Merge branch 'isdn-null-deref'
Karsten Keil says:
====================
Fix potential NULL pointer access and memory leak in ISDN layer2 functions
Insu Yun did brinup the issue with not checking the skb_clone() return
value in the layer2 I-frame ull functions.
This series fix the issue in a way which avoid protocol violations/data loss
on a temporary memory shortage.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/isdn/hisax/isdnl2.c b/drivers/isdn/hisax/isdnl2.c
index 18accb0..c53a53f 100644
--- a/drivers/isdn/hisax/isdnl2.c
+++ b/drivers/isdn/hisax/isdnl2.c
@@ -1247,7 +1247,7 @@
l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
{
struct PStack *st = fi->userdata;
- struct sk_buff *skb;
+ struct sk_buff *skb, *nskb;
struct Layer2 *l2 = &st->l2;
u_char header[MAX_HEADER_LEN];
int i, hdr_space_needed;
@@ -1262,14 +1262,10 @@
return;
hdr_space_needed = l2headersize(l2, 0);
- if (hdr_space_needed > skb_headroom(skb)) {
- struct sk_buff *orig_skb = skb;
-
- skb = skb_realloc_headroom(skb, hdr_space_needed);
- if (!skb) {
- dev_kfree_skb(orig_skb);
- return;
- }
+ nskb = skb_realloc_headroom(skb, hdr_space_needed);
+ if (!nskb) {
+ skb_queue_head(&l2->i_queue, skb);
+ return;
}
spin_lock_irqsave(&l2->lock, flags);
if (test_bit(FLG_MOD128, &l2->flag))
@@ -1282,7 +1278,7 @@
p1);
dev_kfree_skb(l2->windowar[p1]);
}
- l2->windowar[p1] = skb_clone(skb, GFP_ATOMIC);
+ l2->windowar[p1] = skb;
i = sethdraddr(&st->l2, header, CMD);
@@ -1295,8 +1291,8 @@
l2->vs = (l2->vs + 1) % 8;
}
spin_unlock_irqrestore(&l2->lock, flags);
- memcpy(skb_push(skb, i), header, i);
- st->l2.l2l1(st, PH_PULL | INDICATION, skb);
+ memcpy(skb_push(nskb, i), header, i);
+ st->l2.l2l1(st, PH_PULL | INDICATION, nskb);
test_and_clear_bit(FLG_ACK_PEND, &st->l2.flag);
if (!test_and_set_bit(FLG_T200_RUN, &st->l2.flag)) {
FsmDelTimer(&st->l2.t203, 13);
diff --git a/drivers/isdn/mISDN/layer2.c b/drivers/isdn/mISDN/layer2.c
index 949cabb..5eb380a 100644
--- a/drivers/isdn/mISDN/layer2.c
+++ b/drivers/isdn/mISDN/layer2.c
@@ -1476,7 +1476,7 @@
l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
{
struct layer2 *l2 = fi->userdata;
- struct sk_buff *skb, *nskb, *oskb;
+ struct sk_buff *skb, *nskb;
u_char header[MAX_L2HEADER_LEN];
u_int i, p1;
@@ -1486,11 +1486,26 @@
skb = skb_dequeue(&l2->i_queue);
if (!skb)
return;
-
- if (test_bit(FLG_MOD128, &l2->flag))
+ i = sethdraddr(l2, header, CMD);
+ if (test_bit(FLG_MOD128, &l2->flag)) {
+ header[i++] = l2->vs << 1;
+ header[i++] = l2->vr << 1;
+ } else
+ header[i++] = (l2->vr << 5) | (l2->vs << 1);
+ nskb = skb_realloc_headroom(skb, i);
+ if (!nskb) {
+ printk(KERN_WARNING "%s: no headroom(%d) copy for IFrame\n",
+ mISDNDevName4ch(&l2->ch), i);
+ skb_queue_head(&l2->i_queue, skb);
+ return;
+ }
+ if (test_bit(FLG_MOD128, &l2->flag)) {
p1 = (l2->vs - l2->va) % 128;
- else
+ l2->vs = (l2->vs + 1) % 128;
+ } else {
p1 = (l2->vs - l2->va) % 8;
+ l2->vs = (l2->vs + 1) % 8;
+ }
p1 = (p1 + l2->sow) % l2->window;
if (l2->windowar[p1]) {
printk(KERN_WARNING "%s: l2 try overwrite ack queue entry %d\n",
@@ -1498,36 +1513,7 @@
dev_kfree_skb(l2->windowar[p1]);
}
l2->windowar[p1] = skb;
- i = sethdraddr(l2, header, CMD);
- if (test_bit(FLG_MOD128, &l2->flag)) {
- header[i++] = l2->vs << 1;
- header[i++] = l2->vr << 1;
- l2->vs = (l2->vs + 1) % 128;
- } else {
- header[i++] = (l2->vr << 5) | (l2->vs << 1);
- l2->vs = (l2->vs + 1) % 8;
- }
-
- nskb = skb_clone(skb, GFP_ATOMIC);
- p1 = skb_headroom(nskb);
- if (p1 >= i)
- memcpy(skb_push(nskb, i), header, i);
- else {
- printk(KERN_WARNING
- "%s: L2 pull_iqueue skb header(%d/%d) too short\n",
- mISDNDevName4ch(&l2->ch), i, p1);
- oskb = nskb;
- nskb = mI_alloc_skb(oskb->len + i, GFP_ATOMIC);
- if (!nskb) {
- dev_kfree_skb(oskb);
- printk(KERN_WARNING "%s: no skb mem in %s\n",
- mISDNDevName4ch(&l2->ch), __func__);
- return;
- }
- memcpy(skb_put(nskb, i), header, i);
- memcpy(skb_put(nskb, oskb->len), oskb->data, oskb->len);
- dev_kfree_skb(oskb);
- }
+ memcpy(skb_push(nskb, i), header, i);
l2down(l2, PH_DATA_REQ, l2_newid(l2), nskb);
test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
if (!test_and_set_bit(FLG_T200_RUN, &l2->flag)) {