[PATCH] Restore LSM hook calls to sendfile

Patch from "Stephen D. Smalley" <sds@epoch.ncsc.mil>

This patch restores the LSM hook calls in sendfile to 2.5.59.  The hook was
previously added as of 2.5.29 but the hook calls in sendfile were
subsequently lost as a result of the sendfile rewrite as of 2.5.30.

fs/read_write.c

@@ -531,6 +531,10 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
 	if (retval)
 		goto fput_in;
 
+	retval = security_file_permission (in_file, MAY_READ);
+	if (retval)
+		goto fput_in;
+
 	/*
 	 * Get output file, and verify that it is ok..
 	 */
@@ -548,6 +552,10 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos,
 	if (retval)
 		goto fput_out;
 
+	retval = security_file_permission (out_file, MAY_WRITE);
+	if (retval)
+		goto fput_out;
+
 	if (!ppos)
 		ppos = &in_file->f_pos;