2018-09-26 09:36:40

by Zhi Li

Subject: [PATCH-V2] [libtirpc] getnetconfig.c: fix a BAD_FREE (CWE-763)

Signed-off-by: Zhi Li <[email protected]>
---

2018-09-26 09:36:44

by Zhi Li

Subject: [PATCH-V2] [nfs/nfs-utils/libtirpc] src/getnetconfig.c: fix a BAD_FREE (CWE-763)

Signed-off-by: Zhi Li <[email protected]>
---

2018-09-27 00:22:45

by Steve Dickson

Subject: Re: [PATCH-V2] [nfs/nfs-utils/libtirpc] src/getnetconfig.c: fix a BAD_FREE (CWE-763)

On 9/25/18 11:25 PM, Zhi Li wrote:
> Signed-off-by: Zhi Li <[email protected]>
> ---
> From steved:
> Ok... I see why tmp original value needs to be maintained
> to do the free()... but I'm wondering why the freeing
> of p->nc_netid is needed... it appears to me it is part
> of tmp string... so when tmp is freed won't p->nc_netid
> be freed as well?
>
> Reply:
> Yes, you are right, p->nc_neti is a part of tmp string, so freeing tmp can make p->nc_neti be freed as well.
> I have update the issue.
>
> src/getnetconfig.c | 18 +++++++++---------
> 1 file changed, 9 insertions(+), 9 deletions(-)
Committed...

steved.

>
> diff --git a/src/getnetconfig.c b/src/getnetconfig.c
> index d67d97d..cfd33c2 100644
> --- a/src/getnetconfig.c
> +++ b/src/getnetconfig.c
> @@ -681,6 +681,7 @@ struct netconfig *ncp;
> {
> struct netconfig *p;
> char *tmp;
> + char *t;
> u_int i;
>
> if ((tmp=malloc(MAXNETCONFIGLINE)) == NULL)
> @@ -700,22 +701,21 @@ struct netconfig *ncp;
> */
> *p = *ncp;
> p->nc_netid = (char *)strcpy(tmp,ncp->nc_netid);
> - tmp = strchr(tmp, 0) + 1;
> - p->nc_protofmly = (char *)strcpy(tmp,ncp->nc_protofmly);
> - tmp = strchr(tmp, 0) + 1;
> - p->nc_proto = (char *)strcpy(tmp,ncp->nc_proto);
> - tmp = strchr(tmp, 0) + 1;
> - p->nc_device = (char *)strcpy(tmp,ncp->nc_device);
> + t = strchr(tmp, 0) + 1;
> + p->nc_protofmly = (char *)strcpy(t,ncp->nc_protofmly);
> + t = strchr(t, 0) + 1;
> + p->nc_proto = (char *)strcpy(t,ncp->nc_proto);
> + t = strchr(t, 0) + 1;
> + p->nc_device = (char *)strcpy(t,ncp->nc_device);
> p->nc_lookups = (char **)malloc((size_t)(p->nc_nlookups+1) * sizeof(char *));
> if (p->nc_lookups == NULL) {
> - free(p->nc_netid);
> free(p);
> free(tmp);
> return(NULL);
> }
> for (i=0; i < p->nc_nlookups; i++) {
> - tmp = strchr(tmp, 0) + 1;
> - p->nc_lookups[i] = (char *)strcpy(tmp,ncp->nc_lookups[i]);
> + t = strchr(t, 0) + 1;
> + p->nc_lookups[i] = (char *)strcpy(t,ncp->nc_lookups[i]);
> }
> return(p);
> }
>