| Message ID | YWWMO/ZDrvDZ5X4c@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | [v2] security: Return xattr name from security_dentry_init_security() | expand |
On Tue, Oct 12, 2021 at 09:23:07AM -0400, Vivek Goyal wrote: > Right now security_dentry_init_security() only supports single security > label and is used by SELinux only. There are two users of of this hook, > namely ceph and nfs. > > NFS does not care about xattr name. Ceph hardcodes the xattr name to > security.selinux (XATTR_NAME_SELINUX). > > I am making changes to fuse/virtiofs to send security label to virtiofsd > and I need to send xattr name as well. I also hardcoded the name of > xattr to security.selinux. > > Stephen Smalley suggested that it probably is a good idea to modify > security_dentry_init_security() to also return name of xattr so that > we can avoid this hardcoding in the callers. > > This patch adds a new parameter "const char **xattr_name" to > security_dentry_init_security() and LSM puts the name of xattr > too if caller asked for it (xattr_name != NULL). > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > Reviewed-by: Jeff Layton <jlayton@kernel.org> > --- Looks good to me. Reviewed-by: Christian Brauner <christian.brauner@ubuntu.com>
Hi James, I am assuming this patch will need to be routed through security tree. Can you please consider it for inclusion. Thanks Vivek On Tue, Oct 12, 2021 at 09:23:07AM -0400, Vivek Goyal wrote: > Right now security_dentry_init_security() only supports single security > label and is used by SELinux only. There are two users of of this hook, > namely ceph and nfs. > > NFS does not care about xattr name. Ceph hardcodes the xattr name to > security.selinux (XATTR_NAME_SELINUX). > > I am making changes to fuse/virtiofs to send security label to virtiofsd > and I need to send xattr name as well. I also hardcoded the name of > xattr to security.selinux. > > Stephen Smalley suggested that it probably is a good idea to modify > security_dentry_init_security() to also return name of xattr so that > we can avoid this hardcoding in the callers. > > This patch adds a new parameter "const char **xattr_name" to > security_dentry_init_security() and LSM puts the name of xattr > too if caller asked for it (xattr_name != NULL). > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > Reviewed-by: Jeff Layton <jlayton@kernel.org> > --- > > Changes since v1: > - Updated comment to make it clear caller does not have to free the > xattr_name. (Jeff Layton). > - Captured Jeff's Reviewed-by ack. > > I have tested this patch with virtiofs and compile tested for ceph and nfs. > > NFS changes are trivial. Looking for an ack from NFS maintainers. > > --- > fs/ceph/xattr.c | 3 +-- > fs/nfs/nfs4proc.c | 3 ++- > include/linux/lsm_hook_defs.h | 3 ++- > include/linux/lsm_hooks.h | 3 +++ > include/linux/security.h | 6 ++++-- > security/security.c | 7 ++++--- > security/selinux/hooks.c | 6 +++++- > 7 files changed, 21 insertions(+), 10 deletions(-) > > Index: redhat-linux/security/selinux/hooks.c > =================================================================== > --- redhat-linux.orig/security/selinux/hooks.c 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/security/selinux/hooks.c 2021-10-06 15:20:57.745247170 -0400 > @@ -2948,7 +2948,8 @@ static void selinux_inode_free_security( > } > > static int selinux_dentry_init_security(struct dentry *dentry, int mode, > - const struct qstr *name, void **ctx, > + const struct qstr *name, > + const char **xattr_name, void **ctx, > u32 *ctxlen) > { > u32 newsid; > @@ -2961,6 +2962,9 @@ static int selinux_dentry_init_security( > if (rc) > return rc; > > + if (xattr_name) > + *xattr_name = XATTR_NAME_SELINUX; > + > return security_sid_to_context(&selinux_state, newsid, (char **)ctx, > ctxlen); > } > Index: redhat-linux/security/security.c > =================================================================== > --- redhat-linux.orig/security/security.c 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/security/security.c 2021-10-06 15:20:57.749247170 -0400 > @@ -1052,11 +1052,12 @@ void security_inode_free(struct inode *i > } > > int security_dentry_init_security(struct dentry *dentry, int mode, > - const struct qstr *name, void **ctx, > - u32 *ctxlen) > + const struct qstr *name, > + const char **xattr_name, void **ctx, > + u32 *ctxlen) > { > return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode, > - name, ctx, ctxlen); > + name, xattr_name, ctx, ctxlen); > } > EXPORT_SYMBOL(security_dentry_init_security); > > Index: redhat-linux/include/linux/lsm_hooks.h > =================================================================== > --- redhat-linux.orig/include/linux/lsm_hooks.h 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/include/linux/lsm_hooks.h 2021-10-12 09:05:00.830399245 -0400 > @@ -196,6 +196,9 @@ > * @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 > + * @xattr_name pointer to place the pointer to security xattr name. > + * Caller does not have to free the resulting pointer. Its > + * a pointer to static string. > * @ctx pointer to place the pointer to the resulting context in. > * @ctxlen point to place the length of the resulting context. > * @dentry_create_files_as: > Index: redhat-linux/include/linux/security.h > =================================================================== > --- redhat-linux.orig/include/linux/security.h 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/include/linux/security.h 2021-10-06 15:20:57.751247170 -0400 > @@ -317,8 +317,9 @@ int security_add_mnt_opt(const char *opt > int len, void **mnt_opts); > int security_move_mount(const struct path *from_path, const struct path *to_path); > int security_dentry_init_security(struct dentry *dentry, int mode, > - const struct qstr *name, void **ctx, > - u32 *ctxlen); > + const struct qstr *name, > + const char **xattr_name, void **ctx, > + u32 *ctxlen); > int security_dentry_create_files_as(struct dentry *dentry, int mode, > struct qstr *name, > const struct cred *old, > @@ -739,6 +740,7 @@ static inline void security_inode_free(s > static inline int security_dentry_init_security(struct dentry *dentry, > int mode, > const struct qstr *name, > + const char **xattr_name, > void **ctx, > u32 *ctxlen) > { > Index: redhat-linux/include/linux/lsm_hook_defs.h > =================================================================== > --- redhat-linux.orig/include/linux/lsm_hook_defs.h 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/include/linux/lsm_hook_defs.h 2021-10-06 15:20:57.752247170 -0400 > @@ -83,7 +83,8 @@ LSM_HOOK(int, 0, sb_add_mnt_opt, const c > LSM_HOOK(int, 0, move_mount, const struct path *from_path, > const struct path *to_path) > LSM_HOOK(int, 0, dentry_init_security, struct dentry *dentry, > - int mode, const struct qstr *name, void **ctx, u32 *ctxlen) > + int mode, const struct qstr *name, const char **xattr_name, > + void **ctx, u32 *ctxlen) > LSM_HOOK(int, 0, dentry_create_files_as, struct dentry *dentry, int mode, > struct qstr *name, const struct cred *old, struct cred *new) > > Index: redhat-linux/fs/nfs/nfs4proc.c > =================================================================== > --- redhat-linux.orig/fs/nfs/nfs4proc.c 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/fs/nfs/nfs4proc.c 2021-10-06 15:20:57.754247170 -0400 > @@ -127,7 +127,8 @@ nfs4_label_init_security(struct inode *d > return NULL; > > err = security_dentry_init_security(dentry, sattr->ia_mode, > - &dentry->d_name, (void **)&label->label, &label->len); > + &dentry->d_name, NULL, > + (void **)&label->label, &label->len); > if (err == 0) > return label; > > Index: redhat-linux/fs/ceph/xattr.c > =================================================================== > --- redhat-linux.orig/fs/ceph/xattr.c 2021-10-04 15:40:28.978453324 -0400 > +++ redhat-linux/fs/ceph/xattr.c 2021-10-06 15:20:57.756247170 -0400 > @@ -1311,7 +1311,7 @@ int ceph_security_init_secctx(struct den > int err; > > err = security_dentry_init_security(dentry, mode, &dentry->d_name, > - &as_ctx->sec_ctx, > + &name, &as_ctx->sec_ctx, > &as_ctx->sec_ctxlen); > if (err < 0) { > WARN_ON_ONCE(err != -EOPNOTSUPP); > @@ -1335,7 +1335,6 @@ int ceph_security_init_secctx(struct den > * It only supports single security module and only selinux has > * dentry_init_security hook. > */ > - name = XATTR_NAME_SELINUX; > name_len = strlen(name); > err = ceph_pagelist_reserve(pagelist, > 4 * 2 + name_len + as_ctx->sec_ctxlen); >
On Mon, 18 Oct 2021, Vivek Goyal wrote: > Hi James, > > I am assuming this patch will need to be routed through security tree. > Can you please consider it for inclusion. > I'm happy for this to go via Paul's tree as it impacts SELinux and is fairly minor in scope. Acked-by: James Morris <jamorris@linux.microsoft.com>
On Tue, Oct 19, 2021 at 5:02 PM James Morris <jmorris@namei.org> wrote: > > On Mon, 18 Oct 2021, Vivek Goyal wrote: > > > Hi James, > > > > I am assuming this patch will need to be routed through security tree. > > Can you please consider it for inclusion. > > I'm happy for this to go via Paul's tree as it impacts SELinux and is > fairly minor in scope. I'll take a look tomorrow, I ended up spending most of my day today chasing a 32-bit MIPS (!!) bug in libseccomp and now it's dinner time.
On Tue, Oct 12, 2021 at 9:23 AM Vivek Goyal <vgoyal@redhat.com> wrote: > > Right now security_dentry_init_security() only supports single security > label and is used by SELinux only. There are two users of of this hook, > namely ceph and nfs. > > NFS does not care about xattr name. Ceph hardcodes the xattr name to > security.selinux (XATTR_NAME_SELINUX). > > I am making changes to fuse/virtiofs to send security label to virtiofsd > and I need to send xattr name as well. I also hardcoded the name of > xattr to security.selinux. > > Stephen Smalley suggested that it probably is a good idea to modify > security_dentry_init_security() to also return name of xattr so that > we can avoid this hardcoding in the callers. > > This patch adds a new parameter "const char **xattr_name" to > security_dentry_init_security() and LSM puts the name of xattr > too if caller asked for it (xattr_name != NULL). > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > Reviewed-by: Jeff Layton <jlayton@kernel.org> > --- > > Changes since v1: > - Updated comment to make it clear caller does not have to free the > xattr_name. (Jeff Layton). > - Captured Jeff's Reviewed-by ack. > > I have tested this patch with virtiofs and compile tested for ceph and nfs. > > NFS changes are trivial. Looking for an ack from NFS maintainers. > > --- > fs/ceph/xattr.c | 3 +-- > fs/nfs/nfs4proc.c | 3 ++- > include/linux/lsm_hook_defs.h | 3 ++- > include/linux/lsm_hooks.h | 3 +++ > include/linux/security.h | 6 ++++-- > security/security.c | 7 ++++--- > security/selinux/hooks.c | 6 +++++- > 7 files changed, 21 insertions(+), 10 deletions(-) This looks fine to me and considering the trivial nature of the NFS changes I'm okay with merging this without an explicit ACK from the NFS folks. Similarly, I generally dislike merging new functionality once we hit -rc6, but this is trivial enough that I think it's okay; I'm merging this into selinux/next now, thanks everyone.
On Wed, Oct 20, 2021 at 08:24:44AM -0400, Paul Moore wrote: > On Tue, Oct 12, 2021 at 9:23 AM Vivek Goyal <vgoyal@redhat.com> wrote: > > > > Right now security_dentry_init_security() only supports single security > > label and is used by SELinux only. There are two users of of this hook, > > namely ceph and nfs. > > > > NFS does not care about xattr name. Ceph hardcodes the xattr name to > > security.selinux (XATTR_NAME_SELINUX). > > > > I am making changes to fuse/virtiofs to send security label to virtiofsd > > and I need to send xattr name as well. I also hardcoded the name of > > xattr to security.selinux. > > > > Stephen Smalley suggested that it probably is a good idea to modify > > security_dentry_init_security() to also return name of xattr so that > > we can avoid this hardcoding in the callers. > > > > This patch adds a new parameter "const char **xattr_name" to > > security_dentry_init_security() and LSM puts the name of xattr > > too if caller asked for it (xattr_name != NULL). > > > > Signed-off-by: Vivek Goyal <vgoyal@redhat.com> > > Reviewed-by: Jeff Layton <jlayton@kernel.org> > > --- > > > > Changes since v1: > > - Updated comment to make it clear caller does not have to free the > > xattr_name. (Jeff Layton). > > - Captured Jeff's Reviewed-by ack. > > > > I have tested this patch with virtiofs and compile tested for ceph and nfs. > > > > NFS changes are trivial. Looking for an ack from NFS maintainers. > > > > --- > > fs/ceph/xattr.c | 3 +-- > > fs/nfs/nfs4proc.c | 3 ++- > > include/linux/lsm_hook_defs.h | 3 ++- > > include/linux/lsm_hooks.h | 3 +++ > > include/linux/security.h | 6 ++++-- > > security/security.c | 7 ++++--- > > security/selinux/hooks.c | 6 +++++- > > 7 files changed, 21 insertions(+), 10 deletions(-) > > This looks fine to me and considering the trivial nature of the NFS > changes I'm okay with merging this without an explicit ACK from the > NFS folks. Similarly, I generally dislike merging new functionality > once we hit -rc6, but this is trivial enough that I think it's okay; > I'm merging this into selinux/next now, thanks everyone. Thanks Paul. I agree that this a trivial fix with no functionality change and probability of this breaking something is very very low. Vivek
Index: redhat-linux/security/selinux/hooks.c =================================================================== --- redhat-linux.orig/security/selinux/hooks.c 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/security/selinux/hooks.c 2021-10-06 15:20:57.745247170 -0400 @@ -2948,7 +2948,8 @@ static void selinux_inode_free_security( } static int selinux_dentry_init_security(struct dentry *dentry, int mode, - const struct qstr *name, void **ctx, + const struct qstr *name, + const char **xattr_name, void **ctx, u32 *ctxlen) { u32 newsid; @@ -2961,6 +2962,9 @@ static int selinux_dentry_init_security( if (rc) return rc; + if (xattr_name) + *xattr_name = XATTR_NAME_SELINUX; + return security_sid_to_context(&selinux_state, newsid, (char **)ctx, ctxlen); } Index: redhat-linux/security/security.c =================================================================== --- redhat-linux.orig/security/security.c 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/security/security.c 2021-10-06 15:20:57.749247170 -0400 @@ -1052,11 +1052,12 @@ void security_inode_free(struct inode *i } int security_dentry_init_security(struct dentry *dentry, int mode, - const struct qstr *name, void **ctx, - u32 *ctxlen) + const struct qstr *name, + const char **xattr_name, void **ctx, + u32 *ctxlen) { return call_int_hook(dentry_init_security, -EOPNOTSUPP, dentry, mode, - name, ctx, ctxlen); + name, xattr_name, ctx, ctxlen); } EXPORT_SYMBOL(security_dentry_init_security); Index: redhat-linux/include/linux/lsm_hooks.h =================================================================== --- redhat-linux.orig/include/linux/lsm_hooks.h 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/include/linux/lsm_hooks.h 2021-10-12 09:05:00.830399245 -0400 @@ -196,6 +196,9 @@ * @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 + * @xattr_name pointer to place the pointer to security xattr name. + * Caller does not have to free the resulting pointer. Its + * a pointer to static string. * @ctx pointer to place the pointer to the resulting context in. * @ctxlen point to place the length of the resulting context. * @dentry_create_files_as: Index: redhat-linux/include/linux/security.h =================================================================== --- redhat-linux.orig/include/linux/security.h 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/include/linux/security.h 2021-10-06 15:20:57.751247170 -0400 @@ -317,8 +317,9 @@ int security_add_mnt_opt(const char *opt int len, void **mnt_opts); int security_move_mount(const struct path *from_path, const struct path *to_path); int security_dentry_init_security(struct dentry *dentry, int mode, - const struct qstr *name, void **ctx, - u32 *ctxlen); + const struct qstr *name, + const char **xattr_name, void **ctx, + u32 *ctxlen); int security_dentry_create_files_as(struct dentry *dentry, int mode, struct qstr *name, const struct cred *old, @@ -739,6 +740,7 @@ static inline void security_inode_free(s static inline int security_dentry_init_security(struct dentry *dentry, int mode, const struct qstr *name, + const char **xattr_name, void **ctx, u32 *ctxlen) { Index: redhat-linux/include/linux/lsm_hook_defs.h =================================================================== --- redhat-linux.orig/include/linux/lsm_hook_defs.h 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/include/linux/lsm_hook_defs.h 2021-10-06 15:20:57.752247170 -0400 @@ -83,7 +83,8 @@ LSM_HOOK(int, 0, sb_add_mnt_opt, const c LSM_HOOK(int, 0, move_mount, const struct path *from_path, const struct path *to_path) LSM_HOOK(int, 0, dentry_init_security, struct dentry *dentry, - int mode, const struct qstr *name, void **ctx, u32 *ctxlen) + int mode, const struct qstr *name, const char **xattr_name, + void **ctx, u32 *ctxlen) LSM_HOOK(int, 0, dentry_create_files_as, struct dentry *dentry, int mode, struct qstr *name, const struct cred *old, struct cred *new) Index: redhat-linux/fs/nfs/nfs4proc.c =================================================================== --- redhat-linux.orig/fs/nfs/nfs4proc.c 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/fs/nfs/nfs4proc.c 2021-10-06 15:20:57.754247170 -0400 @@ -127,7 +127,8 @@ nfs4_label_init_security(struct inode *d return NULL; err = security_dentry_init_security(dentry, sattr->ia_mode, - &dentry->d_name, (void **)&label->label, &label->len); + &dentry->d_name, NULL, + (void **)&label->label, &label->len); if (err == 0) return label; Index: redhat-linux/fs/ceph/xattr.c =================================================================== --- redhat-linux.orig/fs/ceph/xattr.c 2021-10-04 15:40:28.978453324 -0400 +++ redhat-linux/fs/ceph/xattr.c 2021-10-06 15:20:57.756247170 -0400 @@ -1311,7 +1311,7 @@ int ceph_security_init_secctx(struct den int err; err = security_dentry_init_security(dentry, mode, &dentry->d_name, - &as_ctx->sec_ctx, + &name, &as_ctx->sec_ctx, &as_ctx->sec_ctxlen); if (err < 0) { WARN_ON_ONCE(err != -EOPNOTSUPP); @@ -1335,7 +1335,6 @@ int ceph_security_init_secctx(struct den * It only supports single security module and only selinux has * dentry_init_security hook. */ - name = XATTR_NAME_SELINUX; name_len = strlen(name); err = ceph_pagelist_reserve(pagelist, 4 * 2 + name_len + as_ctx->sec_ctxlen);