From 69b5a44a95bb86f3ad8a50bf2e354057ec450082 Mon Sep 17 00:00:00 2001 From: Casey Schaufler Date: Fri, 21 Sep 2018 17:17:59 -0700 Subject: AppArmor: Abstract use of cred security blob Don't use the cred->security pointer directly. Provide a helper function that provides the security blob pointer. Signed-off-by: Casey Schaufler Reviewed-by: Kees Cook [kees: adjusted for ordered init series] Signed-off-by: Kees Cook --- security/apparmor/domain.c | 2 +- security/apparmor/include/cred.h | 16 +++++++++++++++- security/apparmor/lsm.c | 10 +++++----- security/apparmor/task.c | 6 +++--- 4 files changed, 24 insertions(+), 10 deletions(-) diff --git a/security/apparmor/domain.c b/security/apparmor/domain.c index 08c88de0ffda..726910bba84b 100644 --- a/security/apparmor/domain.c +++ b/security/apparmor/domain.c @@ -975,7 +975,7 @@ int apparmor_bprm_set_creds(struct linux_binprm *bprm) } aa_put_label(cred_label(bprm->cred)); /* transfer reference, released when cred is freed */ - cred_label(bprm->cred) = new; + set_cred_label(bprm->cred, new); done: aa_put_label(label); diff --git a/security/apparmor/include/cred.h b/security/apparmor/include/cred.h index 265ae6641a06..a757370f2a0c 100644 --- a/security/apparmor/include/cred.h +++ b/security/apparmor/include/cred.h @@ -23,8 +23,22 @@ #include "policy_ns.h" #include "task.h" -#define cred_label(X) ((X)->security) +static inline struct aa_label *cred_label(const struct cred *cred) +{ + struct aa_label **blob = cred->security; + + AA_BUG(!blob); + return *blob; +} +static inline void set_cred_label(const struct cred *cred, + struct aa_label *label) +{ + struct aa_label **blob = cred->security; + + AA_BUG(!blob); + *blob = label; +} /** * aa_cred_raw_label - obtain cred's label diff --git a/security/apparmor/lsm.c b/security/apparmor/lsm.c index cda345767cfc..8c2cb4b1a6c3 100644 --- a/security/apparmor/lsm.c +++ b/security/apparmor/lsm.c @@ -60,7 +60,7 @@ DEFINE_PER_CPU(struct aa_buffers, aa_buffers); static void apparmor_cred_free(struct cred *cred) { aa_put_label(cred_label(cred)); - cred_label(cred) = NULL; + set_cred_label(cred, NULL); } /* @@ -68,7 +68,7 @@ static void apparmor_cred_free(struct cred *cred) */ static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) { - cred_label(cred) = NULL; + set_cred_label(cred, NULL); return 0; } @@ -78,7 +78,7 @@ static int apparmor_cred_alloc_blank(struct cred *cred, gfp_t gfp) static int apparmor_cred_prepare(struct cred *new, const struct cred *old, gfp_t gfp) { - cred_label(new) = aa_get_newest_label(cred_label(old)); + set_cred_label(new, aa_get_newest_label(cred_label(old))); return 0; } @@ -87,7 +87,7 @@ static int apparmor_cred_prepare(struct cred *new, const struct cred *old, */ static void apparmor_cred_transfer(struct cred *new, const struct cred *old) { - cred_label(new) = aa_get_newest_label(cred_label(old)); + set_cred_label(new, aa_get_newest_label(cred_label(old))); } static void apparmor_task_free(struct task_struct *task) @@ -1485,7 +1485,7 @@ static int __init set_init_ctx(void) if (!ctx) return -ENOMEM; - cred_label(cred) = aa_get_label(ns_unconfined(root_ns)); + set_cred_label(cred, aa_get_label(ns_unconfined(root_ns))); task_ctx(current) = ctx; return 0; diff --git a/security/apparmor/task.c b/security/apparmor/task.c index c6b78a14da91..4551110f0496 100644 --- a/security/apparmor/task.c +++ b/security/apparmor/task.c @@ -81,7 +81,7 @@ int aa_replace_current_label(struct aa_label *label) */ aa_get_label(label); aa_put_label(cred_label(new)); - cred_label(new) = label; + set_cred_label(new, label); commit_creds(new); return 0; @@ -138,7 +138,7 @@ int aa_set_current_hat(struct aa_label *label, u64 token) return -EACCES; } - cred_label(new) = aa_get_newest_label(label); + set_cred_label(new, aa_get_newest_label(label)); /* clear exec on switching context */ aa_put_label(ctx->onexec); ctx->onexec = NULL; @@ -172,7 +172,7 @@ int aa_restore_previous_label(u64 token) return -ENOMEM; aa_put_label(cred_label(new)); - cred_label(new) = aa_get_newest_label(ctx->previous); + set_cred_label(new, aa_get_newest_label(ctx->previous)); AA_BUG(!cred_label(new)); /* clear exec && prev information when restoring to previous context */ aa_clear_task_ctx_trans(ctx); -- cgit v1.2.3