diff options
Diffstat (limited to 'net/core')
| -rw-r--r-- | net/core/filter.c | 341 |
1 files changed, 125 insertions, 216 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index 2c2d35d9d101..328aaf6ff4d1 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -536,11 +536,13 @@ load_word: * Output: * BPF_R0 - 8/16/32-bit skb data converted to cpu endianness */ + ptr = load_pointer((struct sk_buff *) ctx, off, 4, &tmp); if (likely(ptr != NULL)) { BPF_R0 = get_unaligned_be32(ptr); CONT; } + return 0; LD_ABS_H: /* BPF_R0 = ntohs(*(u16 *) (skb->data + K)) */ off = K; @@ -550,6 +552,7 @@ load_half: BPF_R0 = get_unaligned_be16(ptr); CONT; } + return 0; LD_ABS_B: /* BPF_R0 = *(u8 *) (ctx + K) */ off = K; @@ -559,6 +562,7 @@ load_byte: BPF_R0 = *(u8 *)ptr; CONT; } + return 0; LD_IND_W: /* BPF_R0 = ntohl(*(u32 *) (skb->data + X + K)) */ off = K + X; @@ -1136,44 +1140,46 @@ err: */ static int check_load_and_stores(struct sock_filter *filter, int flen) { - u16 *masks, memvalid = 0; /* one bit per cell, 16 cells */ + 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: + case BPF_ST: + case BPF_STX: memvalid |= (1 << filter[pc].k); break; - case BPF_S_LD_MEM: - case BPF_S_LDX_MEM: + case BPF_LD | BPF_MEM: + case BPF_LDX | BPF_MEM: if (!(memvalid & (1 << filter[pc].k))) { ret = -EINVAL; goto error; } break; - case BPF_S_JMP_JA: - /* a jump must set masks on target */ + case BPF_JMP | BPF_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 */ + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: + /* A jump must set masks on targets */ masks[pc + 1 + filter[pc].jt] &= memvalid; masks[pc + 1 + filter[pc].jf] &= memvalid; memvalid = ~0; @@ -1185,6 +1191,72 @@ error: return ret; } +static bool chk_code_allowed(u16 code_to_probe) +{ + static const bool codes[] = { + /* 32 bit ALU operations */ + [BPF_ALU | BPF_ADD | BPF_K] = true, + [BPF_ALU | BPF_ADD | BPF_X] = true, + [BPF_ALU | BPF_SUB | BPF_K] = true, + [BPF_ALU | BPF_SUB | BPF_X] = true, + [BPF_ALU | BPF_MUL | BPF_K] = true, + [BPF_ALU | BPF_MUL | BPF_X] = true, + [BPF_ALU | BPF_DIV | BPF_K] = true, + [BPF_ALU | BPF_DIV | BPF_X] = true, + [BPF_ALU | BPF_MOD | BPF_K] = true, + [BPF_ALU | BPF_MOD | BPF_X] = true, + [BPF_ALU | BPF_AND | BPF_K] = true, + [BPF_ALU | BPF_AND | BPF_X] = true, + [BPF_ALU | BPF_OR | BPF_K] = true, + [BPF_ALU | BPF_OR | BPF_X] = true, + [BPF_ALU | BPF_XOR | BPF_K] = true, + [BPF_ALU | BPF_XOR | BPF_X] = true, + [BPF_ALU | BPF_LSH | BPF_K] = true, + [BPF_ALU | BPF_LSH | BPF_X] = true, + [BPF_ALU | BPF_RSH | BPF_K] = true, + [BPF_ALU | BPF_RSH | BPF_X] = true, + [BPF_ALU | BPF_NEG] = true, + /* Load instructions */ + [BPF_LD | BPF_W | BPF_ABS] = true, + [BPF_LD | BPF_H | BPF_ABS] = true, + [BPF_LD | BPF_B | BPF_ABS] = true, + [BPF_LD | BPF_W | BPF_LEN] = true, + [BPF_LD | BPF_W | BPF_IND] = true, + [BPF_LD | BPF_H | BPF_IND] = true, + [BPF_LD | BPF_B | BPF_IND] = true, + [BPF_LD | BPF_IMM] = true, + [BPF_LD | BPF_MEM] = true, + [BPF_LDX | BPF_W | BPF_LEN] = true, + [BPF_LDX | BPF_B | BPF_MSH] = true, + [BPF_LDX | BPF_IMM] = true, + [BPF_LDX | BPF_MEM] = true, + /* Store instructions */ + [BPF_ST] = true, + [BPF_STX] = true, + /* Misc instructions */ + [BPF_MISC | BPF_TAX] = true, + [BPF_MISC | BPF_TXA] = true, + /* Return instructions */ + [BPF_RET | BPF_K] = true, + [BPF_RET | BPF_A] = true, + /* Jump instructions */ + [BPF_JMP | BPF_JA] = true, + [BPF_JMP | BPF_JEQ | BPF_K] = true, + [BPF_JMP | BPF_JEQ | BPF_X] = true, + [BPF_JMP | BPF_JGE | BPF_K] = true, + [BPF_JMP | BPF_JGE | BPF_X] = true, + [BPF_JMP | BPF_JGT | BPF_K] = true, + [BPF_JMP | BPF_JGT | BPF_X] = true, + [BPF_JMP | BPF_JSET | BPF_K] = true, + [BPF_JMP | BPF_JSET | BPF_X] = true, + }; + + if (code_to_probe >= ARRAY_SIZE(codes)) + return false; + + return codes[code_to_probe]; +} + /** * sk_chk_filter - verify socket filter code * @filter: filter to verify @@ -1201,154 +1273,76 @@ error: */ int sk_chk_filter(struct sock_filter *filter, unsigned int flen) { - /* - * 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_MOD|BPF_K] = BPF_S_ALU_MOD_K, - [BPF_ALU|BPF_MOD|BPF_X] = BPF_S_ALU_MOD_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_XOR|BPF_K] = BPF_S_ALU_XOR_K, - [BPF_ALU|BPF_XOR|BPF_X] = BPF_S_ALU_XOR_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; bool anc_found; + int pc; if (flen == 0 || flen > BPF_MAXINSNS) return -EINVAL; - /* check the filter code now */ + /* Check the filter code now */ for (pc = 0; pc < flen; pc++) { struct sock_filter *ftest = &filter[pc]; - u16 code = ftest->code; - if (code >= ARRAY_SIZE(codes)) - return -EINVAL; - code = codes[code]; - if (!code) + /* May we actually operate on this code? */ + if (!chk_code_allowed(ftest->code)) return -EINVAL; + /* Some instructions need special checks */ - switch (code) { - case BPF_S_ALU_DIV_K: - case BPF_S_ALU_MOD_K: - /* check for division by zero */ + switch (ftest->code) { + case BPF_ALU | BPF_DIV | BPF_K: + case BPF_ALU | BPF_MOD | BPF_K: + /* Check for division by zero */ if (ftest->k == 0) return -EINVAL; break; - case BPF_S_LD_MEM: - case BPF_S_LDX_MEM: - case BPF_S_ST: - case BPF_S_STX: - /* check for invalid memory addresses */ + case BPF_LD | BPF_MEM: + case BPF_LDX | BPF_MEM: + case BPF_ST: + case BPF_STX: + /* Check for invalid memory addresses */ if (ftest->k >= BPF_MEMWORDS) return -EINVAL; break; - case BPF_S_JMP_JA: - /* - * Note, the large ftest->k might cause loops. + case BPF_JMP | BPF_JA: + /* Note, the large ftest->k might cause loops. * Compare this with conditional jumps below, * where offsets are limited. --ANK (981016) */ - if (ftest->k >= (unsigned int)(flen-pc-1)) + if (ftest->k >= (unsigned int)(flen - pc - 1)) return -EINVAL; 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: - /* for conditionals both must be safe */ + case BPF_JMP | BPF_JEQ | BPF_K: + case BPF_JMP | BPF_JEQ | BPF_X: + case BPF_JMP | BPF_JGE | BPF_K: + case BPF_JMP | BPF_JGE | BPF_X: + case BPF_JMP | BPF_JGT | BPF_K: + case BPF_JMP | BPF_JGT | BPF_X: + case BPF_JMP | BPF_JSET | BPF_K: + case BPF_JMP | BPF_JSET | BPF_X: + /* Both conditionals 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: + case BPF_LD | BPF_W | BPF_ABS: + case BPF_LD | BPF_H | BPF_ABS: + case BPF_LD | BPF_B | BPF_ABS: anc_found = false; -#define ANCILLARY(CODE) case SKF_AD_OFF + SKF_AD_##CODE: \ - code = BPF_S_ANC_##CODE; \ - anc_found = true; \ - 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); - ANCILLARY(ALU_XOR_X); - ANCILLARY(VLAN_TAG); - ANCILLARY(VLAN_TAG_PRESENT); - ANCILLARY(PAY_OFFSET); - ANCILLARY(RANDOM); - } - - /* ancillary operation unknown or unsupported */ + if (bpf_anc_helper(ftest) & BPF_ANC) + anc_found = true; + /* Ancillary operation unknown or unsupported */ if (anc_found == false && ftest->k >= SKF_AD_OFF) return -EINVAL; } - ftest->code = code; } - /* last instruction must be a RET code */ + /* Last instruction must be a RET code */ switch (filter[flen - 1].code) { - case BPF_S_RET_K: - case BPF_S_RET_A: + case BPF_RET | BPF_K: + case BPF_RET | BPF_A: return check_load_and_stores(filter, flen); } + return -EINVAL; } EXPORT_SYMBOL(sk_chk_filter); @@ -1448,7 +1442,7 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, { struct sock_filter *old_prog; struct sk_filter *old_fp; - int i, err, new_len, old_len = fp->len; + int err, new_len, old_len = fp->len; /* We are free to overwrite insns et al right here as it * won't be used at this point in time anymore internally @@ -1458,13 +1452,6 @@ static struct sk_filter *__sk_migrate_filter(struct sk_filter *fp, BUILD_BUG_ON(sizeof(struct sock_filter) != sizeof(struct sock_filter_int)); - /* For now, we need to unfiddle BPF_S_* identifiers in place. - * This can sooner or later on be subject to removal, e.g. when - * JITs have been converted. - */ - for (i = 0; i < fp->len; i++) - sk_decode_filter(&fp->insns[i], &fp->insns[i]); - /* Conversion cannot happen on overlapping memory areas, * so we need to keep the user BPF around until the 2nd * pass. At this time, the user BPF is stored in fp->insns. @@ -1706,84 +1693,6 @@ int sk_detach_filter(struct sock *sk) } EXPORT_SYMBOL_GPL(sk_detach_filter); -void sk_decode_filter(struct sock_filter *filt, struct sock_filter *to) -{ - static const u16 decodes[] = { - [BPF_S_ALU_ADD_K] = BPF_ALU|BPF_ADD|BPF_K, - [BPF_S_ALU_ADD_X] = BPF_ALU|BPF_ADD|BPF_X, - [BPF_S_ALU_SUB_K] = BPF_ALU|BPF_SUB|BPF_K, - [BPF_S_ALU_SUB_X] = BPF_ALU|BPF_SUB|BPF_X, - [BPF_S_ALU_MUL_K] = BPF_ALU|BPF_MUL|BPF_K, - [BPF_S_ALU_MUL_X] = BPF_ALU|BPF_MUL|BPF_X, - [BPF_S_ALU_DIV_X] = BPF_ALU|BPF_DIV|BPF_X, - [BPF_S_ALU_MOD_K] = BPF_ALU|BPF_MOD|BPF_K, - [BPF_S_ALU_MOD_X] = BPF_ALU|BPF_MOD|BPF_X, - [BPF_S_ALU_AND_K] = BPF_ALU|BPF_AND|BPF_K, - [BPF_S_ALU_AND_X] = BPF_ALU|BPF_AND|BPF_X, - [BPF_S_ALU_OR_K] = BPF_ALU|BPF_OR|BPF_K, - [BPF_S_ALU_OR_X] = BPF_ALU|BPF_OR|BPF_X, - [BPF_S_ALU_XOR_K] = BPF_ALU|BPF_XOR|BPF_K, - [BPF_S_ALU_XOR_X] = BPF_ALU|BPF_XOR|BPF_X, - [BPF_S_ALU_LSH_K] = BPF_ALU|BPF_LSH|BPF_K, - [BPF_S_ALU_LSH_X] = BPF_ALU|BPF_LSH|BPF_X, - [BPF_S_ALU_RSH_K] = BPF_ALU|BPF_RSH|BPF_K, - [BPF_S_ALU_RSH_X] = BPF_ALU|BPF_RSH|BPF_X, - [BPF_S_ALU_NEG] = BPF_ALU|BPF_NEG, - [BPF_S_LD_W_ABS] = BPF_LD|BPF_W|BPF_ABS, - [BPF_S_LD_H_ABS] = BPF_LD|BPF_H|BPF_ABS, - [BPF_S_LD_B_ABS] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_PROTOCOL] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_PKTTYPE] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_IFINDEX] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_NLATTR] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_NLATTR_NEST] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_MARK] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_QUEUE] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_HATYPE] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_RXHASH] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_CPU] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_ALU_XOR_X] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_VLAN_TAG] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_VLAN_TAG_PRESENT] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_PAY_OFFSET] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_ANC_RANDOM] = BPF_LD|BPF_B|BPF_ABS, - [BPF_S_LD_W_LEN] = BPF_LD|BPF_W|BPF_LEN, - [BPF_S_LD_W_IND] = BPF_LD|BPF_W|BPF_IND, - [BPF_S_LD_H_IND] = BPF_LD|BPF_H|BPF_IND, - [BPF_S_LD_B_IND] = BPF_LD|BPF_B|BPF_IND, - [BPF_S_LD_IMM] = BPF_LD|BPF_IMM, - [BPF_S_LDX_W_LEN] = BPF_LDX|BPF_W|BPF_LEN, - [BPF_S_LDX_B_MSH] = BPF_LDX|BPF_B|BPF_MSH, - [BPF_S_LDX_IMM] = BPF_LDX|BPF_IMM, - [BPF_S_MISC_TAX] = BPF_MISC|BPF_TAX, - [BPF_S_MISC_TXA] = BPF_MISC|BPF_TXA, - [BPF_S_RET_K] = BPF_RET|BPF_K, - [BPF_S_RET_A] = BPF_RET|BPF_A, - [BPF_S_ALU_DIV_K] = BPF_ALU|BPF_DIV|BPF_K, - [BPF_S_LD_MEM] = BPF_LD|BPF_MEM, - [BPF_S_LDX_MEM] = BPF_LDX|BPF_MEM, - [BPF_S_ST] = BPF_ST, - [BPF_S_STX] = BPF_STX, - [BPF_S_JMP_JA] = BPF_JMP|BPF_JA, - [BPF_S_JMP_JEQ_K] = BPF_JMP|BPF_JEQ|BPF_K, - [BPF_S_JMP_JEQ_X] = BPF_JMP|BPF_JEQ|BPF_X, - [BPF_S_JMP_JGE_K] = BPF_JMP|BPF_JGE|BPF_K, - [BPF_S_JMP_JGE_X] = BPF_JMP|BPF_JGE|BPF_X, - [BPF_S_JMP_JGT_K] = BPF_JMP|BPF_JGT|BPF_K, - [BPF_S_JMP_JGT_X] = BPF_JMP|BPF_JGT|BPF_X, - [BPF_S_JMP_JSET_K] = BPF_JMP|BPF_JSET|BPF_K, - [BPF_S_JMP_JSET_X] = BPF_JMP|BPF_JSET|BPF_X, - }; - u16 code; - - code = filt->code; - - to->code = decodes[code]; - to->jt = filt->jt; - to->jf = filt->jf; - to->k = filt->k; -} - int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf, unsigned int len) { |