From 652bb9b0d6ce007f37c098947b2cc0c45efa3f66 Mon Sep 17 00:00:00 2001 From: Eric Paris Date: Tue, 1 Feb 2011 11:05:40 -0500 Subject: SELinux: Use dentry name in new object labeling Currently SELinux has rules which label new objects according to 3 criteria. The label of the process creating the object, the label of the parent directory, and the type of object (reg, dir, char, block, etc.) This patch adds a 4th criteria, the dentry name, thus we can distinguish between creating a file in an etc_t directory called shadow and one called motd. There is no file globbing, regex parsing, or anything mystical. Either the policy exactly (strcmp) matches the dentry name of the object or it doesn't. This patch has no changes from today if policy does not implement the new rules. Signed-off-by: Eric Paris --- security/selinux/ss/services.c | 45 +++++++++++++++++++++++++++++------------- 1 file changed, 31 insertions(+), 14 deletions(-) (limited to 'security/selinux/ss/services.c') diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index a03cfaf0ee0..2e36e03c21f 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -1343,10 +1343,27 @@ out: return -EACCES; } +static void filename_compute_type(struct policydb *p, struct context *newcontext, + u32 scon, u32 tcon, u16 tclass, + const struct qstr *qstr) +{ + struct filename_trans *ft; + for (ft = p->filename_trans; ft; ft = ft->next) { + if (ft->stype == scon && + ft->ttype == tcon && + ft->tclass == tclass && + !strcmp(ft->name, qstr->name)) { + newcontext->type = ft->otype; + return; + } + } +} + static int security_compute_sid(u32 ssid, u32 tsid, u16 orig_tclass, u32 specified, + const struct qstr *qstr, u32 *out_sid, bool kern) { @@ -1442,6 +1459,11 @@ static int security_compute_sid(u32 ssid, newcontext.type = avdatum->data; } + /* if we have a qstr this is a file trans check so check those rules */ + if (qstr) + filename_compute_type(&policydb, &newcontext, scontext->type, + tcontext->type, tclass, qstr); + /* Check for class-specific changes. */ if (tclass == policydb.process_class) { if (specified & AVTAB_TRANSITION) { @@ -1495,22 +1517,17 @@ out: * if insufficient memory is available, or %0 if the new SID was * computed successfully. */ -int security_transition_sid(u32 ssid, - u32 tsid, - u16 tclass, - u32 *out_sid) +int security_transition_sid(u32 ssid, u32 tsid, u16 tclass, + const struct qstr *qstr, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, - out_sid, true); + qstr, out_sid, true); } -int security_transition_sid_user(u32 ssid, - u32 tsid, - u16 tclass, - u32 *out_sid) +int security_transition_sid_user(u32 ssid, u32 tsid, u16 tclass, u32 *out_sid) { return security_compute_sid(ssid, tsid, tclass, AVTAB_TRANSITION, - out_sid, false); + NULL, out_sid, false); } /** @@ -1531,8 +1548,8 @@ int security_member_sid(u32 ssid, u16 tclass, u32 *out_sid) { - return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, out_sid, - false); + return security_compute_sid(ssid, tsid, tclass, AVTAB_MEMBER, NULL, + out_sid, false); } /** @@ -1553,8 +1570,8 @@ int security_change_sid(u32 ssid, u16 tclass, u32 *out_sid) { - return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, out_sid, - false); + return security_compute_sid(ssid, tsid, tclass, AVTAB_CHANGE, NULL, + out_sid, false); } /* Clone the SID into the new SID table. */ -- cgit v1.2.3-70-g09d2 From 6f5317e730505d5cbc851c435a2dfe3d5a21d343 Mon Sep 17 00:00:00 2001 From: Harry Ciao Date: Wed, 2 Mar 2011 13:32:33 +0800 Subject: SELinux: Socket retains creator role and MLS attribute The socket SID would be computed on creation and no longer inherit its creator's SID by default. Socket may have a different type but needs to retain the creator's role and MLS attribute in order not to break labeled networking and network access control. The kernel value for a class would be used to determine if the class if one of socket classes. If security_compute_sid is called from userspace the policy value for a class would be mapped to the relevant kernel value first. Signed-off-by: Harry Ciao Signed-off-by: Eric Paris Acked-by: Stephen Smalley --- security/selinux/ss/mls.c | 5 +++-- security/selinux/ss/mls.h | 3 ++- security/selinux/ss/services.c | 28 ++++++++++++++++++++++++---- 3 files changed, 29 insertions(+), 7 deletions(-) (limited to 'security/selinux/ss/services.c') diff --git a/security/selinux/ss/mls.c b/security/selinux/ss/mls.c index 1ef8e4e8988..e96174216bc 100644 --- a/security/selinux/ss/mls.c +++ b/security/selinux/ss/mls.c @@ -512,7 +512,8 @@ int mls_compute_sid(struct context *scontext, struct context *tcontext, u16 tclass, u32 specified, - struct context *newcontext) + struct context *newcontext, + bool sock) { struct range_trans rtr; struct mls_range *r; @@ -531,7 +532,7 @@ int mls_compute_sid(struct context *scontext, return mls_range_set(newcontext, r); /* Fallthrough */ case AVTAB_CHANGE: - if (tclass == policydb.process_class) + if ((tclass == policydb.process_class) || (sock == true)) /* Use the process MLS attributes. */ return mls_context_cpy(newcontext, scontext); else diff --git a/security/selinux/ss/mls.h b/security/selinux/ss/mls.h index cd9152632e5..037bf9d82d4 100644 --- a/security/selinux/ss/mls.h +++ b/security/selinux/ss/mls.h @@ -49,7 +49,8 @@ int mls_compute_sid(struct context *scontext, struct context *tcontext, u16 tclass, u32 specified, - struct context *newcontext); + struct context *newcontext, + bool sock); int mls_setup_user_range(struct context *fromcon, struct user_datum *user, struct context *usercon); diff --git a/security/selinux/ss/services.c b/security/selinux/ss/services.c index 2e36e03c21f..3e7544d2a07 100644 --- a/security/selinux/ss/services.c +++ b/security/selinux/ss/services.c @@ -201,6 +201,21 @@ static u16 unmap_class(u16 tclass) return tclass; } +/* + * Get kernel value for class from its policy value + */ +static u16 map_class(u16 pol_value) +{ + u16 i; + + for (i = 1; i < current_mapping_size; i++) { + if (current_mapping[i].value == pol_value) + return i; + } + + return pol_value; +} + static void map_decision(u16 tclass, struct av_decision *avd, int allow_unknown) { @@ -1374,6 +1389,7 @@ static int security_compute_sid(u32 ssid, struct avtab_node *node; u16 tclass; int rc = 0; + bool sock; if (!ss_initialized) { switch (orig_tclass) { @@ -1391,10 +1407,13 @@ static int security_compute_sid(u32 ssid, read_lock(&policy_rwlock); - if (kern) + if (kern) { tclass = unmap_class(orig_tclass); - else + sock = security_is_socket_class(orig_tclass); + } else { tclass = orig_tclass; + sock = security_is_socket_class(map_class(tclass)); + } scontext = sidtab_search(&sidtab, ssid); if (!scontext) { @@ -1425,7 +1444,7 @@ static int security_compute_sid(u32 ssid, } /* Set the role and type to default values. */ - if (tclass == policydb.process_class) { + if ((tclass == policydb.process_class) || (sock == true)) { /* Use the current role and type of process. */ newcontext.role = scontext->role; newcontext.type = scontext->type; @@ -1482,7 +1501,8 @@ static int security_compute_sid(u32 ssid, /* Set the MLS attributes. This is done last because it may allocate memory. */ - rc = mls_compute_sid(scontext, tcontext, tclass, specified, &newcontext); + rc = mls_compute_sid(scontext, tcontext, tclass, specified, + &newcontext, sock); if (rc) goto out_unlock; -- cgit v1.2.3-70-g09d2