diff mbox series

[5.4,085/340] media: em28xx: Fix use-after-free in em28xx_alloc_urbs

Message ID 20210301161052.509353711@linuxfoundation.org
State New
Headers show
Series None | expand

Commit Message

Greg KH March 1, 2021, 4:10 p.m. UTC 
From: Dinghao Liu <dinghao.liu@zju.edu.cn>

[ Upstream commit a26efd1961a18b91ae4cd2e433adbcf865b40fa3 ]

When kzalloc() fails, em28xx_uninit_usb_xfer() will free
usb_bufs->buf and set it to NULL. Thus the later access
to usb_bufs->buf[i] will lead to null pointer dereference.
Also the kfree(usb_bufs->buf) after that is redundant.

Fixes: d571b592c6206 ("media: em28xx: don't use coherent buffer for DMA transfers")
Signed-off-by: Dinghao Liu <dinghao.liu@zju.edu.cn>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/usb/em28xx/em28xx-core.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)
diff mbox series

Patch

diff --git a/drivers/media/usb/em28xx/em28xx-core.c b/drivers/media/usb/em28xx/em28xx-core.c
index e6088b5d1b805..3daa64bb1e1d9 100644
--- a/drivers/media/usb/em28xx/em28xx-core.c
+++ b/drivers/media/usb/em28xx/em28xx-core.c
@@ -956,14 +956,10 @@  int em28xx_alloc_urbs(struct em28xx *dev, enum em28xx_mode mode, int xfer_bulk,
 
 		usb_bufs->buf[i] = kzalloc(sb_size, GFP_KERNEL);
 		if (!usb_bufs->buf[i]) {
-			em28xx_uninit_usb_xfer(dev, mode);
-
 			for (i--; i >= 0; i--)
 				kfree(usb_bufs->buf[i]);
 
-			kfree(usb_bufs->buf);
-			usb_bufs->buf = NULL;
-
+			em28xx_uninit_usb_xfer(dev, mode);
 			return -ENOMEM;
 		}