1 files changed, 278 insertions, 236 deletions

diff --git a/net/core/filter.c b/net/core/filter.c
index ae21a0d3c4a2..2b27d4efdd48 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -37,9 +37,69 @@
 #include <asm/uaccess.h>
 #include <asm/unaligned.h>
 #include <linux/filter.h>
+#include <linux/reciprocal_div.h>
+
+enum {
+	BPF_S_RET_K = 1,
+	BPF_S_RET_A,
+	BPF_S_ALU_ADD_K,
+	BPF_S_ALU_ADD_X,
+	BPF_S_ALU_SUB_K,
+	BPF_S_ALU_SUB_X,
+	BPF_S_ALU_MUL_K,
+	BPF_S_ALU_MUL_X,
+	BPF_S_ALU_DIV_X,
+	BPF_S_ALU_AND_K,
+	BPF_S_ALU_AND_X,
+	BPF_S_ALU_OR_K,
+	BPF_S_ALU_OR_X,
+	BPF_S_ALU_LSH_K,
+	BPF_S_ALU_LSH_X,
+	BPF_S_ALU_RSH_K,
+	BPF_S_ALU_RSH_X,
+	BPF_S_ALU_NEG,
+	BPF_S_LD_W_ABS,
+	BPF_S_LD_H_ABS,
+	BPF_S_LD_B_ABS,
+	BPF_S_LD_W_LEN,
+	BPF_S_LD_W_IND,
+	BPF_S_LD_H_IND,
+	BPF_S_LD_B_IND,
+	BPF_S_LD_IMM,
+	BPF_S_LDX_W_LEN,
+	BPF_S_LDX_B_MSH,
+	BPF_S_LDX_IMM,
+	BPF_S_MISC_TAX,
+	BPF_S_MISC_TXA,
+	BPF_S_ALU_DIV_K,
+	BPF_S_LD_MEM,
+	BPF_S_LDX_MEM,
+	BPF_S_ST,
+	BPF_S_STX,
+	BPF_S_JMP_JA,
+	BPF_S_JMP_JEQ_K,
+	BPF_S_JMP_JEQ_X,
+	BPF_S_JMP_JGE_K,
+	BPF_S_JMP_JGE_X,
+	BPF_S_JMP_JGT_K,
+	BPF_S_JMP_JGT_X,
+	BPF_S_JMP_JSET_K,
+	BPF_S_JMP_JSET_X,
+	/* Ancillary data */
+	BPF_S_ANC_PROTOCOL,
+	BPF_S_ANC_PKTTYPE,
+	BPF_S_ANC_IFINDEX,
+	BPF_S_ANC_NLATTR,
+	BPF_S_ANC_NLATTR_NEST,
+	BPF_S_ANC_MARK,
+	BPF_S_ANC_QUEUE,
+	BPF_S_ANC_HATYPE,
+	BPF_S_ANC_RXHASH,
+	BPF_S_ANC_CPU,
+};
 
 /* No hurry in this branch */
-static void *__load_pointer(struct sk_buff *skb, int k)
+static void *__load_pointer(const struct sk_buff *skb, int k, unsigned int size)
 {
 	u8 *ptr = NULL;
 
@@ -48,21 +108,17 @@ static void *__load_pointer(struct sk_buff *skb, int k)
 	else if (k >= SKF_LL_OFF)
 		ptr = skb_mac_header(skb) + k - SKF_LL_OFF;
 
-	if (ptr >= skb->head && ptr < skb_tail_pointer(skb))
+	if (ptr >= skb->head && ptr + size <= skb_tail_pointer(skb))
 		return ptr;
 	return NULL;
 }
 
-static inline void *load_pointer(struct sk_buff *skb, int k,
+static inline void *load_pointer(const struct sk_buff *skb, int k,
 				 unsigned int size, void *buffer)
 {
 	if (k >= 0)
 		return skb_header_pointer(skb, k, size, buffer);
-	else {
-		if (k >= SKF_AD_OFF)
-			return NULL;
-		return __load_pointer(skb, k);
-	}
+	return __load_pointer(skb, k, size);
 }
 
 /**
@@ -89,7 +145,7 @@ int sk_filter(struct sock *sk, struct sk_buff *skb)
 	rcu_read_lock_bh();
 	filter = rcu_dereference_bh(sk->sk_filter);
 	if (filter) {
-		unsigned int pkt_len = sk_run_filter(skb, filter->insns, filter->len);
+		unsigned int pkt_len = sk_run_filter(skb, filter->insns);
 
 		err = pkt_len ? pskb_trim(skb, pkt_len) : -EPERM;
 	}
@@ -103,50 +159,52 @@ EXPORT_SYMBOL(sk_filter);
  *	sk_run_filter - run a filter on a socket
  *	@skb: buffer to run the filter on
  *	@filter: filter to apply
- *	@flen: length of filter
  *
  * Decode and apply filter instructions to the skb->data.
- * Return length to keep, 0 for none. skb is the data we are
- * filtering, filter is the array of filter instructions, and
- * len is the number of filter blocks in the array.
+ * Return length to keep, 0 for none. @skb is the data we are
+ * filtering, @filter is the array of filter instructions.
+ * Because all jumps are guaranteed to be before last instruction,
+ * and last instruction guaranteed to be a RET, we dont need to check
+ * flen. (We used to pass to this function the length of filter)
  */
-unsigned int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int flen)
+unsigned int sk_run_filter(const struct sk_buff *skb,
+			   const struct sock_filter *fentry)
 {
 	void *ptr;
 	u32 A = 0;			/* Accumulator */
 	u32 X = 0;			/* Index Register */
 	u32 mem[BPF_MEMWORDS];		/* Scratch Memory Store */
-	unsigned long memvalid = 0;
 	u32 tmp;
 	int k;
-	int pc;
 
-	BUILD_BUG_ON(BPF_MEMWORDS > BITS_PER_LONG);
 	/*
 	 * Process array of filter instructions.
 	 */
-	for (pc = 0; pc < flen; pc++) {
-		const struct sock_filter *fentry = &filter[pc];
-		u32 f_k = fentry->k;
+	for (;; fentry++) {
+#if defined(CONFIG_X86_32)
+#define	K (fentry->k)
+#else
+		const u32 K = fentry->k;
+#endif
 
 		switch (fentry->code) {
 		case BPF_S_ALU_ADD_X:
 			A += X;
 			continue;
 		case BPF_S_ALU_ADD_K:
-			A += f_k;
+			A += K;
 			continue;
 		case BPF_S_ALU_SUB_X:
 			A -= X;
 			continue;
 		case BPF_S_ALU_SUB_K:
-			A -= f_k;
+			A -= K;
 			continue;
 		case BPF_S_ALU_MUL_X:
 			A *= X;
 			continue;
 		case BPF_S_ALU_MUL_K:
-			A *= f_k;
+			A *= K;
 			continue;
 		case BPF_S_ALU_DIV_X:
 			if (X == 0)
@@ -154,89 +212,89 @@ unsigned int sk_run_filter(struct sk_buff *skb, struct sock_filter *filter, int
 			A /= X;
 			continue;
 		case BPF_S_ALU_DIV_K:
-			A /= f_k;
+			A = reciprocal_divide(A, K);
 			continue;
 		case BPF_S_ALU_AND_X:
 			A &= X;
 			continue;
 		case BPF_S_ALU_AND_K:
-			A &= f_k;
+			A &= K;
 			continue;
 		case BPF_S_ALU_OR_X:
 			A |= X;
 			continue;
 		case BPF_S_ALU_OR_K:
-			A |= f_k;
+			A |= K;
 			continue;
 		case BPF_S_ALU_LSH_X:
 			A <<= X;
 			continue;
 		case BPF_S_ALU_LSH_K:
-			A <<= f_k;
+			A <<= K;
 			continue;
 		case BPF_S_ALU_RSH_X:
 			A >>= X;
 			continue;
 		case BPF_S_ALU_RSH_K:
-			A >>= f_k;
+			A >>= K;
 			continue;
 		case BPF_S_ALU_NEG:
 			A = -A;
 			continue;
 		case BPF_S_JMP_JA:
-			pc += f_k;
+			fentry += K;
 			continue;
 		case BPF_S_JMP_JGT_K:
-			pc += (A > f_k) ? fentry->jt : fentry->jf;
+			fentry += (A > K) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JGE_K:
-			pc += (A >= f_k) ? fentry->jt : fentry->jf;
+			fentry += (A >= K) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JEQ_K:
-			pc += (A == f_k) ? fentry->jt : fentry->jf;
+			fentry += (A == K) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JSET_K:
-			pc += (A & f_k) ? fentry->jt : fentry->jf;
+			fentry += (A & K) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JGT_X:
-			pc += (A > X) ? fentry->jt : fentry->jf;
+			fentry += (A > X) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JGE_X:
-			pc += (A >= X) ? fentry->jt : fentry->jf;
+			fentry += (A >= X) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JEQ_X:
-			pc += (A == X) ? fentry->jt : fentry->jf;
+			fentry += (A == X) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_JMP_JSET_X:
-			pc += (A & X) ? fentry->jt : fentry->jf;
+			fentry += (A & X) ? fentry->jt : fentry->jf;
 			continue;
 		case BPF_S_LD_W_ABS:
-			k = f_k;
+			k = K;
 load_w:
 			ptr = load_pointer(skb, k, 4, &tmp);
 			if (ptr != NULL) {
 				A = get_unaligned_be32(ptr);
 				continue;
 			}
-			break;
+			return 0;
 		case BPF_S_LD_H_ABS:
-			k = f_k;
+			k = K;
 load_h:
 			ptr = load_pointer(skb, k, 2, &tmp);
 			if (ptr != NULL) {
 				A = get_unaligned_be16(ptr);
 				continue;
 			}
-			break;
+			return 0;
 		case BPF_S_LD_B_ABS:
-			k = f_k;
+			k = K;
 load_b:
 			ptr = load_pointer(skb, k, 1, &tmp);
 			if (ptr != NULL) {
 				A = *(u8 *)ptr;
 				continue;
 			}
-			break;
+			return 0;
 		case BPF_S_LD_W_LEN:
 			A = skb->len;
 			continue;
@@ -244,34 +302,32 @@ load_b:
 			X = skb->len;
 			continue;
 		case BPF_S_LD_W_IND:
-			k = X + f_k;
+			k = X + K;
 			goto load_w;
 		case BPF_S_LD_H_IND:
-			k = X + f_k;
+			k = X + K;
 			goto load_h;
 		case BPF_S_LD_B_IND:
-			k = X + f_k;
+			k = X + K;
 			goto load_b;
 		case BPF_S_LDX_B_MSH:
-			ptr = load_pointer(skb, f_k, 1, &tmp);
+			ptr = load_pointer(skb, K, 1, &tmp);
 			if (ptr != NULL) {
 				X = (*(u8 *)ptr & 0xf) << 2;
 				continue;
 			}
 			return 0;
 		case BPF_S_LD_IMM:
-			A = f_k;
+			A = K;
 			continue;
 		case BPF_S_LDX_IMM:
-			X = f_k;
+			X = K;
 			continue;
 		case BPF_S_LD_MEM:
-			A = (memvalid & (1UL << f_k)) ?
-				mem[f_k] : 0;
+			A = mem[K];
 			continue;
 		case BPF_S_LDX_MEM:
-			X = (memvalid & (1UL << f_k)) ?
-				mem[f_k] : 0;
+			X = mem[K];
 			continue;
 		case BPF_S_MISC_TAX:
 			X = A;
@@ -280,50 +336,44 @@ load_b:
 			A = X;
 			continue;
 		case BPF_S_RET_K:
-			return f_k;
+			return K;
 		case BPF_S_RET_A:
 			return A;
 		case BPF_S_ST:
-			memvalid |= 1UL << f_k;
-			mem[f_k] = A;
+			mem[K] = A;
 			continue;
 		case BPF_S_STX:
-			memvalid |= 1UL << f_k;
-			mem[f_k] = X;
+			mem[K] = X;
 			continue;
-		default:
-			WARN_ON(1);
-			return 0;
-		}
-
-		/*
-		 * Handle ancillary data, which are impossible
-		 * (or very difficult) to get parsing packet contents.
-		 */
-		switch (k-SKF_AD_OFF) {
-		case SKF_AD_PROTOCOL:
+		case BPF_S_ANC_PROTOCOL:
 			A = ntohs(skb->protocol);
 			continue;
-		case SKF_AD_PKTTYPE:
+		case BPF_S_ANC_PKTTYPE:
 			A = skb->pkt_type;
 			continue;
-		case SKF_AD_IFINDEX:
+		case BPF_S_ANC_IFINDEX:
 			if (!skb->dev)
 				return 0;
 			A = skb->dev->ifindex;
 			continue;
-		case SKF_AD_MARK:
+		case BPF_S_ANC_MARK:
 			A = skb->mark;
 			continue;
-		case SKF_AD_QUEUE:
+		case BPF_S_ANC_QUEUE:
 			A = skb->queue_mapping;
 			continue;
-		case SKF_AD_HATYPE:
+		case BPF_S_ANC_HATYPE:
 			if (!skb->dev)
 				return 0;
 			A = skb->dev->type;
 			continue;
-		case SKF_AD_NLATTR: {
+		case BPF_S_ANC_RXHASH:
+			A = skb->rxhash;
+			continue;
+		case BPF_S_ANC_CPU:
+			A = raw_smp_processor_id();
+			continue;
+		case BPF_S_ANC_NLATTR: {
 			struct nlattr *nla;
 
 			if (skb_is_nonlinear(skb))
@@ -339,7 +389,7 @@ load_b:
 				A = 0;
 			continue;
 		}
-		case SKF_AD_NLATTR_NEST: {
+		case BPF_S_ANC_NLATTR_NEST: {
 			struct nlattr *nla;
 
 			if (skb_is_nonlinear(skb))
@@ -359,6 +409,7 @@ load_b:
 			continue;
 		}
 		default:
+			WARN_ON(1);
 			return 0;
 		}
 	}
@@ -367,6 +418,66 @@ load_b:
 }
 EXPORT_SYMBOL(sk_run_filter);
 
+/*
+ * Security :
+ * A BPF program is able to use 16 cells of memory to store intermediate
+ * values (check u32 mem[BPF_MEMWORDS] in sk_run_filter())
+ * As we dont want to clear mem[] array for each packet going through
+ * sk_run_filter(), we check that filter loaded by user never try to read
+ * a cell if not previously written, and we check all branches to be sure
+ * a malicious user doesnt try to abuse us.
+ */
+static int check_load_and_stores(struct sock_filter *filter, int flen)
+{
+	u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */
+	int pc, ret = 0;
+
+	BUILD_BUG_ON(BPF_MEMWORDS > 16);
+	masks = kmalloc(flen * sizeof(*masks), GFP_KERNEL);
+	if (!masks)
+		return -ENOMEM;
+	memset(masks, 0xff, flen * sizeof(*masks));
+
+	for (pc = 0; pc < flen; pc++) {
+		memvalid &= masks[pc];
+
+		switch (filter[pc].code) {
+		case BPF_S_ST:
+		case BPF_S_STX:
+			memvalid |= (1 << filter[pc].k);
+			break;
+		case BPF_S_LD_MEM:
+		case BPF_S_LDX_MEM:
+			if (!(memvalid & (1 << filter[pc].k))) {
+				ret = -EINVAL;
+				goto error;
+			}
+			break;
+		case BPF_S_JMP_JA:
+			/* a jump must set masks on target */
+			masks[pc + 1 + filter[pc].k] &= memvalid;
+			memvalid = ~0;
+			break;
+		case BPF_S_JMP_JEQ_K:
+		case BPF_S_JMP_JEQ_X:
+		case BPF_S_JMP_JGE_K:
+		case BPF_S_JMP_JGE_X:
+		case BPF_S_JMP_JGT_K:
+		case BPF_S_JMP_JGT_X:
+		case BPF_S_JMP_JSET_X:
+		case BPF_S_JMP_JSET_K:
+			/* a jump must set masks on targets */
+			masks[pc + 1 + filter[pc].jt] &= memvalid;
+			masks[pc + 1 + filter[pc].jf] &= memvalid;
+			memvalid = ~0;
+			break;
+		}
+	}
+error:
+	kfree(masks);
+	return ret;
+}
+
 /**
  *	sk_chk_filter - verify socket filter code
  *	@filter: filter to verify
@@ -383,7 +494,57 @@ EXPORT_SYMBOL(sk_run_filter);
  */
 int sk_chk_filter(struct sock_filter *filter, int flen)
 {
-	struct sock_filter *ftest;
+	/*
+	 * Valid instructions are initialized to non-0.
+	 * Invalid instructions are initialized to 0.
+	 */
+	static const u8 codes[] = {
+		[BPF_ALU|BPF_ADD|BPF_K]  = BPF_S_ALU_ADD_K,
+		[BPF_ALU|BPF_ADD|BPF_X]  = BPF_S_ALU_ADD_X,
+		[BPF_ALU|BPF_SUB|BPF_K]  = BPF_S_ALU_SUB_K,
+		[BPF_ALU|BPF_SUB|BPF_X]  = BPF_S_ALU_SUB_X,
+		[BPF_ALU|BPF_MUL|BPF_K]  = BPF_S_ALU_MUL_K,
+		[BPF_ALU|BPF_MUL|BPF_X]  = BPF_S_ALU_MUL_X,
+		[BPF_ALU|BPF_DIV|BPF_X]  = BPF_S_ALU_DIV_X,
+		[BPF_ALU|BPF_AND|BPF_K]  = BPF_S_ALU_AND_K,
+		[BPF_ALU|BPF_AND|BPF_X]  = BPF_S_ALU_AND_X,
+		[BPF_ALU|BPF_OR|BPF_K]   = BPF_S_ALU_OR_K,
+		[BPF_ALU|BPF_OR|BPF_X]   = BPF_S_ALU_OR_X,
+		[BPF_ALU|BPF_LSH|BPF_K]  = BPF_S_ALU_LSH_K,
+		[BPF_ALU|BPF_LSH|BPF_X]  = BPF_S_ALU_LSH_X,
+		[BPF_ALU|BPF_RSH|BPF_K]  = BPF_S_ALU_RSH_K,
+		[BPF_ALU|BPF_RSH|BPF_X]  = BPF_S_ALU_RSH_X,
+		[BPF_ALU|BPF_NEG]        = BPF_S_ALU_NEG,
+		[BPF_LD|BPF_W|BPF_ABS]   = BPF_S_LD_W_ABS,
+		[BPF_LD|BPF_H|BPF_ABS]   = BPF_S_LD_H_ABS,
+		[BPF_LD|BPF_B|BPF_ABS]   = BPF_S_LD_B_ABS,
+		[BPF_LD|BPF_W|BPF_LEN]   = BPF_S_LD_W_LEN,
+		[BPF_LD|BPF_W|BPF_IND]   = BPF_S_LD_W_IND,
+		[BPF_LD|BPF_H|BPF_IND]   = BPF_S_LD_H_IND,
+		[BPF_LD|BPF_B|BPF_IND]   = BPF_S_LD_B_IND,
+		[BPF_LD|BPF_IMM]         = BPF_S_LD_IMM,
+		[BPF_LDX|BPF_W|BPF_LEN]  = BPF_S_LDX_W_LEN,
+		[BPF_LDX|BPF_B|BPF_MSH]  = BPF_S_LDX_B_MSH,
+		[BPF_LDX|BPF_IMM]        = BPF_S_LDX_IMM,
+		[BPF_MISC|BPF_TAX]       = BPF_S_MISC_TAX,
+		[BPF_MISC|BPF_TXA]       = BPF_S_MISC_TXA,
+		[BPF_RET|BPF_K]          = BPF_S_RET_K,
+		[BPF_RET|BPF_A]          = BPF_S_RET_A,
+		[BPF_ALU|BPF_DIV|BPF_K]  = BPF_S_ALU_DIV_K,
+		[BPF_LD|BPF_MEM]         = BPF_S_LD_MEM,
+		[BPF_LDX|BPF_MEM]        = BPF_S_LDX_MEM,
+		[BPF_ST]                 = BPF_S_ST,
+		[BPF_STX]                = BPF_S_STX,
+		[BPF_JMP|BPF_JA]         = BPF_S_JMP_JA,
+		[BPF_JMP|BPF_JEQ|BPF_K]  = BPF_S_JMP_JEQ_K,
+		[BPF_JMP|BPF_JEQ|BPF_X]  = BPF_S_JMP_JEQ_X,
+		[BPF_JMP|BPF_JGE|BPF_K]  = BPF_S_JMP_JGE_K,
+		[BPF_JMP|BPF_JGE|BPF_X]  = BPF_S_JMP_JGE_X,
+		[BPF_JMP|BPF_JGT|BPF_K]  = BPF_S_JMP_JGT_K,
+		[BPF_JMP|BPF_JGT|BPF_X]  = BPF_S_JMP_JGT_X,
+		[BPF_JMP|BPF_JSET|BPF_K] = BPF_S_JMP_JSET_K,
+		[BPF_JMP|BPF_JSET|BPF_X] = BPF_S_JMP_JSET_X,
+	};
 	int pc;
 
 	if (flen == 0 || flen > BPF_MAXINSNS)
@@ -391,136 +552,31 @@ int sk_chk_filter(struct sock_filter *filter, int flen)
 
 	/* check the filter code now */
 	for (pc = 0; pc < flen; pc++) {
-		ftest = &filter[pc];
-
-		/* Only allow valid instructions */
-		switch (ftest->code) {
-		case BPF_ALU|BPF_ADD|BPF_K:
-			ftest->code = BPF_S_ALU_ADD_K;
-			break;
-		case BPF_ALU|BPF_ADD|BPF_X:
-			ftest->code = BPF_S_ALU_ADD_X;
-			break;
-		case BPF_ALU|BPF_SUB|BPF_K:
-			ftest->code = BPF_S_ALU_SUB_K;
-			break;
-		case BPF_ALU|BPF_SUB|BPF_X:
-			ftest->code = BPF_S_ALU_SUB_X;
-			break;
-		case BPF_ALU|BPF_MUL|BPF_K:
-			ftest->code = BPF_S_ALU_MUL_K;
-			break;
-		case BPF_ALU|BPF_MUL|BPF_X:
-			ftest->code = BPF_S_ALU_MUL_X;
-			break;
-		case BPF_ALU|BPF_DIV|BPF_X:
-			ftest->code = BPF_S_ALU_DIV_X;
-			break;
-		case BPF_ALU|BPF_AND|BPF_K:
-			ftest->code = BPF_S_ALU_AND_K;
-			break;
-		case BPF_ALU|BPF_AND|BPF_X:
-			ftest->code = BPF_S_ALU_AND_X;
-			break;
-		case BPF_ALU|BPF_OR|BPF_K:
-			ftest->code = BPF_S_ALU_OR_K;
-			break;
-		case BPF_ALU|BPF_OR|BPF_X:
-			ftest->code = BPF_S_ALU_OR_X;
-			break;
-		case BPF_ALU|BPF_LSH|BPF_K:
-			ftest->code = BPF_S_ALU_LSH_K;
-			break;
-		case BPF_ALU|BPF_LSH|BPF_X:
-			ftest->code = BPF_S_ALU_LSH_X;
-			break;
-		case BPF_ALU|BPF_RSH|BPF_K:
-			ftest->code = BPF_S_ALU_RSH_K;
-			break;
-		case BPF_ALU|BPF_RSH|BPF_X:
-			ftest->code = BPF_S_ALU_RSH_X;
-			break;
-		case BPF_ALU|BPF_NEG:
-			ftest->code = BPF_S_ALU_NEG;
-			break;
-		case BPF_LD|BPF_W|BPF_ABS:
-			ftest->code = BPF_S_LD_W_ABS;
-			break;
-		case BPF_LD|BPF_H|BPF_ABS:
-			ftest->code = BPF_S_LD_H_ABS;
-			break;
-		case BPF_LD|BPF_B|BPF_ABS:
-			ftest->code = BPF_S_LD_B_ABS;
-			break;
-		case BPF_LD|BPF_W|BPF_LEN:
-			ftest->code = BPF_S_LD_W_LEN;
-			break;
-		case BPF_LD|BPF_W|BPF_IND:
-			ftest->code = BPF_S_LD_W_IND;
-			break;
-		case BPF_LD|BPF_H|BPF_IND:
-			ftest->code = BPF_S_LD_H_IND;
-			break;
-		case BPF_LD|BPF_B|BPF_IND:
-			ftest->code = BPF_S_LD_B_IND;
-			break;
-		case BPF_LD|BPF_IMM:
-			ftest->code = BPF_S_LD_IMM;
-			break;
-		case BPF_LDX|BPF_W|BPF_LEN:
-			ftest->code = BPF_S_LDX_W_LEN;
-			break;
-		case BPF_LDX|BPF_B|BPF_MSH:
-			ftest->code = BPF_S_LDX_B_MSH;
-			break;
-		case BPF_LDX|BPF_IMM:
-			ftest->code = BPF_S_LDX_IMM;
-			break;
-		case BPF_MISC|BPF_TAX:
-			ftest->code = BPF_S_MISC_TAX;
-			break;
-		case BPF_MISC|BPF_TXA:
-			ftest->code = BPF_S_MISC_TXA;
-			break;
-		case BPF_RET|BPF_K:
-			ftest->code = BPF_S_RET_K;
-			break;
-		case BPF_RET|BPF_A:
-			ftest->code = BPF_S_RET_A;
-			break;
+		struct sock_filter *ftest = &filter[pc];
+		u16 code = ftest->code;
 
+		if (code >= ARRAY_SIZE(codes))
+			return -EINVAL;
+		code = codes[code];
+		if (!code)
+			return -EINVAL;
 		/* Some instructions need special checks */
-
+		switch (code) {
+		case BPF_S_ALU_DIV_K:
 			/* check for division by zero */
-		case BPF_ALU|BPF_DIV|BPF_K:
 			if (ftest->k == 0)
 				return -EINVAL;
-			ftest->code = BPF_S_ALU_DIV_K;
-			break;
-
-		/* check for invalid memory addresses */
-		case BPF_LD|BPF_MEM:
-			if (ftest->k >= BPF_MEMWORDS)
-				return -EINVAL;
-			ftest->code = BPF_S_LD_MEM;
-			break;
-		case BPF_LDX|BPF_MEM:
-			if (ftest->k >= BPF_MEMWORDS)
-				return -EINVAL;
-			ftest->code = BPF_S_LDX_MEM;
-			break;
-		case BPF_ST:
-			if (ftest->k >= BPF_MEMWORDS)
-				return -EINVAL;
-			ftest->code = BPF_S_ST;
+			ftest->k = reciprocal_value(ftest->k);
 			break;
-		case BPF_STX:
+		case BPF_S_LD_MEM:
+		case BPF_S_LDX_MEM:
+		case BPF_S_ST:
+		case BPF_S_STX:
+			/* check for invalid memory addresses */
 			if (ftest->k >= BPF_MEMWORDS)
 				return -EINVAL;
-			ftest->code = BPF_S_STX;
 			break;
-
-		case BPF_JMP|BPF_JA:
+		case BPF_S_JMP_JA:
 			/*
 			 * Note, the large ftest->k might cause loops.
 			 * Compare this with conditional jumps below,
@@ -528,40 +584,7 @@ int sk_chk_filter(struct sock_filter *filter, int flen)
 			 */
 			if (ftest->k >= (unsigned)(flen-pc-1))
 				return -EINVAL;
-			ftest->code = BPF_S_JMP_JA;
-			break;
-
-		case BPF_JMP|BPF_JEQ|BPF_K:
-			ftest->code = BPF_S_JMP_JEQ_K;
-			break;
-		case BPF_JMP|BPF_JEQ|BPF_X:
-			ftest->code = BPF_S_JMP_JEQ_X;
-			break;
-		case BPF_JMP|BPF_JGE|BPF_K:
-			ftest->code = BPF_S_JMP_JGE_K;
-			break;
-		case BPF_JMP|BPF_JGE|BPF_X:
-			ftest->code = BPF_S_JMP_JGE_X;
-			break;
-		case BPF_JMP|BPF_JGT|BPF_K:
-			ftest->code = BPF_S_JMP_JGT_K;
-			break;
-		case BPF_JMP|BPF_JGT|BPF_X:
-			ftest->code = BPF_S_JMP_JGT_X;
-			break;
-		case BPF_JMP|BPF_JSET|BPF_K:
-			ftest->code = BPF_S_JMP_JSET_K;
-			break;
-		case BPF_JMP|BPF_JSET|BPF_X:
-			ftest->code = BPF_S_JMP_JSET_X;
 			break;
-
-		default:
-			return -EINVAL;
-		}
-
-			/* for conditionals both must be safe */
-		switch (ftest->code) {
 		case BPF_S_JMP_JEQ_K:
 		case BPF_S_JMP_JEQ_X:
 		case BPF_S_JMP_JGE_K:
@@ -570,21 +593,40 @@ int sk_chk_filter(struct sock_filter *filter, int flen)
 		case BPF_S_JMP_JGT_X:
 		case BPF_S_JMP_JSET_X:
 		case BPF_S_JMP_JSET_K:
+			/* for conditionals both must be safe */
 			if (pc + ftest->jt + 1 >= flen ||
 			    pc + ftest->jf + 1 >= flen)
 				return -EINVAL;
+			break;
+		case BPF_S_LD_W_ABS:
+		case BPF_S_LD_H_ABS:
+		case BPF_S_LD_B_ABS:
+#define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE:	\
+				code = BPF_S_ANC_##CODE;	\
+				break
+			switch (ftest->k) {
+			ANCILLARY(PROTOCOL);
+			ANCILLARY(PKTTYPE);
+			ANCILLARY(IFINDEX);
+			ANCILLARY(NLATTR);
+			ANCILLARY(NLATTR_NEST);
+			ANCILLARY(MARK);
+			ANCILLARY(QUEUE);
+			ANCILLARY(HATYPE);
+			ANCILLARY(RXHASH);
+			ANCILLARY(CPU);
+			}
 		}
+		ftest->code = code;
 	}
 
 	/* last instruction must be a RET code */
 	switch (filter[flen - 1].code) {
 	case BPF_S_RET_K:
 	case BPF_S_RET_A:
-		return 0;
-		break;
-		default:
-			return -EINVAL;
-		}
+		return check_load_and_stores(filter, flen);
+	}
+	return -EINVAL;
 }
 EXPORT_SYMBOL(sk_chk_filter);