| Message ID | 20250108154338.1129069-7-mic@digikod.net (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Landlock audit support | expand |
On Wed, Jan 08, 2025 at 04:43:14PM +0100, Mickaël Salaün wrote: > Upgrade domain's handled access masks when creating a domain from a > ruleset, instead of converting them at runtime. This is more consistent > and helps with audit support. > > Cc: Günther Noack <gnoack@google.com> > Signed-off-by: Mickaël Salaün <mic@digikod.net> > Link: https://lore.kernel.org/r/20250108154338.1129069-7-mic@digikod.net Pushed in my next tree to simplify next patch series. > --- > > Changes since v2: > - New patch. > --- > security/landlock/access.h | 17 ++++++++++++++++- > security/landlock/fs.c | 10 +--------- > security/landlock/ruleset.c | 3 ++- > 3 files changed, 19 insertions(+), 11 deletions(-) > > diff --git a/security/landlock/access.h b/security/landlock/access.h > index 9ee4b30a87e6..74fd8f399fbd 100644 > --- a/security/landlock/access.h > +++ b/security/landlock/access.h > @@ -20,7 +20,8 @@ > /* > * All access rights that are denied by default whether they are handled or not > * by a ruleset/layer. This must be ORed with all ruleset->access_masks[] > - * entries when we need to get the absolute handled access masks. > + * entries when we need to get the absolute handled access masks, see > + * landlock_upgrade_handled_access_masks(). > */ > /* clang-format off */ > #define _LANDLOCK_ACCESS_FS_INITIALLY_DENIED ( \ > @@ -59,4 +60,18 @@ typedef u16 layer_mask_t; > /* Makes sure all layers can be checked. */ > static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); > > +/* Upgrades with all initially denied by default access rights. */ > +static inline struct access_masks > +landlock_upgrade_handled_access_masks(struct access_masks access_masks) > +{ > + /* > + * All access rights that are denied by default whether they are > + * explicitly handled or not. > + */ > + if (access_masks.fs) > + access_masks.fs |= _LANDLOCK_ACCESS_FS_INITIALLY_DENIED; > + > + return access_masks; > +} > + > #endif /* _SECURITY_LANDLOCK_ACCESS_H */ > diff --git a/security/landlock/fs.c b/security/landlock/fs.c > index 3da5f1945158..9779170d9199 100644 > --- a/security/landlock/fs.c > +++ b/security/landlock/fs.c > @@ -389,14 +389,6 @@ static bool is_nouser_or_private(const struct dentry *dentry) > unlikely(IS_PRIVATE(d_backing_inode(dentry)))); > } > > -static access_mask_t > -get_handled_fs_accesses(const struct landlock_ruleset *const domain) > -{ > - /* Handles all initially denied by default access rights. */ > - return landlock_union_access_masks(domain).fs | > - _LANDLOCK_ACCESS_FS_INITIALLY_DENIED; > -} > - > static const struct access_masks any_fs = { > .fs = ~0, > }; > @@ -788,7 +780,7 @@ static bool is_access_to_paths_allowed( > * a superset of the meaningful requested accesses). > */ > access_masked_parent1 = access_masked_parent2 = > - get_handled_fs_accesses(domain); > + landlock_union_access_masks(domain).fs; > is_dom_check = true; > } else { > if (WARN_ON_ONCE(dentry_child1 || dentry_child2)) > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index cae69f2f01d9..dbc528f5f3b7 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -385,7 +385,8 @@ static int merge_ruleset(struct landlock_ruleset *const dst, > err = -EINVAL; > goto out_unlock; > } > - dst->access_masks[dst->num_layers - 1] = src->access_masks[0]; > + dst->access_masks[dst->num_layers - 1] = > + landlock_upgrade_handled_access_masks(src->access_masks[0]); > > /* Merges the @src inode tree. */ > err = merge_tree(dst, src, LANDLOCK_KEY_INODE); > -- > 2.47.1 > >
diff --git a/security/landlock/access.h b/security/landlock/access.h index 9ee4b30a87e6..74fd8f399fbd 100644 --- a/security/landlock/access.h +++ b/security/landlock/access.h @@ -20,7 +20,8 @@ /* * All access rights that are denied by default whether they are handled or not * by a ruleset/layer. This must be ORed with all ruleset->access_masks[] - * entries when we need to get the absolute handled access masks. + * entries when we need to get the absolute handled access masks, see + * landlock_upgrade_handled_access_masks(). */ /* clang-format off */ #define _LANDLOCK_ACCESS_FS_INITIALLY_DENIED ( \ @@ -59,4 +60,18 @@ typedef u16 layer_mask_t; /* Makes sure all layers can be checked. */ static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); +/* Upgrades with all initially denied by default access rights. */ +static inline struct access_masks +landlock_upgrade_handled_access_masks(struct access_masks access_masks) +{ + /* + * All access rights that are denied by default whether they are + * explicitly handled or not. + */ + if (access_masks.fs) + access_masks.fs |= _LANDLOCK_ACCESS_FS_INITIALLY_DENIED; + + return access_masks; +} + #endif /* _SECURITY_LANDLOCK_ACCESS_H */ diff --git a/security/landlock/fs.c b/security/landlock/fs.c index 3da5f1945158..9779170d9199 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -389,14 +389,6 @@ static bool is_nouser_or_private(const struct dentry *dentry) unlikely(IS_PRIVATE(d_backing_inode(dentry)))); } -static access_mask_t -get_handled_fs_accesses(const struct landlock_ruleset *const domain) -{ - /* Handles all initially denied by default access rights. */ - return landlock_union_access_masks(domain).fs | - _LANDLOCK_ACCESS_FS_INITIALLY_DENIED; -} - static const struct access_masks any_fs = { .fs = ~0, }; @@ -788,7 +780,7 @@ static bool is_access_to_paths_allowed( * a superset of the meaningful requested accesses). */ access_masked_parent1 = access_masked_parent2 = - get_handled_fs_accesses(domain); + landlock_union_access_masks(domain).fs; is_dom_check = true; } else { if (WARN_ON_ONCE(dentry_child1 || dentry_child2)) diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index cae69f2f01d9..dbc528f5f3b7 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -385,7 +385,8 @@ static int merge_ruleset(struct landlock_ruleset *const dst, err = -EINVAL; goto out_unlock; } - dst->access_masks[dst->num_layers - 1] = src->access_masks[0]; + dst->access_masks[dst->num_layers - 1] = + landlock_upgrade_handled_access_masks(src->access_masks[0]); /* Merges the @src inode tree. */ err = merge_tree(dst, src, LANDLOCK_KEY_INODE);
Upgrade domain's handled access masks when creating a domain from a ruleset, instead of converting them at runtime. This is more consistent and helps with audit support. Cc: Günther Noack <gnoack@google.com> Signed-off-by: Mickaël Salaün <mic@digikod.net> Link: https://lore.kernel.org/r/20250108154338.1129069-7-mic@digikod.net --- Changes since v2: - New patch. --- security/landlock/access.h | 17 ++++++++++++++++- security/landlock/fs.c | 10 +--------- security/landlock/ruleset.c | 3 ++- 3 files changed, 19 insertions(+), 11 deletions(-)