| Message ID | 20200214234203.7086-5-casey@schaufler-ca.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | LSM: Module stacking for AppArmor | expand |
On Fri, Feb 14, 2020 at 6:42 PM Casey Schaufler <casey@schaufler-ca.com> wrote: > > Change the security_kernel_act_as interface to use a lsmblob > structure in place of the single u32 secid in support of > module stacking. Change its only caller, set_security_override, > to do the same. Change that one's only caller, > set_security_override_from_ctx, to call it with the new > parameter type. > > Reviewed-by: Kees Cook <keescook@chromium.org> > Reviewed-by: John Johansen <john.johansen@canonical.com> > Acked-by: Stephen Smalley <sds@tycho.nsa.gov> > Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> > --- > include/linux/cred.h | 3 ++- > include/linux/security.h | 5 +++-- > kernel/cred.c | 10 ++++++---- > security/security.c | 14 ++++++++++++-- > 4 files changed, 23 insertions(+), 9 deletions(-) ... > diff --git a/include/linux/security.h b/include/linux/security.h > index 9d83c6832bae..1bfaf9ece13e 100644 > --- a/include/linux/security.h > +++ b/include/linux/security.h > @@ -439,7 +439,7 @@ void security_cred_free(struct cred *cred); > int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); > void security_transfer_creds(struct cred *new, const struct cred *old); > void security_cred_getsecid(const struct cred *c, u32 *secid); > -int security_kernel_act_as(struct cred *new, u32 secid); > +int security_kernel_act_as(struct cred *new, struct lsmblob *blob); > int security_kernel_create_files_as(struct cred *new, struct inode *inode); > int security_kernel_module_request(char *kmod_name); > int security_kernel_load_data(enum kernel_load_data_id id); > @@ -1045,7 +1045,8 @@ static inline void security_transfer_creds(struct cred *new, > { > } > > -static inline int security_kernel_act_as(struct cred *cred, u32 secid) > +static inline int security_kernel_act_as(struct cred *cred, > + struct lsmblob *blob) > { > return 0; > } > diff --git a/kernel/cred.c b/kernel/cred.c > index 809a985b1793..fae63c0a1b36 100644 > --- a/kernel/cred.c > +++ b/kernel/cred.c > @@ -732,14 +732,14 @@ EXPORT_SYMBOL(prepare_kernel_cred); > /** > * set_security_override - Set the security ID in a set of credentials > * @new: The credentials to alter > - * @secid: The LSM security ID to set > + * @blob: The LSM security information to set > * > * Set the LSM security ID in a set of credentials so that the subjective > * security is overridden when an alternative set of credentials is used. > */ > -int set_security_override(struct cred *new, u32 secid) > +int set_security_override(struct cred *new, struct lsmblob *blob) > { > - return security_kernel_act_as(new, secid); > + return security_kernel_act_as(new, blob); > } > EXPORT_SYMBOL(set_security_override); > > @@ -755,6 +755,7 @@ EXPORT_SYMBOL(set_security_override); > */ > int set_security_override_from_ctx(struct cred *new, const char *secctx) > { > + struct lsmblob blob; > u32 secid; > int ret; > > @@ -762,7 +763,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx) > if (ret < 0) > return ret; > > - return set_security_override(new, secid); > + lsmblob_init(&blob, secid); > + return set_security_override(new, &blob); See my comments in 03/23, this is another case where the value of lsmblob is not yet clear to me, but perhaps it will make sense later in the patchset. > } > EXPORT_SYMBOL(set_security_override_from_ctx);
diff --git a/include/linux/cred.h b/include/linux/cred.h index 18639c069263..03ae0182cba6 100644 --- a/include/linux/cred.h +++ b/include/linux/cred.h @@ -18,6 +18,7 @@ struct cred; struct inode; +struct lsmblob; /* * COW Supplementary groups list @@ -165,7 +166,7 @@ extern const struct cred *override_creds(const struct cred *); extern void revert_creds(const struct cred *); extern struct cred *prepare_kernel_cred(struct task_struct *); extern int change_create_files_as(struct cred *, struct inode *); -extern int set_security_override(struct cred *, u32); +extern int set_security_override(struct cred *, struct lsmblob *); extern int set_security_override_from_ctx(struct cred *, const char *); extern int set_create_files_as(struct cred *, struct inode *); extern int cred_fscmp(const struct cred *, const struct cred *); diff --git a/include/linux/security.h b/include/linux/security.h index 9d83c6832bae..1bfaf9ece13e 100644 --- a/include/linux/security.h +++ b/include/linux/security.h @@ -439,7 +439,7 @@ void security_cred_free(struct cred *cred); int security_prepare_creds(struct cred *new, const struct cred *old, gfp_t gfp); void security_transfer_creds(struct cred *new, const struct cred *old); void security_cred_getsecid(const struct cred *c, u32 *secid); -int security_kernel_act_as(struct cred *new, u32 secid); +int security_kernel_act_as(struct cred *new, struct lsmblob *blob); int security_kernel_create_files_as(struct cred *new, struct inode *inode); int security_kernel_module_request(char *kmod_name); int security_kernel_load_data(enum kernel_load_data_id id); @@ -1045,7 +1045,8 @@ static inline void security_transfer_creds(struct cred *new, { } -static inline int security_kernel_act_as(struct cred *cred, u32 secid) +static inline int security_kernel_act_as(struct cred *cred, + struct lsmblob *blob) { return 0; } diff --git a/kernel/cred.c b/kernel/cred.c index 809a985b1793..fae63c0a1b36 100644 --- a/kernel/cred.c +++ b/kernel/cred.c @@ -732,14 +732,14 @@ EXPORT_SYMBOL(prepare_kernel_cred); /** * set_security_override - Set the security ID in a set of credentials * @new: The credentials to alter - * @secid: The LSM security ID to set + * @blob: The LSM security information to set * * Set the LSM security ID in a set of credentials so that the subjective * security is overridden when an alternative set of credentials is used. */ -int set_security_override(struct cred *new, u32 secid) +int set_security_override(struct cred *new, struct lsmblob *blob) { - return security_kernel_act_as(new, secid); + return security_kernel_act_as(new, blob); } EXPORT_SYMBOL(set_security_override); @@ -755,6 +755,7 @@ EXPORT_SYMBOL(set_security_override); */ int set_security_override_from_ctx(struct cred *new, const char *secctx) { + struct lsmblob blob; u32 secid; int ret; @@ -762,7 +763,8 @@ int set_security_override_from_ctx(struct cred *new, const char *secctx) if (ret < 0) return ret; - return set_security_override(new, secid); + lsmblob_init(&blob, secid); + return set_security_override(new, &blob); } EXPORT_SYMBOL(set_security_override_from_ctx); diff --git a/security/security.c b/security/security.c index b3fab8fdbb57..914aecd89822 100644 --- a/security/security.c +++ b/security/security.c @@ -1647,9 +1647,19 @@ void security_cred_getsecid(const struct cred *c, u32 *secid) } EXPORT_SYMBOL(security_cred_getsecid); -int security_kernel_act_as(struct cred *new, u32 secid) +int security_kernel_act_as(struct cred *new, struct lsmblob *blob) { - return call_int_hook(kernel_act_as, 0, new, secid); + struct security_hook_list *hp; + int rc; + + hlist_for_each_entry(hp, &security_hook_heads.kernel_act_as, list) { + if (WARN_ON(hp->lsmid->slot < 0 || hp->lsmid->slot >= lsm_slot)) + continue; + rc = hp->hook.kernel_act_as(new, blob->secid[hp->lsmid->slot]); + if (rc != 0) + return rc; + } + return 0; } int security_kernel_create_files_as(struct cred *new, struct inode *inode)