() fails.
>
> Fixes: e7afe6c1d486b ("sunrpc: fix 4 more call sites that were using stack memory with a scatterlist")
> Signed-off-by: Dinghao Liu <[email protected]>
> ---
> net/sunrpc/auth_gss/gss_krb5_seqnum.c | 6 ++++--
> 1 file changed, 4 insertions(+), 2 deletions(-)
>
> diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> index 507105127095..88ca58d11082 100644
> --- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> +++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> @@ -53,8 +53,10 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
> return PTR_ERR(cipher);
>
> plain = kmalloc(8, GFP_NOFS);
> - if (!plain)
> - return -ENOMEM;
> + if (!plain) {
> + code = -ENOMEM;
> + goto out;
> + }
>
> plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
> plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
> --
> 2.17.1

2020-08-31 15:29:14

by Ard Biesheuvel

Subject: Re: [PATCH] gss_krb5: Fix memleak in krb5_make_rc4_seq_num

On Sat, 29 Aug 2020 at 18:43, J. Bruce Fields <[email protected]> wrote:
>
> This code is rarely if ever used, and there are pending patches to
> remove it completely, so I don't think it's worth trying to fix a rare
> memory leak at this point.
>
> --b.
>

FYI I just submitted v3 of my series removing this code to the
linux-crypto list, and so hopefully it will disappear in v5.10


> On Thu, Aug 27, 2020 at 04:02:50PM +0800, Dinghao Liu wrote:
> > When kmalloc() fails, cipher should be freed
> > just like when krb5_rc4_setup_seq_key() fails.
> >
> > Fixes: e7afe6c1d486b ("sunrpc: fix 4 more call sites that were using stack memory with a scatterlist")
> > Signed-off-by: Dinghao Liu <[email protected]>
> > ---
> > net/sunrpc/auth_gss/gss_krb5_seqnum.c | 6 ++++--
> > 1 file changed, 4 insertions(+), 2 deletions(-)
> >
> > diff --git a/net/sunrpc/auth_gss/gss_krb5_seqnum.c b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> > index 507105127095..88ca58d11082 100644
> > --- a/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> > +++ b/net/sunrpc/auth_gss/gss_krb5_seqnum.c
> > @@ -53,8 +53,10 @@ krb5_make_rc4_seq_num(struct krb5_ctx *kctx, int direction, s32 seqnum,
> > return PTR_ERR(cipher);
> >
> > plain = kmalloc(8, GFP_NOFS);
> > - if (!plain)
> > - return -ENOMEM;
> > + if (!plain) {
> > + code = -ENOMEM;
> > + goto out;
> > + }
> >
> > plain[0] = (unsigned char) ((seqnum >> 24) & 0xff);
> > plain[1] = (unsigned char) ((seqnum >> 16) & 0xff);
> > --
> > 2.17.1