| Message ID | 1543366526-46767-1-git-send-email-bianpan2016@163.com |
|---|---|
| State | Not Applicable |
| Delegated to: | David Miller |
| Headers | show |
| Series | sis5513: fix potential use after free | expand |
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>
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); } }
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(-)