| Message ID | 20220829170401.834298-3-konstantin.meskhidze@huawei.com (mailing list archive) |
|---|---|
| State | Not Applicable |
| Headers | show |
| Series | Network support for Landlock | expand |
| Context | Check | Description |
|---|---|---|
| netdev/tree_selection | success | Not a local patch, async |
Good to see such clean commit! On 29/08/2022 19:03, Konstantin Meskhidze wrote: > Adds a new landlock_key union and landlock_id structure to support > a socket port rule type. Refactors landlock_insert_rule() and > landlock_find_rule() to support coming network modifications. > This patch also adds is_object_pointer() and get_root() helpers. Please explain a bit what these helpers do. > Now adding or searching a rule in a ruleset depends on a landlock id > argument provided in refactored functions mentioned above. More explanation: A struct landlock_id identifies a unique entry in a ruleset: either a kernel object (e.g inode) or a typed data (e.g. TCP port). There is one red-black tree per key type. > > Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> Because most changes come from https://git.kernel.org/mic/c/8f4104b3dc59e7f110c9b83cdf034d010a2d006f and https://git.kernel.org/mic/c/7d6cf40a6f81adf607ad3cc17aaa11e256beeea4 you can append Co-developed-by: Mickaël Salaün <mic@digikod.net> > --- > > Changes since v6: > * Adds union landlock_key, enum landlock_key_type, and struct > landlock_id. > * Refactors ruleset functions and improves switch/cases: create_rule(), > insert_rule(), get_root(), is_object_pointer(), free_rule(), > landlock_find_rule(). > * Refactors landlock_append_fs_rule() functions to support new > landlock_id type. > > Changes since v5: > * Formats code with clang-format-14. > > Changes since v4: > * Refactors insert_rule() and create_rule() functions by deleting > rule_type from their arguments list, it helps to reduce useless code. > > Changes since v3: > * Splits commit. > * Refactors landlock_insert_rule and landlock_find_rule functions. > * Rename new_ruleset->root_inode. > > --- > security/landlock/fs.c | 21 ++++-- > security/landlock/ruleset.c | 146 +++++++++++++++++++++++++----------- > security/landlock/ruleset.h | 51 ++++++++++--- > 3 files changed, 156 insertions(+), 62 deletions(-) [...] > diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h > index 647d44284080..bb1408cc8dd2 100644 > --- a/security/landlock/ruleset.h > +++ b/security/landlock/ruleset.h > @@ -49,6 +49,33 @@ struct landlock_layer { > access_mask_t access; > }; > > +/** > + * union landlock_key - Key of a ruleset's red-black tree > + */ > +union landlock_key { > + struct landlock_object *object; > + uintptr_t data; > +}; > + > +/** > + * enum landlock_key_type - Type of &union landlock_key > + */ > +enum landlock_key_type { > + /** > + * @LANDLOCK_KEY_INODE: Type of &landlock_ruleset.root_inode's node > + * keys. > + */ > + LANDLOCK_KEY_INODE = 1, > +}; > + > +/** > + * struct landlock_id - Unique rule identifier for a ruleset > + */ > +struct landlock_id { > + union landlock_key key; > + const enum landlock_key_type type; > +}; You can add these new types to Documentation/security/landlock.rst (with this commit). You need to complete all the new field descriptions though (otherwise you'll get Sphinx warnings): object, data, key, type.
9/6/2022 11:07 AM, Mickaël Salaün пишет: > Good to see such clean commit! > > On 29/08/2022 19:03, Konstantin Meskhidze wrote: >> Adds a new landlock_key union and landlock_id structure to support >> a socket port rule type. Refactors landlock_insert_rule() and >> landlock_find_rule() to support coming network modifications. > >> This patch also adds is_object_pointer() and get_root() helpers. > > Please explain a bit what these helpers do. > Ok. I will fix it. > >> Now adding or searching a rule in a ruleset depends on a landlock id >> argument provided in refactored functions mentioned above. > > More explanation: > A struct landlock_id identifies a unique entry in a ruleset: either a > kernel object (e.g inode) or a typed data (e.g. TCP port). There is one > red-black tree per key type. > Got it. >> >> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> > > Because most changes come from > https://git.kernel.org/mic/c/8f4104b3dc59e7f110c9b83cdf034d010a2d006f > and > https://git.kernel.org/mic/c/7d6cf40a6f81adf607ad3cc17aaa11e256beeea4 > you can append > Co-developed-by: Mickaël Salaün <mic@digikod.net> > Ok. Thank you for help here. >> --- >> >> Changes since v6: >> * Adds union landlock_key, enum landlock_key_type, and struct >> landlock_id. >> * Refactors ruleset functions and improves switch/cases: create_rule(), >> insert_rule(), get_root(), is_object_pointer(), free_rule(), >> landlock_find_rule(). >> * Refactors landlock_append_fs_rule() functions to support new >> landlock_id type. >> >> Changes since v5: >> * Formats code with clang-format-14. >> >> Changes since v4: >> * Refactors insert_rule() and create_rule() functions by deleting >> rule_type from their arguments list, it helps to reduce useless code. >> >> Changes since v3: >> * Splits commit. >> * Refactors landlock_insert_rule and landlock_find_rule functions. >> * Rename new_ruleset->root_inode. >> >> --- >> security/landlock/fs.c | 21 ++++-- >> security/landlock/ruleset.c | 146 +++++++++++++++++++++++++----------- >> security/landlock/ruleset.h | 51 ++++++++++--- >> 3 files changed, 156 insertions(+), 62 deletions(-) > > [...] > >> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >> index 647d44284080..bb1408cc8dd2 100644 >> --- a/security/landlock/ruleset.h >> +++ b/security/landlock/ruleset.h >> @@ -49,6 +49,33 @@ struct landlock_layer { >> access_mask_t access; >> }; >> >> +/** >> + * union landlock_key - Key of a ruleset's red-black tree >> + */ >> +union landlock_key { >> + struct landlock_object *object; >> + uintptr_t data; >> +}; >> + >> +/** >> + * enum landlock_key_type - Type of &union landlock_key >> + */ >> +enum landlock_key_type { >> + /** >> + * @LANDLOCK_KEY_INODE: Type of &landlock_ruleset.root_inode's node >> + * keys. >> + */ >> + LANDLOCK_KEY_INODE = 1, >> +}; >> + >> +/** >> + * struct landlock_id - Unique rule identifier for a ruleset >> + */ >> +struct landlock_id { >> + union landlock_key key; >> + const enum landlock_key_type type; >> +}; > > You can add these new types to Documentation/security/landlock.rst (with > this commit). You need to complete all the new field descriptions though > (otherwise you'll get Sphinx warnings): object, data, key, type. Sorry I did not get this tip. Can you explain more detailed here, about Sphinx warnings? > .
On 09/09/2022 12:48, Konstantin Meskhidze (A) wrote: > > > 9/6/2022 11:07 AM, Mickaël Salaün пишет: [...] >>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >>> index 647d44284080..bb1408cc8dd2 100644 >>> --- a/security/landlock/ruleset.h >>> +++ b/security/landlock/ruleset.h >>> @@ -49,6 +49,33 @@ struct landlock_layer { >>> access_mask_t access; >>> }; >>> >>> +/** >>> + * union landlock_key - Key of a ruleset's red-black tree >>> + */ >>> +union landlock_key { >>> + struct landlock_object *object; >>> + uintptr_t data; >>> +}; >>> + >>> +/** >>> + * enum landlock_key_type - Type of &union landlock_key >>> + */ >>> +enum landlock_key_type { >>> + /** >>> + * @LANDLOCK_KEY_INODE: Type of &landlock_ruleset.root_inode's node >>> + * keys. >>> + */ >>> + LANDLOCK_KEY_INODE = 1, >>> +}; >>> + >>> +/** >>> + * struct landlock_id - Unique rule identifier for a ruleset >>> + */ >>> +struct landlock_id { >>> + union landlock_key key; >>> + const enum landlock_key_type type; >>> +}; >> >> You can add these new types to Documentation/security/landlock.rst (with >> this commit). You need to complete all the new field descriptions though >> (otherwise you'll get Sphinx warnings): object, data, key, type. > > Sorry I did not get this tip. Can you explain more detailed here, > about Sphinx warnings? You need to add comments for all the fields as it is done for other structs. The Sphinx warnings come from make htmldocs.
9/6/2022 11:07 AM, Mickaël Salaün пишет: > Good to see such clean commit! > > On 29/08/2022 19:03, Konstantin Meskhidze wrote: >> Adds a new landlock_key union and landlock_id structure to support >> a socket port rule type. Refactors landlock_insert_rule() and >> landlock_find_rule() to support coming network modifications. > >> This patch also adds is_object_pointer() and get_root() helpers. > > Please explain a bit what these helpers do. > > >> Now adding or searching a rule in a ruleset depends on a landlock id >> argument provided in refactored functions mentioned above. > > More explanation: > A struct landlock_id identifies a unique entry in a ruleset: either a > kernel object (e.g inode) or a typed data (e.g. TCP port). There is one > red-black tree per key type. > >> >> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> > > Because most changes come from > https://git.kernel.org/mic/c/8f4104b3dc59e7f110c9b83cdf034d010a2d006f > and > https://git.kernel.org/mic/c/7d6cf40a6f81adf607ad3cc17aaa11e256beeea4 > you can append > Co-developed-by: Mickaël Salaün <mic@digikod.net> Do I need to add Co-developed-by: Mickaël Salaün <mic@digikod.net> and Signed-off-by: Mickaël Salaün <mic@digikod.net> or just Co-developed-by: Mickaël Salaün <mic@digikod.net> ???? Cause Submiting patches article says: https://www.kernel.org/doc/html/latest/process/submitting-patches.html "...Since Co-developed-by: denotes authorship, every Co-developed-by: must be immediately followed by a Signed-off-by: of the associated co-author...." Is this correct signing for this patch: Co-developed-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Mickaël Salaün <mic@digikod.net> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> > >> --- >> >> Changes since v6: >> * Adds union landlock_key, enum landlock_key_type, and struct >> landlock_id. >> * Refactors ruleset functions and improves switch/cases: create_rule(), >> insert_rule(), get_root(), is_object_pointer(), free_rule(), >> landlock_find_rule(). >> * Refactors landlock_append_fs_rule() functions to support new >> landlock_id type. >> >> Changes since v5: >> * Formats code with clang-format-14. >> >> Changes since v4: >> * Refactors insert_rule() and create_rule() functions by deleting >> rule_type from their arguments list, it helps to reduce useless code. >> >> Changes since v3: >> * Splits commit. >> * Refactors landlock_insert_rule and landlock_find_rule functions. >> * Rename new_ruleset->root_inode. >> >> --- >> security/landlock/fs.c | 21 ++++-- >> security/landlock/ruleset.c | 146 +++++++++++++++++++++++++----------- >> security/landlock/ruleset.h | 51 ++++++++++--- >> 3 files changed, 156 insertions(+), 62 deletions(-) > > [...] > >> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >> index 647d44284080..bb1408cc8dd2 100644 >> --- a/security/landlock/ruleset.h >> +++ b/security/landlock/ruleset.h >> @@ -49,6 +49,33 @@ struct landlock_layer { >> access_mask_t access; >> }; >> >> +/** >> + * union landlock_key - Key of a ruleset's red-black tree >> + */ >> +union landlock_key { >> + struct landlock_object *object; >> + uintptr_t data; >> +}; >> + >> +/** >> + * enum landlock_key_type - Type of &union landlock_key >> + */ >> +enum landlock_key_type { >> + /** >> + * @LANDLOCK_KEY_INODE: Type of &landlock_ruleset.root_inode's node >> + * keys. >> + */ >> + LANDLOCK_KEY_INODE = 1, >> +}; >> + >> +/** >> + * struct landlock_id - Unique rule identifier for a ruleset >> + */ >> +struct landlock_id { >> + union landlock_key key; >> + const enum landlock_key_type type; >> +}; > > You can add these new types to Documentation/security/landlock.rst (with > this commit). You need to complete all the new field descriptions though > (otherwise you'll get Sphinx warnings): object, data, key, type. > .
On 12/10/2022 10:37, Konstantin Meskhidze (A) wrote: > > > 9/6/2022 11:07 AM, Mickaël Salaün пишет: >> Good to see such clean commit! >> >> On 29/08/2022 19:03, Konstantin Meskhidze wrote: >>> Adds a new landlock_key union and landlock_id structure to support >>> a socket port rule type. Refactors landlock_insert_rule() and >>> landlock_find_rule() to support coming network modifications. >> >>> This patch also adds is_object_pointer() and get_root() helpers. >> >> Please explain a bit what these helpers do. >> >> >>> Now adding or searching a rule in a ruleset depends on a landlock id >>> argument provided in refactored functions mentioned above. >> >> More explanation: >> A struct landlock_id identifies a unique entry in a ruleset: either a >> kernel object (e.g inode) or a typed data (e.g. TCP port). There is one >> red-black tree per key type. >> >>> >>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >> >> Because most changes come from >> https://git.kernel.org/mic/c/8f4104b3dc59e7f110c9b83cdf034d010a2d006f >> and >> https://git.kernel.org/mic/c/7d6cf40a6f81adf607ad3cc17aaa11e256beeea4 >> you can append >> Co-developed-by: Mickaël Salaün <mic@digikod.net> > > Do I need to add Co-developed-by: Mickaël Salaün <mic@digikod.net> > and Signed-off-by: Mickaël Salaün <mic@digikod.net> or just > Co-developed-by: Mickaël Salaün <mic@digikod.net> ???? > > Cause Submiting patches article says: > https://www.kernel.org/doc/html/latest/process/submitting-patches.html > > "...Since Co-developed-by: denotes authorship, every Co-developed-by: > must be immediately followed by a Signed-off-by: of the associated > co-author...." > > Is this correct signing for this patch: > > Co-developed-by: Mickaël Salaün <mic@digikod.net> > Signed-off-by: Mickaël Salaün <mic@digikod.net> > Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> Because I'll merge your patches in my tree, I'll add my Signed-off-by to all patches. You can then just add Co-developed-by after your Signed-off-by for this one and I'll add the rest.
10/12/2022 1:06 PM, Mickaël Salaün пишет: > > On 12/10/2022 10:37, Konstantin Meskhidze (A) wrote: >> >> >> 9/6/2022 11:07 AM, Mickaël Salaün пишет: >>> Good to see such clean commit! >>> >>> On 29/08/2022 19:03, Konstantin Meskhidze wrote: >>>> Adds a new landlock_key union and landlock_id structure to support >>>> a socket port rule type. Refactors landlock_insert_rule() and >>>> landlock_find_rule() to support coming network modifications. >>> >>>> This patch also adds is_object_pointer() and get_root() helpers. >>> >>> Please explain a bit what these helpers do. >>> >>> >>>> Now adding or searching a rule in a ruleset depends on a landlock id >>>> argument provided in refactored functions mentioned above. >>> >>> More explanation: >>> A struct landlock_id identifies a unique entry in a ruleset: either a >>> kernel object (e.g inode) or a typed data (e.g. TCP port). There is one >>> red-black tree per key type. >>> >>>> >>>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >>> >>> Because most changes come from >>> https://git.kernel.org/mic/c/8f4104b3dc59e7f110c9b83cdf034d010a2d006f >>> and >>> https://git.kernel.org/mic/c/7d6cf40a6f81adf607ad3cc17aaa11e256beeea4 >>> you can append >>> Co-developed-by: Mickaël Salaün <mic@digikod.net> >> >> Do I need to add Co-developed-by: Mickaël Salaün <mic@digikod.net> >> and Signed-off-by: Mickaël Salaün <mic@digikod.net> or just >> Co-developed-by: Mickaël Salaün <mic@digikod.net> ???? >> >> Cause Submiting patches article says: >> https://www.kernel.org/doc/html/latest/process/submitting-patches.html >> >> "...Since Co-developed-by: denotes authorship, every Co-developed-by: >> must be immediately followed by a Signed-off-by: of the associated >> co-author...." >> >> Is this correct signing for this patch: >> >> Co-developed-by: Mickaël Salaün <mic@digikod.net> >> Signed-off-by: Mickaël Salaün <mic@digikod.net> >> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> > > Because I'll merge your patches in my tree, I'll add my Signed-off-by to > all patches. You can then just add Co-developed-by after your > Signed-off-by for this one and I'll add the rest. Ok. I got it. Thanks for the explaning. > .
diff --git a/security/landlock/fs.c b/security/landlock/fs.c index e2d1cc28729a..cca87fcd222d 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -158,7 +158,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, access_mask_t access_rights) { int err; - struct landlock_object *object; + struct landlock_id id = { + .type = LANDLOCK_KEY_INODE, + }; /* Files only get access rights that make sense. */ if (!d_is_dir(path->dentry) && @@ -170,17 +172,17 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, /* Transforms relative access rights to absolute ones. */ access_rights |= LANDLOCK_MASK_ACCESS_FS & ~landlock_get_fs_access_mask(ruleset, 0); - object = get_inode_object(d_backing_inode(path->dentry)); - if (IS_ERR(object)) - return PTR_ERR(object); + id.key.object = get_inode_object(d_backing_inode(path->dentry)); + if (IS_ERR(id.key.object)) + return PTR_ERR(id.key.object); mutex_lock(&ruleset->lock); - err = landlock_insert_rule(ruleset, object, access_rights); + err = landlock_insert_rule(ruleset, id, access_rights); mutex_unlock(&ruleset->lock); /* * No need to check for an error because landlock_insert_rule() * increments the refcount for the new object if needed. */ - landlock_put_object(object); + landlock_put_object(id.key.object); return err; } @@ -197,6 +199,9 @@ find_rule(const struct landlock_ruleset *const domain, { const struct landlock_rule *rule; const struct inode *inode; + struct landlock_id id = { + .type = LANDLOCK_KEY_INODE, + }; /* Ignores nonexistent leafs. */ if (d_is_negative(dentry)) @@ -204,8 +209,8 @@ find_rule(const struct landlock_ruleset *const domain, inode = d_backing_inode(dentry); rcu_read_lock(); - rule = landlock_find_rule( - domain, rcu_dereference(landlock_inode(inode)->object)); + id.key.object = rcu_dereference(landlock_inode(inode)->object); + rule = landlock_find_rule(domain, id); rcu_read_unlock(); return rule; } diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 1f3188b4e313..41de17d1869e 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -35,7 +35,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) return ERR_PTR(-ENOMEM); refcount_set(&new_ruleset->usage, 1); mutex_init(&new_ruleset->lock); - new_ruleset->root = RB_ROOT; + new_ruleset->root_inode = RB_ROOT; new_ruleset->num_layers = num_layers; /* * hierarchy = NULL @@ -68,8 +68,18 @@ static void build_check_rule(void) BUILD_BUG_ON(rule.num_layers < LANDLOCK_MAX_NUM_LAYERS); } +static inline bool is_object_pointer(const enum landlock_key_type key_type) +{ + switch (key_type) { + case LANDLOCK_KEY_INODE: + return true; + } + WARN_ON_ONCE(1); + return false; +} + static struct landlock_rule * -create_rule(struct landlock_object *const object, +create_rule(const struct landlock_id id, const struct landlock_layer (*const layers)[], const u32 num_layers, const struct landlock_layer *const new_layer) { @@ -90,8 +100,13 @@ create_rule(struct landlock_object *const object, if (!new_rule) return ERR_PTR(-ENOMEM); RB_CLEAR_NODE(&new_rule->node); - landlock_get_object(object); - new_rule->object = object; + if (is_object_pointer(id.type)) { + /* This should be catched by insert_rule(). */ + WARN_ON_ONCE(!id.key.object); + landlock_get_object(id.key.object); + } + + new_rule->key = id.key; new_rule->num_layers = new_num_layers; /* Copies the original layer stack. */ memcpy(new_rule->layers, layers, @@ -102,12 +117,29 @@ create_rule(struct landlock_object *const object, return new_rule; } -static void free_rule(struct landlock_rule *const rule) +static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, + const enum landlock_key_type key_type) +{ + struct rb_root *root = NULL; + + switch (key_type) { + case LANDLOCK_KEY_INODE: + root = &ruleset->root_inode; + break; + } + if (WARN_ON_ONCE(!root)) + return ERR_PTR(-EINVAL); + return root; +} + +static void free_rule(struct landlock_rule *const rule, + const enum landlock_key_type key_type) { might_sleep(); if (!rule) return; - landlock_put_object(rule->object); + if (is_object_pointer(key_type)) + landlock_put_object(rule->key.object); kfree(rule); } @@ -129,8 +161,8 @@ static void build_check_ruleset(void) * insert_rule - Create and insert a rule in a ruleset * * @ruleset: The ruleset to be updated. - * @object: The object to build the new rule with. The underlying kernel - * object must be held by the caller. + * @id: The ID to build the new rule with. The underlying kernel object, if + * any, must be held by the caller. * @layers: One or multiple layers to be copied into the new rule. * @num_layers: The number of @layers entries. * @@ -144,26 +176,37 @@ static void build_check_ruleset(void) * access rights. */ static int insert_rule(struct landlock_ruleset *const ruleset, - struct landlock_object *const object, + const struct landlock_id id, const struct landlock_layer (*const layers)[], - size_t num_layers) + const size_t num_layers) { struct rb_node **walker_node; struct rb_node *parent_node = NULL; struct landlock_rule *new_rule; + struct rb_root *root; might_sleep(); lockdep_assert_held(&ruleset->lock); - if (WARN_ON_ONCE(!object || !layers)) + if (WARN_ON_ONCE(!layers)) return -ENOENT; - walker_node = &(ruleset->root.rb_node); + + if (is_object_pointer(id.type)) { + if (WARN_ON_ONCE(!id.key.object)) + return -ENOENT; + } + + root = get_root(ruleset, id.type); + if (IS_ERR(root)) + return PTR_ERR(root); + + walker_node = &root->rb_node; while (*walker_node) { struct landlock_rule *const this = rb_entry(*walker_node, struct landlock_rule, node); - if (this->object != object) { + if (this->key.data != id.key.data) { parent_node = *walker_node; - if (this->object < object) + if (this->key.data < id.key.data) walker_node = &((*walker_node)->rb_right); else walker_node = &((*walker_node)->rb_left); @@ -195,24 +238,24 @@ static int insert_rule(struct landlock_ruleset *const ruleset, * Intersects access rights when it is a merge between a * ruleset and a domain. */ - new_rule = create_rule(object, &this->layers, this->num_layers, + new_rule = create_rule(id, &this->layers, this->num_layers, &(*layers)[0]); if (IS_ERR(new_rule)) return PTR_ERR(new_rule); - rb_replace_node(&this->node, &new_rule->node, &ruleset->root); - free_rule(this); + rb_replace_node(&this->node, &new_rule->node, root); + free_rule(this, id.type); return 0; } - /* There is no match for @object. */ + /* There is no match for @id. */ build_check_ruleset(); if (ruleset->num_rules >= LANDLOCK_MAX_NUM_RULES) return -E2BIG; - new_rule = create_rule(object, layers, num_layers, NULL); + new_rule = create_rule(id, layers, num_layers, NULL); if (IS_ERR(new_rule)) return PTR_ERR(new_rule); rb_link_node(&new_rule->node, parent_node, walker_node); - rb_insert_color(&new_rule->node, &ruleset->root); + rb_insert_color(&new_rule->node, root); ruleset->num_rules++; return 0; } @@ -230,7 +273,7 @@ static void build_check_layer(void) /* @ruleset must be locked by the caller. */ int landlock_insert_rule(struct landlock_ruleset *const ruleset, - struct landlock_object *const object, + const struct landlock_id id, const access_mask_t access) { struct landlock_layer layers[] = { { @@ -240,7 +283,7 @@ int landlock_insert_rule(struct landlock_ruleset *const ruleset, } }; build_check_layer(); - return insert_rule(ruleset, object, &layers, ARRAY_SIZE(layers)); + return insert_rule(ruleset, id, &layers, ARRAY_SIZE(layers)); } static inline void get_hierarchy(struct landlock_hierarchy *const hierarchy) @@ -263,6 +306,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, struct landlock_ruleset *const src) { struct landlock_rule *walker_rule, *next_rule; + struct rb_root *src_root; int err = 0; might_sleep(); @@ -273,6 +317,10 @@ static int merge_ruleset(struct landlock_ruleset *const dst, if (WARN_ON_ONCE(!dst || !dst->hierarchy)) return -EINVAL; + src_root = get_root(src, LANDLOCK_KEY_INODE); + if (IS_ERR(src_root)) + return PTR_ERR(src_root); + /* Locks @dst first because we are its only owner. */ mutex_lock(&dst->lock); mutex_lock_nested(&src->lock, SINGLE_DEPTH_NESTING); @@ -285,23 +333,23 @@ static int merge_ruleset(struct landlock_ruleset *const dst, dst->access_masks[dst->num_layers - 1] = src->access_masks[0]; /* Merges the @src tree. */ - rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, &src->root, + rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, src_root, node) { struct landlock_layer layers[] = { { .level = dst->num_layers, } }; + const struct landlock_id id = { + .key = walker_rule->key, + .type = LANDLOCK_KEY_INODE, + }; - if (WARN_ON_ONCE(walker_rule->num_layers != 1)) { - err = -EINVAL; - goto out_unlock; - } - if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) { - err = -EINVAL; - goto out_unlock; - } + if (WARN_ON_ONCE(walker_rule->num_layers != 1)) + return -EINVAL; + if (WARN_ON_ONCE(walker_rule->layers[0].level != 0)) + return -EINVAL; layers[0].access = walker_rule->layers[0].access; - err = insert_rule(dst, walker_rule->object, &layers, - ARRAY_SIZE(layers)); + + err = insert_rule(dst, id, &layers, ARRAY_SIZE(layers)); if (err) goto out_unlock; } @@ -316,21 +364,29 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, struct landlock_ruleset *const child) { struct landlock_rule *walker_rule, *next_rule; + struct rb_root *parent_root; int err = 0; might_sleep(); if (!parent) return 0; + parent_root = get_root(parent, LANDLOCK_KEY_INODE); + if (IS_ERR(parent_root)) + return PTR_ERR(parent_root); + /* Locks @child first because we are its only owner. */ mutex_lock(&child->lock); mutex_lock_nested(&parent->lock, SINGLE_DEPTH_NESTING); /* Copies the @parent tree. */ rbtree_postorder_for_each_entry_safe(walker_rule, next_rule, - &parent->root, node) { - err = insert_rule(child, walker_rule->object, - &walker_rule->layers, + parent_root, node) { + const struct landlock_id id = { + .key = walker_rule->key, + .type = LANDLOCK_KEY_INODE, + }; + err = insert_rule(child, id, &walker_rule->layers, walker_rule->num_layers); if (err) goto out_unlock; @@ -362,8 +418,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) struct landlock_rule *freeme, *next; might_sleep(); - rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root, node) - free_rule(freeme); + rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, + node) + free_rule(freeme, LANDLOCK_KEY_INODE); put_hierarchy(ruleset->hierarchy); kfree(ruleset); } @@ -454,20 +511,23 @@ landlock_merge_ruleset(struct landlock_ruleset *const parent, */ const struct landlock_rule * landlock_find_rule(const struct landlock_ruleset *const ruleset, - const struct landlock_object *const object) + const struct landlock_id id) { + const struct rb_root *root; const struct rb_node *node; - if (!object) + root = get_root((struct landlock_ruleset *)ruleset, id.type); + if (IS_ERR(root)) return NULL; - node = ruleset->root.rb_node; + node = root->rb_node; + while (node) { struct landlock_rule *this = rb_entry(node, struct landlock_rule, node); - if (this->object == object) + if (this->key.data == id.key.data) return this; - if (this->object < object) + if (this->key.data < id.key.data) node = node->rb_right; else node = node->rb_left; diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index 647d44284080..bb1408cc8dd2 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -49,6 +49,33 @@ struct landlock_layer { access_mask_t access; }; +/** + * union landlock_key - Key of a ruleset's red-black tree + */ +union landlock_key { + struct landlock_object *object; + uintptr_t data; +}; + +/** + * enum landlock_key_type - Type of &union landlock_key + */ +enum landlock_key_type { + /** + * @LANDLOCK_KEY_INODE: Type of &landlock_ruleset.root_inode's node + * keys. + */ + LANDLOCK_KEY_INODE = 1, +}; + +/** + * struct landlock_id - Unique rule identifier for a ruleset + */ +struct landlock_id { + union landlock_key key; + const enum landlock_key_type type; +}; + /** * struct landlock_rule - Access rights tied to an object */ @@ -58,12 +85,13 @@ struct landlock_rule { */ struct rb_node node; /** - * @object: Pointer to identify a kernel object (e.g. an inode). This - * is used as a key for this ruleset element. This pointer is set once - * and never modified. It always points to an allocated object because - * each rule increments the refcount of its object. + * @key: A union to identify either a kernel object (e.g. an inode) or + * a raw data value (e.g. a network socket port). This is used as a key + * for this ruleset element. The pointer is set once and never + * modified. It always points to an allocated object because each rule + * increments the refcount of its object. */ - struct landlock_object *object; + union landlock_key key; /** * @num_layers: Number of entries in @layers. */ @@ -99,11 +127,12 @@ struct landlock_hierarchy { */ struct landlock_ruleset { /** - * @root: Root of a red-black tree containing &struct landlock_rule - * nodes. Once a ruleset is tied to a process (i.e. as a domain), this - * tree is immutable until @usage reaches zero. + * @root_inode: Root of a red-black tree containing &struct + * landlock_rule nodes with inode object. Once a ruleset is tied to a + * process (i.e. as a domain), this tree is immutable until @usage + * reaches zero. */ - struct rb_root root; + struct rb_root root_inode; /** * @hierarchy: Enables hierarchy identification even when a parent * domain vanishes. This is needed for the ptrace protection. @@ -165,7 +194,7 @@ void landlock_put_ruleset(struct landlock_ruleset *const ruleset); void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); int landlock_insert_rule(struct landlock_ruleset *const ruleset, - struct landlock_object *const object, + const struct landlock_id id, const access_mask_t access); struct landlock_ruleset * @@ -174,7 +203,7 @@ landlock_merge_ruleset(struct landlock_ruleset *const parent, const struct landlock_rule * landlock_find_rule(const struct landlock_ruleset *const ruleset, - const struct landlock_object *const object); + const struct landlock_id id); static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) {
Adds a new landlock_key union and landlock_id structure to support a socket port rule type. Refactors landlock_insert_rule() and landlock_find_rule() to support coming network modifications. This patch also adds is_object_pointer() and get_root() helpers. Now adding or searching a rule in a ruleset depends on a landlock id argument provided in refactored functions mentioned above. Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> --- Changes since v6: * Adds union landlock_key, enum landlock_key_type, and struct landlock_id. * Refactors ruleset functions and improves switch/cases: create_rule(), insert_rule(), get_root(), is_object_pointer(), free_rule(), landlock_find_rule(). * Refactors landlock_append_fs_rule() functions to support new landlock_id type. Changes since v5: * Formats code with clang-format-14. Changes since v4: * Refactors insert_rule() and create_rule() functions by deleting rule_type from their arguments list, it helps to reduce useless code. Changes since v3: * Splits commit. * Refactors landlock_insert_rule and landlock_find_rule functions. * Rename new_ruleset->root_inode. --- security/landlock/fs.c | 21 ++++-- security/landlock/ruleset.c | 146 +++++++++++++++++++++++++----------- security/landlock/ruleset.h | 51 ++++++++++--- 3 files changed, 156 insertions(+), 62 deletions(-) -- 2.25.1