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    SubjectRe: [PATCH 02/14] LSM/SELinux: inode_{get,set,notify}secctx hooks to access LSM security context information.
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    Date
    Fixed.

    On Tue, 2008-09-30 at 15:01 -0500, Serge E. Hallyn wrote:
    > Quoting David P. Quigley (dpquigl@tycho.nsa.gov):
    > > This patch introduces three new hooks. The inode_getsecctx hook is used to get
    > > all relevant information from an LSM about an inode. The inode_setsecctx is
    > > used to set both the in-core and on-disk state for the inode based on a context
    > > derived from inode_getsecctx.The final hook inode_notifysecctx will notify the
    > > LSM of a change for the in-core state of the inode in question. These hooks are
    > > for use in the labeled NFS code and addresses concerns of how to set security
    > > on an inode in a multi-xattr LSM. For historical reasons Stephen Smalley's
    > > explanation of the reason for these hooks is pasted below.
    > >
    > > Quote Stephen Smalley
    > >
    > > inode_setsecctx: Change the security context of an inode. Updates the
    > > in core security context managed by the security module and invokes the
    > > fs code as needed (via __vfs_setxattr_noperm) to update any backing
    > > xattrs that represent the context. Example usage: NFS server invokes
    > > this hook to change the security context in its incore inode and on the
    > > backing file system to a value provided by the client on a SETATTR
    > > operation.
    > >
    > > inode_notifysecctx: Notify the security module of what the security
    > > context of an inode should be. Initializes the incore security context
    > > managed by the security module for this inode. Example usage: NFS
    > > client invokes this hook to initialize the security context in its
    > > incore inode to the value provided by the server for the file when the
    > > server returned the file's attributes to the client.
    > >
    > > Signed-off-by: Matthew N. Dodd <Matthew.Dodd@sparta.com>
    > > Signed-off-by: David P. Quigley <dpquigl@tycho.nsa.gov>
    > > ---
    > > include/linux/security.h | 50 ++++++++++++++++++++++++++++++++++++++++++++++
    > > security/security.c | 18 ++++++++++++++++
    > > security/selinux/hooks.c | 25 +++++++++++++++++++++++
    > > 3 files changed, 93 insertions(+), 0 deletions(-)
    > >
    > > diff --git a/include/linux/security.h b/include/linux/security.h
    > > index 80c4d00..8b5b041 100644
    > > --- a/include/linux/security.h
    > > +++ b/include/linux/security.h
    > > @@ -1289,6 +1289,36 @@ static inline void security_free_mnt_opts(struct security_mnt_opts *opts)
    > > * audit_rule_init.
    > > * @rule contains the allocated rule
    > > *
    > > + * @inode_notifysecctx:
    > > + * Notify the security module of what the security context of an inode
    > > + * should be. Initializes the incore security context managed by the
    > > + * security module for this inode. Example usage: NFS client invokes
    > > + * this hook to initialize the security context in its incore inode to the
    > > + * value provided by the server for the file when the server returned the
    > > + * file's attributes to the client.
    > > + *
    > > + * @inode we wish to set the security context of.
    > > + * @ctx contains the string which we wish to set in the inode.
    > > + * @ctxlen contains the length of @ctx.
    > > + *
    > > + * @inode_setsecctx:
    > > + * Change the security context of an inode. Updates the
    > > + * incore security context managed by the security module and invokes the
    > > + * fs code as needed (via __vfs_setxattr_noperm) to update any backing
    > > + * xattrs that represent the context. Example usage: NFS server invokes
    > > + * this hook to change the security context in its incore inode and on the
    > > + * backing filesystem to a value provided by the client on a SETATTR
    > > + * operation.
    > > + *
    > > + * @dentry contains the inode we wish to set the security context of.
    > > + * @ctx contains the string which we wish to set in the inode.
    > > + * @ctxlen contains the length of @ctx.
    > > + *
    > > + * @inode_getsecctx:
    > > + * Returns a string containing all relavent security context information
    > > + * @inode we wish to set the security context of.
    > > + * @ctx is a pointer to place the allocated security context should be placed.
    >
    > sentence above is odd. How about
    >
    > @ctx is a pointer in which to place the allocated security context
    >
    > > + * @ctxlen points to the place to put the length of @ctx.
    > > * This is the main security structure.
    > > */
    > > struct security_operations {
    > > @@ -1479,6 +1509,10 @@ struct security_operations {
    > > int (*secctx_to_secid) (const char *secdata, u32 seclen, u32 *secid);
    > > void (*release_secctx) (char *secdata, u32 seclen);
    > >
    > > + int (*inode_notifysecctx)(struct inode *inode, void *ctx, u32 ctxlen);
    > > + int (*inode_setsecctx)(struct dentry *dentry, void *ctx, u32 ctxlen);
    > > + int (*inode_getsecctx)(struct inode *inode, void **ctx, u32 *ctxlen);
    > > +
    > > #ifdef CONFIG_SECURITY_NETWORK
    > > int (*unix_stream_connect) (struct socket *sock,
    > > struct socket *other, struct sock *newsk);
    > > @@ -1727,6 +1761,9 @@ 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);
    > >
    > > +int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen);
    > > +int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen);
    > > +int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen);
    > > #else /* CONFIG_SECURITY */
    > > struct security_mnt_opts {
    > > };
    > > @@ -2458,6 +2495,19 @@ static inline int security_secctx_to_secid(const char *secdata,
    > > static inline void security_release_secctx(char *secdata, u32 seclen)
    > > {
    > > }
    > > +
    > > +static inline int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
    > > +{
    > > + return -EOPNOTSUPP;
    > > +}
    > > +static inline int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
    > > +{
    > > + return -EOPNOTSUPP;
    > > +}
    > > +static inline int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
    > > +{
    > > + return -EOPNOTSUPP;
    > > +}
    > > #endif /* CONFIG_SECURITY */
    > >
    > > #ifdef CONFIG_SECURITY_NETWORK
    > > diff --git a/security/security.c b/security/security.c
    > > index 3a4b4f5..d0fd42a 100644
    > > --- a/security/security.c
    > > +++ b/security/security.c
    > > @@ -869,6 +869,24 @@ void security_release_secctx(char *secdata, u32 seclen)
    > > }
    > > EXPORT_SYMBOL(security_release_secctx);
    > >
    > > +int security_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
    > > +{
    > > + return security_ops->inode_notifysecctx(inode, ctx, ctxlen);
    > > +}
    > > +EXPORT_SYMBOL(security_inode_notifysecctx);
    > > +
    > > +int security_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
    > > +{
    > > + return security_ops->inode_setsecctx(dentry, ctx, ctxlen);
    > > +}
    > > +EXPORT_SYMBOL(security_inode_setsecctx);
    > > +
    > > +int security_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
    > > +{
    > > + return security_ops->inode_getsecctx(inode, ctx, ctxlen);
    > > +}
    > > +EXPORT_SYMBOL(security_inode_getsecctx);
    > > +
    > > #ifdef CONFIG_SECURITY_NETWORK
    > >
    > > int security_unix_stream_connect(struct socket *sock, struct socket *other,
    > > diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
    > > index 03fc6a8..b07871b 100644
    > > --- a/security/selinux/hooks.c
    > > +++ b/security/selinux/hooks.c
    > > @@ -5285,6 +5285,28 @@ static void selinux_release_secctx(char *secdata, u32 seclen)
    > > kfree(secdata);
    > > }
    > >
    > > +/*
    > > + * This hook requires that the inode i_mutex be locked
    >
    > 'called with inode->i_mutex locked' would make more sense here.
    > Requirements on the callers would make more sense in the comments
    > in include/linux/security.h, right?
    >
    > No code objections, though.
    >
    > Acked-by: Serge Hallyn <serue@us.ibm.com>
    >
    > > + */
    > > +static int selinux_inode_notifysecctx(struct inode *inode, void *ctx, u32 ctxlen)
    > > +{
    > > + return selinux_inode_setsecurity(inode, XATTR_SELINUX_SUFFIX, ctx, ctxlen, 0);
    > > +}
    > > +
    > > +/*
    > > + * This hook requires that the inode i_mutex be locked
    > > + */
    > > +static int selinux_inode_setsecctx(struct dentry *dentry, void *ctx, u32 ctxlen)
    > > +{
    > > + return __vfs_setxattr_noperm(dentry, XATTR_NAME_SELINUX, ctx, ctxlen, 0);
    > > +}
    > > +
    > > +static int selinux_inode_getsecctx(struct inode *inode, void **ctx, u32 *ctxlen)
    > > +{
    > > + *ctxlen = selinux_inode_getsecurity(inode, XATTR_SELINUX_SUFFIX,
    > > + ctx, true);
    > > + return *ctxlen;
    > > +}
    > > #ifdef CONFIG_KEYS
    > >
    > > static int selinux_key_alloc(struct key *k, struct task_struct *tsk,
    > > @@ -5491,6 +5513,9 @@ static struct security_operations selinux_ops = {
    > > .secid_to_secctx = selinux_secid_to_secctx,
    > > .secctx_to_secid = selinux_secctx_to_secid,
    > > .release_secctx = selinux_release_secctx,
    > > + .inode_notifysecctx = selinux_inode_notifysecctx,
    > > + .inode_setsecctx = selinux_inode_setsecctx,
    > > + .inode_getsecctx = selinux_inode_getsecctx,
    > >
    > > .unix_stream_connect = selinux_socket_unix_stream_connect,
    > > .unix_may_send = selinux_socket_unix_may_send,
    > > --
    > > 1.5.5.1
    > >
    > >
    > > --
    > > This message was distributed to subscribers of the selinux mailing list.
    > > If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with
    > > the words "unsubscribe selinux" without quotes as the message.



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