* [PATCH] linux/blktap: fix various checks
@ 2010-04-19 13:20 Jan Beulich
0 siblings, 0 replies; only message in thread
From: Jan Beulich @ 2010-04-19 13:20 UTC (permalink / raw)
To: xen-devel
[-- Attachment #1: Type: text/plain, Size: 5341 bytes --]
- array indices got checked after having indexed the array already
- several were off by one
- BLKTAP_IOCTL_FREEINTF should not be used on other than the control
device (or the logic should be changed to that when thus used only
the respective device can be freed)
- BLKTAP_IOCTL_MINOR can reasonably also be used on non-control devices
(returning that device's minor and ignoring the passed in argument)
Written and tested on 2.6.32.11 and made apply to the 2.6.18 tree
without further testing.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- sle11sp1-2010-04-12.orig/drivers/xen/blktap/blktap.c 2010-04-19 09:24:00.000000000 +0200
+++ sle11sp1-2010-04-12/drivers/xen/blktap/blktap.c 2010-04-19 11:59:19.000000000 +0200
@@ -558,11 +558,11 @@ void signal_tapdisk(int idx)
* if the userland tools set things up wrong, this could be negative;
* just don't try to signal in this case
*/
- if (idx < 0)
+ if (idx < 0 || idx >= MAX_TAP_DEV)
return;
info = tapfds[idx];
- if ((idx < 0) || (idx > MAX_TAP_DEV) || !info)
+ if (!info)
return;
if (info->pid > 0) {
@@ -586,10 +586,13 @@ static int blktap_open(struct inode *ino
/* ctrl device, treat differently */
if (!idx)
return 0;
+ if (idx < 0 || idx >= MAX_TAP_DEV) {
+ WPRINTK("No device /dev/xen/blktap%d\n", idx);
+ return -ENODEV;
+ }
info = tapfds[idx];
-
- if ((idx < 0) || (idx > MAX_TAP_DEV) || !info) {
+ if (!info) {
WPRINTK("Unable to open device /dev/xen/blktap%d\n",
idx);
return -ENODEV;
@@ -852,9 +855,11 @@ static int blktap_ioctl(struct inode *in
unsigned long dev = arg;
unsigned long flags;
- info = tapfds[dev];
+ if (info || dev >= MAX_TAP_DEV)
+ return -EINVAL;
- if ((dev > MAX_TAP_DEV) || !info)
+ info = tapfds[dev];
+ if (!info)
return 0; /* should this be an error? */
spin_lock_irqsave(&pending_free_lock, flags);
@@ -865,16 +870,19 @@ static int blktap_ioctl(struct inode *in
return 0;
}
case BLKTAP_IOCTL_MINOR:
- {
- unsigned long dev = arg;
+ if (!info) {
+ unsigned long dev = arg;
- info = tapfds[dev];
+ if (dev >= MAX_TAP_DEV)
+ return -EINVAL;
- if ((dev > MAX_TAP_DEV) || !info)
- return -EINVAL;
+ info = tapfds[dev];
+ if (!info)
+ return -EINVAL;
+ }
return info->minor;
- }
+
case BLKTAP_IOCTL_MAJOR:
return blktap_major;
@@ -908,9 +916,11 @@ static void blktap_kick_user(int idx)
{
tap_blkif_t *info;
- info = tapfds[idx];
+ if (idx < 0 || idx >= MAX_TAP_DEV)
+ return;
- if ((idx < 0) || (idx > MAX_TAP_DEV) || !info)
+ info = tapfds[idx];
+ if (!info)
return;
wake_up_interruptible(&info->wait);
@@ -1056,9 +1066,8 @@ static void fast_flush_area(pending_req_
struct mm_struct *mm;
- info = tapfds[tapidx];
-
- if ((tapidx < 0) || (tapidx > MAX_TAP_DEV) || !info) {
+ if ((tapidx < 0) || (tapidx >= MAX_TAP_DEV)
+ || !(info = tapfds[tapidx])) {
WPRINTK("fast_flush: Couldn't get info!\n");
return;
}
@@ -1306,7 +1315,7 @@ static int do_block_io_op(blkif_t *blkif
rmb(); /* Ensure we see queued requests up to 'rp'. */
/*Check blkif has corresponding UE ring*/
- if (blkif->dev_num < 0) {
+ if (blkif->dev_num < 0 || blkif->dev_num >= MAX_TAP_DEV) {
/*oops*/
if (print_dbug) {
WPRINTK("Corresponding UE "
@@ -1318,8 +1327,7 @@ static int do_block_io_op(blkif_t *blkif
info = tapfds[blkif->dev_num];
- if (blkif->dev_num > MAX_TAP_DEV || !info ||
- !test_bit(0, &info->dev_inuse)) {
+ if (!info || !test_bit(0, &info->dev_inuse)) {
if (print_dbug) {
WPRINTK("Can't get UE info!\n");
print_dbug = 0;
@@ -1427,7 +1435,7 @@ static void dispatch_rw_block_io(blkif_t
struct mm_struct *mm;
struct vm_area_struct *vma = NULL;
- if (blkif->dev_num < 0 || blkif->dev_num > MAX_TAP_DEV)
+ if (blkif->dev_num < 0 || blkif->dev_num >= MAX_TAP_DEV)
goto fail_response;
info = tapfds[blkif->dev_num];
@@ -1748,7 +1756,7 @@ static int __init blkif_init(void)
/* tapfds[0] is always NULL */
blktap_next_minor++;
- DPRINTK("Created misc_dev [/dev/xen/blktap%d]\n",i);
+ DPRINTK("Created misc_dev %d:0 [/dev/xen/blktap0]\n", ret);
/* Make sure the xen class exists */
if ((class = get_xen_class()) != NULL) {
--- sle11sp1-2010-04-12.orig/drivers/xen/blktap2/control.c 2009-11-06 10:51:17.000000000 +0100
+++ sle11sp1-2010-04-12/drivers/xen/blktap2/control.c 2010-04-14 15:41:58.000000000 +0200
@@ -136,7 +136,7 @@ blktap_control_ioctl(struct inode *inode
case BLKTAP2_IOCTL_FREE_TAP:
dev = arg;
- if (dev > MAX_BLKTAP_DEVICE || !blktaps[dev])
+ if (dev >= MAX_BLKTAP_DEVICE || !blktaps[dev])
return -EINVAL;
blktap_control_destroy_device(blktaps[dev]);
--- sle11sp1-2010-04-12.orig/drivers/xen/blktap2/ring.c 2009-11-06 10:51:32.000000000 +0100
+++ sle11sp1-2010-04-12/drivers/xen/blktap2/ring.c 2010-04-14 15:42:20.000000000 +0200
@@ -215,7 +215,7 @@ blktap_ring_open(struct inode *inode, st
struct blktap *tap;
idx = iminor(inode);
- if (idx < 0 || idx > MAX_BLKTAP_DEVICE || blktaps[idx] == NULL) {
+ if (idx < 0 || idx >= MAX_BLKTAP_DEVICE || blktaps[idx] == NULL) {
BTERR("unable to open device blktap%d\n", idx);
return -ENODEV;
}
[-- Attachment #2: xen-blktap-checks.patch --]
[-- Type: text/plain, Size: 5376 bytes --]
Subject: blktap: fix various checks
- array indices got checked after having indexed the array already
- several were off by one
- BLKTAP_IOCTL_FREEINTF should not be used on other than the control
device (or the logic should be changed to that when thus used only
the respective device can be freed)
- BLKTAP_IOCTL_MINOR can reasonably also be used on non-control devices
(returning that device's minor and ignoring the passed in argument)
Written and tested on 2.6.32.11 and made apply to the 2.6.18 tree
without further testing.
Signed-off-by: Jan Beulich <jbeulich@novell.com>
--- sle11sp1-2010-04-12.orig/drivers/xen/blktap/blktap.c 2010-04-19 09:24:00.000000000 +0200
+++ sle11sp1-2010-04-12/drivers/xen/blktap/blktap.c 2010-04-19 11:59:19.000000000 +0200
@@ -558,11 +558,11 @@ void signal_tapdisk(int idx)
* if the userland tools set things up wrong, this could be negative;
* just don't try to signal in this case
*/
- if (idx < 0)
+ if (idx < 0 || idx >= MAX_TAP_DEV)
return;
info = tapfds[idx];
- if ((idx < 0) || (idx > MAX_TAP_DEV) || !info)
+ if (!info)
return;
if (info->pid > 0) {
@@ -586,10 +586,13 @@ static int blktap_open(struct inode *ino
/* ctrl device, treat differently */
if (!idx)
return 0;
+ if (idx < 0 || idx >= MAX_TAP_DEV) {
+ WPRINTK("No device /dev/xen/blktap%d\n", idx);
+ return -ENODEV;
+ }
info = tapfds[idx];
-
- if ((idx < 0) || (idx > MAX_TAP_DEV) || !info) {
+ if (!info) {
WPRINTK("Unable to open device /dev/xen/blktap%d\n",
idx);
return -ENODEV;
@@ -852,9 +855,11 @@ static int blktap_ioctl(struct inode *in
unsigned long dev = arg;
unsigned long flags;
- info = tapfds[dev];
+ if (info || dev >= MAX_TAP_DEV)
+ return -EINVAL;
- if ((dev > MAX_TAP_DEV) || !info)
+ info = tapfds[dev];
+ if (!info)
return 0; /* should this be an error? */
spin_lock_irqsave(&pending_free_lock, flags);
@@ -865,16 +870,19 @@ static int blktap_ioctl(struct inode *in
return 0;
}
case BLKTAP_IOCTL_MINOR:
- {
- unsigned long dev = arg;
+ if (!info) {
+ unsigned long dev = arg;
- info = tapfds[dev];
+ if (dev >= MAX_TAP_DEV)
+ return -EINVAL;
- if ((dev > MAX_TAP_DEV) || !info)
- return -EINVAL;
+ info = tapfds[dev];
+ if (!info)
+ return -EINVAL;
+ }
return info->minor;
- }
+
case BLKTAP_IOCTL_MAJOR:
return blktap_major;
@@ -908,9 +916,11 @@ static void blktap_kick_user(int idx)
{
tap_blkif_t *info;
- info = tapfds[idx];
+ if (idx < 0 || idx >= MAX_TAP_DEV)
+ return;
- if ((idx < 0) || (idx > MAX_TAP_DEV) || !info)
+ info = tapfds[idx];
+ if (!info)
return;
wake_up_interruptible(&info->wait);
@@ -1056,9 +1066,8 @@ static void fast_flush_area(pending_req_
struct mm_struct *mm;
- info = tapfds[tapidx];
-
- if ((tapidx < 0) || (tapidx > MAX_TAP_DEV) || !info) {
+ if ((tapidx < 0) || (tapidx >= MAX_TAP_DEV)
+ || !(info = tapfds[tapidx])) {
WPRINTK("fast_flush: Couldn't get info!\n");
return;
}
@@ -1306,7 +1315,7 @@ static int do_block_io_op(blkif_t *blkif
rmb(); /* Ensure we see queued requests up to 'rp'. */
/*Check blkif has corresponding UE ring*/
- if (blkif->dev_num < 0) {
+ if (blkif->dev_num < 0 || blkif->dev_num >= MAX_TAP_DEV) {
/*oops*/
if (print_dbug) {
WPRINTK("Corresponding UE "
@@ -1318,8 +1327,7 @@ static int do_block_io_op(blkif_t *blkif
info = tapfds[blkif->dev_num];
- if (blkif->dev_num > MAX_TAP_DEV || !info ||
- !test_bit(0, &info->dev_inuse)) {
+ if (!info || !test_bit(0, &info->dev_inuse)) {
if (print_dbug) {
WPRINTK("Can't get UE info!\n");
print_dbug = 0;
@@ -1427,7 +1435,7 @@ static void dispatch_rw_block_io(blkif_t
struct mm_struct *mm;
struct vm_area_struct *vma = NULL;
- if (blkif->dev_num < 0 || blkif->dev_num > MAX_TAP_DEV)
+ if (blkif->dev_num < 0 || blkif->dev_num >= MAX_TAP_DEV)
goto fail_response;
info = tapfds[blkif->dev_num];
@@ -1748,7 +1756,7 @@ static int __init blkif_init(void)
/* tapfds[0] is always NULL */
blktap_next_minor++;
- DPRINTK("Created misc_dev [/dev/xen/blktap%d]\n",i);
+ DPRINTK("Created misc_dev %d:0 [/dev/xen/blktap0]\n", ret);
/* Make sure the xen class exists */
if ((class = get_xen_class()) != NULL) {
--- sle11sp1-2010-04-12.orig/drivers/xen/blktap2/control.c 2009-11-06 10:51:17.000000000 +0100
+++ sle11sp1-2010-04-12/drivers/xen/blktap2/control.c 2010-04-14 15:41:58.000000000 +0200
@@ -136,7 +136,7 @@ blktap_control_ioctl(struct inode *inode
case BLKTAP2_IOCTL_FREE_TAP:
dev = arg;
- if (dev > MAX_BLKTAP_DEVICE || !blktaps[dev])
+ if (dev >= MAX_BLKTAP_DEVICE || !blktaps[dev])
return -EINVAL;
blktap_control_destroy_device(blktaps[dev]);
--- sle11sp1-2010-04-12.orig/drivers/xen/blktap2/ring.c 2009-11-06 10:51:32.000000000 +0100
+++ sle11sp1-2010-04-12/drivers/xen/blktap2/ring.c 2010-04-14 15:42:20.000000000 +0200
@@ -215,7 +215,7 @@ blktap_ring_open(struct inode *inode, st
struct blktap *tap;
idx = iminor(inode);
- if (idx < 0 || idx > MAX_BLKTAP_DEVICE || blktaps[idx] == NULL) {
+ if (idx < 0 || idx >= MAX_BLKTAP_DEVICE || blktaps[idx] == NULL) {
BTERR("unable to open device blktap%d\n", idx);
return -ENODEV;
}
[-- Attachment #3: Type: text/plain, Size: 138 bytes --]
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