| Message ID | 20221021152644.155136-2-konstantin.meskhidze@huawei.com (mailing list archive) |
|---|---|
| State | Handled Elsewhere |
| Headers | show |
| Series | Network support for Landlock | expand |
On 21/10/2022 17:26, Konstantin Meskhidze wrote: > To support network type rules, this modification renames ruleset's > access masks and modifies it's type to access_masks_t. This patch > adds filesystem helper functions to add and get filesystem mask. > > Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> > --- > > Changes since v7: > * Refactors commit message. > > Changes since v6: > * Adds a new access_masks_t for struct ruleset. > * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() > because it OR values. > * Makes landlock_add_fs_access_mask() more resilient incorrect values. > * Refactors landlock_get_fs_access_mask(). > > Changes since v6: > * Adds a new access_masks_t for struct ruleset. > * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() > because it OR values. > * Makes landlock_add_fs_access_mask() more resilient incorrect values. > * Refactors landlock_get_fs_access_mask(). > > Changes since v5: > * Changes access_mask_t to u32. > * Formats code with clang-format-14. > > Changes since v4: > * Deletes struct landlock_access_mask. > > Changes since v3: > * Splits commit. > * Adds get_mask, set_mask helpers for filesystem. > * Adds new struct landlock_access_mask. > > --- > security/landlock/fs.c | 10 +++++----- > security/landlock/limits.h | 1 + > security/landlock/ruleset.c | 17 +++++++++-------- > security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- > security/landlock/syscalls.c | 7 ++++--- > 5 files changed, 50 insertions(+), 20 deletions(-) > > diff --git a/security/landlock/fs.c b/security/landlock/fs.c > index adcea0fe7e68..0d57c6479d29 100644 > --- a/security/landlock/fs.c > +++ b/security/landlock/fs.c > @@ -178,9 +178,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, > return -EINVAL; > > /* Transforms relative access rights to absolute ones. */ > - access_rights |= > - LANDLOCK_MASK_ACCESS_FS & > - ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); > + access_rights |= LANDLOCK_MASK_ACCESS_FS & > + ~(landlock_get_fs_access_mask(ruleset, 0) | > + ACCESS_INITIALLY_DENIED); > object = get_inode_object(d_backing_inode(path->dentry)); > if (IS_ERR(object)) > return PTR_ERR(object); > @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) > size_t layer_level; > > for (layer_level = 0; layer_level < domain->num_layers; layer_level++) > - access_dom |= domain->fs_access_masks[layer_level]; > + access_dom |= landlock_get_fs_access_mask(domain, layer_level); > return access_dom & LANDLOCK_MASK_ACCESS_FS; You can remove `& LANDLOCK_MASK_ACCESS_FS` here because it is now part of landlock_get_fs_access_mask(). > } > > @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, > * access rights. > */ > if (BIT_ULL(access_bit) & > - (domain->fs_access_masks[layer_level] | > + (landlock_get_fs_access_mask(domain, layer_level) | > ACCESS_INITIALLY_DENIED)) { > (*layer_masks)[access_bit] |= > BIT_ULL(layer_level); > diff --git a/security/landlock/limits.h b/security/landlock/limits.h > index 82288f0e9e5e..bafb3b8dc677 100644 > --- a/security/landlock/limits.h > +++ b/security/landlock/limits.h > @@ -21,6 +21,7 @@ > #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE > #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) > #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) > +#define LANDLOCK_SHIFT_ACCESS_FS 0 > > /* clang-format on */ > > diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c > index 996484f98bfd..1f3188b4e313 100644 > --- a/security/landlock/ruleset.c > +++ b/security/landlock/ruleset.c > @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > struct landlock_ruleset *new_ruleset; > > new_ruleset = > - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), > + kzalloc(struct_size(new_ruleset, access_masks, num_layers), > GFP_KERNEL_ACCOUNT); > if (!new_ruleset) > return ERR_PTR(-ENOMEM); > @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) > /* > * hierarchy = NULL > * num_rules = 0 > - * fs_access_masks[] = 0 > + * access_masks[] = 0 > */ > return new_ruleset; > } > @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) > return ERR_PTR(-ENOMSG); > new_ruleset = create_ruleset(1); > if (!IS_ERR(new_ruleset)) > - new_ruleset->fs_access_masks[0] = fs_access_mask; > + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); > return new_ruleset; > } > > @@ -117,11 +117,12 @@ static void build_check_ruleset(void) > .num_rules = ~0, > .num_layers = ~0, > }; > - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; > + typeof(ruleset.access_masks[0]) access_masks = ~0; > > BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); > BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); > - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); > + BUILD_BUG_ON(access_masks < > + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); > } > > /** > @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, > err = -EINVAL; > goto out_unlock; > } > - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; > + 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, > @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, > goto out_unlock; > } > /* Copies the parent layer stack and leaves a space for the new layer. */ > - memcpy(child->fs_access_masks, parent->fs_access_masks, > - flex_array_size(parent, fs_access_masks, parent->num_layers)); > + memcpy(child->access_masks, parent->access_masks, > + flex_array_size(parent, access_masks, parent->num_layers)); > > if (WARN_ON_ONCE(!parent->hierarchy)) { > err = -EINVAL; > diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h > index d43231b783e4..f2ad932d396c 100644 > --- a/security/landlock/ruleset.h > +++ b/security/landlock/ruleset.h > @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); > /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ > static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); > > +/* Ruleset access masks. */ > +typedef u16 access_masks_t; > +/* Makes sure all ruleset access rights can be stored. */ > +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); > + > typedef u16 layer_mask_t; > /* Makes sure all layers can be checked. */ > static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); > @@ -110,7 +115,7 @@ struct landlock_ruleset { > * section. This is only used by > * landlock_put_ruleset_deferred() when @usage reaches zero. > * The fields @lock, @usage, @num_rules, @num_layers and > - * @fs_access_masks are then unused. > + * @access_masks are then unused. > */ > struct work_struct work_free; > struct { > @@ -137,7 +142,7 @@ struct landlock_ruleset { > */ > u32 num_layers; > /** > - * @fs_access_masks: Contains the subset of filesystem > + * @access_masks: Contains the subset of filesystem > * actions that are restricted by a ruleset. A domain > * saves all layers of merged rulesets in a stack > * (FAM), starting from the first layer to the last > @@ -148,13 +153,13 @@ struct landlock_ruleset { > * layers are set once and never changed for the > * lifetime of the ruleset. > */ > - access_mask_t fs_access_masks[]; > + access_masks_t access_masks[]; > }; > }; > }; > > struct landlock_ruleset * > -landlock_create_ruleset(const access_mask_t fs_access_mask); > +landlock_create_ruleset(const access_mask_t access_mask); > > void landlock_put_ruleset(struct landlock_ruleset *const ruleset); > void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); > @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) > refcount_inc(&ruleset->usage); > } > > +static inline void > +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, > + const access_mask_t fs_access_mask, > + const u16 layer_level) > +{ > + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; > + > + /* Should already be checked in sys_landlock_create_ruleset(). */ > + WARN_ON_ONCE(fs_access_mask != fs_mask); > + // TODO: Add tests to check "|=" and not "=" This todo should be done and removed. No more todos must remain. > + ruleset->access_masks[layer_level] |= > + (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); > +} > + > +static inline access_mask_t > +landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, > + const u16 layer_level) > +{ > + return (ruleset->access_masks[layer_level] >> > + LANDLOCK_SHIFT_ACCESS_FS) & > + LANDLOCK_MASK_ACCESS_FS; > +} > #endif /* _SECURITY_LANDLOCK_RULESET_H */ > diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c > index 245cc650a4dc..71aca7f990bc 100644 > --- a/security/landlock/syscalls.c > +++ b/security/landlock/syscalls.c > @@ -346,10 +346,11 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, > } > /* > * Checks that allowed_access matches the @ruleset constraints > - * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). > + * (ruleset->access_masks[0] is automatically upgraded to 64-bits). > */ > - if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != > - ruleset->fs_access_masks[0]) { > + if ((path_beneath_attr.allowed_access | > + landlock_get_fs_access_mask(ruleset, 0)) != > + landlock_get_fs_access_mask(ruleset, 0)) { > err = -EINVAL; > goto out_put_ruleset; > } > -- > 2.25.1 > I'll send a patch to be applied after this one.
11/17/2022 9:41 PM, Mickaël Salaün пишет: > > On 21/10/2022 17:26, Konstantin Meskhidze wrote: >> To support network type rules, this modification renames ruleset's >> access masks and modifies it's type to access_masks_t. This patch >> adds filesystem helper functions to add and get filesystem mask. >> >> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >> --- >> >> Changes since v7: >> * Refactors commit message. >> >> Changes since v6: >> * Adds a new access_masks_t for struct ruleset. >> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >> because it OR values. >> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >> * Refactors landlock_get_fs_access_mask(). >> >> Changes since v6: >> * Adds a new access_masks_t for struct ruleset. >> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >> because it OR values. >> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >> * Refactors landlock_get_fs_access_mask(). >> >> Changes since v5: >> * Changes access_mask_t to u32. >> * Formats code with clang-format-14. >> >> Changes since v4: >> * Deletes struct landlock_access_mask. >> >> Changes since v3: >> * Splits commit. >> * Adds get_mask, set_mask helpers for filesystem. >> * Adds new struct landlock_access_mask. >> >> --- >> security/landlock/fs.c | 10 +++++----- >> security/landlock/limits.h | 1 + >> security/landlock/ruleset.c | 17 +++++++++-------- >> security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- >> security/landlock/syscalls.c | 7 ++++--- >> 5 files changed, 50 insertions(+), 20 deletions(-) >> >> diff --git a/security/landlock/fs.c b/security/landlock/fs.c >> index adcea0fe7e68..0d57c6479d29 100644 >> --- a/security/landlock/fs.c >> +++ b/security/landlock/fs.c >> @@ -178,9 +178,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, >> return -EINVAL; >> >> /* Transforms relative access rights to absolute ones. */ >> - access_rights |= >> - LANDLOCK_MASK_ACCESS_FS & >> - ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); >> + access_rights |= LANDLOCK_MASK_ACCESS_FS & >> + ~(landlock_get_fs_access_mask(ruleset, 0) | >> + ACCESS_INITIALLY_DENIED); >> object = get_inode_object(d_backing_inode(path->dentry)); >> if (IS_ERR(object)) >> return PTR_ERR(object); >> @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) >> size_t layer_level; >> >> for (layer_level = 0; layer_level < domain->num_layers; layer_level++) >> - access_dom |= domain->fs_access_masks[layer_level]; >> + access_dom |= landlock_get_fs_access_mask(domain, layer_level); >> return access_dom & LANDLOCK_MASK_ACCESS_FS; > > You can remove `& LANDLOCK_MASK_ACCESS_FS` here because it is now part > of landlock_get_fs_access_mask(). Ok. I got it. Thanks. > > >> } >> >> @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, >> * access rights. >> */ >> if (BIT_ULL(access_bit) & >> - (domain->fs_access_masks[layer_level] | >> + (landlock_get_fs_access_mask(domain, layer_level) | >> ACCESS_INITIALLY_DENIED)) { >> (*layer_masks)[access_bit] |= >> BIT_ULL(layer_level); >> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >> index 82288f0e9e5e..bafb3b8dc677 100644 >> --- a/security/landlock/limits.h >> +++ b/security/landlock/limits.h >> @@ -21,6 +21,7 @@ >> #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE >> #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) >> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >> +#define LANDLOCK_SHIFT_ACCESS_FS 0 >> >> /* clang-format on */ >> >> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >> index 996484f98bfd..1f3188b4e313 100644 >> --- a/security/landlock/ruleset.c >> +++ b/security/landlock/ruleset.c >> @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >> struct landlock_ruleset *new_ruleset; >> >> new_ruleset = >> - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), >> + kzalloc(struct_size(new_ruleset, access_masks, num_layers), >> GFP_KERNEL_ACCOUNT); >> if (!new_ruleset) >> return ERR_PTR(-ENOMEM); >> @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >> /* >> * hierarchy = NULL >> * num_rules = 0 >> - * fs_access_masks[] = 0 >> + * access_masks[] = 0 >> */ >> return new_ruleset; >> } >> @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) >> return ERR_PTR(-ENOMSG); >> new_ruleset = create_ruleset(1); >> if (!IS_ERR(new_ruleset)) >> - new_ruleset->fs_access_masks[0] = fs_access_mask; >> + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >> return new_ruleset; >> } >> >> @@ -117,11 +117,12 @@ static void build_check_ruleset(void) >> .num_rules = ~0, >> .num_layers = ~0, >> }; >> - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; >> + typeof(ruleset.access_masks[0]) access_masks = ~0; >> >> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >> - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); >> + BUILD_BUG_ON(access_masks < >> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >> } >> >> /** >> @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >> err = -EINVAL; >> goto out_unlock; >> } >> - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; >> + 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, >> @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >> goto out_unlock; >> } >> /* Copies the parent layer stack and leaves a space for the new layer. */ >> - memcpy(child->fs_access_masks, parent->fs_access_masks, >> - flex_array_size(parent, fs_access_masks, parent->num_layers)); >> + memcpy(child->access_masks, parent->access_masks, >> + flex_array_size(parent, access_masks, parent->num_layers)); >> >> if (WARN_ON_ONCE(!parent->hierarchy)) { >> err = -EINVAL; >> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >> index d43231b783e4..f2ad932d396c 100644 >> --- a/security/landlock/ruleset.h >> +++ b/security/landlock/ruleset.h >> @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >> /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ >> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >> >> +/* Ruleset access masks. */ >> +typedef u16 access_masks_t; >> +/* Makes sure all ruleset access rights can be stored. */ >> +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); >> + >> typedef u16 layer_mask_t; >> /* Makes sure all layers can be checked. */ >> static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); >> @@ -110,7 +115,7 @@ struct landlock_ruleset { >> * section. This is only used by >> * landlock_put_ruleset_deferred() when @usage reaches zero. >> * The fields @lock, @usage, @num_rules, @num_layers and >> - * @fs_access_masks are then unused. >> + * @access_masks are then unused. >> */ >> struct work_struct work_free; >> struct { >> @@ -137,7 +142,7 @@ struct landlock_ruleset { >> */ >> u32 num_layers; >> /** >> - * @fs_access_masks: Contains the subset of filesystem >> + * @access_masks: Contains the subset of filesystem >> * actions that are restricted by a ruleset. A domain >> * saves all layers of merged rulesets in a stack >> * (FAM), starting from the first layer to the last >> @@ -148,13 +153,13 @@ struct landlock_ruleset { >> * layers are set once and never changed for the >> * lifetime of the ruleset. >> */ >> - access_mask_t fs_access_masks[]; >> + access_masks_t access_masks[]; >> }; >> }; >> }; >> >> struct landlock_ruleset * >> -landlock_create_ruleset(const access_mask_t fs_access_mask); >> +landlock_create_ruleset(const access_mask_t access_mask); >> >> void landlock_put_ruleset(struct landlock_ruleset *const ruleset); >> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); >> @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) >> refcount_inc(&ruleset->usage); >> } >> >> +static inline void >> +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >> + const access_mask_t fs_access_mask, >> + const u16 layer_level) >> +{ >> + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; >> + >> + /* Should already be checked in sys_landlock_create_ruleset(). */ >> + WARN_ON_ONCE(fs_access_mask != fs_mask); >> + // TODO: Add tests to check "|=" and not "=" > > This todo should be done and removed. No more todos must remain. > I delete it in 10/12 Patch when add network seltests. > >> + ruleset->access_masks[layer_level] |= >> + (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); >> +} >> + >> +static inline access_mask_t >> +landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, >> + const u16 layer_level) >> +{ >> + return (ruleset->access_masks[layer_level] >> >> + LANDLOCK_SHIFT_ACCESS_FS) & >> + LANDLOCK_MASK_ACCESS_FS; >> +} >> #endif /* _SECURITY_LANDLOCK_RULESET_H */ >> diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c >> index 245cc650a4dc..71aca7f990bc 100644 >> --- a/security/landlock/syscalls.c >> +++ b/security/landlock/syscalls.c >> @@ -346,10 +346,11 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, >> } >> /* >> * Checks that allowed_access matches the @ruleset constraints >> - * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). >> + * (ruleset->access_masks[0] is automatically upgraded to 64-bits). >> */ >> - if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != >> - ruleset->fs_access_masks[0]) { >> + if ((path_beneath_attr.allowed_access | >> + landlock_get_fs_access_mask(ruleset, 0)) != >> + landlock_get_fs_access_mask(ruleset, 0)) { >> err = -EINVAL; >> goto out_put_ruleset; >> } >> -- >> 2.25.1 >> > > I'll send a patch to be applied after this one. > .
On 28/11/2022 03:53, Konstantin Meskhidze (A) wrote: > > > 11/17/2022 9:41 PM, Mickaël Salaün пишет: >> >> On 21/10/2022 17:26, Konstantin Meskhidze wrote: >>> To support network type rules, this modification renames ruleset's >>> access masks and modifies it's type to access_masks_t. This patch >>> adds filesystem helper functions to add and get filesystem mask. >>> >>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >>> --- >>> >>> Changes since v7: >>> * Refactors commit message. >>> >>> Changes since v6: >>> * Adds a new access_masks_t for struct ruleset. >>> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >>> because it OR values. >>> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >>> * Refactors landlock_get_fs_access_mask(). >>> >>> Changes since v6: >>> * Adds a new access_masks_t for struct ruleset. >>> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >>> because it OR values. >>> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >>> * Refactors landlock_get_fs_access_mask(). >>> >>> Changes since v5: >>> * Changes access_mask_t to u32. >>> * Formats code with clang-format-14. >>> >>> Changes since v4: >>> * Deletes struct landlock_access_mask. >>> >>> Changes since v3: >>> * Splits commit. >>> * Adds get_mask, set_mask helpers for filesystem. >>> * Adds new struct landlock_access_mask. >>> >>> --- >>> security/landlock/fs.c | 10 +++++----- >>> security/landlock/limits.h | 1 + >>> security/landlock/ruleset.c | 17 +++++++++-------- >>> security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- >>> security/landlock/syscalls.c | 7 ++++--- >>> 5 files changed, 50 insertions(+), 20 deletions(-) >>> >>> diff --git a/security/landlock/fs.c b/security/landlock/fs.c >>> index adcea0fe7e68..0d57c6479d29 100644 >>> --- a/security/landlock/fs.c >>> +++ b/security/landlock/fs.c >>> @@ -178,9 +178,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, >>> return -EINVAL; >>> >>> /* Transforms relative access rights to absolute ones. */ >>> - access_rights |= >>> - LANDLOCK_MASK_ACCESS_FS & >>> - ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); >>> + access_rights |= LANDLOCK_MASK_ACCESS_FS & >>> + ~(landlock_get_fs_access_mask(ruleset, 0) | >>> + ACCESS_INITIALLY_DENIED); >>> object = get_inode_object(d_backing_inode(path->dentry)); >>> if (IS_ERR(object)) >>> return PTR_ERR(object); >>> @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) >>> size_t layer_level; >>> >>> for (layer_level = 0; layer_level < domain->num_layers; layer_level++) >>> - access_dom |= domain->fs_access_masks[layer_level]; >>> + access_dom |= landlock_get_fs_access_mask(domain, layer_level); >>> return access_dom & LANDLOCK_MASK_ACCESS_FS; >> >> You can remove `& LANDLOCK_MASK_ACCESS_FS` here because it is now part >> of landlock_get_fs_access_mask(). > > Ok. I got it. Thanks. >> >> >>> } >>> >>> @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, >>> * access rights. >>> */ >>> if (BIT_ULL(access_bit) & >>> - (domain->fs_access_masks[layer_level] | >>> + (landlock_get_fs_access_mask(domain, layer_level) | >>> ACCESS_INITIALLY_DENIED)) { >>> (*layer_masks)[access_bit] |= >>> BIT_ULL(layer_level); >>> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >>> index 82288f0e9e5e..bafb3b8dc677 100644 >>> --- a/security/landlock/limits.h >>> +++ b/security/landlock/limits.h >>> @@ -21,6 +21,7 @@ >>> #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE >>> #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) >>> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >>> +#define LANDLOCK_SHIFT_ACCESS_FS 0 >>> >>> /* clang-format on */ >>> >>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >>> index 996484f98bfd..1f3188b4e313 100644 >>> --- a/security/landlock/ruleset.c >>> +++ b/security/landlock/ruleset.c >>> @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>> struct landlock_ruleset *new_ruleset; >>> >>> new_ruleset = >>> - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), >>> + kzalloc(struct_size(new_ruleset, access_masks, num_layers), >>> GFP_KERNEL_ACCOUNT); >>> if (!new_ruleset) >>> return ERR_PTR(-ENOMEM); >>> @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>> /* >>> * hierarchy = NULL >>> * num_rules = 0 >>> - * fs_access_masks[] = 0 >>> + * access_masks[] = 0 >>> */ >>> return new_ruleset; >>> } >>> @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) >>> return ERR_PTR(-ENOMSG); >>> new_ruleset = create_ruleset(1); >>> if (!IS_ERR(new_ruleset)) >>> - new_ruleset->fs_access_masks[0] = fs_access_mask; >>> + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >>> return new_ruleset; >>> } >>> >>> @@ -117,11 +117,12 @@ static void build_check_ruleset(void) >>> .num_rules = ~0, >>> .num_layers = ~0, >>> }; >>> - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; >>> + typeof(ruleset.access_masks[0]) access_masks = ~0; >>> >>> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >>> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >>> - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); >>> + BUILD_BUG_ON(access_masks < >>> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >>> } >>> >>> /** >>> @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >>> err = -EINVAL; >>> goto out_unlock; >>> } >>> - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; >>> + 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, >>> @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >>> goto out_unlock; >>> } >>> /* Copies the parent layer stack and leaves a space for the new layer. */ >>> - memcpy(child->fs_access_masks, parent->fs_access_masks, >>> - flex_array_size(parent, fs_access_masks, parent->num_layers)); >>> + memcpy(child->access_masks, parent->access_masks, >>> + flex_array_size(parent, access_masks, parent->num_layers)); >>> >>> if (WARN_ON_ONCE(!parent->hierarchy)) { >>> err = -EINVAL; >>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >>> index d43231b783e4..f2ad932d396c 100644 >>> --- a/security/landlock/ruleset.h >>> +++ b/security/landlock/ruleset.h >>> @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >>> /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ >>> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >>> >>> +/* Ruleset access masks. */ >>> +typedef u16 access_masks_t; >>> +/* Makes sure all ruleset access rights can be stored. */ >>> +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); >>> + >>> typedef u16 layer_mask_t; >>> /* Makes sure all layers can be checked. */ >>> static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); >>> @@ -110,7 +115,7 @@ struct landlock_ruleset { >>> * section. This is only used by >>> * landlock_put_ruleset_deferred() when @usage reaches zero. >>> * The fields @lock, @usage, @num_rules, @num_layers and >>> - * @fs_access_masks are then unused. >>> + * @access_masks are then unused. >>> */ >>> struct work_struct work_free; >>> struct { >>> @@ -137,7 +142,7 @@ struct landlock_ruleset { >>> */ >>> u32 num_layers; >>> /** >>> - * @fs_access_masks: Contains the subset of filesystem >>> + * @access_masks: Contains the subset of filesystem >>> * actions that are restricted by a ruleset. A domain >>> * saves all layers of merged rulesets in a stack >>> * (FAM), starting from the first layer to the last >>> @@ -148,13 +153,13 @@ struct landlock_ruleset { >>> * layers are set once and never changed for the >>> * lifetime of the ruleset. >>> */ >>> - access_mask_t fs_access_masks[]; >>> + access_masks_t access_masks[]; >>> }; >>> }; >>> }; >>> >>> struct landlock_ruleset * >>> -landlock_create_ruleset(const access_mask_t fs_access_mask); >>> +landlock_create_ruleset(const access_mask_t access_mask); >>> >>> void landlock_put_ruleset(struct landlock_ruleset *const ruleset); >>> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); >>> @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) >>> refcount_inc(&ruleset->usage); >>> } >>> >>> +static inline void >>> +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >>> + const access_mask_t fs_access_mask, >>> + const u16 layer_level) >>> +{ >>> + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; >>> + >>> + /* Should already be checked in sys_landlock_create_ruleset(). */ >>> + WARN_ON_ONCE(fs_access_mask != fs_mask); >>> + // TODO: Add tests to check "|=" and not "=" >> >> This todo should be done and removed. No more todos must remain. >> > I delete it in 10/12 Patch when add network seltests. You can delete it in this patch then. I'm reviewing the tests.
11/28/2022 11:22 PM, Mickaël Salaün пишет: > > On 28/11/2022 03:53, Konstantin Meskhidze (A) wrote: >> >> >> 11/17/2022 9:41 PM, Mickaël Salaün пишет: >>> >>> On 21/10/2022 17:26, Konstantin Meskhidze wrote: >>>> To support network type rules, this modification renames ruleset's >>>> access masks and modifies it's type to access_masks_t. This patch >>>> adds filesystem helper functions to add and get filesystem mask. >>>> >>>> Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> >>>> --- >>>> >>>> Changes since v7: >>>> * Refactors commit message. >>>> >>>> Changes since v6: >>>> * Adds a new access_masks_t for struct ruleset. >>>> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >>>> because it OR values. >>>> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >>>> * Refactors landlock_get_fs_access_mask(). >>>> >>>> Changes since v6: >>>> * Adds a new access_masks_t for struct ruleset. >>>> * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() >>>> because it OR values. >>>> * Makes landlock_add_fs_access_mask() more resilient incorrect values. >>>> * Refactors landlock_get_fs_access_mask(). >>>> >>>> Changes since v5: >>>> * Changes access_mask_t to u32. >>>> * Formats code with clang-format-14. >>>> >>>> Changes since v4: >>>> * Deletes struct landlock_access_mask. >>>> >>>> Changes since v3: >>>> * Splits commit. >>>> * Adds get_mask, set_mask helpers for filesystem. >>>> * Adds new struct landlock_access_mask. >>>> >>>> --- >>>> security/landlock/fs.c | 10 +++++----- >>>> security/landlock/limits.h | 1 + >>>> security/landlock/ruleset.c | 17 +++++++++-------- >>>> security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- >>>> security/landlock/syscalls.c | 7 ++++--- >>>> 5 files changed, 50 insertions(+), 20 deletions(-) >>>> >>>> diff --git a/security/landlock/fs.c b/security/landlock/fs.c >>>> index adcea0fe7e68..0d57c6479d29 100644 >>>> --- a/security/landlock/fs.c >>>> +++ b/security/landlock/fs.c >>>> @@ -178,9 +178,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, >>>> return -EINVAL; >>>> >>>> /* Transforms relative access rights to absolute ones. */ >>>> - access_rights |= >>>> - LANDLOCK_MASK_ACCESS_FS & >>>> - ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); >>>> + access_rights |= LANDLOCK_MASK_ACCESS_FS & >>>> + ~(landlock_get_fs_access_mask(ruleset, 0) | >>>> + ACCESS_INITIALLY_DENIED); >>>> object = get_inode_object(d_backing_inode(path->dentry)); >>>> if (IS_ERR(object)) >>>> return PTR_ERR(object); >>>> @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) >>>> size_t layer_level; >>>> >>>> for (layer_level = 0; layer_level < domain->num_layers; layer_level++) >>>> - access_dom |= domain->fs_access_masks[layer_level]; >>>> + access_dom |= landlock_get_fs_access_mask(domain, layer_level); >>>> return access_dom & LANDLOCK_MASK_ACCESS_FS; >>> >>> You can remove `& LANDLOCK_MASK_ACCESS_FS` here because it is now part >>> of landlock_get_fs_access_mask(). >> >> Ok. I got it. Thanks. >>> >>> >>>> } >>>> >>>> @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, >>>> * access rights. >>>> */ >>>> if (BIT_ULL(access_bit) & >>>> - (domain->fs_access_masks[layer_level] | >>>> + (landlock_get_fs_access_mask(domain, layer_level) | >>>> ACCESS_INITIALLY_DENIED)) { >>>> (*layer_masks)[access_bit] |= >>>> BIT_ULL(layer_level); >>>> diff --git a/security/landlock/limits.h b/security/landlock/limits.h >>>> index 82288f0e9e5e..bafb3b8dc677 100644 >>>> --- a/security/landlock/limits.h >>>> +++ b/security/landlock/limits.h >>>> @@ -21,6 +21,7 @@ >>>> #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE >>>> #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) >>>> #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) >>>> +#define LANDLOCK_SHIFT_ACCESS_FS 0 >>>> >>>> /* clang-format on */ >>>> >>>> diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c >>>> index 996484f98bfd..1f3188b4e313 100644 >>>> --- a/security/landlock/ruleset.c >>>> +++ b/security/landlock/ruleset.c >>>> @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>>> struct landlock_ruleset *new_ruleset; >>>> >>>> new_ruleset = >>>> - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), >>>> + kzalloc(struct_size(new_ruleset, access_masks, num_layers), >>>> GFP_KERNEL_ACCOUNT); >>>> if (!new_ruleset) >>>> return ERR_PTR(-ENOMEM); >>>> @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) >>>> /* >>>> * hierarchy = NULL >>>> * num_rules = 0 >>>> - * fs_access_masks[] = 0 >>>> + * access_masks[] = 0 >>>> */ >>>> return new_ruleset; >>>> } >>>> @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) >>>> return ERR_PTR(-ENOMSG); >>>> new_ruleset = create_ruleset(1); >>>> if (!IS_ERR(new_ruleset)) >>>> - new_ruleset->fs_access_masks[0] = fs_access_mask; >>>> + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); >>>> return new_ruleset; >>>> } >>>> >>>> @@ -117,11 +117,12 @@ static void build_check_ruleset(void) >>>> .num_rules = ~0, >>>> .num_layers = ~0, >>>> }; >>>> - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; >>>> + typeof(ruleset.access_masks[0]) access_masks = ~0; >>>> >>>> BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); >>>> BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); >>>> - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); >>>> + BUILD_BUG_ON(access_masks < >>>> + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); >>>> } >>>> >>>> /** >>>> @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, >>>> err = -EINVAL; >>>> goto out_unlock; >>>> } >>>> - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; >>>> + 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, >>>> @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, >>>> goto out_unlock; >>>> } >>>> /* Copies the parent layer stack and leaves a space for the new layer. */ >>>> - memcpy(child->fs_access_masks, parent->fs_access_masks, >>>> - flex_array_size(parent, fs_access_masks, parent->num_layers)); >>>> + memcpy(child->access_masks, parent->access_masks, >>>> + flex_array_size(parent, access_masks, parent->num_layers)); >>>> >>>> if (WARN_ON_ONCE(!parent->hierarchy)) { >>>> err = -EINVAL; >>>> diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h >>>> index d43231b783e4..f2ad932d396c 100644 >>>> --- a/security/landlock/ruleset.h >>>> +++ b/security/landlock/ruleset.h >>>> @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); >>>> /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ >>>> static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); >>>> >>>> +/* Ruleset access masks. */ >>>> +typedef u16 access_masks_t; >>>> +/* Makes sure all ruleset access rights can be stored. */ >>>> +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); >>>> + >>>> typedef u16 layer_mask_t; >>>> /* Makes sure all layers can be checked. */ >>>> static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); >>>> @@ -110,7 +115,7 @@ struct landlock_ruleset { >>>> * section. This is only used by >>>> * landlock_put_ruleset_deferred() when @usage reaches zero. >>>> * The fields @lock, @usage, @num_rules, @num_layers and >>>> - * @fs_access_masks are then unused. >>>> + * @access_masks are then unused. >>>> */ >>>> struct work_struct work_free; >>>> struct { >>>> @@ -137,7 +142,7 @@ struct landlock_ruleset { >>>> */ >>>> u32 num_layers; >>>> /** >>>> - * @fs_access_masks: Contains the subset of filesystem >>>> + * @access_masks: Contains the subset of filesystem >>>> * actions that are restricted by a ruleset. A domain >>>> * saves all layers of merged rulesets in a stack >>>> * (FAM), starting from the first layer to the last >>>> @@ -148,13 +153,13 @@ struct landlock_ruleset { >>>> * layers are set once and never changed for the >>>> * lifetime of the ruleset. >>>> */ >>>> - access_mask_t fs_access_masks[]; >>>> + access_masks_t access_masks[]; >>>> }; >>>> }; >>>> }; >>>> >>>> struct landlock_ruleset * >>>> -landlock_create_ruleset(const access_mask_t fs_access_mask); >>>> +landlock_create_ruleset(const access_mask_t access_mask); >>>> >>>> void landlock_put_ruleset(struct landlock_ruleset *const ruleset); >>>> void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); >>>> @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) >>>> refcount_inc(&ruleset->usage); >>>> } >>>> >>>> +static inline void >>>> +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, >>>> + const access_mask_t fs_access_mask, >>>> + const u16 layer_level) >>>> +{ >>>> + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; >>>> + >>>> + /* Should already be checked in sys_landlock_create_ruleset(). */ >>>> + WARN_ON_ONCE(fs_access_mask != fs_mask); >>>> + // TODO: Add tests to check "|=" and not "=" >>> >>> This todo should be done and removed. No more todos must remain. >>> >> I delete it in 10/12 Patch when add network seltests. > > You can delete it in this patch then. I'm reviewing the tests. Ok. Thanks. > .
diff --git a/security/landlock/fs.c b/security/landlock/fs.c index adcea0fe7e68..0d57c6479d29 100644 --- a/security/landlock/fs.c +++ b/security/landlock/fs.c @@ -178,9 +178,9 @@ int landlock_append_fs_rule(struct landlock_ruleset *const ruleset, return -EINVAL; /* Transforms relative access rights to absolute ones. */ - access_rights |= - LANDLOCK_MASK_ACCESS_FS & - ~(ruleset->fs_access_masks[0] | ACCESS_INITIALLY_DENIED); + access_rights |= LANDLOCK_MASK_ACCESS_FS & + ~(landlock_get_fs_access_mask(ruleset, 0) | + ACCESS_INITIALLY_DENIED); object = get_inode_object(d_backing_inode(path->dentry)); if (IS_ERR(object)) return PTR_ERR(object); @@ -294,7 +294,7 @@ get_handled_accesses(const struct landlock_ruleset *const domain) size_t layer_level; for (layer_level = 0; layer_level < domain->num_layers; layer_level++) - access_dom |= domain->fs_access_masks[layer_level]; + access_dom |= landlock_get_fs_access_mask(domain, layer_level); return access_dom & LANDLOCK_MASK_ACCESS_FS; } @@ -336,7 +336,7 @@ init_layer_masks(const struct landlock_ruleset *const domain, * access rights. */ if (BIT_ULL(access_bit) & - (domain->fs_access_masks[layer_level] | + (landlock_get_fs_access_mask(domain, layer_level) | ACCESS_INITIALLY_DENIED)) { (*layer_masks)[access_bit] |= BIT_ULL(layer_level); diff --git a/security/landlock/limits.h b/security/landlock/limits.h index 82288f0e9e5e..bafb3b8dc677 100644 --- a/security/landlock/limits.h +++ b/security/landlock/limits.h @@ -21,6 +21,7 @@ #define LANDLOCK_LAST_ACCESS_FS LANDLOCK_ACCESS_FS_TRUNCATE #define LANDLOCK_MASK_ACCESS_FS ((LANDLOCK_LAST_ACCESS_FS << 1) - 1) #define LANDLOCK_NUM_ACCESS_FS __const_hweight64(LANDLOCK_MASK_ACCESS_FS) +#define LANDLOCK_SHIFT_ACCESS_FS 0 /* clang-format on */ diff --git a/security/landlock/ruleset.c b/security/landlock/ruleset.c index 996484f98bfd..1f3188b4e313 100644 --- a/security/landlock/ruleset.c +++ b/security/landlock/ruleset.c @@ -29,7 +29,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) struct landlock_ruleset *new_ruleset; new_ruleset = - kzalloc(struct_size(new_ruleset, fs_access_masks, num_layers), + kzalloc(struct_size(new_ruleset, access_masks, num_layers), GFP_KERNEL_ACCOUNT); if (!new_ruleset) return ERR_PTR(-ENOMEM); @@ -40,7 +40,7 @@ static struct landlock_ruleset *create_ruleset(const u32 num_layers) /* * hierarchy = NULL * num_rules = 0 - * fs_access_masks[] = 0 + * access_masks[] = 0 */ return new_ruleset; } @@ -55,7 +55,7 @@ landlock_create_ruleset(const access_mask_t fs_access_mask) return ERR_PTR(-ENOMSG); new_ruleset = create_ruleset(1); if (!IS_ERR(new_ruleset)) - new_ruleset->fs_access_masks[0] = fs_access_mask; + landlock_add_fs_access_mask(new_ruleset, fs_access_mask, 0); return new_ruleset; } @@ -117,11 +117,12 @@ static void build_check_ruleset(void) .num_rules = ~0, .num_layers = ~0, }; - typeof(ruleset.fs_access_masks[0]) fs_access_mask = ~0; + typeof(ruleset.access_masks[0]) access_masks = ~0; BUILD_BUG_ON(ruleset.num_rules < LANDLOCK_MAX_NUM_RULES); BUILD_BUG_ON(ruleset.num_layers < LANDLOCK_MAX_NUM_LAYERS); - BUILD_BUG_ON(fs_access_mask < LANDLOCK_MASK_ACCESS_FS); + BUILD_BUG_ON(access_masks < + (LANDLOCK_MASK_ACCESS_FS << LANDLOCK_SHIFT_ACCESS_FS)); } /** @@ -281,7 +282,7 @@ static int merge_ruleset(struct landlock_ruleset *const dst, err = -EINVAL; goto out_unlock; } - dst->fs_access_masks[dst->num_layers - 1] = src->fs_access_masks[0]; + 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, @@ -340,8 +341,8 @@ static int inherit_ruleset(struct landlock_ruleset *const parent, goto out_unlock; } /* Copies the parent layer stack and leaves a space for the new layer. */ - memcpy(child->fs_access_masks, parent->fs_access_masks, - flex_array_size(parent, fs_access_masks, parent->num_layers)); + memcpy(child->access_masks, parent->access_masks, + flex_array_size(parent, access_masks, parent->num_layers)); if (WARN_ON_ONCE(!parent->hierarchy)) { err = -EINVAL; diff --git a/security/landlock/ruleset.h b/security/landlock/ruleset.h index d43231b783e4..f2ad932d396c 100644 --- a/security/landlock/ruleset.h +++ b/security/landlock/ruleset.h @@ -25,6 +25,11 @@ static_assert(BITS_PER_TYPE(access_mask_t) >= LANDLOCK_NUM_ACCESS_FS); /* Makes sure for_each_set_bit() and for_each_clear_bit() calls are OK. */ static_assert(sizeof(unsigned long) >= sizeof(access_mask_t)); +/* Ruleset access masks. */ +typedef u16 access_masks_t; +/* Makes sure all ruleset access rights can be stored. */ +static_assert(BITS_PER_TYPE(access_masks_t) >= LANDLOCK_NUM_ACCESS_FS); + typedef u16 layer_mask_t; /* Makes sure all layers can be checked. */ static_assert(BITS_PER_TYPE(layer_mask_t) >= LANDLOCK_MAX_NUM_LAYERS); @@ -110,7 +115,7 @@ struct landlock_ruleset { * section. This is only used by * landlock_put_ruleset_deferred() when @usage reaches zero. * The fields @lock, @usage, @num_rules, @num_layers and - * @fs_access_masks are then unused. + * @access_masks are then unused. */ struct work_struct work_free; struct { @@ -137,7 +142,7 @@ struct landlock_ruleset { */ u32 num_layers; /** - * @fs_access_masks: Contains the subset of filesystem + * @access_masks: Contains the subset of filesystem * actions that are restricted by a ruleset. A domain * saves all layers of merged rulesets in a stack * (FAM), starting from the first layer to the last @@ -148,13 +153,13 @@ struct landlock_ruleset { * layers are set once and never changed for the * lifetime of the ruleset. */ - access_mask_t fs_access_masks[]; + access_masks_t access_masks[]; }; }; }; struct landlock_ruleset * -landlock_create_ruleset(const access_mask_t fs_access_mask); +landlock_create_ruleset(const access_mask_t access_mask); void landlock_put_ruleset(struct landlock_ruleset *const ruleset); void landlock_put_ruleset_deferred(struct landlock_ruleset *const ruleset); @@ -177,4 +182,26 @@ static inline void landlock_get_ruleset(struct landlock_ruleset *const ruleset) refcount_inc(&ruleset->usage); } +static inline void +landlock_add_fs_access_mask(struct landlock_ruleset *const ruleset, + const access_mask_t fs_access_mask, + const u16 layer_level) +{ + access_mask_t fs_mask = fs_access_mask & LANDLOCK_MASK_ACCESS_FS; + + /* Should already be checked in sys_landlock_create_ruleset(). */ + WARN_ON_ONCE(fs_access_mask != fs_mask); + // TODO: Add tests to check "|=" and not "=" + ruleset->access_masks[layer_level] |= + (fs_mask << LANDLOCK_SHIFT_ACCESS_FS); +} + +static inline access_mask_t +landlock_get_fs_access_mask(const struct landlock_ruleset *const ruleset, + const u16 layer_level) +{ + return (ruleset->access_masks[layer_level] >> + LANDLOCK_SHIFT_ACCESS_FS) & + LANDLOCK_MASK_ACCESS_FS; +} #endif /* _SECURITY_LANDLOCK_RULESET_H */ diff --git a/security/landlock/syscalls.c b/security/landlock/syscalls.c index 245cc650a4dc..71aca7f990bc 100644 --- a/security/landlock/syscalls.c +++ b/security/landlock/syscalls.c @@ -346,10 +346,11 @@ SYSCALL_DEFINE4(landlock_add_rule, const int, ruleset_fd, } /* * Checks that allowed_access matches the @ruleset constraints - * (ruleset->fs_access_masks[0] is automatically upgraded to 64-bits). + * (ruleset->access_masks[0] is automatically upgraded to 64-bits). */ - if ((path_beneath_attr.allowed_access | ruleset->fs_access_masks[0]) != - ruleset->fs_access_masks[0]) { + if ((path_beneath_attr.allowed_access | + landlock_get_fs_access_mask(ruleset, 0)) != + landlock_get_fs_access_mask(ruleset, 0)) { err = -EINVAL; goto out_put_ruleset; }
To support network type rules, this modification renames ruleset's access masks and modifies it's type to access_masks_t. This patch adds filesystem helper functions to add and get filesystem mask. Signed-off-by: Konstantin Meskhidze <konstantin.meskhidze@huawei.com> --- Changes since v7: * Refactors commit message. Changes since v6: * Adds a new access_masks_t for struct ruleset. * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() because it OR values. * Makes landlock_add_fs_access_mask() more resilient incorrect values. * Refactors landlock_get_fs_access_mask(). Changes since v6: * Adds a new access_masks_t for struct ruleset. * Renames landlock_set_fs_access_mask() to landlock_add_fs_access_mask() because it OR values. * Makes landlock_add_fs_access_mask() more resilient incorrect values. * Refactors landlock_get_fs_access_mask(). Changes since v5: * Changes access_mask_t to u32. * Formats code with clang-format-14. Changes since v4: * Deletes struct landlock_access_mask. Changes since v3: * Splits commit. * Adds get_mask, set_mask helpers for filesystem. * Adds new struct landlock_access_mask. --- security/landlock/fs.c | 10 +++++----- security/landlock/limits.h | 1 + security/landlock/ruleset.c | 17 +++++++++-------- security/landlock/ruleset.h | 35 +++++++++++++++++++++++++++++++---- security/landlock/syscalls.c | 7 ++++--- 5 files changed, 50 insertions(+), 20 deletions(-) -- 2.25.1