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-rw-r--r--security/selinux/avc.c36
-rw-r--r--security/selinux/hooks.c26
-rw-r--r--security/selinux/include/avc.h18
3 files changed, 55 insertions, 25 deletions
diff --git a/security/selinux/avc.c b/security/selinux/avc.c
index 9da6420e2056..1d027e29ce8d 100644
--- a/security/selinux/avc.c
+++ b/security/selinux/avc.c
@@ -471,6 +471,7 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
* @avd: access vector decisions
* @result: result from avc_has_perm_noaudit
* @a: auxiliary audit data
+ * @flags: VFS walk flags
*
* Audit the granting or denial of permissions in accordance
* with the policy. This function is typically called by
@@ -481,9 +482,10 @@ static void avc_audit_post_callback(struct audit_buffer *ab, void *a)
* be performed under a lock, to allow the lock to be released
* before calling the auditing code.
*/
-void avc_audit(u32 ssid, u32 tsid,
+int avc_audit(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
- struct av_decision *avd, int result, struct common_audit_data *a)
+ struct av_decision *avd, int result, struct common_audit_data *a,
+ unsigned flags)
{
struct common_audit_data stack_data;
u32 denied, audited;
@@ -515,11 +517,24 @@ void avc_audit(u32 ssid, u32 tsid,
else
audited = requested & avd->auditallow;
if (!audited)
- return;
+ return 0;
+
if (!a) {
a = &stack_data;
COMMON_AUDIT_DATA_INIT(a, NONE);
}
+
+ /*
+ * When in a RCU walk do the audit on the RCU retry. This is because
+ * the collection of the dname in an inode audit message is not RCU
+ * safe. Note this may drop some audits when the situation changes
+ * during retry. However this is logically just as if the operation
+ * happened a little later.
+ */
+ if ((a->type == LSM_AUDIT_DATA_FS) &&
+ (flags & IPERM_FLAG_RCU))
+ return -ECHILD;
+
a->selinux_audit_data.tclass = tclass;
a->selinux_audit_data.requested = requested;
a->selinux_audit_data.ssid = ssid;
@@ -529,6 +544,7 @@ void avc_audit(u32 ssid, u32 tsid,
a->lsm_pre_audit = avc_audit_pre_callback;
a->lsm_post_audit = avc_audit_post_callback;
common_lsm_audit(a);
+ return 0;
}
/**
@@ -793,6 +809,7 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
* @tclass: target security class
* @requested: requested permissions, interpreted based on @tclass
* @auditdata: auxiliary audit data
+ * @flags: VFS walk flags
*
* Check the AVC to determine whether the @requested permissions are granted
* for the SID pair (@ssid, @tsid), interpreting the permissions
@@ -802,14 +819,19 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
* permissions are granted, -%EACCES if any permissions are denied, or
* another -errno upon other errors.
*/
-int avc_has_perm(u32 ssid, u32 tsid, u16 tclass,
- u32 requested, struct common_audit_data *auditdata)
+int avc_has_perm_flags(u32 ssid, u32 tsid, u16 tclass,
+ u32 requested, struct common_audit_data *auditdata,
+ unsigned flags)
{
struct av_decision avd;
- int rc;
+ int rc, rc2;
rc = avc_has_perm_noaudit(ssid, tsid, tclass, requested, 0, &avd);
- avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata);
+
+ rc2 = avc_audit(ssid, tsid, tclass, requested, &avd, rc, auditdata,
+ flags);
+ if (rc2)
+ return rc2;
return rc;
}
diff --git a/security/selinux/hooks.c b/security/selinux/hooks.c
index 9a220be17a3f..ed5f29aa0a38 100644
--- a/security/selinux/hooks.c
+++ b/security/selinux/hooks.c
@@ -1447,8 +1447,11 @@ static int task_has_capability(struct task_struct *tsk,
}
rc = avc_has_perm_noaudit(sid, sid, sclass, av, 0, &avd);
- if (audit == SECURITY_CAP_AUDIT)
- avc_audit(sid, sid, sclass, av, &avd, rc, &ad);
+ if (audit == SECURITY_CAP_AUDIT) {
+ int rc2 = avc_audit(sid, sid, sclass, av, &avd, rc, &ad, 0);
+ if (rc2)
+ return rc2;
+ }
return rc;
}
@@ -1468,7 +1471,8 @@ static int task_has_system(struct task_struct *tsk,
static int inode_has_perm(const struct cred *cred,
struct inode *inode,
u32 perms,
- struct common_audit_data *adp)
+ struct common_audit_data *adp,
+ unsigned flags)
{
struct inode_security_struct *isec;
struct common_audit_data ad;
@@ -1488,7 +1492,7 @@ static int inode_has_perm(const struct cred *cred,
ad.u.fs.inode = inode;
}
- return avc_has_perm(sid, isec->sid, isec->sclass, perms, adp);
+ return avc_has_perm_flags(sid, isec->sid, isec->sclass, perms, adp, flags);
}
/* Same as inode_has_perm, but pass explicit audit data containing
@@ -1505,7 +1509,7 @@ static inline int dentry_has_perm(const struct cred *cred,
COMMON_AUDIT_DATA_INIT(&ad, FS);
ad.u.fs.path.mnt = mnt;
ad.u.fs.path.dentry = dentry;
- return inode_has_perm(cred, inode, av, &ad);
+ return inode_has_perm(cred, inode, av, &ad, 0);
}
/* Check whether a task can use an open file descriptor to
@@ -1541,7 +1545,7 @@ static int file_has_perm(const struct cred *cred,
/* av is zero if only checking access to the descriptor. */
rc = 0;
if (av)
- rc = inode_has_perm(cred, inode, av, &ad);
+ rc = inode_has_perm(cred, inode, av, &ad, 0);
out:
return rc;
@@ -2103,7 +2107,7 @@ static inline void flush_unauthorized_files(const struct cred *cred,
file = file_priv->file;
inode = file->f_path.dentry->d_inode;
if (inode_has_perm(cred, inode,
- FILE__READ | FILE__WRITE, NULL)) {
+ FILE__READ | FILE__WRITE, NULL, 0)) {
drop_tty = 1;
}
}
@@ -2649,10 +2653,6 @@ static int selinux_inode_permission(struct inode *inode, int mask, unsigned flag
if (!mask)
return 0;
- /* May be droppable after audit */
- if (flags & IPERM_FLAG_RCU)
- return -ECHILD;
-
COMMON_AUDIT_DATA_INIT(&ad, FS);
ad.u.fs.inode = inode;
@@ -2661,7 +2661,7 @@ static int selinux_inode_permission(struct inode *inode, int mask, unsigned flag
perms = file_mask_to_av(inode->i_mode, mask);
- return inode_has_perm(cred, inode, perms, &ad);
+ return inode_has_perm(cred, inode, perms, &ad, flags);
}
static int selinux_inode_setattr(struct dentry *dentry, struct iattr *iattr)
@@ -3208,7 +3208,7 @@ static int selinux_dentry_open(struct file *file, const struct cred *cred)
* new inode label or new policy.
* This check is not redundant - do not remove.
*/
- return inode_has_perm(cred, inode, open_file_to_av(file), NULL);
+ return inode_has_perm(cred, inode, open_file_to_av(file), NULL, 0);
}
/* task security operations */
diff --git a/security/selinux/include/avc.h b/security/selinux/include/avc.h
index 5615081b73ec..e77b2ac2908b 100644
--- a/security/selinux/include/avc.h
+++ b/security/selinux/include/avc.h
@@ -54,11 +54,11 @@ struct avc_cache_stats {
void __init avc_init(void);
-void avc_audit(u32 ssid, u32 tsid,
+int avc_audit(u32 ssid, u32 tsid,
u16 tclass, u32 requested,
struct av_decision *avd,
int result,
- struct common_audit_data *a);
+ struct common_audit_data *a, unsigned flags);
#define AVC_STRICT 1 /* Ignore permissive mode. */
int avc_has_perm_noaudit(u32 ssid, u32 tsid,
@@ -66,9 +66,17 @@ int avc_has_perm_noaudit(u32 ssid, u32 tsid,
unsigned flags,
struct av_decision *avd);
-int avc_has_perm(u32 ssid, u32 tsid,
- u16 tclass, u32 requested,
- struct common_audit_data *auditdata);
+int avc_has_perm_flags(u32 ssid, u32 tsid,
+ u16 tclass, u32 requested,
+ struct common_audit_data *auditdata,
+ unsigned);
+
+static inline int avc_has_perm(u32 ssid, u32 tsid,
+ u16 tclass, u32 requested,
+ struct common_audit_data *auditdata)
+{
+ return avc_has_perm_flags(ssid, tsid, tclass, requested, auditdata, 0);
+}
u32 avc_policy_seqno(void);