AUDIT: Avoid sleeping function in SElinux AVC audit.
This patch changes the SELinux AVC to defer logging of paths to the audit
framework upon syscall exit, by saving a reference to the (dentry,vfsmount)
pair in an auxiliary audit item on the current audit context for processing
by audit_log_exit.
Signed-off-by: Stephen Smalley <sds@tycho.nsa.gov>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 78d7a13..8dc5b27 100644
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -34,6 +34,7 @@
#include <asm/types.h>
#include <linux/mm.h>
#include <linux/module.h>
+#include <linux/mount.h>
#include <linux/socket.h>
#include <linux/audit.h>
#include <linux/personality.h>
@@ -124,6 +125,11 @@
char a[0];
};
+struct audit_aux_data_path {
+ struct audit_aux_data d;
+ struct dentry *dentry;
+ struct vfsmount *mnt;
+};
/* The per-task audit context. */
struct audit_context {
@@ -553,6 +559,11 @@
struct audit_aux_data *aux;
while ((aux = context->aux)) {
+ if (aux->type == AUDIT_AVC_PATH) {
+ struct audit_aux_data_path *axi = (void *)aux;
+ dput(axi->dentry);
+ mntput(axi->mnt);
+ }
context->aux = aux->next;
kfree(aux);
}
@@ -724,6 +735,14 @@
audit_log_format(ab, "saddr=");
audit_log_hex(ab, axs->a, axs->len);
break; }
+
+ case AUDIT_AVC_PATH: {
+ struct audit_aux_data_path *axi = (void *)aux;
+ audit_log_d_path(ab, "path=", axi->dentry, axi->mnt);
+ dput(axi->dentry);
+ mntput(axi->mnt);
+ break; }
+
}
audit_log_end(ab);
@@ -1124,6 +1143,27 @@
return 0;
}
+int audit_avc_path(struct dentry *dentry, struct vfsmount *mnt)
+{
+ struct audit_aux_data_path *ax;
+ struct audit_context *context = current->audit_context;
+
+ if (likely(!context))
+ return 0;
+
+ ax = kmalloc(sizeof(*ax), GFP_ATOMIC);
+ if (!ax)
+ return -ENOMEM;
+
+ ax->dentry = dget(dentry);
+ ax->mnt = mntget(mnt);
+
+ ax->d.type = AUDIT_AVC_PATH;
+ ax->d.next = context->aux;
+ context->aux = (void *)ax;
+ return 0;
+}
+
void audit_signal_info(int sig, struct task_struct *t)
{
extern pid_t audit_sig_pid;
