Return-Path: linux-nfs-owner@vger.kernel.org Received: from tundra.namei.org ([65.99.196.166]:39904 "EHLO tundra.namei.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754661Ab3EBXc6 (ORCPT ); Thu, 2 May 2013 19:32:58 -0400 Date: Fri, 3 May 2013 09:36:27 +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 04/17] Security: Add hook to calculate context based on a negative dentry. In-Reply-To: <1367515151-31015-5-git-send-email-SteveD@redhat.com> Message-ID: References: <1367515151-31015-1-git-send-email-SteveD@redhat.com> <1367515151-31015-5-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 > > There is a time where we need to calculate a context without the > inode having been created yet. To do this we take the negative dentry and > calculate a context based on the process and the parent directory contexts. > > 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 | 27 +++++++++++++++++++++++++++ > security/capability.c | 8 ++++++++ > security/security.c | 10 ++++++++++ > security/selinux/hooks.c | 35 +++++++++++++++++++++++++++++++++++ > 4 files changed, 80 insertions(+) > > diff --git a/include/linux/security.h b/include/linux/security.h > index 032c366..f3d7956 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -26,6 +26,7 @@ > #include > #include > #include > +#include > > struct linux_binprm; > struct cred; > @@ -306,6 +307,15 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts) > * Parse a string of security data filling in the opts structure > * @options string containing all mount options known by the LSM > * @opts binary data structure usable by the LSM > + * @dentry_init_security: > + * Compute a context for a dentry as the inode is not yet available > + * since NFSv4 has no label backed by an EA anyway. > + * @dentry dentry to use in calculating the context. > + * @mode mode used to determine resource type. > + * @name name of the last path component used to create file > + * @ctx pointer to place the pointer to the resulting context in. > + * @ctxlen point to place the length of the resulting context. > + * > * > * Security hooks for inode operations. > * > @@ -1443,6 +1453,10 @@ struct security_operations { > void (*sb_clone_mnt_opts) (const struct super_block *oldsb, > struct super_block *newsb); > int (*sb_parse_opts_str) (char *options, struct security_mnt_opts *opts); > + int (*dentry_init_security) (struct dentry *dentry, int mode, > + struct qstr *name, void **ctx, > + u32 *ctxlen); > + > > #ifdef CONFIG_SECURITY_PATH > int (*path_unlink) (struct path *dir, struct dentry *dentry); > @@ -1729,6 +1743,9 @@ int security_sb_set_mnt_opts(struct super_block *sb, struct security_mnt_opts *o > void security_sb_clone_mnt_opts(const struct super_block *oldsb, > struct super_block *newsb); > int security_sb_parse_opts_str(char *options, struct security_mnt_opts *opts); > +int security_dentry_init_security(struct dentry *dentry, int mode, > + struct qstr *name, void **ctx, > + u32 *ctxlen); > > int security_inode_alloc(struct inode *inode); > void security_inode_free(struct inode *inode); > @@ -2033,6 +2050,16 @@ static inline int security_inode_alloc(struct inode *inode) > static inline void security_inode_free(struct inode *inode) > { } > > +static inline int security_dentry_init_security(struct dentry *dentry, > + int mode, > + struct qstr *name, > + void **ctx, > + u32 *ctxlen) > +{ > + return -EOPNOTSUPP; > +} > + > + > static inline int security_inode_init_security(struct inode *inode, > struct inode *dir, > const struct qstr *qstr, > diff --git a/security/capability.c b/security/capability.c > index 6783c3e..782045e 100644 > --- a/security/capability.c > +++ b/security/capability.c > @@ -108,6 +108,13 @@ static int cap_sb_parse_opts_str(char *options, struct security_mnt_opts *opts) > return 0; > } > > +static int cap_dentry_init_security(struct dentry *dentry, int mode, > + struct qstr *name, void **ctx, > + u32 *ctxlen) > +{ > + return 0; > +} > + > static int cap_inode_alloc_security(struct inode *inode) > { > return 0; > @@ -930,6 +937,7 @@ void __init security_fixup_ops(struct security_operations *ops) > set_to_cap_if_null(ops, sb_set_mnt_opts); > set_to_cap_if_null(ops, sb_clone_mnt_opts); > set_to_cap_if_null(ops, sb_parse_opts_str); > + set_to_cap_if_null(ops, dentry_init_security); > set_to_cap_if_null(ops, inode_alloc_security); > set_to_cap_if_null(ops, inode_free_security); > set_to_cap_if_null(ops, inode_init_security); > diff --git a/security/security.c b/security/security.c > index 03f248b..7c18e3c 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -12,6 +12,7 @@ > */ > > #include > +#include > #include > #include > #include > @@ -324,6 +325,15 @@ void security_inode_free(struct inode *inode) > security_ops->inode_free_security(inode); > } > > +int security_dentry_init_security(struct dentry *dentry, int mode, > + struct qstr *name, void **ctx, > + u32 *ctxlen) > +{ > + return security_ops->dentry_init_security(dentry, mode, name, > + ctx, ctxlen); > +} > +EXPORT_SYMBOL(security_dentry_init_security); > + > int security_inode_init_security(struct inode *inode, struct inode *dir, > const struct qstr *qstr, > const initxattrs initxattrs, void *fs_data) > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c > index 7171a95..622b205 100644 > --- a/security/selinux/hooks.c > +++ b/security/selinux/hooks.c > @@ -2484,6 +2484,40 @@ static void selinux_inode_free_security(struct inode *inode) > inode_free_security(inode); > } > > +static int selinux_dentry_init_security(struct dentry *dentry, int mode, > + struct qstr *name, void **ctx, > + u32 *ctxlen) > +{ > + const struct cred *cred = current_cred(); > + struct task_security_struct *tsec; > + struct inode_security_struct *dsec; > + struct superblock_security_struct *sbsec; > + struct inode *dir = dentry->d_parent->d_inode; > + u32 newsid; > + int rc; > + > + tsec = cred->security; > + dsec = dir->i_security; > + sbsec = dir->i_sb->s_security; > + > + if (tsec->create_sid && sbsec->behavior != SECURITY_FS_USE_MNTPOINT) { > + newsid = tsec->create_sid; > + } else { > + rc = security_transition_sid(tsec->sid, dsec->sid, > + inode_mode_to_security_class(mode), > + name, > + &newsid); > + if (rc) { > + printk(KERN_WARNING > + "%s: security_transition_sid failed, rc=%d\n", > + __func__, -rc); > + return rc; > + } > + } > + > + return security_sid_to_context(newsid, (char **)ctx, ctxlen); > +} > + > static int selinux_inode_init_security(struct inode *inode, struct inode *dir, > const struct qstr *qstr, char **name, > void **value, size_t *len) > @@ -5531,6 +5565,7 @@ static struct security_operations selinux_ops = { > .sb_clone_mnt_opts = selinux_sb_clone_mnt_opts, > .sb_parse_opts_str = selinux_parse_opts_str, > > + .dentry_init_security = selinux_dentry_init_security, > > .inode_alloc_security = selinux_inode_alloc_security, > .inode_free_security = selinux_inode_free_security, > -- > 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