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From:   Sasha Levin <sashal@kernel.org>
To:     linux-kernel@vger.kernel.org, stable@vger.kernel.org
Cc:     Zheyu Ma <zheyuma97@gmail.com>,
        Hans Verkuil <hverkuil-cisco@xs4all.nl>,
        Mauro Carvalho Chehab <mchehab@kernel.org>,
        Sasha Levin <sashal@kernel.org>, linux-media@vger.kernel.org
Subject: [PATCH AUTOSEL 5.4 16/55] media: pci: cx23885: Fix the error handling in cx23885_initdev()
Date:   Mon, 30 May 2022 09:46:22 -0400
Message-Id: <20220530134701.1935933-16-sashal@kernel.org>
In-Reply-To: <20220530134701.1935933-1-sashal@kernel.org>
References: <20220530134701.1935933-1-sashal@kernel.org>
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From: Zheyu Ma <zheyuma97@gmail.com>

[ Upstream commit e8123311cf06d7dae71e8c5fe78e0510d20cd30b ]

When the driver fails to call the dma_set_mask(), the driver will get
the following splat:

[   55.853884] BUG: KASAN: use-after-free in __process_removed_driver+0x3c/0x240
[   55.854486] Read of size 8 at addr ffff88810de60408 by task modprobe/590
[   55.856822] Call Trace:
[   55.860327]  __process_removed_driver+0x3c/0x240
[   55.861347]  bus_for_each_dev+0x102/0x160
[   55.861681]  i2c_del_driver+0x2f/0x50

This is because the driver has initialized the i2c related resources
in cx23885_dev_setup() but not released them in error handling, fix this
bug by modifying the error path that jumps after failing to call the
dma_set_mask().

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/media/pci/cx23885/cx23885-core.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/media/pci/cx23885/cx23885-core.c b/drivers/media/pci/cx23885/cx23885-core.c
index ead0acb7807c..6747ecb4911b 100644
--- a/drivers/media/pci/cx23885/cx23885-core.c
+++ b/drivers/media/pci/cx23885/cx23885-core.c
@@ -2154,7 +2154,7 @@ static int cx23885_initdev(struct pci_dev *pci_dev,
 	err = pci_set_dma_mask(pci_dev, 0xffffffff);
 	if (err) {
 		pr_err("%s/0: Oops: no 32bit PCI DMA ???\n", dev->name);
-		goto fail_ctrl;
+		goto fail_dma_set_mask;
 	}
 
 	err = request_irq(pci_dev->irq, cx23885_irq,
@@ -2162,7 +2162,7 @@ static int cx23885_initdev(struct pci_dev *pci_dev,
 	if (err < 0) {
 		pr_err("%s: can't get IRQ %d\n",
 		       dev->name, pci_dev->irq);
-		goto fail_irq;
+		goto fail_dma_set_mask;
 	}
 
 	switch (dev->board) {
@@ -2184,7 +2184,7 @@ static int cx23885_initdev(struct pci_dev *pci_dev,
 
 	return 0;
 
-fail_irq:
+fail_dma_set_mask:
 	cx23885_dev_unregister(dev);
 fail_ctrl:
 	v4l2_ctrl_handler_free(hdl);
-- 
2.35.1