Re: [PATCH v15 04/23] LSM: Use lsmblob in security_kernel_act_as
From: Paul Moore <paul@paul-moore.com>
Date: 2020-03-06 22:06:49
Also in:
selinux
On Fri, Feb 14, 2020 at 6:42 PM Casey Schaufler [off-list ref] 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 <redacted> Reviewed-by: John Johansen <john.johansen@canonical.com> Acked-by: Stephen Smalley <redacted> 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(-)
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quoted hunk ↗ jump to hunk
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);
-- paul moore www.paul-moore.com