1 files changed, 17 insertions, 21 deletions

diff --git a/net/xfrm/xfrm_ipcomp.c b/net/xfrm/xfrm_ipcomp.c
index 4d422447aadc..80143360bf09 100644
--- a/net/xfrm/xfrm_ipcomp.c
+++ b/net/xfrm/xfrm_ipcomp.c
@@ -41,19 +41,16 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
 	const int plen = skb->len;
 	int dlen = IPCOMP_SCRATCH_SIZE;
 	const u8 *start = skb->data;
-	const int cpu = get_cpu();
-	u8 *scratch = *per_cpu_ptr(ipcomp_scratches, cpu);
-	struct crypto_comp *tfm = *per_cpu_ptr(ipcd->tfms, cpu);
+	u8 *scratch = *this_cpu_ptr(ipcomp_scratches);
+	struct crypto_comp *tfm = *this_cpu_ptr(ipcd->tfms);
 	int err = crypto_comp_decompress(tfm, start, plen, scratch, &dlen);
 	int len;
 
 	if (err)
-		goto out;
+		return err;
 
-	if (dlen < (plen + sizeof(struct ip_comp_hdr))) {
-		err = -EINVAL;
-		goto out;
-	}
+	if (dlen < (plen + sizeof(struct ip_comp_hdr)))
+		return -EINVAL;
 
 	len = dlen - plen;
 	if (len > skb_tailroom(skb))
@@ -68,16 +65,14 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
 		skb_frag_t *frag;
 		struct page *page;
 
-		err = -EMSGSIZE;
 		if (WARN_ON(skb_shinfo(skb)->nr_frags >= MAX_SKB_FRAGS))
-			goto out;
+			return -EMSGSIZE;
 
 		frag = skb_shinfo(skb)->frags + skb_shinfo(skb)->nr_frags;
 		page = alloc_page(GFP_ATOMIC);
 
-		err = -ENOMEM;
 		if (!page)
-			goto out;
+			return -ENOMEM;
 
 		__skb_frag_set_page(frag, page);
 
@@ -96,11 +91,7 @@ static int ipcomp_decompress(struct xfrm_state *x, struct sk_buff *skb)
 		skb_shinfo(skb)->nr_frags++;
 	}
 
-	err = 0;
-
-out:
-	put_cpu();
-	return err;
+	return 0;
 }
 
 int ipcomp_input(struct xfrm_state *x, struct sk_buff *skb)
@@ -212,6 +203,7 @@ static void ipcomp_free_scratches(void)
 		vfree(*per_cpu_ptr(scratches, i));
 
 	free_percpu(scratches);
+	ipcomp_scratches = NULL;
 }
 
 static void * __percpu *ipcomp_alloc_scratches(void)
@@ -250,7 +242,7 @@ static void ipcomp_free_tfms(struct crypto_comp * __percpu *tfms)
 			break;
 	}
 
-	WARN_ON(!pos);
+	WARN_ON(list_entry_is_head(pos, &ipcomp_tfms_list, list));
 
 	if (--pos->users)
 		return;
@@ -334,18 +326,22 @@ void ipcomp_destroy(struct xfrm_state *x)
 }
 EXPORT_SYMBOL_GPL(ipcomp_destroy);
 
-int ipcomp_init_state(struct xfrm_state *x)
+int ipcomp_init_state(struct xfrm_state *x, struct netlink_ext_ack *extack)
 {
 	int err;
 	struct ipcomp_data *ipcd;
 	struct xfrm_algo_desc *calg_desc;
 
 	err = -EINVAL;
-	if (!x->calg)
+	if (!x->calg) {
+		NL_SET_ERR_MSG(extack, "Missing required compression algorithm");
 		goto out;
+	}
 
-	if (x->encap)
+	if (x->encap) {
+		NL_SET_ERR_MSG(extack, "IPComp is not compatible with encapsulation");
 		goto out;
+	}
 
 	err = -ENOMEM;
 	ipcd = kzalloc(sizeof(*ipcd), GFP_KERNEL);