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* [PATCH] dma-buf/udmabuf: Fix NULL pointer dereference in udmabuf_create
@ 2018-09-04 19:07 Gustavo A. R. Silva
  2018-09-05  6:34 ` Gerd Hoffmann
  0 siblings, 1 reply; 2+ messages in thread
From: Gustavo A. R. Silva @ 2018-09-04 19:07 UTC (permalink / raw)
  To: Gerd Hoffmann, Sumit Semwal
  Cc: linux-media, linaro-mm-sig, linux-kernel, Gustavo A. R. Silva

There is a potential execution path in which pointer memfd is NULL when
passed as argument to fput(), hence there is a NULL pointer dereference
in fput().

Fix this by null checking *memfd* before calling fput().

Addresses-Coverity-ID: 1473174 ("Explicit null dereferenced")
Fixes: fbb0de795078 ("Add udmabuf misc device")
Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
---
 drivers/dma-buf/udmabuf.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/dma-buf/udmabuf.c b/drivers/dma-buf/udmabuf.c
index 8e24204..2e85022 100644
--- a/drivers/dma-buf/udmabuf.c
+++ b/drivers/dma-buf/udmabuf.c
@@ -194,7 +194,8 @@ static long udmabuf_create(struct udmabuf_create_list *head,
 	while (pgbuf > 0)
 		put_page(ubuf->pages[--pgbuf]);
 err_free_ubuf:
-	fput(memfd);
+	if (memfd)
+		fput(memfd);
 	kfree(ubuf->pages);
 	kfree(ubuf);
 	return ret;
-- 
2.7.4

^ permalink raw reply related	[flat|nested] 2+ messages in thread

* Re: [PATCH] dma-buf/udmabuf: Fix NULL pointer dereference in udmabuf_create
  2018-09-04 19:07 [PATCH] dma-buf/udmabuf: Fix NULL pointer dereference in udmabuf_create Gustavo A. R. Silva
@ 2018-09-05  6:34 ` Gerd Hoffmann
  0 siblings, 0 replies; 2+ messages in thread
From: Gerd Hoffmann @ 2018-09-05  6:34 UTC (permalink / raw)
  To: Gustavo A. R. Silva
  Cc: Sumit Semwal, linux-media, linaro-mm-sig, linux-kernel

On Tue, Sep 04, 2018 at 02:07:49PM -0500, Gustavo A. R. Silva wrote:
> There is a potential execution path in which pointer memfd is NULL when
> passed as argument to fput(), hence there is a NULL pointer dereference
> in fput().
> 
> Fix this by null checking *memfd* before calling fput().
> 
> Addresses-Coverity-ID: 1473174 ("Explicit null dereferenced")
> Fixes: fbb0de795078 ("Add udmabuf misc device")
> Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>

Pushed to drm-misc-next.

thanks,
  Gerd

^ permalink raw reply	[flat|nested] 2+ messages in thread

end of thread, other threads:[~2018-09-05 11:03 UTC | newest]

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2018-09-04 19:07 [PATCH] dma-buf/udmabuf: Fix NULL pointer dereference in udmabuf_create Gustavo A. R. Silva
2018-09-05  6:34 ` Gerd Hoffmann

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