[added to the 3.18 stable tree] PCI: Don't read past the end of sysfs "driver_override" buffer

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



This patch has been added to the 3.18 stable tree. If you have any
objections, please let us know.

===============

[ Upstream commit 4efe874aace57dba967624ce1c48322da2447b75 ]

When printing the driver_override parameter when it is 4095 and 4094 bytes
long, the printing code would access invalid memory because we need count+1
bytes for printing.

Fixes: 782a985d7af2 ("PCI: Introduce new device binding path using pci_dev.driver_override")
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
Signed-off-by: Bjorn Helgaas <bhelgaas@xxxxxxxxxx>
Acked-by: Alex Williamson <alex.williamson@xxxxxxxxxx>
CC: stable@xxxxxxxxxxxxxxx	# v3.16+
CC: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
CC: Alexander Graf <agraf@xxxxxxx>
CC: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sasha.levin@xxxxxxxxxx>
---
 drivers/pci/pci-sysfs.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index 2c6643f..eb15438 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -515,7 +515,8 @@ static ssize_t driver_override_store(struct device *dev,
 	struct pci_dev *pdev = to_pci_dev(dev);
 	char *driver_override, *old = pdev->driver_override, *cp;
 
-	if (count > PATH_MAX)
+	/* We need to keep extra room for a newline */
+	if (count >= (PAGE_SIZE - 1))
 		return -EINVAL;
 
 	driver_override = kstrndup(buf, count, GFP_KERNEL);
@@ -543,7 +544,7 @@ static ssize_t driver_override_show(struct device *dev,
 {
 	struct pci_dev *pdev = to_pci_dev(dev);
 
-	return sprintf(buf, "%s\n", pdev->driver_override);
+	return snprintf(buf, PAGE_SIZE, "%s\n", pdev->driver_override);
 }
 static DEVICE_ATTR_RW(driver_override);
 
-- 
2.1.0

--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html




[Index of Archives]     [Linux Kernel]     [Kernel Development Newbies]     [Linux USB Devel]     [Video for Linux]     [Linux Audio Users]     [Yosemite Hiking]     [Linux Kernel]     [Linux SCSI]