| Message ID | 20220829170401.834298-9-konstantin.meskhidze@huawei.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | Network support for Landlock | expand |
On 29/08/2022 19:03, Konstantin Meskhidze wrote: > This commit adds network rules support in internal landlock functions > (presented in ruleset.c) and landlock_create_ruleset syscall. > > Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> > --- > > Changes since v6: > * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask() > because it OR values. > * Makes landlock_add_net_access_mask() more resilient incorrect values. > * Refactors landlock_get_net_access_mask(). > * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use > LANDLOCK_NUM_ACCESS_FS as value. > * Updates access_masks_t to u32 to support network access actions. > * Refactors landlock internal functions to support network actions with > landlock_key/key_type/id types. > > Changes since v5: > * Gets rid of partial revert from landlock_add_rule > syscall. > * Formats code with clang-format-14. > > Changes since v4: > * Refactors landlock_create_ruleset() - splits ruleset and > masks checks. > * Refactors landlock_create_ruleset() and landlock mask > setters/getters to support two rule types. > * Refactors landlock_add_rule syscall add_rule_path_beneath > function by factoring out get_ruleset_from_fd() and > landlock_put_ruleset(). > > Changes since v3: > * Splits commit. > * Adds network rule support for internal landlock functions. > * Adds set_mask and get_mask for network. > * Adds rb_root root_net_port. > > --- > security/landlock/limits.h | 6 +++++- > security/landlock/ruleset.c | 38 +++++++++++++++++++++++++++++---- > security/landlock/ruleset.h | 41 ++++++++++++++++++++++++++++++++++-- > security/landlock/syscalls.c | 8 ++++++- > 4 files changed, 85 insertions(+), 8 deletions(-) > > diff --git a/security/landlock/limits.h b/security/landlock/limits.h > index bafb3b8dc677..8a1a6463c64e 100644 > --- a/security/landlock/limits.h > +++ b/security/landlock/limits.h > @@ -23,6 +23,10 @@ > #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) > #define LANDLOCK_SHIFT_ACCESS_FS 0 > > -/* clang-format on */ > +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP > +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) > +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET) > +#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS > > +/* clang-format on */ > #endif /* _SECURITY_LANDLOCK_LIMITS_H */ > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index 84fcd8eb30d4..442f212039df 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -36,6 +36,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > refcount_set(&new_ruleset->usage, 1); > mutex_init(&new_ruleset->lock); > new_ruleset->root_inode = RB_ROOT; > + new_ruleset->root_net_port = RB_ROOT; > new_ruleset->num_layers = num_layers; > /* > * hierarchy = NULL > @@ -46,16 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > } > > struct landlock_ruleset * > -landlock_create_ruleset(const access_mask_t fs_access_mask) > +landlock_create_ruleset(const access_mask_t fs_access_mask, > + const access_mask_t net_access_mask) > { > struct landlock_ruleset *new_ruleset; > > /* Informs about useless ruleset. */ > - if (!fs_access_mask) > + if (!fs_access_mask && !net_access_mask) > return ERR_PTR(-ENOMSG); > new_ruleset = create_ruleset(1); > - if (!IS_ERR(new_ruleset)) > + if (IS_ERR(new_ruleset)) > + return new_ruleset; > + if (fs_access_mask) > landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); > + if (net_access_mask) > + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); > return new_ruleset; > } > > @@ -73,6 +79,8 @@ static inline bool is_object_pointer(const enum landlock_key_type key_type) > switch (key_type) { > case LANDLOCK_KEY_INODE: > return true; > + case LANDLOCK_KEY_NET_PORT: > + return false; > } > WARN_ON_ONCE(1); > return false; > @@ -126,6 +134,9 @@ static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, > case LANDLOCK_KEY_INODE: > root = &ruleset->root_inode; > break; > + case LANDLOCK_KEY_NET_PORT: > + root = &ruleset->root_net_port; > + break; > } > if (WARN_ON_ONCE(!root)) > return ERR_PTR(-EINVAL); > @@ -154,7 +165,9 @@ static void build_check_ruleset(void) > BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); > BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); > BUILD_BUG_ON(access_masks < > - (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); > + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS) + > + (LANDLOCK_MASK_ACCESS_NET > + << LANDLOCK_SHIFT_ACCESS_NET)); > } > > /** > @@ -367,6 +380,11 @@ static int merge_ruleset(struct landlock_ruleset *const dst, > if (err) > goto out_unlock; > > + /* Merges the @src network port tree. */ > + err = merge_tree(dst, src, LANDLOCK_KEY_NET_PORT); > + if (err) > + goto out_unlock; > + > out_unlock: > mutex_unlock(&src->lock); > mutex_unlock(&dst->lock); > @@ -419,6 +437,11 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, > if (err) > goto out_unlock; > > + /* Copies the @parent network port tree. */ > + err = inherit_tree(parent, child, LANDLOCK_KEY_NET_PORT); > + if (err) > + goto out_unlock; > + > if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { > err = -EINVAL; > goto out_unlock; > @@ -451,6 +474,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) > rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, > node) > free_rule(freeme, LANDLOCK_KEY_INODE); > + rbtree_postorder_for_each_entry_safe(freeme, next, > + &ruleset->root_net_port, node) > + free_rule(freeme, LANDLOCK_KEY_NET_PORT); > put_hierarchy(ruleset->hierarchy); > kfree(ruleset); > } > @@ -640,6 +666,10 @@ access_mask_t init_layer_masks(const struct landlock_ruleset *const domain, > get_access_mask = landlock_get_fs_access_mask; > num_access = LANDLOCK_NUM_ACCESS_FS; > break; > + case LANDLOCK_KEY_NET_PORT: > + get_access_mask = landlock_get_net_access_mask; > + num_access = LANDLOCK_NUM_ACCESS_NET; > + break; > default: > WARN_ON_ONCE(1); > return 0; > diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h > index 2083855bf42d..d456ee90b648 100644 > --- a/security/landlock/ruleset.h > +++ b/security/landlock/ruleset.h > @@ -26,7 +26,7 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); > static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); > > /* Ruleset access masks. */ > -typedef u16 access_masks_t; > +typedef u32 access_masks_t; > /* Makes sure all ruleset access rights can be stored. */ > static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); There is some fixes missing from my patch. > > @@ -66,6 +66,11 @@ enum landlock_key_type { > * keys. > */ > LANDLOCK_KEY_INODE = 1, #if IS_ENABLED(CONFIG_INET) > + /** > + * @LANDLOCK_KEY_NET_PORT: Type of &landlock_ruleset.root_net_port's > + * node keys. > + */ > + LANDLOCK_KEY_NET_PORT = 2, #endif /* IS_ENABLED(CONFIG_INET) */ And then all use of LANDLOCK_KEY_NET_PORT should be surrounded by the same check (but not directly in the net.c file). > }; > > /** > @@ -133,6 +138,12 @@ struct landlock_ruleset { > * reaches zero. > */ > struct rb_root root_inode; #if IS_ENABLED(CONFIG_INET) > + /** > + * @root_net_port: Root of a red-black tree containing object nodes > + * for network port. Once a ruleset is tied to a process (i.e. as a domain), > + * this tree is immutable until @usage reaches zero. > + */ There is some fixes missing from my patch. Please explain everything that you didn't take. > + struct rb_root root_net_port; #endif /* IS_ENABLED(CONFIG_INET) */ And then all use of root_net_port should be surrounded by the same check. I think it should be OK to keep all other remaining network references though (e.g. access_masks and the ). > /** > * @hierarchy: Enables hierarchy identification even when a parent > * domain vanishes. This is needed for the ptrace protection. > @@ -188,7 +199,8 @@ struct landlock_ruleset { > }; > > struct landlock_ruleset * > -landlock_create_ruleset(const access_mask_t access_mask); > +landlock_create_ruleset(const access_mask_t access_mask_fs, > + const access_mask_t access_mask_net); > > void landlock_put_ruleset(struct landlock_ruleset *const ruleset); > void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); > @@ -226,6 +238,21 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, > (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); > } > > +/* A helper function to set a network mask. */ I already said that this comment is useless, and I removed it in my patch. Please take a closer look at reviews. > +static inline void > +landlock_add_net_access_mask(struct landlock_ruleset *const ruleset, > + const access_mask_t net_access_mask, > + const u16 layer_level) > +{ > + access_mask_t net_mask = net_access_mask & LANDLOCK_MASK_ACCESS_NET; > + > + /* Should already be checked in sys_landlock_create_ruleset(). */ > + WARN_ON_ONCE(net_access_mask != net_mask); > + // TODO: Add tests to check "|=" and not "=" > + ruleset->access_masks[layer_level] |= > + (net_mask << LANDLOCK_SHIFT_ACCESS_NET); > +} > + > /* A helper function to get a filesystem mask. */ > static inline access_mask_t > landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > @@ -236,6 +263,16 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > LANDLOCK_MASK_ACCESS_FS; > } > > +/* A helper function to get a network mask. */ > +static inline access_mask_t > +landlock_get_net_access_mask(const struct landlock_ruleset *const ruleset, > + const u16 layer_level) > +{ > + return (ruleset->access_masks[layer_level] >> > + LANDLOCK_SHIFT_ACCESS_NET) & > + LANDLOCK_MASK_ACCESS_NET; > +} > + This hunk doesn't match my patch. > bool unmask_layers(const struct landlock_rule *const rule, > const access_mask_t access_request, > layer_mask_t (*const layer_masks)[], > diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c > index ffd5805eddd9..641155f6f6f8 100644 > --- a/security/landlock/syscalls.c > +++ b/security/landlock/syscalls.c > @@ -189,8 +189,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, > LANDLOCK_MASK_ACCESS_FS) > return -EINVAL; > > + /* Checks network content (and 32-bits cast). */ > + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != > + LANDLOCK_MASK_ACCESS_NET) > + return -EINVAL; > + > /* Checks arguments and transforms to kernel struct. */ > - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); > + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs, > + ruleset_attr.handled_access_net); > if (IS_ERR(ruleset)) > return PTR_ERR(ruleset); > > -- > 2.25.1 >
9/6/2022 11:08 AM, Mickaël Salaün пишет: > > On 29/08/2022 19:03, Konstantin Meskhidze wrote: >> This commit adds network rules support in internal landlock functions >> (presented in ruleset.c) and landlock_create_ruleset syscall. >> >> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >> --- >> >> Changes since v6: >> * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask() >> because it OR values. >> * Makes landlock_add_net_access_mask() more resilient incorrect values. >> * Refactors landlock_get_net_access_mask(). >> * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use >> LANDLOCK_NUM_ACCESS_FS as value. >> * Updates access_masks_t to u32 to support network access actions. >> * Refactors landlock internal functions to support network actions with >> landlock_key/key_type/id types. >> >> Changes since v5: >> * Gets rid of partial revert from landlock_add_rule >> syscall. >> * Formats code with clang-format-14. >> >> Changes since v4: >> * Refactors landlock_create_ruleset() - splits ruleset and >> masks checks. >> * Refactors landlock_create_ruleset() and landlock mask >> setters/getters to support two rule types. >> * Refactors landlock_add_rule syscall add_rule_path_beneath >> function by factoring out get_ruleset_from_fd() and >> landlock_put_ruleset(). >> >> Changes since v3: >> * Splits commit. >> * Adds network rule support for internal landlock functions. >> * Adds set_mask and get_mask for network. >> * Adds rb_root root_net_port. >> >> --- >> security/landlock/limits.h | 6 +++++- >> security/landlock/ruleset.c | 38 +++++++++++++++++++++++++++++---- >> security/landlock/ruleset.h | 41 ++++++++++++++++++++++++++++++++++-- >> security/landlock/syscalls.c | 8 ++++++- >> 4 files changed, 85 insertions(+), 8 deletions(-) >> >> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >> index bafb3b8dc677..8a1a6463c64e 100644 >> --- a/security/landlock/limits.h >> +++ b/security/landlock/limits.h >> @@ -23,6 +23,10 @@ >> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >> #define LANDLOCK_SHIFT_ACCESS_FS 0 >> >> -/* clang-format on */ >> +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP >> +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) >> +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET) >> +#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS >> >> +/* clang-format on */ >> #endif /* _SECURITY_LANDLOCK_LIMITS_H */ >> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >> index 84fcd8eb30d4..442f212039df 100644 >> --- a/security/landlock/ruleset.c >> +++ b/security/landlock/ruleset.c >> @@ -36,6 +36,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >> refcount_set(&new_ruleset->usage, 1); >> mutex_init(&new_ruleset->lock); >> new_ruleset->root_inode = RB_ROOT; >> + new_ruleset->root_net_port = RB_ROOT; >> new_ruleset->num_layers = num_layers; >> /* >> * hierarchy = NULL >> @@ -46,16 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >> } >> >> struct landlock_ruleset * >> -landlock_create_ruleset(const access_mask_t fs_access_mask) >> +landlock_create_ruleset(const access_mask_t fs_access_mask, >> + const access_mask_t net_access_mask) >> { >> struct landlock_ruleset *new_ruleset; >> >> /* Informs about useless ruleset. */ >> - if (!fs_access_mask) >> + if (!fs_access_mask && !net_access_mask) >> return ERR_PTR(-ENOMSG); >> new_ruleset = create_ruleset(1); >> - if (!IS_ERR(new_ruleset)) >> + if (IS_ERR(new_ruleset)) >> + return new_ruleset; >> + if (fs_access_mask) >> landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >> + if (net_access_mask) >> + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); >> return new_ruleset; >> } >> >> @@ -73,6 +79,8 @@ static inline bool is_object_pointer(const enum landlock_key_type key_type) >> switch (key_type) { >> case LANDLOCK_KEY_INODE: >> return true; >> + case LANDLOCK_KEY_NET_PORT: >> + return false; >> } >> WARN_ON_ONCE(1); >> return false; >> @@ -126,6 +134,9 @@ static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, >> case LANDLOCK_KEY_INODE: >> root = &ruleset->root_inode; >> break; >> + case LANDLOCK_KEY_NET_PORT: >> + root = &ruleset->root_net_port; >> + break; >> } >> if (WARN_ON_ONCE(!root)) >> return ERR_PTR(-EINVAL); >> @@ -154,7 +165,9 @@ static void build_check_ruleset(void) >> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >> BUILD_BUG_ON(access_masks < >> - (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS) + >> + (LANDLOCK_MASK_ACCESS_NET >> + << LANDLOCK_SHIFT_ACCESS_NET)); >> } >> >> /** >> @@ -367,6 +380,11 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >> if (err) >> goto out_unlock; >> >> + /* Merges the @src network port tree. */ >> + err = merge_tree(dst, src, LANDLOCK_KEY_NET_PORT); >> + if (err) >> + goto out_unlock; >> + >> out_unlock: >> mutex_unlock(&src->lock); >> mutex_unlock(&dst->lock); >> @@ -419,6 +437,11 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >> if (err) >> goto out_unlock; >> >> + /* Copies the @parent network port tree. */ >> + err = inherit_tree(parent, child, LANDLOCK_KEY_NET_PORT); >> + if (err) >> + goto out_unlock; >> + >> if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { >> err = -EINVAL; >> goto out_unlock; >> @@ -451,6 +474,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) >> rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, >> node) >> free_rule(freeme, LANDLOCK_KEY_INODE); >> + rbtree_postorder_for_each_entry_safe(freeme, next, >> + &ruleset->root_net_port, node) >> + free_rule(freeme, LANDLOCK_KEY_NET_PORT); >> put_hierarchy(ruleset->hierarchy); >> kfree(ruleset); >> } >> @@ -640,6 +666,10 @@ access_mask_t init_layer_masks(const struct landlock_ruleset *const domain, >> get_access_mask = landlock_get_fs_access_mask; >> num_access = LANDLOCK_NUM_ACCESS_FS; >> break; >> + case LANDLOCK_KEY_NET_PORT: >> + get_access_mask = landlock_get_net_access_mask; >> + num_access = LANDLOCK_NUM_ACCESS_NET; >> + break; >> default: >> WARN_ON_ONCE(1); >> return 0; >> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >> index 2083855bf42d..d456ee90b648 100644 >> --- a/security/landlock/ruleset.h >> +++ b/security/landlock/ruleset.h >> @@ -26,7 +26,7 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >> >> /* Ruleset access masks. */ >> -typedef u16 access_masks_t; >> +typedef u32 access_masks_t; >> /* Makes sure all ruleset access rights can be stored. */ >> static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); > > There is some fixes missing from my patch. > > >> >> @@ -66,6 +66,11 @@ enum landlock_key_type { >> * keys. >> */ >> LANDLOCK_KEY_INODE = 1, > > > #if IS_ENABLED(CONFIG_INET) > >> + /** >> + * @LANDLOCK_KEY_NET_PORT: Type of &landlock_ruleset.root_net_port's >> + * node keys. >> + */ >> + LANDLOCK_KEY_NET_PORT = 2, > > #endif /* IS_ENABLED(CONFIG_INET) */ > > And then all use of LANDLOCK_KEY_NET_PORT should be surrounded by the > same check (but not directly in the net.c file). I checked the branch with your patches: tmp-net (7d6cf40a6f81adf607ad3cc17aaa11e256beeea4), but I did not find #if IS_ENABLED(CONFIG_INET) surrounding LANDLOCK_KEY_NET_PORT. > > >> }; >> >> /** >> @@ -133,6 +138,12 @@ struct landlock_ruleset { >> * reaches zero. >> */ >> struct rb_root root_inode; > > #if IS_ENABLED(CONFIG_INET) > >> + /** >> + * @root_net_port: Root of a red-black tree containing object nodes >> + * for network port. Once a ruleset is tied to a process (i.e. as a domain), >> + * this tree is immutable until @usage reaches zero. >> + */ > > There is some fixes missing from my patch. Please explain everything > that you didn't take. Sorry. I did merge your patch manually and did not tell the difference here. Will be fixed > > >> + struct rb_root root_net_port; > > > #endif /* IS_ENABLED(CONFIG_INET) */ > > And then all use of root_net_port should be surrounded by the same check. The same - I did not find #if IS_ENABLED(CONFIG_INET) surrounding root_net_port in tmp-net (7d6cf40a6f81adf607ad3cc17aaa11e256beeea4) > > I think it should be OK to keep all other remaining network references > though (e.g. access_masks and the ). Ok. Thanks. > > >> /** >> * @hierarchy: Enables hierarchy identification even when a parent >> * domain vanishes. This is needed for the ptrace protection. >> @@ -188,7 +199,8 @@ struct landlock_ruleset { >> }; >> >> struct landlock_ruleset * >> -landlock_create_ruleset(const access_mask_t access_mask); >> +landlock_create_ruleset(const access_mask_t access_mask_fs, >> + const access_mask_t access_mask_net); >> >> void landlock_put_ruleset(struct landlock_ruleset *const ruleset); >> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); >> @@ -226,6 +238,21 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >> (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); >> } >> >> +/* A helper function to set a network mask. */ > > I already said that this comment is useless, and I removed it in my > patch. Please take a closer look at reviews. Sorry. I missed that in your patch. Will be fixed. > > >> +static inline void >> +landlock_add_net_access_mask(struct landlock_ruleset *const ruleset, >> + const access_mask_t net_access_mask, >> + const u16 layer_level) >> +{ >> + access_mask_t net_mask = net_access_mask & LANDLOCK_MASK_ACCESS_NET; >> + >> + /* Should already be checked in sys_landlock_create_ruleset(). */ >> + WARN_ON_ONCE(net_access_mask != net_mask); >> + // TODO: Add tests to check "|=" and not "=" >> + ruleset->access_masks[layer_level] |= >> + (net_mask << LANDLOCK_SHIFT_ACCESS_NET); >> +} >> + >> /* A helper function to get a filesystem mask. */ >> static inline access_mask_t >> landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >> @@ -236,6 +263,16 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >> LANDLOCK_MASK_ACCESS_FS; >> } >> >> +/* A helper function to get a network mask. */ >> +static inline access_mask_t >> +landlock_get_net_access_mask(const struct landlock_ruleset *const ruleset, >> + const u16 layer_level) >> +{ >> + return (ruleset->access_masks[layer_level] >> >> + LANDLOCK_SHIFT_ACCESS_NET) & >> + LANDLOCK_MASK_ACCESS_NET; >> +} >> + > > This hunk doesn't match my patch. Do you mean landlock_get_net_access_mask? If yes, there is no diff with your patch here. > > >> bool unmask_layers(const struct landlock_rule *const rule, >> const access_mask_t access_request, >> layer_mask_t (*const layer_masks)[], >> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c >> index ffd5805eddd9..641155f6f6f8 100644 >> --- a/security/landlock/syscalls.c >> +++ b/security/landlock/syscalls.c >> @@ -189,8 +189,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, >> LANDLOCK_MASK_ACCESS_FS) >> return -EINVAL; >> >> + /* Checks network content (and 32-bits cast). */ >> + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != >> + LANDLOCK_MASK_ACCESS_NET) >> + return -EINVAL; >> + >> /* Checks arguments and transforms to kernel struct. */ >> - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); >> + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs, >> + ruleset_attr.handled_access_net); >> if (IS_ERR(ruleset)) >> return PTR_ERR(ruleset); >> >> -- >> 2.25.1 >> > .
On 10/09/2022 20:27, Konstantin Meskhidze (A) wrote: > > > 9/6/2022 11:08 AM, Mickaël Salaün пишет: >> >> On 29/08/2022 19:03, Konstantin Meskhidze wrote: >>> This commit adds network rules support in internal landlock functions >>> (presented in ruleset.c) and landlock_create_ruleset syscall. >>> >>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >>> --- >>> >>> Changes since v6: >>> * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask() >>> because it OR values. >>> * Makes landlock_add_net_access_mask() more resilient incorrect values. >>> * Refactors landlock_get_net_access_mask(). >>> * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use >>> LANDLOCK_NUM_ACCESS_FS as value. >>> * Updates access_masks_t to u32 to support network access actions. >>> * Refactors landlock internal functions to support network actions with >>> landlock_key/key_type/id types. >>> >>> Changes since v5: >>> * Gets rid of partial revert from landlock_add_rule >>> syscall. >>> * Formats code with clang-format-14. >>> >>> Changes since v4: >>> * Refactors landlock_create_ruleset() - splits ruleset and >>> masks checks. >>> * Refactors landlock_create_ruleset() and landlock mask >>> setters/getters to support two rule types. >>> * Refactors landlock_add_rule syscall add_rule_path_beneath >>> function by factoring out get_ruleset_from_fd() and >>> landlock_put_ruleset(). >>> >>> Changes since v3: >>> * Splits commit. >>> * Adds network rule support for internal landlock functions. >>> * Adds set_mask and get_mask for network. >>> * Adds rb_root root_net_port. >>> >>> --- >>> security/landlock/limits.h | 6 +++++- >>> security/landlock/ruleset.c | 38 +++++++++++++++++++++++++++++---- >>> security/landlock/ruleset.h | 41 ++++++++++++++++++++++++++++++++++-- >>> security/landlock/syscalls.c | 8 ++++++- >>> 4 files changed, 85 insertions(+), 8 deletions(-) >>> >>> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >>> index bafb3b8dc677..8a1a6463c64e 100644 >>> --- a/security/landlock/limits.h >>> +++ b/security/landlock/limits.h >>> @@ -23,6 +23,10 @@ >>> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >>> #define LANDLOCK_SHIFT_ACCESS_FS 0 >>> >>> -/* clang-format on */ >>> +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP >>> +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) >>> +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET) >>> +#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS >>> >>> +/* clang-format on */ >>> #endif /* _SECURITY_LANDLOCK_LIMITS_H */ >>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >>> index 84fcd8eb30d4..442f212039df 100644 >>> --- a/security/landlock/ruleset.c >>> +++ b/security/landlock/ruleset.c >>> @@ -36,6 +36,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>> refcount_set(&new_ruleset->usage, 1); >>> mutex_init(&new_ruleset->lock); >>> new_ruleset->root_inode = RB_ROOT; >>> + new_ruleset->root_net_port = RB_ROOT; >>> new_ruleset->num_layers = num_layers; >>> /* >>> * hierarchy = NULL >>> @@ -46,16 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>> } >>> >>> struct landlock_ruleset * >>> -landlock_create_ruleset(const access_mask_t fs_access_mask) >>> +landlock_create_ruleset(const access_mask_t fs_access_mask, >>> + const access_mask_t net_access_mask) >>> { >>> struct landlock_ruleset *new_ruleset; >>> >>> /* Informs about useless ruleset. */ >>> - if (!fs_access_mask) >>> + if (!fs_access_mask && !net_access_mask) >>> return ERR_PTR(-ENOMSG); >>> new_ruleset = create_ruleset(1); >>> - if (!IS_ERR(new_ruleset)) >>> + if (IS_ERR(new_ruleset)) >>> + return new_ruleset; >>> + if (fs_access_mask) >>> landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >>> + if (net_access_mask) >>> + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); >>> return new_ruleset; >>> } >>> >>> @@ -73,6 +79,8 @@ static inline bool is_object_pointer(const enum landlock_key_type key_type) >>> switch (key_type) { >>> case LANDLOCK_KEY_INODE: >>> return true; >>> + case LANDLOCK_KEY_NET_PORT: >>> + return false; >>> } >>> WARN_ON_ONCE(1); >>> return false; >>> @@ -126,6 +134,9 @@ static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, >>> case LANDLOCK_KEY_INODE: >>> root = &ruleset->root_inode; >>> break; >>> + case LANDLOCK_KEY_NET_PORT: >>> + root = &ruleset->root_net_port; >>> + break; >>> } >>> if (WARN_ON_ONCE(!root)) >>> return ERR_PTR(-EINVAL); >>> @@ -154,7 +165,9 @@ static void build_check_ruleset(void) >>> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >>> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >>> BUILD_BUG_ON(access_masks < >>> - (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >>> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS) + >>> + (LANDLOCK_MASK_ACCESS_NET >>> + << LANDLOCK_SHIFT_ACCESS_NET)); >>> } >>> >>> /** >>> @@ -367,6 +380,11 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >>> if (err) >>> goto out_unlock; >>> >>> + /* Merges the @src network port tree. */ >>> + err = merge_tree(dst, src, LANDLOCK_KEY_NET_PORT); >>> + if (err) >>> + goto out_unlock; >>> + >>> out_unlock: >>> mutex_unlock(&src->lock); >>> mutex_unlock(&dst->lock); >>> @@ -419,6 +437,11 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >>> if (err) >>> goto out_unlock; >>> >>> + /* Copies the @parent network port tree. */ >>> + err = inherit_tree(parent, child, LANDLOCK_KEY_NET_PORT); >>> + if (err) >>> + goto out_unlock; >>> + >>> if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { >>> err = -EINVAL; >>> goto out_unlock; >>> @@ -451,6 +474,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) >>> rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, >>> node) >>> free_rule(freeme, LANDLOCK_KEY_INODE); >>> + rbtree_postorder_for_each_entry_safe(freeme, next, >>> + &ruleset->root_net_port, node) >>> + free_rule(freeme, LANDLOCK_KEY_NET_PORT); >>> put_hierarchy(ruleset->hierarchy); >>> kfree(ruleset); >>> } >>> @@ -640,6 +666,10 @@ access_mask_t init_layer_masks(const struct landlock_ruleset *const domain, >>> get_access_mask = landlock_get_fs_access_mask; >>> num_access = LANDLOCK_NUM_ACCESS_FS; >>> break; >>> + case LANDLOCK_KEY_NET_PORT: >>> + get_access_mask = landlock_get_net_access_mask; >>> + num_access = LANDLOCK_NUM_ACCESS_NET; >>> + break; >>> default: >>> WARN_ON_ONCE(1); >>> return 0; >>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >>> index 2083855bf42d..d456ee90b648 100644 >>> --- a/security/landlock/ruleset.h >>> +++ b/security/landlock/ruleset.h >>> @@ -26,7 +26,7 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >>> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >>> >>> /* Ruleset access masks. */ >>> -typedef u16 access_masks_t; >>> +typedef u32 access_masks_t; >>> /* Makes sure all ruleset access rights can be stored. */ >>> static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); >> >> There is some fixes missing from my patch. >> >> >>> >>> @@ -66,6 +66,11 @@ enum landlock_key_type { >>> * keys. >>> */ >>> LANDLOCK_KEY_INODE = 1, >> >> >> #if IS_ENABLED(CONFIG_INET) >> >>> + /** >>> + * @LANDLOCK_KEY_NET_PORT: Type of &landlock_ruleset.root_net_port's >>> + * node keys. >>> + */ >>> + LANDLOCK_KEY_NET_PORT = 2, >> >> #endif /* IS_ENABLED(CONFIG_INET) */ >> >> And then all use of LANDLOCK_KEY_NET_PORT should be surrounded by the >> same check (but not directly in the net.c file). > > I checked the branch with your patches: tmp-net > (7d6cf40a6f81adf607ad3cc17aaa11e256beeea4), but I did not find #if > IS_ENABLED(CONFIG_INET) surrounding LANDLOCK_KEY_NET_PORT. You need to write that yourself. >> >> >>> }; >>> >>> /** >>> @@ -133,6 +138,12 @@ struct landlock_ruleset { >>> * reaches zero. >>> */ >>> struct rb_root root_inode; >> >> #if IS_ENABLED(CONFIG_INET) >> >>> + /** >>> + * @root_net_port: Root of a red-black tree containing object nodes >>> + * for network port. Once a ruleset is tied to a process (i.e. as a domain), >>> + * this tree is immutable until @usage reaches zero. >>> + */ >> >> There is some fixes missing from my patch. Please explain everything >> that you didn't take. > > Sorry. I did merge your patch manually and did not tell the > difference here. Will be fixed You can use git diff to be sure to not miss some parts. BTW, tools such as git cherry-pick, read-tree, diff and "add -p" can save you some time. >> >> >>> + struct rb_root root_net_port; >> >> >> #endif /* IS_ENABLED(CONFIG_INET) */ >> >> And then all use of root_net_port should be surrounded by the same check. > > The same - I did not find #if IS_ENABLED(CONFIG_INET) surrounding > root_net_port in tmp-net (7d6cf40a6f81adf607ad3cc17aaa11e256beeea4) >> >> I think it should be OK to keep all other remaining network references >> though (e.g. access_masks and the ). > > Ok. Thanks. >> >> >>> /** >>> * @hierarchy: Enables hierarchy identification even when a parent >>> * domain vanishes. This is needed for the ptrace protection. >>> @@ -188,7 +199,8 @@ struct landlock_ruleset { >>> }; >>> >>> struct landlock_ruleset * >>> -landlock_create_ruleset(const access_mask_t access_mask); >>> +landlock_create_ruleset(const access_mask_t access_mask_fs, >>> + const access_mask_t access_mask_net); >>> >>> void landlock_put_ruleset(struct landlock_ruleset *const ruleset); >>> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); >>> @@ -226,6 +238,21 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >>> (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); >>> } >>> >>> +/* A helper function to set a network mask. */ >> >> I already said that this comment is useless, and I removed it in my >> patch. Please take a closer look at reviews. > > Sorry. I missed that in your patch. Will be fixed. >> >> >>> +static inline void >>> +landlock_add_net_access_mask(struct landlock_ruleset *const ruleset, >>> + const access_mask_t net_access_mask, >>> + const u16 layer_level) >>> +{ >>> + access_mask_t net_mask = net_access_mask & LANDLOCK_MASK_ACCESS_NET; >>> + >>> + /* Should already be checked in sys_landlock_create_ruleset(). */ >>> + WARN_ON_ONCE(net_access_mask != net_mask); >>> + // TODO: Add tests to check "|=" and not "=" >>> + ruleset->access_masks[layer_level] |= >>> + (net_mask << LANDLOCK_SHIFT_ACCESS_NET); >>> +} >>> + >>> /* A helper function to get a filesystem mask. */ >>> static inline access_mask_t >>> landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >>> @@ -236,6 +263,16 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >>> LANDLOCK_MASK_ACCESS_FS; >>> } >>> >>> +/* A helper function to get a network mask. */ >>> +static inline access_mask_t >>> +landlock_get_net_access_mask(const struct landlock_ruleset *const ruleset, >>> + const u16 layer_level) >>> +{ >>> + return (ruleset->access_masks[layer_level] >> >>> + LANDLOCK_SHIFT_ACCESS_NET) & >>> + LANDLOCK_MASK_ACCESS_NET; >>> +} >>> + >> >> This hunk doesn't match my patch. > > Do you mean landlock_get_net_access_mask? If yes, there is no diff > with your patch here. I removed useless comments, please do a diff (and look at the changes in the commit messages). Some code also moved. >> >> >>> bool unmask_layers(const struct landlock_rule *const rule, >>> const access_mask_t access_request, >>> layer_mask_t (*const layer_masks)[], >>> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c >>> index ffd5805eddd9..641155f6f6f8 100644 >>> --- a/security/landlock/syscalls.c >>> +++ b/security/landlock/syscalls.c >>> @@ -189,8 +189,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, >>> LANDLOCK_MASK_ACCESS_FS) >>> return -EINVAL; >>> >>> + /* Checks network content (and 32-bits cast). */ >>> + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != >>> + LANDLOCK_MASK_ACCESS_NET) >>> + return -EINVAL; >>> + >>> /* Checks arguments and transforms to kernel struct. */ >>> - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); >>> + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs, >>> + ruleset_attr.handled_access_net); >>> if (IS_ERR(ruleset)) >>> return PTR_ERR(ruleset); >>> >>> -- >>> 2.25.1 >>> >> .
diff --git a/security/landlock/limits.h b/security/landlock/limits.h index bafb3b8dc677..8a1a6463c64e 100644 --- a/security/landlock/limits.h +++ b/security/landlock/limits.h @@ -23,6 +23,10 @@ #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) #define LANDLOCK_SHIFT_ACCESS_FS 0 -/* clang-format on */ +#define LANDLOCK_LAST_ACCESS_NET LANDLOCK_ACCESS_NET_CONNECT_TCP +#define LANDLOCK_MASK_ACCESS_NET ((LANDLOCK_LAST_ACCESS_NET << 1) - 1) +#define LANDLOCK_NUM_ACCESS_NET __const_hweight64(LANDLOCK_MASK_ACCESS_NET) +#define LANDLOCK_SHIFT_ACCESS_NET LANDLOCK_NUM_ACCESS_FS +/* clang-format on */ #endif /* _SECURITY_LANDLOCK_LIMITS_H */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 84fcd8eb30d4..442f212039df 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -36,6 +36,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) refcount_set(&new_ruleset->usage, 1); mutex_init(&new_ruleset->lock); new_ruleset->root_inode = RB_ROOT; + new_ruleset->root_net_port = RB_ROOT; new_ruleset->num_layers = num_layers; /* * hierarchy = NULL @@ -46,16 +47,21 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) } struct landlock_ruleset * -landlock_create_ruleset(const access_mask_t fs_access_mask) +landlock_create_ruleset(const access_mask_t fs_access_mask, + const access_mask_t net_access_mask) { struct landlock_ruleset *new_ruleset; /* Informs about useless ruleset. */ - if (!fs_access_mask) + if (!fs_access_mask && !net_access_mask) return ERR_PTR(-ENOMSG); new_ruleset = create_ruleset(1); - if (!IS_ERR(new_ruleset)) + if (IS_ERR(new_ruleset)) + return new_ruleset; + if (fs_access_mask) landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); + if (net_access_mask) + landlock_add_net_access_mask(new_ruleset, net_access_mask, 0); return new_ruleset; } @@ -73,6 +79,8 @@ static inline bool is_object_pointer(const enum landlock_key_type key_type) switch (key_type) { case LANDLOCK_KEY_INODE: return true; + case LANDLOCK_KEY_NET_PORT: + return false; } WARN_ON_ONCE(1); return false; @@ -126,6 +134,9 @@ static inline struct rb_root *get_root(struct landlock_ruleset *const ruleset, case LANDLOCK_KEY_INODE: root = &ruleset->root_inode; break; + case LANDLOCK_KEY_NET_PORT: + root = &ruleset->root_net_port; + break; } if (WARN_ON_ONCE(!root)) return ERR_PTR(-EINVAL); @@ -154,7 +165,9 @@ static void build_check_ruleset(void) BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); BUILD_BUG_ON(access_masks < - (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS) + + (LANDLOCK_MASK_ACCESS_NET + << LANDLOCK_SHIFT_ACCESS_NET)); } /** @@ -367,6 +380,11 @@ static int merge_ruleset(struct landlock_ruleset *const dst, if (err) goto out_unlock; + /* Merges the @src network port tree. */ + err = merge_tree(dst, src, LANDLOCK_KEY_NET_PORT); + if (err) + goto out_unlock; + out_unlock: mutex_unlock(&src->lock); mutex_unlock(&dst->lock); @@ -419,6 +437,11 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, if (err) goto out_unlock; + /* Copies the @parent network port tree. */ + err = inherit_tree(parent, child, LANDLOCK_KEY_NET_PORT); + if (err) + goto out_unlock; + if (WARN_ON_ONCE(child->num_layers <= parent->num_layers)) { err = -EINVAL; goto out_unlock; @@ -451,6 +474,9 @@ static void free_ruleset(struct landlock_ruleset *const ruleset) rbtree_postorder_for_each_entry_safe(freeme, next, &ruleset->root_inode, node) free_rule(freeme, LANDLOCK_KEY_INODE); + rbtree_postorder_for_each_entry_safe(freeme, next, + &ruleset->root_net_port, node) + free_rule(freeme, LANDLOCK_KEY_NET_PORT); put_hierarchy(ruleset->hierarchy); kfree(ruleset); } @@ -640,6 +666,10 @@ access_mask_t init_layer_masks(const struct landlock_ruleset *const domain, get_access_mask = landlock_get_fs_access_mask; num_access = LANDLOCK_NUM_ACCESS_FS; break; + case LANDLOCK_KEY_NET_PORT: + get_access_mask = landlock_get_net_access_mask; + num_access = LANDLOCK_NUM_ACCESS_NET; + break; default: WARN_ON_ONCE(1); return 0; diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index 2083855bf42d..d456ee90b648 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -26,7 +26,7 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); /* Ruleset access masks. */ -typedef u16 access_masks_t; +typedef u32 access_masks_t; /* Makes sure all ruleset access rights can be stored. */ static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); @@ -66,6 +66,11 @@ enum landlock_key_type { * keys. */ LANDLOCK_KEY_INODE = 1, + /** + * @LANDLOCK_KEY_NET_PORT: Type of &landlock_ruleset.root_net_port's + * node keys. + */ + LANDLOCK_KEY_NET_PORT = 2, }; /** @@ -133,6 +138,12 @@ struct landlock_ruleset { * reaches zero. */ struct rb_root root_inode; + /** + * @root_net_port: Root of a red-black tree containing object nodes + * for network port. 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_net_port; /** * @hierarchy: Enables hierarchy identification even when a parent * domain vanishes. This is needed for the ptrace protection. @@ -188,7 +199,8 @@ struct landlock_ruleset { }; struct landlock_ruleset * -landlock_create_ruleset(const access_mask_t access_mask); +landlock_create_ruleset(const access_mask_t access_mask_fs, + const access_mask_t access_mask_net); void landlock_put_ruleset(struct landlock_ruleset *const ruleset); void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); @@ -226,6 +238,21 @@ landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); } +/* A helper function to set a network mask. */ +static inline void +landlock_add_net_access_mask(struct landlock_ruleset *const ruleset, + const access_mask_t net_access_mask, + const u16 layer_level) +{ + access_mask_t net_mask = net_access_mask & LANDLOCK_MASK_ACCESS_NET; + + /* Should already be checked in sys_landlock_create_ruleset(). */ + WARN_ON_ONCE(net_access_mask != net_mask); + // TODO: Add tests to check "|=" and not "=" + ruleset->access_masks[layer_level] |= + (net_mask << LANDLOCK_SHIFT_ACCESS_NET); +} + /* A helper function to get a filesystem mask. */ static inline access_mask_t landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, @@ -236,6 +263,16 @@ landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, LANDLOCK_MASK_ACCESS_FS; } +/* A helper function to get a network mask. */ +static inline access_mask_t +landlock_get_net_access_mask(const struct landlock_ruleset *const ruleset, + const u16 layer_level) +{ + return (ruleset->access_masks[layer_level] >> + LANDLOCK_SHIFT_ACCESS_NET) & + LANDLOCK_MASK_ACCESS_NET; +} + bool unmask_layers(const struct landlock_rule *const rule, const access_mask_t access_request, layer_mask_t (*const layer_masks)[], diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index ffd5805eddd9..641155f6f6f8 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -189,8 +189,14 @@ SYSCALL_DEFINE3(landlock_create_ruleset, LANDLOCK_MASK_ACCESS_FS) return -EINVAL; + /* Checks network content (and 32-bits cast). */ + if ((ruleset_attr.handled_access_net | LANDLOCK_MASK_ACCESS_NET) != + LANDLOCK_MASK_ACCESS_NET) + return -EINVAL; + /* Checks arguments and transforms to kernel struct. */ - ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs); + ruleset = landlock_create_ruleset(ruleset_attr.handled_access_fs, + ruleset_attr.handled_access_net); if (IS_ERR(ruleset)) return PTR_ERR(ruleset);
This commit adds network rules support in internal landlock functions (presented in ruleset.c) and landlock_create_ruleset syscall. Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> --- Changes since v6: * Renames landlock_set_net_access_mask() to landlock_add_net_access_mask() because it OR values. * Makes landlock_add_net_access_mask() more resilient incorrect values. * Refactors landlock_get_net_access_mask(). * Renames LANDLOCK_MASK_SHIFT_NET to LANDLOCK_SHIFT_ACCESS_NET and use LANDLOCK_NUM_ACCESS_FS as value. * Updates access_masks_t to u32 to support network access actions. * Refactors landlock internal functions to support network actions with landlock_key/key_type/id types. Changes since v5: * Gets rid of partial revert from landlock_add_rule syscall. * Formats code with clang-format-14. Changes since v4: * Refactors landlock_create_ruleset() - splits ruleset and masks checks. * Refactors landlock_create_ruleset() and landlock mask setters/getters to support two rule types. * Refactors landlock_add_rule syscall add_rule_path_beneath function by factoring out get_ruleset_from_fd() and landlock_put_ruleset(). Changes since v3: * Splits commit. * Adds network rule support for internal landlock functions. * Adds set_mask and get_mask for network. * Adds rb_root root_net_port. --- security/landlock/limits.h | 6 +++++- security/landlock/ruleset.c | 38 +++++++++++++++++++++++++++++---- security/landlock/ruleset.h | 41 ++++++++++++++++++++++++++++++++++-- security/landlock/syscalls.c | 8 ++++++- 4 files changed, 85 insertions(+), 8 deletions(-) -- 2.25.1