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Commit c978e7bb authored by David S. Miller's avatar David S. Miller
Browse files

hisax: Fix unchecked alloc_skb() return. 



Jesper Juhl noticed that l2_pull_iqueue() does not
check to see if alloc_skb() fails.

Fix this by first trying to reallocate the headroom
if necessary, rather than later after we've made hard
to undo state changes.

Reported-by: default avatarJesper Juhl <jj@chaosbits.net>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent ab60707f

drivers/isdn/hisax/isdnl2.c

+20 −15
Original line number Diff line number Diff line
@@ -1243,14 +1243,21 @@ l2_st7_tout_203(struct FsmInst *fi, int event, void *arg) 
	st->l2.rc = 0;

}



static int l2_hdr_space_needed(struct Layer2 *l2)

{

	int len = test_bit(FLG_LAPD, &l2->flag) ? 2 : 1;



	return len + (test_bit(FLG_LAPD, &l2->flag) ? 2 : 1);

}



static void

l2_pull_iqueue(struct FsmInst *fi, int event, void *arg)

{

	struct PStack *st = fi->userdata;

	struct sk_buff *skb, *oskb;

	struct sk_buff *skb;

	struct Layer2 *l2 = &st->l2;

	u_char header[MAX_HEADER_LEN];

	int i;

	int i, hdr_space_needed;

	int unsigned p1;

	u_long flags;
@@ -1261,6 +1268,16 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) 
	if (!skb)

		return;



	hdr_space_needed = l2_hdr_space_needed(l2);

	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;

		}

	}

	spin_lock_irqsave(&l2->lock, flags);

	if(test_bit(FLG_MOD128, &l2->flag))

		p1 = (l2->vs - l2->va) % 128;
@@ -1285,19 +1302,7 @@ l2_pull_iqueue(struct FsmInst *fi, int event, void *arg) 
		l2->vs = (l2->vs + 1) % 8;

	}

	spin_unlock_irqrestore(&l2->lock, flags);

	p1 = skb->data - skb->head;

	if (p1 >= i)

	memcpy(skb_push(skb, i), header, i);

	else {

		printk(KERN_WARNING

		"isdl2 pull_iqueue skb header(%d/%d) too short\n", i, p1);

		oskb = skb;

		skb = alloc_skb(oskb->len + i, GFP_ATOMIC);

		memcpy(skb_put(skb, i), header, i);

		skb_copy_from_linear_data(oskb,

					  skb_put(skb, oskb->len), oskb->len);

		dev_kfree_skb(oskb);

	}

	st->l2.l2l1(st, PH_PULL | INDICATION, skb);

	test_and_clear_bit(FLG_ACK_PEND, &st->l2.flag);

	if (!test_and_set_bit(FLG_T200_RUN, &st->l2.flag)) {