Commit 92a93fd5 authored by David S. Miller's avatar David S. Miller

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: default avatarDavid S. Miller <davem@davemloft.net>
parents 4ef7ea91 c96356a9
...@@ -1247,7 +1247,7 @@ static void ...@@ -1247,7 +1247,7 @@ static void
l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
{ {
struct PStack *st = fi->userdata; struct PStack *st = fi->userdata;
struct sk_buff *skb; struct sk_buff *skb, *nskb;
struct Layer2 *l2 = &st->l2; struct Layer2 *l2 = &st->l2;
u_char header[MAX_HEADER_LEN]; u_char header[MAX_HEADER_LEN];
int i, hdr_space_needed; int i, hdr_space_needed;
...@@ -1262,15 +1262,11 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) ...@@ -1262,15 +1262,11 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
return; return;
hdr_space_needed = l2headersize(l2, 0); hdr_space_needed = l2headersize(l2, 0);
if (hdr_space_needed > skb_headroom(skb)) { nskb = skb_realloc_headroom(skb, hdr_space_needed);
struct sk_buff *orig_skb = skb; if (!nskb) {
skb_queue_head(&l2->i_queue, skb);
skb = skb_realloc_headroom(skb, hdr_space_needed);
if (!skb) {
dev_kfree_skb(orig_skb);
return; return;
} }
}
spin_lock_irqsave(&l2->lock, flags); spin_lock_irqsave(&l2->lock, flags);
if (test_bit(FLG_MOD128, &l2->flag)) if (test_bit(FLG_MOD128, &l2->flag))
p1 = (l2->vs - l2->va) % 128; p1 = (l2->vs - l2->va) % 128;
...@@ -1282,7 +1278,7 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) ...@@ -1282,7 +1278,7 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
p1); p1);
dev_kfree_skb(l2->windowar[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); i = sethdraddr(&st->l2, header, CMD);
...@@ -1295,8 +1291,8 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) ...@@ -1295,8 +1291,8 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
l2->vs = (l2->vs + 1) % 8; l2->vs = (l2->vs + 1) % 8;
} }
spin_unlock_irqrestore(&l2->lock, flags); spin_unlock_irqrestore(&l2->lock, flags);
memcpy(skb_push(skb, i), header, i); memcpy(skb_push(nskb, i), header, i);
st->l2.l2l1(st, PH_PULL | INDICATION, skb); st->l2.l2l1(st, PH_PULL | INDICATION, nskb);
test_and_clear_bit(FLG_ACK_PEND, &st->l2.flag); test_and_clear_bit(FLG_ACK_PEND, &st->l2.flag);
if (!test_and_set_bit(FLG_T200_RUN, &st->l2.flag)) { if (!test_and_set_bit(FLG_T200_RUN, &st->l2.flag)) {
FsmDelTimer(&st->l2.t203, 13); FsmDelTimer(&st->l2.t203, 13);
......
...@@ -1476,7 +1476,7 @@ static void ...@@ -1476,7 +1476,7 @@ static void
l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
{ {
struct layer2 *l2 = fi->userdata; struct layer2 *l2 = fi->userdata;
struct sk_buff *skb, *nskb, *oskb; struct sk_buff *skb, *nskb;
u_char header[MAX_L2HEADER_LEN]; u_char header[MAX_L2HEADER_LEN];
u_int i, p1; u_int i, p1;
...@@ -1486,11 +1486,26 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) ...@@ -1486,11 +1486,26 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
skb = skb_dequeue(&l2->i_queue); skb = skb_dequeue(&l2->i_queue);
if (!skb) if (!skb)
return; return;
i = sethdraddr(l2, header, CMD);
if (test_bit(FLG_MOD128, &l2->flag)) 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; p1 = (l2->vs - l2->va) % 128;
else l2->vs = (l2->vs + 1) % 128;
} else {
p1 = (l2->vs - l2->va) % 8; p1 = (l2->vs - l2->va) % 8;
l2->vs = (l2->vs + 1) % 8;
}
p1 = (p1 + l2->sow) % l2->window; p1 = (p1 + l2->sow) % l2->window;
if (l2->windowar[p1]) { if (l2->windowar[p1]) {
printk(KERN_WARNING "%s: l2 try overwrite ack queue entry %d\n", printk(KERN_WARNING "%s: l2 try overwrite ack queue entry %d\n",
...@@ -1498,36 +1513,7 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) ...@@ -1498,36 +1513,7 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)
dev_kfree_skb(l2->windowar[p1]); dev_kfree_skb(l2->windowar[p1]);
} }
l2->windowar[p1] = skb; 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); 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);
}
l2down(l2, PH_DATA_REQ, l2_newid(l2), nskb); l2down(l2, PH_DATA_REQ, l2_newid(l2), nskb);
test_and_clear_bit(FLG_ACK_PEND, &l2->flag); test_and_clear_bit(FLG_ACK_PEND, &l2->flag);
if (!test_and_set_bit(FLG_T200_RUN, &l2->flag)) { if (!test_and_set_bit(FLG_T200_RUN, &l2->flag)) {
......
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