Re: [PATCH] nfs-utils: fix addrinfo usage with musl-1.1.21

[Chuck Lever <chuck.lever@oracle.com>]

Hi Peter-

> On Feb 17, 2019, at 11:39 AM, Peter Wagner <tripolar@gmx.at> wrote:
> 
> Afer the update to musl 1.1.21 freeaddrinfo is broken in some places in
> the nfs-utils code because glibc seems to ignore when freeaddrinfo is
> called with a NULL pointer which seems to be not defined in the spec.
> 
> See: https://www.openwall.com/lists/musl/2019/02/03/4

It might be cleaner to define a local version of freeaddrinfo in
nfs-utils to reduce duplication of code and provide a place
in the code itself to document this issue with a comment.


> The free in support/export/hostname.c is removed too
> 
> See: https://www.openwall.com/lists/musl/2019/02/17/2

Actually this seems like a separate issue because a distribution
that uses another C library might decide it is pertinent to apply
separately from the other changes here.

Please create a separate patch. It should remove the free(3)
call instead of commenting it out, and the patch description
should have its own copy of Rich’s email comments.

Thanks!


> From 43e27735553b4c1e75964f32b2f887e84398055f Mon Sep 17 00:00:00 2001
> From: Peter Wagner <tripolar@gmx.at>
> Date: Sun, 17 Feb 2019 17:32:08 +0100
> Subject: [PATCH] fix addrinfo usage
> 
> Signed-off-by: Peter Wagner <tripolar@gmx.at>
> ---
> support/export/client.c   |  3 ++-
> support/export/hostname.c |  2 +-
> utils/exportfs/exportfs.c | 12 ++++++++----
> utils/mount/stropts.c     |  3 ++-
> utils/mountd/cache.c      |  6 ++++--
> utils/statd/hostname.c    |  6 ++++--
> 6 files changed, 21 insertions(+), 11 deletions(-)
> 
> diff --git a/support/export/client.c b/support/export/client.c
> index baf59c8..750eb7d 100644
> --- a/support/export/client.c
> +++ b/support/export/client.c
> @@ -309,7 +309,8 @@ client_lookup(char *hname, int canonical)
>       init_addrlist(clp, ai);
> 
> out:
> -    freeaddrinfo(ai);
> +    if (ai)
> +        freeaddrinfo(ai);
>   return clp;
> }
> 
> diff --git a/support/export/hostname.c b/support/export/hostname.c
> index 5c4c824..710bf61 100644
> --- a/support/export/hostname.c
> +++ b/support/export/hostname.c
> @@ -354,7 +354,7 @@ host_numeric_addrinfo(const struct sockaddr *sap)
>    * getaddrinfo(AI_NUMERICHOST) never fills in ai_canonname
>    */
>   if (ai != NULL) {
> -        free(ai->ai_canonname);        /* just in case */
> +        //free(ai->ai_canonname);        /* just in case */
>       ai->ai_canonname = strdup(buf);
>       if (ai->ai_canonname == NULL) {
>           freeaddrinfo(ai);
> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
> index cd3c979..2f8d59a 100644
> --- a/utils/exportfs/exportfs.c
> +++ b/utils/exportfs/exportfs.c
> @@ -282,7 +282,8 @@ exportfs_parsed(char *hname, char *path, char *options, int verbose)
>   validate_export(exp);
> 
> out:
> -    freeaddrinfo(ai);
> +    if (ai)
> +        freeaddrinfo(ai);
> }
> 
> static int exportfs_generic(char *arg, char *options, int verbose)
> @@ -395,7 +396,8 @@ unexportfs_parsed(char *hname, char *path, int verbose)
>   if (!success)
>       xlog(L_ERROR, "Could not find '%s:%s' to unexport.", hname, path);
> 
> -    freeaddrinfo(ai);
> +    if (ai)
> +        freeaddrinfo(ai);
> }
> 
> static int unexportfs_generic(char *arg, int verbose)
> @@ -639,8 +641,10 @@ matchhostname(const char *hostname1, const char *hostname2)
>           }
> 
> out:
> -    freeaddrinfo(results1);
> -    freeaddrinfo(results2);
> +    if (results1)
> +        freeaddrinfo(results1);
> +    if (results2)
> +        freeaddrinfo(results2);
>   return result;
> }
> 
> diff --git a/utils/mount/stropts.c b/utils/mount/stropts.c
> index 0a25b1f..8b7a0a8 100644
> --- a/utils/mount/stropts.c
> +++ b/utils/mount/stropts.c
> @@ -1268,7 +1268,8 @@ int nfsmount_string(const char *spec, const char *node, char *type,
>   } else
>       nfs_error(_("%s: internal option parsing error"), progname);
> 
> -    freeaddrinfo(mi.address);
> +    if (mi.address)
> +        freeaddrinfo(mi.address);
>   free(mi.hostname);
>   return retval;
> }
> diff --git a/utils/mountd/cache.c b/utils/mountd/cache.c
> index 7e8d403..8cee1c8 100644
> --- a/utils/mountd/cache.c
> +++ b/utils/mountd/cache.c
> @@ -834,7 +834,8 @@ static void nfsd_fh(int f)
> out:
>   if (found_path)
>       free(found_path);
> -    freeaddrinfo(ai);
> +    if(ai)
> +        freeaddrinfo(ai);
>   free(dom);
>   xlog(D_CALL, "nfsd_fh: found %p path %s", found, found ? found->e_path : NULL);
> }
> @@ -1355,7 +1356,8 @@ static void nfsd_export(int f)
>   xlog(D_CALL, "nfsd_export: found %p path %s", found, path ? path : NULL);
>   if (dom) free(dom);
>   if (path) free(path);
> -    freeaddrinfo(ai);
> +    if (ai)
> +        freeaddrinfo(ai);
> }
> 
> 
> diff --git a/utils/statd/hostname.c b/utils/statd/hostname.c
> index 8cccdb8..6556ab1 100644
> --- a/utils/statd/hostname.c
> +++ b/utils/statd/hostname.c
> @@ -308,8 +308,10 @@ statd_matchhostname(const char *hostname1, const char *hostname2)
>           }
> 
> out:
> -    freeaddrinfo(results2);
> -    freeaddrinfo(results1);
> +    if (results2)
> +        freeaddrinfo(results2);
> +    if (results1)
> +        freeaddrinfo(results1);
> 
>   xlog(D_CALL, "%s: hostnames %s and %s %s", __func__,
>           hostname1, hostname2,
> -- 
> 2.20.1
>