[v5] vfs, security: Fix automount superblock LSM init problem, preventing NFS sb sharing
Commit Message
When NFS superblocks are created by automounting, their LSM parameters
aren't set in the fs_context struct prior to sget_fc() being called,
leading to failure to match existing superblocks.
Fix this by adding a new LSM hook to load fc->security for submount
creation when alloc_fs_context() is creating the fs_context for it.
However, this uncovers a further bug: nfs_get_root() initialises the
superblock security manually by calling security_sb_set_mnt_opts() or
security_sb_clone_mnt_opts() - but then vfs_get_tree() calls
security_sb_set_mnt_opts(), which can lead to SELinux, at least,
complaining.
Fix that by adding a flag to the fs_context that suppresses the
security_sb_set_mnt_opts() call in vfs_get_tree(). This can be set by NFS
when it sets the LSM context on the new superblock.
The first bug leads to messages like the following appearing in dmesg:
NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)
Changes
=======
ver #5)
- Removed unused variable.
- Only allocate smack_mnt_opts if we're dealing with a submount.
ver #4)
- When doing a FOR_SUBMOUNT mount, don't set the root label in SELinux or
Smack.
ver #3)
- Made LSM parameter extraction dependent on fc->purpose ==
FS_CONTEXT_FOR_SUBMOUNT. Shouldn't happen on FOR_RECONFIGURE.
ver #2)
- Added Smack support
- Made LSM parameter extraction dependent on reference != NULL.
Signed-off-by: David Howells <dhowells@redhat.com>
Fixes: 9bc61ab18b1d ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
Fixes: 779df6a5480f ("NFS: Ensure security label is set for root inode)
Tested-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
cc: Trond Myklebust <trond.myklebust@hammerspace.com>
cc: Anna Schumaker <anna@kernel.org>
cc: Alexander Viro <viro@zeniv.linux.org.uk>
cc: Scott Mayhew <smayhew@redhat.com>
cc: Jeff Layton <jlayton@kernel.org>
cc: Paul Moore <paul@paul-moore.com>
cc: linux-nfs@vger.kernel.org
cc: selinux@vger.kernel.org
cc: linux-security-module@vger.kernel.org
cc: linux-fsdevel@vger.kernel.org
Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
---
fs/fs_context.c | 4 +++
fs/nfs/getroot.c | 1 +
fs/super.c | 10 +++++---
include/linux/fs_context.h | 1 +
include/linux/lsm_hook_defs.h | 1 +
include/linux/lsm_hooks.h | 6 ++++-
include/linux/security.h | 6 +++++
security/security.c | 5 ++++
security/selinux/hooks.c | 25 +++++++++++++++++++
security/smack/smack_lsm.c | 54 +++++++++++++++++++++++++++++++++++++++++
10 files changed, 108 insertions(+), 5 deletions(-)
Comments
On Thu, Nov 10, 2022 at 6:09 AM David Howells <dhowells@redhat.com> wrote:
>
> When NFS superblocks are created by automounting, their LSM parameters
> aren't set in the fs_context struct prior to sget_fc() being called,
> leading to failure to match existing superblocks.
>
> Fix this by adding a new LSM hook to load fc->security for submount
> creation when alloc_fs_context() is creating the fs_context for it.
>
> However, this uncovers a further bug: nfs_get_root() initialises the
> superblock security manually by calling security_sb_set_mnt_opts() or
> security_sb_clone_mnt_opts() - but then vfs_get_tree() calls
> security_sb_set_mnt_opts(), which can lead to SELinux, at least,
> complaining.
>
> Fix that by adding a flag to the fs_context that suppresses the
> security_sb_set_mnt_opts() call in vfs_get_tree(). This can be set by NFS
> when it sets the LSM context on the new superblock.
>
> The first bug leads to messages like the following appearing in dmesg:
>
> NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)
>
> Changes
> =======
> ver #5)
> - Removed unused variable.
> - Only allocate smack_mnt_opts if we're dealing with a submount.
>
> ver #4)
> - When doing a FOR_SUBMOUNT mount, don't set the root label in SELinux or
> Smack.
>
> ver #3)
> - Made LSM parameter extraction dependent on fc->purpose ==
> FS_CONTEXT_FOR_SUBMOUNT. Shouldn't happen on FOR_RECONFIGURE.
>
> ver #2)
> - Added Smack support
> - Made LSM parameter extraction dependent on reference != NULL.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> Fixes: 9bc61ab18b1d ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
> Fixes: 779df6a5480f ("NFS: Ensure security label is set for root inode)
> Tested-by: Jeff Layton <jlayton@kernel.org>
> Reviewed-by: Jeff Layton <jlayton@kernel.org>
> Acked-by: Casey Schaufler <casey@schaufler-ca.com>
> Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
> cc: Trond Myklebust <trond.myklebust@hammerspace.com>
> cc: Anna Schumaker <anna@kernel.org>
> cc: Alexander Viro <viro@zeniv.linux.org.uk>
> cc: Scott Mayhew <smayhew@redhat.com>
> cc: Jeff Layton <jlayton@kernel.org>
> cc: Paul Moore <paul@paul-moore.com>
> cc: linux-nfs@vger.kernel.org
> cc: selinux@vger.kernel.org
> cc: linux-security-module@vger.kernel.org
> cc: linux-fsdevel@vger.kernel.org
> Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
> Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
> Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
> Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
> Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
> ---
>
> fs/fs_context.c | 4 +++
> fs/nfs/getroot.c | 1 +
> fs/super.c | 10 +++++---
> include/linux/fs_context.h | 1 +
> include/linux/lsm_hook_defs.h | 1 +
> include/linux/lsm_hooks.h | 6 ++++-
> include/linux/security.h | 6 +++++
> security/security.c | 5 ++++
> security/selinux/hooks.c | 25 +++++++++++++++++++
> security/smack/smack_lsm.c | 54 +++++++++++++++++++++++++++++++++++++++++
> 10 files changed, 108 insertions(+), 5 deletions(-)
>
> diff --git a/fs/fs_context.c b/fs/fs_context.c
> index 24ce12f0db32..22248b8a88a8 100644
> --- a/fs/fs_context.c
> +++ b/fs/fs_context.c
> @@ -282,6 +282,10 @@ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
> break;
> }
>
> + ret = security_fs_context_init(fc, reference);
> + if (ret < 0)
> + goto err_fc;
> +
> /* TODO: Make all filesystems support this unconditionally */
> init_fs_context = fc->fs_type->init_fs_context;
> if (!init_fs_context)
> diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
> index 11ff2b2e060f..651bffb0067e 100644
> --- a/fs/nfs/getroot.c
> +++ b/fs/nfs/getroot.c
> @@ -144,6 +144,7 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc)
> }
> if (error)
> goto error_splat_root;
> + fc->lsm_set = true;
> if (server->caps & NFS_CAP_SECURITY_LABEL &&
> !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
> server->caps &= ~NFS_CAP_SECURITY_LABEL;
> diff --git a/fs/super.c b/fs/super.c
> index 8d39e4f11cfa..f200ae0549ca 100644
> --- a/fs/super.c
> +++ b/fs/super.c
> @@ -1553,10 +1553,12 @@ int vfs_get_tree(struct fs_context *fc)
> smp_wmb();
> sb->s_flags |= SB_BORN;
>
> - error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
> - if (unlikely(error)) {
> - fc_drop_locked(fc);
> - return error;
> + if (!(fc->lsm_set)) {
> + error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
> + if (unlikely(error)) {
> + fc_drop_locked(fc);
> + return error;
> + }
> }
Thinking about all the different things that an LSM could do, would it
ever be possible that a LSM would want the security_sb_set_mnt_opts()
call to happen here? I'm wondering if we are better off leaving it up
to the LSM by passing the fs_context in the security_sb_set_mnt_opts()
hook; those that want to effectively skip this call due to a submount
setup already done in security_fs_context_init() can check the
fs_context::purpose value in the security_sb_set_mnt_opts() hook.
Thoughts?
On Fri, Nov 11, 2022 at 12:40 PM Paul Moore <paul@paul-moore.com> wrote:
> On Thu, Nov 10, 2022 at 6:09 AM David Howells <dhowells@redhat.com> wrote:
> >
> > When NFS superblocks are created by automounting, their LSM parameters
> > aren't set in the fs_context struct prior to sget_fc() being called,
> > leading to failure to match existing superblocks.
> >
> > Fix this by adding a new LSM hook to load fc->security for submount
> > creation when alloc_fs_context() is creating the fs_context for it.
> >
> > However, this uncovers a further bug: nfs_get_root() initialises the
> > superblock security manually by calling security_sb_set_mnt_opts() or
> > security_sb_clone_mnt_opts() - but then vfs_get_tree() calls
> > security_sb_set_mnt_opts(), which can lead to SELinux, at least,
> > complaining.
> >
> > Fix that by adding a flag to the fs_context that suppresses the
> > security_sb_set_mnt_opts() call in vfs_get_tree(). This can be set by NFS
> > when it sets the LSM context on the new superblock.
> >
> > The first bug leads to messages like the following appearing in dmesg:
> >
> > NFS: Cache volume key already in use (nfs,4.2,2,108,106a8c0,1,,,,100000,100000,2ee,3a98,1d4c,3a98,1)
> >
> > Changes
> > =======
> > ver #5)
> > - Removed unused variable.
> > - Only allocate smack_mnt_opts if we're dealing with a submount.
> >
> > ver #4)
> > - When doing a FOR_SUBMOUNT mount, don't set the root label in SELinux or
> > Smack.
> >
> > ver #3)
> > - Made LSM parameter extraction dependent on fc->purpose ==
> > FS_CONTEXT_FOR_SUBMOUNT. Shouldn't happen on FOR_RECONFIGURE.
> >
> > ver #2)
> > - Added Smack support
> > - Made LSM parameter extraction dependent on reference != NULL.
> >
> > Signed-off-by: David Howells <dhowells@redhat.com>
> > Fixes: 9bc61ab18b1d ("vfs: Introduce fs_context, switch vfs_kern_mount() to it.")
> > Fixes: 779df6a5480f ("NFS: Ensure security label is set for root inode)
> > Tested-by: Jeff Layton <jlayton@kernel.org>
> > Reviewed-by: Jeff Layton <jlayton@kernel.org>
> > Acked-by: Casey Schaufler <casey@schaufler-ca.com>
> > Acked-by: Christian Brauner (Microsoft) <brauner@kernel.org>
> > cc: Trond Myklebust <trond.myklebust@hammerspace.com>
> > cc: Anna Schumaker <anna@kernel.org>
> > cc: Alexander Viro <viro@zeniv.linux.org.uk>
> > cc: Scott Mayhew <smayhew@redhat.com>
> > cc: Jeff Layton <jlayton@kernel.org>
> > cc: Paul Moore <paul@paul-moore.com>
> > cc: linux-nfs@vger.kernel.org
> > cc: selinux@vger.kernel.org
> > cc: linux-security-module@vger.kernel.org
> > cc: linux-fsdevel@vger.kernel.org
> > Link: https://lore.kernel.org/r/165962680944.3334508.6610023900349142034.stgit@warthog.procyon.org.uk/ # v1
> > Link: https://lore.kernel.org/r/165962729225.3357250.14350728846471527137.stgit@warthog.procyon.org.uk/ # v2
> > Link: https://lore.kernel.org/r/165970659095.2812394.6868894171102318796.stgit@warthog.procyon.org.uk/ # v3
> > Link: https://lore.kernel.org/r/166133579016.3678898.6283195019480567275.stgit@warthog.procyon.org.uk/ # v4
> > Link: https://lore.kernel.org/r/217595.1662033775@warthog.procyon.org.uk/ # v5
> > ---
> >
> > fs/fs_context.c | 4 +++
> > fs/nfs/getroot.c | 1 +
> > fs/super.c | 10 +++++---
> > include/linux/fs_context.h | 1 +
> > include/linux/lsm_hook_defs.h | 1 +
> > include/linux/lsm_hooks.h | 6 ++++-
> > include/linux/security.h | 6 +++++
> > security/security.c | 5 ++++
> > security/selinux/hooks.c | 25 +++++++++++++++++++
> > security/smack/smack_lsm.c | 54 +++++++++++++++++++++++++++++++++++++++++
> > 10 files changed, 108 insertions(+), 5 deletions(-)
> >
> > diff --git a/fs/fs_context.c b/fs/fs_context.c
> > index 24ce12f0db32..22248b8a88a8 100644
> > --- a/fs/fs_context.c
> > +++ b/fs/fs_context.c
> > @@ -282,6 +282,10 @@ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
> > break;
> > }
> >
> > + ret = security_fs_context_init(fc, reference);
> > + if (ret < 0)
> > + goto err_fc;
> > +
> > /* TODO: Make all filesystems support this unconditionally */
> > init_fs_context = fc->fs_type->init_fs_context;
> > if (!init_fs_context)
> > diff --git a/fs/nfs/getroot.c b/fs/nfs/getroot.c
> > index 11ff2b2e060f..651bffb0067e 100644
> > --- a/fs/nfs/getroot.c
> > +++ b/fs/nfs/getroot.c
> > @@ -144,6 +144,7 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc)
> > }
> > if (error)
> > goto error_splat_root;
> > + fc->lsm_set = true;
> > if (server->caps & NFS_CAP_SECURITY_LABEL &&
> > !(kflags_out & SECURITY_LSM_NATIVE_LABELS))
> > server->caps &= ~NFS_CAP_SECURITY_LABEL;
> > diff --git a/fs/super.c b/fs/super.c
> > index 8d39e4f11cfa..f200ae0549ca 100644
> > --- a/fs/super.c
> > +++ b/fs/super.c
> > @@ -1553,10 +1553,12 @@ int vfs_get_tree(struct fs_context *fc)
> > smp_wmb();
> > sb->s_flags |= SB_BORN;
> >
> > - error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
> > - if (unlikely(error)) {
> > - fc_drop_locked(fc);
> > - return error;
> > + if (!(fc->lsm_set)) {
> > + error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
> > + if (unlikely(error)) {
> > + fc_drop_locked(fc);
> > + return error;
> > + }
> > }
>
> Thinking about all the different things that an LSM could do, would it
> ever be possible that a LSM would want the security_sb_set_mnt_opts()
> call to happen here? I'm wondering if we are better off leaving it up
> to the LSM by passing the fs_context in the security_sb_set_mnt_opts()
> hook; those that want to effectively skip this call due to a submount
> setup already done in security_fs_context_init() can check the
> fs_context::purpose value in the security_sb_set_mnt_opts() hook.
Actually, we could probably also create a LSM specific flag in
fs_context::security to indicate that the setup has already been done.
That's probably a little safer than relying on fs_context::purpose in
the security_sb_set_mnt_opts() hook.
> Thoughts?
On Thu, Nov 10, 2022 at 11:09:27AM +0000, David Howells wrote:
> When NFS superblocks are created by automounting, their LSM parameters
> aren't set in the fs_context struct prior to sget_fc() being called,
> leading to failure to match existing superblocks.
>
> Fix this by adding a new LSM hook to load fc->security for submount
> creation when alloc_fs_context() is creating the fs_context for it.
FWIW, it feels like security_sb_mnt_opts_compat() would be a saner place
for that. It would need to get struct dentry *reference passed to it,
but that should be it...
@@ -282,6 +282,10 @@ static struct fs_context *alloc_fs_context(struct file_system_type *fs_type,
break;
}
+ ret = security_fs_context_init(fc, reference);
+ if (ret < 0)
+ goto err_fc;
+
/* TODO: Make all filesystems support this unconditionally */
init_fs_context = fc->fs_type->init_fs_context;
if (!init_fs_context)
@@ -144,6 +144,7 @@ int nfs_get_root(struct super_block *s, struct fs_context *fc)
}
if (error)
goto error_splat_root;
+ fc->lsm_set = true;
if (server->caps & NFS_CAP_SECURITY_LABEL &&
!(kflags_out & SECURITY_LSM_NATIVE_LABELS))
server->caps &= ~NFS_CAP_SECURITY_LABEL;
@@ -1553,10 +1553,12 @@ int vfs_get_tree(struct fs_context *fc)
smp_wmb();
sb->s_flags |= SB_BORN;
- error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
- if (unlikely(error)) {
- fc_drop_locked(fc);
- return error;
+ if (!(fc->lsm_set)) {
+ error = security_sb_set_mnt_opts(sb, fc->security, 0, NULL);
+ if (unlikely(error)) {
+ fc_drop_locked(fc);
+ return error;
+ }
}
/*
@@ -110,6 +110,7 @@ struct fs_context {
bool need_free:1; /* Need to call ops->free() */
bool global:1; /* Goes into &init_user_ns */
bool oldapi:1; /* Coming from mount(2) */
+ bool lsm_set:1; /* security_sb_set/clone_mnt_opts() already done */
};
struct fs_context_operations {
@@ -54,6 +54,7 @@ LSM_HOOK(int, 0, bprm_creds_from_file, struct linux_binprm *bprm, struct file *f
LSM_HOOK(int, 0, bprm_check_security, struct linux_binprm *bprm)
LSM_HOOK(void, LSM_RET_VOID, bprm_committing_creds, struct linux_binprm *bprm)
LSM_HOOK(void, LSM_RET_VOID, bprm_committed_creds, struct linux_binprm *bprm)
+LSM_HOOK(int, 0, fs_context_init, struct fs_context *fc, struct dentry *reference)
LSM_HOOK(int, 0, fs_context_dup, struct fs_context *fc,
struct fs_context *src_sc)
LSM_HOOK(int, -ENOPARAM, fs_context_parse_param, struct fs_context *fc,
@@ -87,8 +87,12 @@
* Security hooks for mount using fs_context.
* [See also Documentation/filesystems/mount_api.rst]
*
+ * @fs_context_init:
+ * Initialise fc->security. This is initialised to NULL by the caller.
+ * @fc indicates the new filesystem context.
+ * @dentry indicates a reference for submount/remount
* @fs_context_dup:
- * Allocate and attach a security structure to sc->security. This pointer
+ * Allocate and attach a security structure to fc->security. This pointer
* is initialised to NULL by the caller.
* @fc indicates the new filesystem context.
* @src_fc indicates the original filesystem context.
@@ -293,6 +293,7 @@ int security_bprm_creds_from_file(struct linux_binprm *bprm, struct file *file);
int security_bprm_check(struct linux_binprm *bprm);
void security_bprm_committing_creds(struct linux_binprm *bprm);
void security_bprm_committed_creds(struct linux_binprm *bprm);
+int security_fs_context_init(struct fs_context *fc, struct dentry *reference);
int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc);
int security_fs_context_parse_param(struct fs_context *fc, struct fs_parameter *param);
int security_sb_alloc(struct super_block *sb);
@@ -625,6 +626,11 @@ static inline void security_bprm_committed_creds(struct linux_binprm *bprm)
{
}
+static inline int security_fs_context_init(struct fs_context *fc,
+ struct dentry *reference)
+{
+ return 0;
+}
static inline int security_fs_context_dup(struct fs_context *fc,
struct fs_context *src_fc)
{
@@ -882,6 +882,11 @@ void security_bprm_committed_creds(struct linux_binprm *bprm)
call_void_hook(bprm_committed_creds, bprm);
}
+int security_fs_context_init(struct fs_context *fc, struct dentry *reference)
+{
+ return call_int_hook(fs_context_init, 0, fc, reference);
+}
+
int security_fs_context_dup(struct fs_context *fc, struct fs_context *src_fc)
{
return call_int_hook(fs_context_dup, 0, fc, src_fc);
@@ -2766,6 +2766,30 @@ static int selinux_umount(struct vfsmount *mnt, int flags)
FILESYSTEM__UNMOUNT, NULL);
}
+static int selinux_fs_context_init(struct fs_context *fc,
+ struct dentry *reference)
+{
+ const struct superblock_security_struct *sbsec;
+ struct selinux_mnt_opts *opts;
+
+ if (fc->purpose == FS_CONTEXT_FOR_SUBMOUNT) {
+ opts = kzalloc(sizeof(*opts), GFP_KERNEL);
+ if (!opts)
+ return -ENOMEM;
+
+ sbsec = selinux_superblock(reference->d_sb);
+ if (sbsec->flags & FSCONTEXT_MNT)
+ opts->fscontext_sid = sbsec->sid;
+ if (sbsec->flags & CONTEXT_MNT)
+ opts->context_sid = sbsec->mntpoint_sid;
+ if (sbsec->flags & DEFCONTEXT_MNT)
+ opts->defcontext_sid = sbsec->def_sid;
+ fc->security = opts;
+ }
+
+ return 0;
+}
+
static int selinux_fs_context_dup(struct fs_context *fc,
struct fs_context *src_fc)
{
@@ -7263,6 +7287,7 @@ static struct security_hook_list selinux_hooks[] __lsm_ro_after_init = {
/*
* PUT "CLONING" (ACCESSING + ALLOCATING) HOOKS HERE
*/
+ LSM_HOOK_INIT(fs_context_init, selinux_fs_context_init),
LSM_HOOK_INIT(fs_context_dup, selinux_fs_context_dup),
LSM_HOOK_INIT(fs_context_parse_param, selinux_fs_context_parse_param),
LSM_HOOK_INIT(sb_eat_lsm_opts, selinux_sb_eat_lsm_opts),
@@ -611,6 +611,59 @@ static int smack_add_opt(int token, const char *s, void **mnt_opts)
return -EINVAL;
}
+/**
+ * smack_fs_context_init - Initialise security data for a filesystem context
+ * @fc: The filesystem context.
+ * @reference: Reference dentry (automount/reconfigure) or NULL
+ *
+ * Returns 0 on success or -ENOMEM on error.
+ */
+static int smack_fs_context_init(struct fs_context *fc,
+ struct dentry *reference)
+{
+ struct superblock_smack *sbsp;
+ struct smack_mnt_opts *ctx;
+ struct inode_smack *isp;
+
+ if (fc->purpose == FS_CONTEXT_FOR_SUBMOUNT) {
+ ctx = kzalloc(sizeof(*ctx), GFP_KERNEL);
+ if (!ctx)
+ return -ENOMEM;
+ fc->security = ctx;
+
+ sbsp = smack_superblock(reference->d_sb);
+ isp = smack_inode(reference->d_sb->s_root->d_inode);
+
+ if (sbsp->smk_default) {
+ ctx->fsdefault = kstrdup(sbsp->smk_default->smk_known, GFP_KERNEL);
+ if (!ctx->fsdefault)
+ return -ENOMEM;
+ }
+
+ if (sbsp->smk_floor) {
+ ctx->fsfloor = kstrdup(sbsp->smk_floor->smk_known, GFP_KERNEL);
+ if (!ctx->fsfloor)
+ return -ENOMEM;
+ }
+
+ if (sbsp->smk_hat) {
+ ctx->fshat = kstrdup(sbsp->smk_hat->smk_known, GFP_KERNEL);
+ if (!ctx->fshat)
+ return -ENOMEM;
+ }
+
+ if (isp->smk_flags & SMK_INODE_TRANSMUTE) {
+ if (sbsp->smk_root) {
+ ctx->fstransmute = kstrdup(sbsp->smk_root->smk_known, GFP_KERNEL);
+ if (!ctx->fstransmute)
+ return -ENOMEM;
+ }
+ }
+ }
+
+ return 0;
+}
+
/**
* smack_fs_context_dup - Duplicate the security data on fs_context duplication
* @fc: The new filesystem context.
@@ -4792,6 +4845,7 @@ static struct security_hook_list smack_hooks[] __lsm_ro_after_init = {
LSM_HOOK_INIT(ptrace_traceme, smack_ptrace_traceme),
LSM_HOOK_INIT(syslog, smack_syslog),
+ LSM_HOOK_INIT(fs_context_init, smack_fs_context_init),
LSM_HOOK_INIT(fs_context_dup, smack_fs_context_dup),
LSM_HOOK_INIT(fs_context_parse_param, smack_fs_context_parse_param),