Return-Path: linux-nfs-owner@vger.kernel.org Received: from tundra.namei.org ([65.99.196.166]:39909 "EHLO tundra.namei.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752643Ab3EBXdN (ORCPT ); Thu, 2 May 2013 19:33:13 -0400 Date: Fri, 3 May 2013 09:36:44 +1000 (EST) From: James Morris To: Steve Dickson cc: Trond Myklebust , "J. Bruce Fields" , "David P. Quigley" , Linux NFS list , Linux FS devel list , Linux Security List , SELinux List Subject: Re: [PATCH 05/17] Security: Add Hook to test if the particular xattr is part of a MAC model. In-Reply-To: <1367515151-31015-6-git-send-email-SteveD@redhat.com> Message-ID: References: <1367515151-31015-1-git-send-email-SteveD@redhat.com> <1367515151-31015-6-git-send-email-SteveD@redhat.com> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 2 May 2013, Steve Dickson wrote: > From: David Quigley > > The interface to request security labels from user space is the xattr > interface. When requesting the security label from an NFS server it is > important to make sure the requested xattr actually is a MAC label. This allows > us to make sure that we get the desired semantics from the attribute instead of > something else such as capabilities or a time based LSM. > > Signed-off-by: Matthew N. Dodd > Signed-off-by: Miguel Rodel Felipe > Signed-off-by: Phua Eu Gene > Signed-off-by: Khin Mi Mi Aung Acked-by: James Morris > --- > include/linux/security.h | 14 ++++++++++++++ > security/capability.c | 6 ++++++ > security/security.c | 6 ++++++ > security/selinux/hooks.c | 6 ++++++ > security/smack/smack_lsm.c | 11 +++++++++++ > 5 files changed, 43 insertions(+) > > diff --git a/include/linux/security.h b/include/linux/security.h > index f3d7956..934f96f 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -1323,6 +1323,13 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) > * @pages contains the number of pages. > * Return 0 if permission is granted. > * > + * @ismaclabel: > + * Check if the extended attribute specified by @name > + * represents a MAC label. Returns 1 if name is a MAC > + * attribute otherwise returns 0. > + * @name full extended attribute name to check against > + * LSM as a MAC label. > + * > * @secid_to_secctx: > * Convert secid to security context. If secdata is NULL the length of > * the result will be returned in seclen, but no secdata will be returned. > @@ -1604,6 +1611,7 @@ struct security_operations { > > int (*getprocattr) (struct task_struct *p, char *name, char **value); > int (*setprocattr) (struct task_struct *p, char *name, void *value, size_t size); > + int (*ismaclabel) (const char *name); > int (*secid_to_secctx) (u32 secid, char **secdata, u32 *seclen); > int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid); > void (*release_secctx) (char *secdata, u32 seclen); > @@ -1857,6 +1865,7 @@ void security_d_instantiate(struct dentry *dentry, struct inode *inode); > int security_getprocattr(struct task_struct *p, char *name, char **value); > int security_setprocattr(struct task_struct *p, char *name, void *value, size_t size); > int security_netlink_send(struct sock *sk, struct sk_buff *skb); > +int security_ismaclabel(const char *name); > int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen); > int security_secctx_to_secid(const char *secdata, u32 seclen, u32 *secid); > void security_release_secctx(char *secdata, u32 seclen); > @@ -2545,6 +2554,11 @@ static inline int security_netlink_send(struct sock *sk, struct sk_buff *skb) > return cap_netlink_send(sk, skb); > } > > +static inline int security_ismaclabel(const char *name) > +{ > + return 0; > +} > + > static inline int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) > { > return -EOPNOTSUPP; > diff --git a/security/capability.c b/security/capability.c > index 782045e..71e5052 100644 > --- a/security/capability.c > +++ b/security/capability.c > @@ -822,6 +822,11 @@ static int cap_setprocattr(struct task_struct *p, char *name, void *value, > return -EINVAL; > } > > +static int cap_ismaclabel(const char *name) > +{ > + return 0; > +} > + > static int cap_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) > { > return -EOPNOTSUPP; > @@ -1041,6 +1046,7 @@ void __init security_fixup_ops(struct security_operations *ops) > set_to_cap_if_null(ops, d_instantiate); > set_to_cap_if_null(ops, getprocattr); > set_to_cap_if_null(ops, setprocattr); > + set_to_cap_if_null(ops, ismaclabel); > set_to_cap_if_null(ops, secid_to_secctx); > set_to_cap_if_null(ops, secctx_to_secid); > set_to_cap_if_null(ops, release_secctx); > diff --git a/security/security.c b/security/security.c > index 7c18e3c..07391f3 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -1057,6 +1057,12 @@ int security_netlink_send(struct sock *sk, struct sk_buff *skb) > return security_ops->netlink_send(sk, skb); > } > > +int security_ismaclabel(const char *name) > +{ > + return security_ops->ismaclabel(name); > +} > +EXPORT_SYMBOL(security_ismaclabel); > + > int security_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) > { > return security_ops->secid_to_secctx(secid, secdata, seclen); > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 622b205..273e28b 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -5423,6 +5423,11 @@ abort_change: > return error; > } > > +static int selinux_ismaclabel(const char *name) > +{ > + return (strcmp(name, XATTR_SELINUX_SUFFIX) == 0); > +} > + > static int selinux_secid_to_secctx(u32 secid, char **secdata, u32 *seclen) > { > return security_sid_to_context(secid, secdata, seclen); > @@ -5661,6 +5666,7 @@ static struct security_operations selinux_ops = { > .getprocattr = selinux_getprocattr, > .setprocattr = selinux_setprocattr, > > + .ismaclabel = selinux_ismaclabel, > .secid_to_secctx = selinux_secid_to_secctx, > .secctx_to_secid = selinux_secctx_to_secid, > .release_secctx = selinux_release_secctx, > diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c > index fa64740..ca01d71 100644 > --- a/security/smack/smack_lsm.c > +++ b/security/smack/smack_lsm.c > @@ -3329,6 +3329,16 @@ static void smack_audit_rule_free(void *vrule) > #endif /* CONFIG_AUDIT */ > > /** > + * smack_ismaclabel - check if xattr @name references a smack MAC label > + * @name: Full xattr name to check. > + */ > +static int smack_ismaclabel(const char *name) > +{ > + return (strcmp(name, XATTR_SMACK_SUFFIX) == 0); > +} > + > + > +/** > * smack_secid_to_secctx - return the smack label for a secid > * @secid: incoming integer > * @secdata: destination > @@ -3524,6 +3534,7 @@ struct security_operations smack_ops = { > .audit_rule_free = smack_audit_rule_free, > #endif /* CONFIG_AUDIT */ > > + .ismaclabel = smack_ismaclabel, > .secid_to_secctx = smack_secid_to_secctx, > .secctx_to_secid = smack_secctx_to_secid, > .release_secctx = smack_release_secctx, > -- > 1.8.1.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- James Morris