diff options
Diffstat (limited to 'meta-agl-bsp/recipes-kernel/linux/linux-4.14/Smack-Privilege-check-on-key-operations.patch')
| -rw-r--r-- | meta-agl-bsp/recipes-kernel/linux/linux-4.14/Smack-Privilege-check-on-key-operations.patch | 109 |
1 files changed, 109 insertions, 0 deletions
diff --git a/meta-agl-bsp/recipes-kernel/linux/linux-4.14/Smack-Privilege-check-on-key-operations.patch b/meta-agl-bsp/recipes-kernel/linux/linux-4.14/Smack-Privilege-check-on-key-operations.patch new file mode 100644 index 000000000..4100bb8fd --- /dev/null +++ b/meta-agl-bsp/recipes-kernel/linux/linux-4.14/Smack-Privilege-check-on-key-operations.patch @@ -0,0 +1,109 @@ +Smack: Privilege check on key operations + +Operations on key objects are subjected to Smack policy +even if the process is privileged. This is inconsistent +with the general behavior of Smack and may cause issues +with authentication by privileged daemons. This patch +allows processes with CAP_MAC_OVERRIDE to access keys +even if the Smack rules indicate otherwise. + +Reported-by: Jose Bollo <jobol@nonadev.net> +Signed-off-by: Casey Schaufler <casey@schaufler-ca.com> +--- + security/smack/smack.h | 1 + + security/smack/smack_access.c | 40 +++++++++++++++++++++++++++++----------- + security/smack/smack_lsm.c | 4 ++++ + 3 files changed, 34 insertions(+), 11 deletions(-) + +diff --git a/security/smack/smack.h b/security/smack/smack.h +index 6a71fc7..f7db791 100644 +--- a/security/smack/smack.h ++++ b/security/smack/smack.h +@@ -321,6 +321,7 @@ struct smack_known *smk_import_entry(const char *, int); + void smk_insert_entry(struct smack_known *skp); + struct smack_known *smk_find_entry(const char *); + bool smack_privileged(int cap); ++bool smack_privileged_cred(int cap, const struct cred *cred); + void smk_destroy_label_list(struct list_head *list); + + /* +diff --git a/security/smack/smack_access.c b/security/smack/smack_access.c +index 1a30041..141ffac 100644 +--- a/security/smack/smack_access.c ++++ b/security/smack/smack_access.c +@@ -623,26 +623,24 @@ struct smack_known *smack_from_secid(const u32 secid) + LIST_HEAD(smack_onlycap_list); + DEFINE_MUTEX(smack_onlycap_lock); + +-/* ++/** ++ * smack_privileged_cred - are all privilege requirements met by cred ++ * @cap: The requested capability ++ * @cred: the credential to use ++ * + * Is the task privileged and allowed to be privileged + * by the onlycap rule. + * + * Returns true if the task is allowed to be privileged, false if it's not. + */ +-bool smack_privileged(int cap) ++bool smack_privileged_cred(int cap, const struct cred *cred) + { +- struct smack_known *skp = smk_of_current(); ++ struct task_smack *tsp = cred->security; ++ struct smack_known *skp = tsp->smk_task; + struct smack_known_list_elem *sklep; + int rc; + +- /* +- * All kernel tasks are privileged +- */ +- if (unlikely(current->flags & PF_KTHREAD)) +- return true; +- +- rc = cap_capable(current_cred(), &init_user_ns, cap, +- SECURITY_CAP_AUDIT); ++ rc = cap_capable(cred, &init_user_ns, cap, SECURITY_CAP_AUDIT); + if (rc) + return false; + +@@ -662,3 +660,23 @@ bool smack_privileged(int cap) + + return false; + } ++ ++/** ++ * smack_privileged - are all privilege requirements met ++ * @cap: The requested capability ++ * ++ * Is the task privileged and allowed to be privileged ++ * by the onlycap rule. ++ * ++ * Returns true if the task is allowed to be privileged, false if it's not. ++ */ ++bool smack_privileged(int cap) ++{ ++ /* ++ * All kernel tasks are privileged ++ */ ++ if (unlikely(current->flags & PF_KTHREAD)) ++ return true; ++ ++ return smack_privileged_cred(cap, current_cred()); ++} +diff --git a/security/smack/smack_lsm.c b/security/smack/smack_lsm.c +index 30f2c3d..03fdecb 100644 +--- a/security/smack/smack_lsm.c ++++ b/security/smack/smack_lsm.c +@@ -4369,6 +4369,10 @@ static int smack_key_permission(key_ref_t key_ref, + */ + if (tkp == NULL) + return -EACCES; ++ ++ if (smack_privileged_cred(CAP_MAC_OVERRIDE, cred)) ++ return 0; ++ + #ifdef CONFIG_AUDIT + smk_ad_init(&ad, __func__, LSM_AUDIT_DATA_KEY); + ad.a.u.key_struct.key = keyp->serial; + |