[PATCH] fix deadlock in audit_log_task_context()

GFP_KERNEL allocations in non-blocking context; fixed by killing
an idiotic use of security_getprocattr().

Acked-by: Stephen Smalley <sds@tycho.nsa.gov>
Acked-by: James Morris <jmorris@namei.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

diff --git a/kernel/auditsc.c b/kernel/auditsc.c
index 3599558..628c7ac 100644 (file)
--- a/kernel/auditsc.c
+++ b/kernel/auditsc.c
@@ -739,28 +739,26 @@ static inline void audit_free_context(struct audit_context *context)
 void audit_log_task_context(struct audit_buffer *ab)
 {
        char *ctx = NULL;
-       ssize_t len = 0;
+       unsigned len;
+       int error;
+       u32 sid;
+
+       selinux_get_task_sid(current, &sid);
+       if (!sid)
+               return;
 
-       len = security_getprocattr(current, "current", NULL, 0);
-       if (len < 0) {
-               if (len != -EINVAL)
+       error = selinux_sid_to_string(sid, &ctx, &len);
+       if (error) {
+               if (error != -EINVAL)
                        goto error_path;
                return;
        }
 
-       ctx = kmalloc(len, GFP_KERNEL);
-       if (!ctx)
-               goto error_path;
-
-       len = security_getprocattr(current, "current", ctx, len);
-       if (len < 0 )
-               goto error_path;
-
        audit_log_format(ab, " subj=%s", ctx);
+       kfree(ctx);
        return;
 
 error_path:
-       kfree(ctx);
        audit_panic("error in audit_log_task_context");
        return;
 }