Merge tag 'v5.2-rc2-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6

Pull cifs fixes from Steve French:
"Four small smb3 fixes, one for stable"

* tag 'v5.2-rc2-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6:
CIFS: cifs_read_allocate_pages: don't iterate through whole page array on ENOMEM
dfs_cache: fix a wrong use of kfree in flush_cache_ent()
fs/cifs/smb2pdu.c: fix buffer free in SMB2_ioctl_free
cifs: fix memory leak of pneg_inbuf on -EOPNOTSUPP ioctl case

fs/cifs/dfs_cache.c

···
 		return;
 
 	hlist_del_init_rcu(&ce->ce_hlist);
-	kfree(ce->ce_path);
+	kfree_const(ce->ce_path);
 	free_tgts(ce);
 	dfs_cache_count--;
 	call_rcu(&ce->ce_rcu, free_cache_entry);
···
 
 	rc = copy_ref_data(refs, numrefs, ce, NULL);
 	if (rc) {
-		kfree(ce->ce_path);
+		kfree_const(ce->ce_path);
 		kmem_cache_free(dfs_cache_slab, ce);
 		ce = ERR_PTR(rc);
 	}

fs/cifs/file.c

···
 	}
 
 	if (rc) {
-		for (i = 0; i < nr_pages; i++) {
+		unsigned int nr_page_failed = i;
+
+		for (i = 0; i < nr_page_failed; i++) {
 			put_page(rdata->pages[i]);
 			rdata->pages[i] = NULL;
 		}

fs/cifs/smb2pdu.c

···
 		 * not supported error. Client should accept it.
 		 */
 		cifs_dbg(VFS, "Server does not support validate negotiate\n");
-		return 0;
+		rc = 0;
+		goto out_free_inbuf;
 	} else if (rc != 0) {
 		cifs_dbg(VFS, "validate protocol negotiate failed: %d\n", rc);
 		rc = -EIO;
···
 void
 SMB2_ioctl_free(struct smb_rqst *rqst)
 {
+	int i;
 	if (rqst && rqst->rq_iov) {
 		cifs_small_buf_release(rqst->rq_iov[0].iov_base); /* request */
-		if (rqst->rq_iov[1].iov_len)
-			kfree(rqst->rq_iov[1].iov_base);
+		for (i = 1; i < rqst->rq_nvec; i++)
+			if (rqst->rq_iov[i].iov_base != smb2_padding)
+				kfree(rqst->rq_iov[i].iov_base);
 	}
 }