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-rw-r--r--security/selinux/avc.c61
1 files changed, 34 insertions, 27 deletions
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index cc0b0af20296..1f2680bcc43a 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -174,13 +174,15 @@ int avc_get_hash_stats(char *page)
* using a linked list for extended_perms_decision lookup because the list is
* always small. i.e. less than 5, typically 1
*/
-static struct extended_perms_decision *avc_xperms_decision_lookup(u8 driver,
- struct avc_xperms_node *xp_node)
+static struct extended_perms_decision *
+avc_xperms_decision_lookup(u8 driver, u8 base_perm,
+ struct avc_xperms_node *xp_node)
{
struct avc_xperms_decision_node *xpd_node;
list_for_each_entry(xpd_node, &xp_node->xpd_head, xpd_list) {
- if (xpd_node->xpd.driver == driver)
+ if (xpd_node->xpd.driver == driver &&
+ xpd_node->xpd.base_perm == base_perm)
return &xpd_node->xpd;
}
return NULL;
@@ -205,11 +207,12 @@ avc_xperms_has_perm(struct extended_perms_decision *xpd,
}
static void avc_xperms_allow_perm(struct avc_xperms_node *xp_node,
- u8 driver, u8 perm)
+ u8 driver, u8 base_perm, u8 perm)
{
struct extended_perms_decision *xpd;
security_xperm_set(xp_node->xp.drivers.p, driver);
- xpd = avc_xperms_decision_lookup(driver, xp_node);
+ xp_node->xp.base_perms |= base_perm;
+ xpd = avc_xperms_decision_lookup(driver, base_perm, xp_node);
if (xpd && xpd->allowed)
security_xperm_set(xpd->allowed->p, perm);
}
@@ -245,6 +248,7 @@ static void avc_xperms_free(struct avc_xperms_node *xp_node)
static void avc_copy_xperms_decision(struct extended_perms_decision *dest,
struct extended_perms_decision *src)
{
+ dest->base_perm = src->base_perm;
dest->driver = src->driver;
dest->used = src->used;
if (dest->used & XPERMS_ALLOWED)
@@ -272,6 +276,7 @@ static inline void avc_quick_copy_xperms_decision(u8 perm,
*/
u8 i = perm >> 5;
+ dest->base_perm = src->base_perm;
dest->used = src->used;
if (dest->used & XPERMS_ALLOWED)
dest->allowed->p[i] = src->allowed->p[i];
@@ -357,6 +362,7 @@ static int avc_xperms_populate(struct avc_node *node,
memcpy(dest->xp.drivers.p, src->xp.drivers.p, sizeof(dest->xp.drivers.p));
dest->xp.len = src->xp.len;
+ dest->xp.base_perms = src->xp.base_perms;
/* for each source xpd allocate a destination xpd and copy */
list_for_each_entry(src_xpd, &src->xpd_head, xpd_list) {
@@ -807,6 +813,7 @@ out:
* @event : Updating event
* @perms : Permission mask bits
* @driver: xperm driver information
+ * @base_perm: the base permission associated with the extended permission
* @xperm: xperm permissions
* @ssid: AVC entry source sid
* @tsid: AVC entry target sid
@@ -820,10 +827,9 @@ out:
* otherwise, this function updates the AVC entry. The original AVC-entry object
* will release later by RCU.
*/
-static int avc_update_node(u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid,
- u32 tsid, u16 tclass, u32 seqno,
- struct extended_perms_decision *xpd,
- u32 flags)
+static int avc_update_node(u32 event, u32 perms, u8 driver, u8 base_perm,
+ u8 xperm, u32 ssid, u32 tsid, u16 tclass, u32 seqno,
+ struct extended_perms_decision *xpd, u32 flags)
{
u32 hvalue;
int rc = 0;
@@ -880,7 +886,7 @@ static int avc_update_node(u32 event, u32 perms, u8 driver, u8 xperm, u32 ssid,
case AVC_CALLBACK_GRANT:
node->ae.avd.allowed |= perms;
if (node->ae.xp_node && (flags & AVC_EXTENDED_PERMS))
- avc_xperms_allow_perm(node->ae.xp_node, driver, xperm);
+ avc_xperms_allow_perm(node->ae.xp_node, driver, base_perm, xperm);
break;
case AVC_CALLBACK_TRY_REVOKE:
case AVC_CALLBACK_REVOKE:
@@ -987,10 +993,9 @@ static noinline void avc_compute_av(u32 ssid, u32 tsid, u16 tclass,
avc_insert(ssid, tsid, tclass, avd, xp_node);
}
-static noinline int avc_denied(u32 ssid, u32 tsid,
- u16 tclass, u32 requested,
- u8 driver, u8 xperm, unsigned int flags,
- struct av_decision *avd)
+static noinline int avc_denied(u32 ssid, u32 tsid, u16 tclass, u32 requested,
+ u8 driver, u8 base_perm, u8 xperm,
+ unsigned int flags, struct av_decision *avd)
{
if (flags & AVC_STRICT)
return -EACCES;
@@ -999,7 +1004,7 @@ static noinline int avc_denied(u32 ssid, u32 tsid,
!(avd->flags & AVD_FLAGS_PERMISSIVE))
return -EACCES;
- avc_update_node(AVC_CALLBACK_GRANT, requested, driver,
+ avc_update_node(AVC_CALLBACK_GRANT, requested, driver, base_perm,
xperm, ssid, tsid, tclass, avd->seqno, NULL, flags);
return 0;
}
@@ -1012,7 +1017,8 @@ static noinline int avc_denied(u32 ssid, u32 tsid,
* driver field is used to specify which set contains the permission.
*/
int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested,
- u8 driver, u8 xperm, struct common_audit_data *ad)
+ u8 driver, u8 base_perm, u8 xperm,
+ struct common_audit_data *ad)
{
struct avc_node *node;
struct av_decision avd;
@@ -1047,22 +1053,23 @@ int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested,
local_xpd.auditallow = &auditallow;
local_xpd.dontaudit = &dontaudit;
- xpd = avc_xperms_decision_lookup(driver, xp_node);
+ xpd = avc_xperms_decision_lookup(driver, base_perm, xp_node);
if (unlikely(!xpd)) {
/*
* Compute the extended_perms_decision only if the driver
- * is flagged
+ * is flagged and the base permission is known.
*/
- if (!security_xperm_test(xp_node->xp.drivers.p, driver)) {
+ if (!security_xperm_test(xp_node->xp.drivers.p, driver) ||
+ !(xp_node->xp.base_perms & base_perm)) {
avd.allowed &= ~requested;
goto decision;
}
rcu_read_unlock();
- security_compute_xperms_decision(ssid, tsid, tclass,
- driver, &local_xpd);
+ security_compute_xperms_decision(ssid, tsid, tclass, driver,
+ base_perm, &local_xpd);
rcu_read_lock();
- avc_update_node(AVC_CALLBACK_ADD_XPERMS, requested,
- driver, xperm, ssid, tsid, tclass, avd.seqno,
+ avc_update_node(AVC_CALLBACK_ADD_XPERMS, requested, driver,
+ base_perm, xperm, ssid, tsid, tclass, avd.seqno,
&local_xpd, 0);
} else {
avc_quick_copy_xperms_decision(xperm, &local_xpd, xpd);
@@ -1075,8 +1082,8 @@ int avc_has_extended_perms(u32 ssid, u32 tsid, u16 tclass, u32 requested,
decision:
denied = requested & ~(avd.allowed);
if (unlikely(denied))
- rc = avc_denied(ssid, tsid, tclass, requested,
- driver, xperm, AVC_EXTENDED_PERMS, &avd);
+ rc = avc_denied(ssid, tsid, tclass, requested, driver,
+ base_perm, xperm, AVC_EXTENDED_PERMS, &avd);
rcu_read_unlock();
@@ -1110,7 +1117,7 @@ static noinline int avc_perm_nonode(u32 ssid, u32 tsid, u16 tclass,
avc_compute_av(ssid, tsid, tclass, avd, &xp_node);
denied = requested & ~(avd->allowed);
if (unlikely(denied))
- return avc_denied(ssid, tsid, tclass, requested, 0, 0,
+ return avc_denied(ssid, tsid, tclass, requested, 0, 0, 0,
flags, avd);
return 0;
}
@@ -1158,7 +1165,7 @@ inline int avc_has_perm_noaudit(u32 ssid, u32 tsid,
rcu_read_unlock();
if (unlikely(denied))
- return avc_denied(ssid, tsid, tclass, requested, 0, 0,
+ return avc_denied(ssid, tsid, tclass, requested, 0, 0, 0,
flags, avd);
return 0;
}
generated by cgit v1.2.3 (git 2.39.1) at 2025-01-18 09:53:48 +0100