Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

Daniel Borkmann says:

====================
pull-request: bpf 2018-03-08

The following pull-request contains BPF updates for your *net* tree.

The main changes are:

1) Fix various BPF helpers which adjust the skb and its GSO information
   with regards to SCTP GSO. The latter is a special case where gso_size
   is of value GSO_BY_FRAGS, so mangling that will end up corrupting
   the skb, thus bail out when seeing SCTP GSO packets, from Daniel(s).

2) Fix a compilation error in bpftool where BPF_FS_MAGIC is not defined
   due to too old kernel headers in the system, from Jiri.

3) Increase the number of x64 JIT passes in order to allow larger images
   to converge instead of punting them to interpreter or having them
   rejected when the interpreter is not built into the kernel, from Daniel.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 42 insertions, 18 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index 0c121adbdbaa..48aa7c7320db 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -2087,6 +2087,10 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
 	u32 off = skb_mac_header_len(skb);
 	int ret;
 
+	/* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+	if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+		return -ENOTSUPP;
+
 	ret = skb_cow(skb, len_diff);
 	if (unlikely(ret < 0))
 		return ret;
@@ -2096,19 +2100,21 @@ static int bpf_skb_proto_4_to_6(struct sk_buff *skb)
 		return ret;
 
 	if (skb_is_gso(skb)) {
+		struct skb_shared_info *shinfo = skb_shinfo(skb);
+
 		/* SKB_GSO_TCPV4 needs to be changed into
 		 * SKB_GSO_TCPV6.
 		 */
-		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV4) {
-			skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV4;
-			skb_shinfo(skb)->gso_type |=  SKB_GSO_TCPV6;
+		if (shinfo->gso_type & SKB_GSO_TCPV4) {
+			shinfo->gso_type &= ~SKB_GSO_TCPV4;
+			shinfo->gso_type |=  SKB_GSO_TCPV6;
 		}
 
 		/* Due to IPv6 header, MSS needs to be downgraded. */
-		skb_shinfo(skb)->gso_size -= len_diff;
+		skb_decrease_gso_size(shinfo, len_diff);
 		/* Header must be checked, and gso_segs recomputed. */
-		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
-		skb_shinfo(skb)->gso_segs = 0;
+		shinfo->gso_type |= SKB_GSO_DODGY;
+		shinfo->gso_segs = 0;
 	}
 
 	skb->protocol = htons(ETH_P_IPV6);
@@ -2123,6 +2129,10 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
 	u32 off = skb_mac_header_len(skb);
 	int ret;
 
+	/* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+	if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+		return -ENOTSUPP;
+
 	ret = skb_unclone(skb, GFP_ATOMIC);
 	if (unlikely(ret < 0))
 		return ret;
@@ -2132,19 +2142,21 @@ static int bpf_skb_proto_6_to_4(struct sk_buff *skb)
 		return ret;
 
 	if (skb_is_gso(skb)) {
+		struct skb_shared_info *shinfo = skb_shinfo(skb);
+
 		/* SKB_GSO_TCPV6 needs to be changed into
 		 * SKB_GSO_TCPV4.
 		 */
-		if (skb_shinfo(skb)->gso_type & SKB_GSO_TCPV6) {
-			skb_shinfo(skb)->gso_type &= ~SKB_GSO_TCPV6;
-			skb_shinfo(skb)->gso_type |=  SKB_GSO_TCPV4;
+		if (shinfo->gso_type & SKB_GSO_TCPV6) {
+			shinfo->gso_type &= ~SKB_GSO_TCPV6;
+			shinfo->gso_type |=  SKB_GSO_TCPV4;
 		}
 
 		/* Due to IPv4 header, MSS can be upgraded. */
-		skb_shinfo(skb)->gso_size += len_diff;
+		skb_increase_gso_size(shinfo, len_diff);
 		/* Header must be checked, and gso_segs recomputed. */
-		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
-		skb_shinfo(skb)->gso_segs = 0;
+		shinfo->gso_type |= SKB_GSO_DODGY;
+		shinfo->gso_segs = 0;
 	}
 
 	skb->protocol = htons(ETH_P_IP);
@@ -2243,6 +2255,10 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 len_diff)
 	u32 off = skb_mac_header_len(skb) + bpf_skb_net_base_len(skb);
 	int ret;
 
+	/* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+	if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+		return -ENOTSUPP;
+
 	ret = skb_cow(skb, len_diff);
 	if (unlikely(ret < 0))
 		return ret;
@@ -2252,11 +2268,13 @@ static int bpf_skb_net_grow(struct sk_buff *skb, u32 len_diff)
 		return ret;
 
 	if (skb_is_gso(skb)) {
+		struct skb_shared_info *shinfo = skb_shinfo(skb);
+
 		/* Due to header grow, MSS needs to be downgraded. */
-		skb_shinfo(skb)->gso_size -= len_diff;
+		skb_decrease_gso_size(shinfo, len_diff);
 		/* Header must be checked, and gso_segs recomputed. */
-		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
-		skb_shinfo(skb)->gso_segs = 0;
+		shinfo->gso_type |= SKB_GSO_DODGY;
+		shinfo->gso_segs = 0;
 	}
 
 	return 0;
@@ -2267,6 +2285,10 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 len_diff)
 	u32 off = skb_mac_header_len(skb) + bpf_skb_net_base_len(skb);
 	int ret;
 
+	/* SCTP uses GSO_BY_FRAGS, thus cannot adjust it. */
+	if (skb_is_gso(skb) && unlikely(skb_is_gso_sctp(skb)))
+		return -ENOTSUPP;
+
 	ret = skb_unclone(skb, GFP_ATOMIC);
 	if (unlikely(ret < 0))
 		return ret;
@@ -2276,11 +2298,13 @@ static int bpf_skb_net_shrink(struct sk_buff *skb, u32 len_diff)
 		return ret;
 
 	if (skb_is_gso(skb)) {
+		struct skb_shared_info *shinfo = skb_shinfo(skb);
+
 		/* Due to header shrink, MSS can be upgraded. */
-		skb_shinfo(skb)->gso_size += len_diff;
+		skb_increase_gso_size(shinfo, len_diff);
 		/* Header must be checked, and gso_segs recomputed. */
-		skb_shinfo(skb)->gso_type |= SKB_GSO_DODGY;
-		skb_shinfo(skb)->gso_segs = 0;
+		shinfo->gso_type |= SKB_GSO_DODGY;
+		shinfo->gso_segs = 0;
 	}
 
 	return 0;