diff options
| -rw-r--r-- | security/selinux/hooks.c | 47 | ||||
| -rw-r--r-- | security/selinux/include/classmap.h | 2 | ||||
| -rw-r--r-- | security/selinux/include/security.h | 2 | ||||
| -rw-r--r-- | security/selinux/ss/services.c | 7 |
4 files changed, 42 insertions, 16 deletions
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c index 00ad46e..04b8e10 100644 --- a/security/selinux/hooks.c +++ b/security/selinux/hooks.c @@ -2318,6 +2318,7 @@ static int check_nnp_nosuid(const struct linux_binprm *bprm, int nnp = (bprm->unsafe & LSM_UNSAFE_NO_NEW_PRIVS); int nosuid = !mnt_may_suid(bprm->file->f_path.mnt); int rc; + u32 av; if (!nnp && !nosuid) return 0; /* neither NNP nor nosuid */ @@ -2326,24 +2327,40 @@ static int check_nnp_nosuid(const struct linux_binprm *bprm, return 0; /* No change in credentials */ /* - * The only transitions we permit under NNP or nosuid - * are transitions to bounded SIDs, i.e. SIDs that are - * guaranteed to only be allowed a subset of the permissions - * of the current SID. + * If the policy enables the nnp_nosuid_transition policy capability, + * then we permit transitions under NNP or nosuid if the + * policy allows the corresponding permission between + * the old and new contexts. */ - rc = security_bounded_transition(old_tsec->sid, new_tsec->sid); - if (rc) { - /* - * On failure, preserve the errno values for NNP vs nosuid. - * NNP: Operation not permitted for caller. - * nosuid: Permission denied to file. - */ + if (selinux_policycap_nnp_nosuid_transition) { + av = 0; if (nnp) - return -EPERM; - else - return -EACCES; + av |= PROCESS2__NNP_TRANSITION; + if (nosuid) + av |= PROCESS2__NOSUID_TRANSITION; + rc = avc_has_perm(old_tsec->sid, new_tsec->sid, + SECCLASS_PROCESS2, av, NULL); + if (!rc) + return 0; } - return 0; + + /* + * We also permit NNP or nosuid transitions to bounded SIDs, + * i.e. SIDs that are guaranteed to only be allowed a subset + * of the permissions of the current SID. + */ + rc = security_bounded_transition(old_tsec->sid, new_tsec->sid); + if (!rc) + return 0; + + /* + * On failure, preserve the errno values for NNP vs nosuid. + * NNP: Operation not permitted for caller. + * nosuid: Permission denied to file. + */ + if (nnp) + return -EPERM; + return -EACCES; } static int selinux_bprm_set_creds(struct linux_binprm *bprm) diff --git a/security/selinux/include/classmap.h b/security/selinux/include/classmap.h index b9fe343..35ffb29 100644 --- a/security/selinux/include/classmap.h +++ b/security/selinux/include/classmap.h @@ -48,6 +48,8 @@ struct security_class_mapping secclass_map[] = { "setrlimit", "rlimitinh", "dyntransition", "setcurrent", "execmem", "execstack", "execheap", "setkeycreate", "setsockcreate", "getrlimit", NULL } }, + { "process2", + { "nnp_transition", "nosuid_transition", NULL } }, { "system", { "ipc_info", "syslog_read", "syslog_mod", "syslog_console", "module_request", "module_load", NULL } }, diff --git a/security/selinux/include/security.h b/security/selinux/include/security.h index e91f08c..3e32317 100644 --- a/security/selinux/include/security.h +++ b/security/selinux/include/security.h @@ -73,6 +73,7 @@ enum { POLICYDB_CAPABILITY_EXTSOCKCLASS, POLICYDB_CAPABILITY_ALWAYSNETWORK, POLICYDB_CAPABILITY_CGROUPSECLABEL, + POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION, __POLICYDB_CAPABILITY_MAX }; #define POLICYDB_CAPABILITY_MAX (__POLICYDB_CAPABILITY_MAX - 1) @@ -84,6 +85,7 @@ extern int selinux_policycap_openperm; extern int selinux_policycap_extsockclass; extern int selinux_policycap_alwaysnetwork; extern int selinux_policycap_cgroupseclabel; +extern int selinux_policycap_nnp_nosuid_transition; /* * type_datum properties diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 2f02fa6..16c55de 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -76,7 +76,8 @@ char *selinux_policycap_names[__POLICYDB_CAPABILITY_MAX] = { "open_perms", "extended_socket_class", "always_check_network", - "cgroup_seclabel" + "cgroup_seclabel", + "nnp_nosuid_transition" }; int selinux_policycap_netpeer; @@ -84,6 +85,7 @@ int selinux_policycap_openperm; int selinux_policycap_extsockclass; int selinux_policycap_alwaysnetwork; int selinux_policycap_cgroupseclabel; +int selinux_policycap_nnp_nosuid_transition; static DEFINE_RWLOCK(policy_rwlock); @@ -2009,6 +2011,9 @@ static void security_load_policycaps(void) selinux_policycap_cgroupseclabel = ebitmap_get_bit(&policydb.policycaps, POLICYDB_CAPABILITY_CGROUPSECLABEL); + selinux_policycap_nnp_nosuid_transition = + ebitmap_get_bit(&policydb.policycaps, + POLICYDB_CAPABILITY_NNP_NOSUID_TRANSITION); for (i = 0; i < ARRAY_SIZE(selinux_policycap_names); i++) pr_info("SELinux: policy capability %s=%d\n", |
