[ 118/143] libertas: potential oops in debugfs

Willy Tarreau
2014-05-12T02:09:42Z

From: Dan Carpenter <dan.carpenter@oracle.com>

If we do a zero size allocation then it will oops. Also we can't be
sure the user passes us a NUL terminated string so I've added a
terminator.

This code can only be triggered by root.

Reported-by: Nico Golde <nico@ngolde.de>
Reported-by: Fabian Yamaguchi <fabs@goesec.de>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Dan Williams <dcbw@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
(cherry picked from commit a497e47d4aec37aaf8f13509f3ef3d1f6a717d88)
Signed-off-by: Willy Tarreau <w@1wt.eu>
---
drivers/net/wireless/libertas/debugfs.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/wireless/libertas/debugfs.c b/drivers/net/wireless/libertas/debugfs.c
index 893a55c..89532a6 100644
--- a/drivers/net/wireless/libertas/debugfs.c
+++ b/drivers/net/wireless/libertas/debugfs.c
@@ -925,7 +925,10 @@ static ssize_t lbs_debugfs_write(struct file *f, const char __user *buf,
char *p2;
struct debug_data *d = (struct debug_data *)f->private_data;

- pdata = kmalloc(cnt, GFP_KERNEL);
+ if (cnt == 0)
+ return 0;
+
+ pdata = kmalloc(cnt + 1, GFP_KERNEL);
if (pdata == NULL)
return 0;

@@ -934,6 +937,7 @@ static ssize_t lbs_debugfs_write(struct file *f, const char __user *buf,
kfree(pdata);
return 0;
}
+ pdata[cnt] = '\0';

p0 = pdata;
for (i = 0; i < num_of_items; i++) {
--
1.7.12.2.21.g234cd45.dirty