From: Karsten Keil <kkeil@suse.de>
Date: Sat, 1 Dec 2007 20:16:15 +0000 (-0800)
Subject: I4L: fix isdn_ioctl memory overrun vulnerability
X-Git-Tag: v2.6.22.15~26
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=909633b01897ae2cc689e1ab25c697fc11ceb6e8;p=thirdparty%2Fkernel%2Fstable.git

I4L: fix isdn_ioctl memory overrun vulnerability

patch eafe1aa37e6ec2d56f14732b5240c4dd09f0613a in mainline.

Fix possible memory overrun issue in the isdn ioctl code.  Found by ADLAB
<adlab@venustech.com.cn>

Signed-off-by: Karsten Keil <kkeil@suse.de>
Cc: ADLAB <adlab@venustech.com.cn>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
---

diff --git a/drivers/isdn/i4l/isdn_common.c b/drivers/isdn/i4l/isdn_common.c
index c97330b198772..eb9a247a9df50 100644
--- a/drivers/isdn/i4l/isdn_common.c
+++ b/drivers/isdn/i4l/isdn_common.c
@@ -1514,6 +1514,7 @@ isdn_ioctl(struct inode *inode, struct file *file, uint cmd, ulong arg)
 					if (copy_from_user(&iocts, argp,
 					     sizeof(isdn_ioctl_struct)))
 						return -EFAULT;
+					iocts.drvid[sizeof(iocts.drvid)-1] = 0;
 					if (strlen(iocts.drvid)) {
 						if ((p = strchr(iocts.drvid, ',')))
 							*p = 0;
@@ -1598,6 +1599,7 @@ isdn_ioctl(struct inode *inode, struct file *file, uint cmd, ulong arg)
 					if (copy_from_user(&iocts, argp,
 					     sizeof(isdn_ioctl_struct)))
 						return -EFAULT;
+					iocts.drvid[sizeof(iocts.drvid)-1] = 0;
 					if (strlen(iocts.drvid)) {
 						drvidx = -1;
 						for (i = 0; i < ISDN_MAX_DRIVERS; i++)
@@ -1642,7 +1644,7 @@ isdn_ioctl(struct inode *inode, struct file *file, uint cmd, ulong arg)
 					} else {
 						p = (char __user *) iocts.arg;
 						for (i = 0; i < 10; i++) {
-							sprintf(bname, "%s%s",
+							snprintf(bname, sizeof(bname), "%s%s",
 								strlen(dev->drv[drvidx]->msn2eaz[i]) ?
 								dev->drv[drvidx]->msn2eaz[i] : "_",
 								(i < 9) ? "," : "\0");
@@ -1672,6 +1674,7 @@ isdn_ioctl(struct inode *inode, struct file *file, uint cmd, ulong arg)
 					char *p;
 					if (copy_from_user(&iocts, argp, sizeof(isdn_ioctl_struct)))
 						return -EFAULT;
+					iocts.drvid[sizeof(iocts.drvid)-1] = 0;
 					if (strlen(iocts.drvid)) {
 						if ((p = strchr(iocts.drvid, ',')))
 							*p = 0;