[PATCH 06/11] staging: gasket: page table: fixup error path allocating coherent mem

Todd Poynor toddpoynor at gmail.com
Mon Oct 15 04:59:22 UTC 2018


From: Nick Ewalt <nicholasewalt at google.com>

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 at google.com>
Signed-off-by: Todd Poynor <toddpoynor at google.com>
---
 drivers/staging/gasket/gasket_page_table.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/staging/gasket/gasket_page_table.c b/drivers/staging/gasket/gasket_page_table.c
index 9c2f8671216b5..a88f2ae0cee8b 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;
-- 
2.19.0.605.g01d371f741-goog



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