| Message ID | 20240221-idmap-fscap-refactor-v2-11-3039364623bd@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | fs: use type-safe uid representation for filesystem capabilities | expand |
On Wed, Feb 21, 2024 at 4:26 PM Seth Forshee (DigitalOcean) <sforshee@kernel.org> wrote: > > In preparation for moving fscaps out of the xattr code paths, add new > security hooks. These hooks are largely needed because common kernel > code will pass around struct vfs_caps pointers, which EVM will need to > convert to raw xattr data for verification and updates of its hashes. > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> > --- > include/linux/lsm_hook_defs.h | 7 +++++ > include/linux/security.h | 33 +++++++++++++++++++++ > security/security.c | 69 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 109 insertions(+) One minor problem below, but assuming you fix that, this looks okay to me. Acked-by: Paul Moore <paul@paul-moore.com> > diff --git a/security/security.c b/security/security.c > index 3aaad75c9ce8..0d210da9862c 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -2351,6 +2351,75 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, ... > +/** > + * security_inode_get_fscaps() - Check if reading fscaps is allowed > + * @dentry: file You are missing an entry for the @idmap parameter. > + * Check permission before getting fscaps. > + * > + * Return: Returns 0 if permission is granted. > + */ > +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) > +{ > + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) > + return 0; > + return call_int_hook(inode_get_fscaps, 0, idmap, dentry); > +}
On Wed, Feb 21, 2024 at 06:31:42PM -0500, Paul Moore wrote: > On Wed, Feb 21, 2024 at 4:26 PM Seth Forshee (DigitalOcean) > <sforshee@kernel.org> wrote: > > > > In preparation for moving fscaps out of the xattr code paths, add new > > security hooks. These hooks are largely needed because common kernel > > code will pass around struct vfs_caps pointers, which EVM will need to > > convert to raw xattr data for verification and updates of its hashes. > > > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> > > --- > > include/linux/lsm_hook_defs.h | 7 +++++ > > include/linux/security.h | 33 +++++++++++++++++++++ > > security/security.c | 69 +++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 109 insertions(+) > > One minor problem below, but assuming you fix that, this looks okay to me. > > Acked-by: Paul Moore <paul@paul-moore.com> > > > diff --git a/security/security.c b/security/security.c > > index 3aaad75c9ce8..0d210da9862c 100644 > > --- a/security/security.c > > +++ b/security/security.c > > @@ -2351,6 +2351,75 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, > > ... > > > +/** > > + * security_inode_get_fscaps() - Check if reading fscaps is allowed > > + * @dentry: file > > You are missing an entry for the @idmap parameter. Fixed, thanks!
On Wed, Feb 21, 2024 at 03:24:42PM -0600, Seth Forshee (DigitalOcean) wrote: > In preparation for moving fscaps out of the xattr code paths, add new > security hooks. These hooks are largely needed because common kernel > code will pass around struct vfs_caps pointers, which EVM will need to > convert to raw xattr data for verification and updates of its hashes. > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> > --- Looks good, Reviewed-by: Christian Brauner <brauner@kernel.org>
On Wed, 2024-02-21 at 15:24 -0600, Seth Forshee (DigitalOcean) wrote: > In preparation for moving fscaps out of the xattr code paths, add new > security hooks. These hooks are largely needed because common kernel > code will pass around struct vfs_caps pointers, which EVM will need to > convert to raw xattr data for verification and updates of its hashes. > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> > --- > include/linux/lsm_hook_defs.h | 7 +++++ > include/linux/security.h | 33 +++++++++++++++++++++ > security/security.c | 69 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 109 insertions(+) > > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > index 76458b6d53da..7b3c23f9e4a5 100644 > --- a/include/linux/lsm_hook_defs.h > +++ b/include/linux/lsm_hook_defs.h > @@ -152,6 +152,13 @@ LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap, > struct dentry *dentry, const char *acl_name) > LSM_HOOK(int, 0, inode_remove_acl, struct mnt_idmap *idmap, > struct dentry *dentry, const char *acl_name) > +LSM_HOOK(int, 0, inode_set_fscaps, struct mnt_idmap *idmap, > + struct dentry *dentry, const struct vfs_caps *caps, int flags); > +LSM_HOOK(void, LSM_RET_VOID, inode_post_set_fscaps, struct mnt_idmap *idmap, > + struct dentry *dentry, const struct vfs_caps *caps, int flags); > +LSM_HOOK(int, 0, inode_get_fscaps, struct mnt_idmap *idmap, struct dentry *dentry); > +LSM_HOOK(int, 0, inode_remove_fscaps, struct mnt_idmap *idmap, > + struct dentry *dentry); Uhm, there should not be semicolons here. Roberto > LSM_HOOK(int, 0, inode_need_killpriv, struct dentry *dentry) > LSM_HOOK(int, 0, inode_killpriv, struct mnt_idmap *idmap, > struct dentry *dentry) > diff --git a/include/linux/security.h b/include/linux/security.h > index d0eb20f90b26..40be548e5e12 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -378,6 +378,13 @@ int security_inode_getxattr(struct dentry *dentry, const char *name); > int security_inode_listxattr(struct dentry *dentry); > int security_inode_removexattr(struct mnt_idmap *idmap, > struct dentry *dentry, const char *name); > +int security_inode_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry, > + const struct vfs_caps *caps, int flags); > +void security_inode_post_set_fscaps(struct mnt_idmap *idmap, > + struct dentry *dentry, > + const struct vfs_caps *caps, int flags); > +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry); > +int security_inode_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry); > int security_inode_need_killpriv(struct dentry *dentry); > int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry); > int security_inode_getsecurity(struct mnt_idmap *idmap, > @@ -935,6 +942,32 @@ static inline int security_inode_removexattr(struct mnt_idmap *idmap, > return cap_inode_removexattr(idmap, dentry, name); > } > > +static inline int security_inode_set_fscaps(struct mnt_idmap *idmap, > + struct dentry *dentry, > + const struct vfs_caps *caps, > + int flags) > +{ > + return 0; > +} > +static void security_inode_post_set_fscaps(struct mnt_idmap *idmap, > + struct dentry *dentry, > + const struct vfs_caps *caps, > + int flags) > +{ > +} > + > +static int security_inode_get_fscaps(struct mnt_idmap *idmap, > + struct dentry *dentry) > +{ > + return 0; > +} > + > +static int security_inode_remove_fscaps(struct mnt_idmap *idmap, > + struct dentry *dentry) > +{ > + return 0; > +} > + > static inline int security_inode_need_killpriv(struct dentry *dentry) > { > return cap_inode_need_killpriv(dentry); > diff --git a/security/security.c b/security/security.c > index 3aaad75c9ce8..0d210da9862c 100644 > --- a/security/security.c > +++ b/security/security.c > @@ -2351,6 +2351,75 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, > return evm_inode_remove_acl(idmap, dentry, acl_name); > } > > +/** > + * security_inode_set_fscaps() - Check if setting fscaps is allowed > + * @idmap: idmap of the mount > + * @dentry: file > + * @caps: fscaps to be written > + * @flags: flags for setxattr > + * > + * Check permission before setting the file capabilities given in @vfs_caps. > + * > + * Return: Returns 0 if permission is granted. > + */ > +int security_inode_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry, > + const struct vfs_caps *caps, int flags) > +{ > + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) > + return 0; > + return call_int_hook(inode_set_fscaps, 0, idmap, dentry, caps, flags); > +} > + > +/** > + * security_inode_post_set_fscaps() - Update the inode after setting fscaps > + * @idmap: idmap of the mount > + * @dentry: file > + * @caps: fscaps to be written > + * @flags: flags for setxattr > + * > + * Update inode security field after successfully setting fscaps. > + * > + */ > +void security_inode_post_set_fscaps(struct mnt_idmap *idmap, > + struct dentry *dentry, > + const struct vfs_caps *caps, int flags) > +{ > + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) > + return; > + call_void_hook(inode_post_set_fscaps, idmap, dentry, caps, flags); > +} > + > +/** > + * security_inode_get_fscaps() - Check if reading fscaps is allowed > + * @dentry: file > + * > + * Check permission before getting fscaps. > + * > + * Return: Returns 0 if permission is granted. > + */ > +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) > +{ > + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) > + return 0; > + return call_int_hook(inode_get_fscaps, 0, idmap, dentry); > +} > + > +/** > + * security_inode_remove_fscaps() - Check if removing fscaps is allowed > + * @idmap: idmap of the mount > + * @dentry: file > + * > + * Check permission before removing fscaps. > + * > + * Return: Returns 0 if permission is granted. > + */ > +int security_inode_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) > +{ > + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) > + return 0; > + return call_int_hook(inode_remove_fscaps, 0, idmap, dentry); > +} > + > /** > * security_inode_post_setxattr() - Update the inode after a setxattr operation > * @dentry: file >
On Fri, Mar 01, 2024 at 04:59:16PM +0100, Roberto Sassu wrote: > On Wed, 2024-02-21 at 15:24 -0600, Seth Forshee (DigitalOcean) wrote: > > In preparation for moving fscaps out of the xattr code paths, add new > > security hooks. These hooks are largely needed because common kernel > > code will pass around struct vfs_caps pointers, which EVM will need to > > convert to raw xattr data for verification and updates of its hashes. > > > > Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> > > --- > > include/linux/lsm_hook_defs.h | 7 +++++ > > include/linux/security.h | 33 +++++++++++++++++++++ > > security/security.c | 69 +++++++++++++++++++++++++++++++++++++++++++ > > 3 files changed, 109 insertions(+) > > > > diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h > > index 76458b6d53da..7b3c23f9e4a5 100644 > > --- a/include/linux/lsm_hook_defs.h > > +++ b/include/linux/lsm_hook_defs.h > > @@ -152,6 +152,13 @@ LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap, > > struct dentry *dentry, const char *acl_name) > > LSM_HOOK(int, 0, inode_remove_acl, struct mnt_idmap *idmap, > > struct dentry *dentry, const char *acl_name) > > +LSM_HOOK(int, 0, inode_set_fscaps, struct mnt_idmap *idmap, > > + struct dentry *dentry, const struct vfs_caps *caps, int flags); > > +LSM_HOOK(void, LSM_RET_VOID, inode_post_set_fscaps, struct mnt_idmap *idmap, > > + struct dentry *dentry, const struct vfs_caps *caps, int flags); > > +LSM_HOOK(int, 0, inode_get_fscaps, struct mnt_idmap *idmap, struct dentry *dentry); > > +LSM_HOOK(int, 0, inode_remove_fscaps, struct mnt_idmap *idmap, > > + struct dentry *dentry); > > Uhm, there should not be semicolons here. Yes, I've fixed this already for the next version. Thanks, Seth
diff --git a/include/linux/lsm_hook_defs.h b/include/linux/lsm_hook_defs.h index 76458b6d53da..7b3c23f9e4a5 100644 --- a/include/linux/lsm_hook_defs.h +++ b/include/linux/lsm_hook_defs.h @@ -152,6 +152,13 @@ LSM_HOOK(int, 0, inode_get_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) LSM_HOOK(int, 0, inode_remove_acl, struct mnt_idmap *idmap, struct dentry *dentry, const char *acl_name) +LSM_HOOK(int, 0, inode_set_fscaps, struct mnt_idmap *idmap, + struct dentry *dentry, const struct vfs_caps *caps, int flags); +LSM_HOOK(void, LSM_RET_VOID, inode_post_set_fscaps, struct mnt_idmap *idmap, + struct dentry *dentry, const struct vfs_caps *caps, int flags); +LSM_HOOK(int, 0, inode_get_fscaps, struct mnt_idmap *idmap, struct dentry *dentry); +LSM_HOOK(int, 0, inode_remove_fscaps, struct mnt_idmap *idmap, + struct dentry *dentry); LSM_HOOK(int, 0, inode_need_killpriv, struct dentry *dentry) LSM_HOOK(int, 0, inode_killpriv, struct mnt_idmap *idmap, struct dentry *dentry) diff --git a/include/linux/security.h b/include/linux/security.h index d0eb20f90b26..40be548e5e12 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -378,6 +378,13 @@ int security_inode_getxattr(struct dentry *dentry, const char *name); int security_inode_listxattr(struct dentry *dentry); int security_inode_removexattr(struct mnt_idmap *idmap, struct dentry *dentry, const char *name); +int security_inode_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry, + const struct vfs_caps *caps, int flags); +void security_inode_post_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, int flags); +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry); +int security_inode_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry); int security_inode_need_killpriv(struct dentry *dentry); int security_inode_killpriv(struct mnt_idmap *idmap, struct dentry *dentry); int security_inode_getsecurity(struct mnt_idmap *idmap, @@ -935,6 +942,32 @@ static inline int security_inode_removexattr(struct mnt_idmap *idmap, return cap_inode_removexattr(idmap, dentry, name); } +static inline int security_inode_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, + int flags) +{ + return 0; +} +static void security_inode_post_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, + int flags) +{ +} + +static int security_inode_get_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry) +{ + return 0; +} + +static int security_inode_remove_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry) +{ + return 0; +} + static inline int security_inode_need_killpriv(struct dentry *dentry) { return cap_inode_need_killpriv(dentry); diff --git a/security/security.c b/security/security.c index 3aaad75c9ce8..0d210da9862c 100644 --- a/security/security.c +++ b/security/security.c @@ -2351,6 +2351,75 @@ int security_inode_remove_acl(struct mnt_idmap *idmap, return evm_inode_remove_acl(idmap, dentry, acl_name); } +/** + * security_inode_set_fscaps() - Check if setting fscaps is allowed + * @idmap: idmap of the mount + * @dentry: file + * @caps: fscaps to be written + * @flags: flags for setxattr + * + * Check permission before setting the file capabilities given in @vfs_caps. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_set_fscaps(struct mnt_idmap *idmap, struct dentry *dentry, + const struct vfs_caps *caps, int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_set_fscaps, 0, idmap, dentry, caps, flags); +} + +/** + * security_inode_post_set_fscaps() - Update the inode after setting fscaps + * @idmap: idmap of the mount + * @dentry: file + * @caps: fscaps to be written + * @flags: flags for setxattr + * + * Update inode security field after successfully setting fscaps. + * + */ +void security_inode_post_set_fscaps(struct mnt_idmap *idmap, + struct dentry *dentry, + const struct vfs_caps *caps, int flags) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return; + call_void_hook(inode_post_set_fscaps, idmap, dentry, caps, flags); +} + +/** + * security_inode_get_fscaps() - Check if reading fscaps is allowed + * @dentry: file + * + * Check permission before getting fscaps. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_get_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_get_fscaps, 0, idmap, dentry); +} + +/** + * security_inode_remove_fscaps() - Check if removing fscaps is allowed + * @idmap: idmap of the mount + * @dentry: file + * + * Check permission before removing fscaps. + * + * Return: Returns 0 if permission is granted. + */ +int security_inode_remove_fscaps(struct mnt_idmap *idmap, struct dentry *dentry) +{ + if (unlikely(IS_PRIVATE(d_backing_inode(dentry)))) + return 0; + return call_int_hook(inode_remove_fscaps, 0, idmap, dentry); +} + /** * security_inode_post_setxattr() - Update the inode after a setxattr operation * @dentry: file
In preparation for moving fscaps out of the xattr code paths, add new security hooks. These hooks are largely needed because common kernel code will pass around struct vfs_caps pointers, which EVM will need to convert to raw xattr data for verification and updates of its hashes. Signed-off-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org> --- include/linux/lsm_hook_defs.h | 7 +++++ include/linux/security.h | 33 +++++++++++++++++++++ security/security.c | 69 +++++++++++++++++++++++++++++++++++++++++++ 3 files changed, 109 insertions(+)