lkml.org 
[lkml]   [2015]   [Jan]   [1]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
From
Subject[PATCH] PCI/sysfs: off by two and memory corruption in driver_override parameter
Date
There are two different issues fixed here:

- On nun-NULL terminated input a random byte of memory would get flipped
from '\n' to '\0'.
- When printing the driver_override parameter when it is 4095 and 4094 bytes
long the printing code would access invalid memory.

Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
---
drivers/pci/pci-sysfs.c | 10 +++++-----
1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/drivers/pci/pci-sysfs.c b/drivers/pci/pci-sysfs.c
index aa012fb..be6b2b1 100644
--- a/drivers/pci/pci-sysfs.c
+++ b/drivers/pci/pci-sysfs.c
@@ -521,17 +521,17 @@ 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 >= (PATH_MAX - 1))
return -EINVAL;

driver_override = kstrndup(buf, count, GFP_KERNEL);
if (!driver_override)
return -ENOMEM;

- cp = strchr(driver_override, '\n');
- if (cp)
- *cp = '\0';
-
+ driver_override[count] = '\0';
+ if (driver_override[count - 1] == '\n')
+ driver_override[count - 1] = 0;
if (strlen(driver_override)) {
pdev->driver_override = driver_override;
} else {
--
1.7.10.4


\
 
 \ /
  Last update: 2015-01-02 01:41    [W:0.038 / U:2.092 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site