From: Nick Ewalt <nicholasewalt@google.com>
Date: Mon, 15 Oct 2018 04:59:22 +0000 (-0700)
Subject: staging: gasket: page table: fixup error path allocating coherent mem
X-Git-Tag: v4.20-rc1~72^2~17
X-Git-Url: https://asedeno.scripts.mit.edu/gitweb/?a=commitdiff_plain;h=54be7ec98875e3061e6ae788d6e7088cffa5ed2e;p=linux.git

staging: gasket: page table: fixup error path allocating coherent mem

Correctly clean up data structure state in gasket_alloc_coherent_memory
error path, to ensure no double free on the stale pointer value.

Signed-off-by: Nick Ewalt <nicholasewalt@google.com>
Signed-off-by: Todd Poynor <toddpoynor@google.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index 9c2f8671216b..a88f2ae0cee8 100644
--- a/drivers/staging/gasket/gasket_page_table.c
+++ b/drivers/staging/gasket/gasket_page_table.c
@@ -1332,9 +1332,13 @@ int gasket_alloc_coherent_memory(struct gasket_dev *gasket_dev, u64 size,
 	return 0;
 
 nomem:
-	if (mem)
+	if (mem) {
 		dma_free_coherent(gasket_get_device(gasket_dev),
 				  num_pages * PAGE_SIZE, mem, handle);
+		gasket_dev->coherent_buffer.length_bytes = 0;
+		gasket_dev->coherent_buffer.virt_base = NULL;
+		gasket_dev->coherent_buffer.phys_base = 0;
+	}
 
 	kfree(gasket_dev->page_table[index]->coherent_pages);
 	gasket_dev->page_table[index]->coherent_pages = NULL;