On Wed, Sep 17, 2008 at 11:17:57AM -0500, Chuck Lever wrote:
> The NLM performs a silly test to see that incoming NOTIFY requests are
> relatively secure. Make sure the test works for both AF_INET and AF_INET6
> addresses.
Makes sense. (Why's the test silly? If it prevents local users from
telling lockd to drop a client's locks, that seems good.)
--b.
>
> Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
> ---
>
> fs/lockd/svc4proc.c | 6 ++----
> fs/lockd/svcproc.c | 6 ++----
> include/linux/lockd/lockd.h | 41 +++++++++++++++++++++++++++++++++++++++++
> 3 files changed, 45 insertions(+), 8 deletions(-)
>
> diff --git a/fs/lockd/svc4proc.c b/fs/lockd/svc4proc.c
> index 9e1c751..6a5ef9f 100644
> --- a/fs/lockd/svc4proc.c
> +++ b/fs/lockd/svc4proc.c
> @@ -432,11 +432,9 @@ nlm4svc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
> {
> struct sockaddr_in saddr;
>
> - memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
> -
> dprintk("lockd: SM_NOTIFY called\n");
> - if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
> - || ntohs(saddr.sin_port) >= 1024) {
> +
> + if (!nlm_privileged_requester(rqstp)) {
> char buf[RPC_MAX_ADDRBUFLEN];
> printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
> svc_print_addr(rqstp, buf, sizeof(buf)));
> diff --git a/fs/lockd/svcproc.c b/fs/lockd/svcproc.c
> index fcb7998..62fcfdb 100644
> --- a/fs/lockd/svcproc.c
> +++ b/fs/lockd/svcproc.c
> @@ -464,11 +464,9 @@ nlmsvc_proc_sm_notify(struct svc_rqst *rqstp, struct nlm_reboot *argp,
> {
> struct sockaddr_in saddr;
>
> - memcpy(&saddr, svc_addr_in(rqstp), sizeof(saddr));
> -
> dprintk("lockd: SM_NOTIFY called\n");
> - if (saddr.sin_addr.s_addr != htonl(INADDR_LOOPBACK)
> - || ntohs(saddr.sin_port) >= 1024) {
> +
> + if (!nlm_privileged_requester(rqstp)) {
> char buf[RPC_MAX_ADDRBUFLEN];
> printk(KERN_WARNING "lockd: rejected NSM callback from %s\n",
> svc_print_addr(rqstp, buf, sizeof(buf)));
> diff --git a/include/linux/lockd/lockd.h b/include/linux/lockd/lockd.h
> index 075095f..409eab4 100644
> --- a/include/linux/lockd/lockd.h
> +++ b/include/linux/lockd/lockd.h
> @@ -280,6 +280,47 @@ static inline struct inode *nlmsvc_file_inode(struct nlm_file *file)
> return file->f_file->f_path.dentry->d_inode;
> }
>
> +static inline int __nlm_privileged_request4(const struct sockaddr *sap)
> +{
> + const struct sockaddr_in *sin = (struct sockaddr_in *)sap;
> + return (sin->sin_addr.s_addr == htonl(INADDR_LOOPBACK)) &&
> + (ntohs(sin->sin_port) < 1024);
> +}
> +
> +#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
> +static inline int __nlm_privileged_request6(const struct sockaddr *sap)
> +{
> + const struct sockaddr_in6 *sin6 = (struct sockaddr_in6 *)sap;
> + return (ipv6_addr_type(&sin6->sin6_addr) & IPV6_ADDR_LOOPBACK) &&
> + (ntohs(sin6->sin6_port) < 1024);
> +}
> +#else /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
> +static inline int __nlm_privileged_request6(const struct sockaddr *sap)
> +{
> + return 0;
> +}
> +#endif /* defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE) */
> +
> +/*
> + * Ensure incoming requests are suitably "secure"
> + *
> + * Return TRUE if sender is local and is connecting via a privileged port;
> + * otherwise return FALSE.
> + */
> +static inline int nlm_privileged_requester(const struct svc_rqst *rqstp)
> +{
> + const struct sockaddr *sap = svc_addr(rqstp);
> +
> + switch (sap->sa_family) {
> + case AF_INET:
> + return __nlm_privileged_request4(sap);
> + case AF_INET6:
> + return __nlm_privileged_request6(sap);
> + default:
> + return 0;
> + }
> +}
> +
> static inline int __nlm_cmp_addr4(const struct sockaddr *sap1,
> const struct sockaddr *sap2)
> {
>
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