* [PATCH] sis5513: fix potential use after free
@ 2018-11-28 0:55 Pan Bian
2018-11-28 7:05 ` Christoph Hellwig
0 siblings, 1 reply; 2+ messages in thread
From: Pan Bian @ 2018-11-28 0:55 UTC (permalink / raw)
To: David S. Miller; +Cc: linux-ide, linux-kernel, Pan Bian
The function sis_find_family drops lpc_bridge reference via pci_dev_put,
however, after that, field lpc_bridge->revision is read. This may result
in a use after free bug. The patch moves the put operation after the
condition check.
Signed-off-by: Pan Bian <bianpan2016@163.com>
---
drivers/ide/sis5513.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)
diff --git a/drivers/ide/sis5513.c b/drivers/ide/sis5513.c
index 024bc7b..69f9889 100644
--- a/drivers/ide/sis5513.c
+++ b/drivers/ide/sis5513.c
@@ -434,7 +434,6 @@ static int sis_find_family(struct pci_dev *dev)
lpc_bridge = pci_get_slot(dev->bus, 0x10); /* Bus 0, Dev 2, Fn 0 */
pci_read_config_byte(dev, 0x49, &prefctl);
- pci_dev_put(lpc_bridge);
if (lpc_bridge->revision == 0x10 && (prefctl & 0x80)) {
printk(KERN_INFO DRV_NAME " %s: SiS 961B MuTIOL IDE UDMA133 controller\n",
@@ -445,6 +444,8 @@ static int sis_find_family(struct pci_dev *dev)
pci_name(dev));
chipset_family = ATA_100;
}
+
+ pci_dev_put(lpc_bridge);
}
}
--
2.7.4
^ permalink raw reply related [flat|nested] 2+ messages in thread
* Re: [PATCH] sis5513: fix potential use after free
2018-11-28 0:55 [PATCH] sis5513: fix potential use after free Pan Bian
@ 2018-11-28 7:05 ` Christoph Hellwig
0 siblings, 0 replies; 2+ messages in thread
From: Christoph Hellwig @ 2018-11-28 7:05 UTC (permalink / raw)
To: Pan Bian; +Cc: David S. Miller, linux-ide, linux-kernel
On Wed, Nov 28, 2018 at 08:55:26AM +0800, Pan Bian wrote:
> The function sis_find_family drops lpc_bridge reference via pci_dev_put,
> however, after that, field lpc_bridge->revision is read. This may result
> in a use after free bug. The patch moves the put operation after the
> condition check.
>
> Signed-off-by: Pan Bian <bianpan2016@163.com>
Looks good,
Reviewed-by: Christoph Hellwig <hch@lst.de>
^ permalink raw reply [flat|nested] 2+ messages in thread
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