From bc7d811ace4ad39a3941089ca871633366878719 Mon Sep 17 00:00:00 2001 From: Eric Sesterhenn Date: Mon, 13 Nov 2017 09:09:40 +0100 Subject: [PATCH] netfilter: nf_ct_h323: Convert CHECK_BOUND macro to function It is bad practive to return in a macro, this patch moves the check into a function. Signed-off-by: Eric Sesterhenn Signed-off-by: Pablo Neira Ayuso --- net/netfilter/nf_conntrack_h323_asn1.c | 94 +++++++++++++++++++++++----------- 1 file changed, 65 insertions(+), 29 deletions(-) diff --git a/net/netfilter/nf_conntrack_h323_asn1.c b/net/netfilter/nf_conntrack_h323_asn1.c index cf1bf26..3d9a009 100644 --- a/net/netfilter/nf_conntrack_h323_asn1.c +++ b/net/netfilter/nf_conntrack_h323_asn1.c @@ -103,7 +103,6 @@ struct bitstr { #define INC_BIT(bs) if((++(bs)->bit)>7){(bs)->cur++;(bs)->bit=0;} #define INC_BITS(bs,b) if(((bs)->bit+=(b))>7){(bs)->cur+=(bs)->bit>>3;(bs)->bit&=7;} #define BYTE_ALIGN(bs) if((bs)->bit){(bs)->cur++;(bs)->bit=0;} -#define CHECK_BOUND(bs,n) if((bs)->cur+(n)>(bs)->end)return(H323_ERROR_BOUND) static unsigned int get_len(struct bitstr *bs); static unsigned int get_bit(struct bitstr *bs); static unsigned int get_bits(struct bitstr *bs, unsigned int b); @@ -165,6 +164,14 @@ static unsigned int get_len(struct bitstr *bs) return v; } +static int nf_h323_error_boundary(struct bitstr *bs, size_t bytes) +{ + if (*bs->cur + bytes > *bs->end) + return 1; + + return 0; +} + /****************************************************************************/ static unsigned int get_bit(struct bitstr *bs) { @@ -280,7 +287,8 @@ static int decode_bool(struct bitstr *bs, const struct field_t *f, INC_BIT(bs); - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -293,11 +301,14 @@ static int decode_oid(struct bitstr *bs, const struct field_t *f, PRINT("%*.s%s\n", level * TAB_SIZE, " ", f->name); BYTE_ALIGN(bs); - CHECK_BOUND(bs, 1); + if (nf_h323_error_boundary(bs, 1)) + return H323_ERROR_BOUND; + len = *bs->cur++; bs->cur += len; + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; - CHECK_BOUND(bs, 0); return H323_ERROR_NONE; } @@ -330,7 +341,8 @@ static int decode_int(struct bitstr *bs, const struct field_t *f, break; case UNCO: BYTE_ALIGN(bs); - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = get_len(bs); bs->cur += len; break; @@ -341,7 +353,8 @@ static int decode_int(struct bitstr *bs, const struct field_t *f, PRINT("\n"); - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -357,7 +370,8 @@ static int decode_enum(struct bitstr *bs, const struct field_t *f, INC_BITS(bs, f->sz); } - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -375,12 +389,14 @@ static int decode_bitstr(struct bitstr *bs, const struct field_t *f, len = f->lb; break; case WORD: /* 2-byte length */ - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = (*bs->cur++) << 8; len += (*bs->cur++) + f->lb; break; case SEMI: - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = get_len(bs); break; default: @@ -391,7 +407,8 @@ static int decode_bitstr(struct bitstr *bs, const struct field_t *f, bs->cur += len >> 3; bs->bit = len & 7; - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -409,7 +426,8 @@ static int decode_numstr(struct bitstr *bs, const struct field_t *f, BYTE_ALIGN(bs); INC_BITS(bs, (len << 2)); - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -440,12 +458,14 @@ static int decode_octstr(struct bitstr *bs, const struct field_t *f, break; case BYTE: /* Range == 256 */ BYTE_ALIGN(bs); - CHECK_BOUND(bs, 1); + if (nf_h323_error_boundary(bs, 1)) + return H323_ERROR_BOUND; len = (*bs->cur++) + f->lb; break; case SEMI: BYTE_ALIGN(bs); - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = get_len(bs) + f->lb; break; default: /* 2 <= Range <= 255 */ @@ -458,7 +478,8 @@ static int decode_octstr(struct bitstr *bs, const struct field_t *f, PRINT("\n"); - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -473,7 +494,8 @@ static int decode_bmpstr(struct bitstr *bs, const struct field_t *f, switch (f->sz) { case BYTE: /* Range == 256 */ BYTE_ALIGN(bs); - CHECK_BOUND(bs, 1); + if (nf_h323_error_boundary(bs, 1)) + return H323_ERROR_BOUND; len = (*bs->cur++) + f->lb; break; default: /* 2 <= Range <= 255 */ @@ -484,7 +506,8 @@ static int decode_bmpstr(struct bitstr *bs, const struct field_t *f, bs->cur += len << 1; - CHECK_BOUND(bs, 0); + if (nf_h323_error_boundary(bs, 0)) + return H323_ERROR_BOUND; return H323_ERROR_NONE; } @@ -525,9 +548,11 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f, /* Decode */ if (son->attr & OPEN) { /* Open field */ - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = get_len(bs); - CHECK_BOUND(bs, len); + if (nf_h323_error_boundary(bs, len)) + return H323_ERROR_BOUND; if (!base || !(son->attr & DECODE)) { PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name); @@ -556,7 +581,8 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f, /* Get the extension bitmap */ bmp2_len = get_bits(bs, 7) + 1; - CHECK_BOUND(bs, (bmp2_len + 7) >> 3); + if (nf_h323_error_boundary(bs, (bmp2_len + 7) >> 3)) + return H323_ERROR_BOUND; bmp2 = get_bitmap(bs, bmp2_len); bmp |= bmp2 >> f->sz; if (base) @@ -567,9 +593,11 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f, for (opt = 0; opt < bmp2_len; opt++, i++, son++) { /* Check Range */ if (i >= f->ub) { /* Newer Version? */ - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = get_len(bs); - CHECK_BOUND(bs, len); + if (nf_h323_error_boundary(bs, len)) + return H323_ERROR_BOUND; bs->cur += len; continue; } @@ -583,9 +611,11 @@ static int decode_seq(struct bitstr *bs, const struct field_t *f, if (!((0x80000000 >> opt) & bmp2)) /* Not present */ continue; - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; len = get_len(bs); - CHECK_BOUND(bs, len); + if (nf_h323_error_boundary(bs, len)) + return H323_ERROR_BOUND; if (!base || !(son->attr & DECODE)) { PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name); @@ -623,19 +653,22 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f, switch (f->sz) { case BYTE: BYTE_ALIGN(bs); - CHECK_BOUND(bs, 1); + if (nf_h323_error_boundary(bs, 1)) + return H323_ERROR_BOUND; count = *bs->cur++; break; case WORD: BYTE_ALIGN(bs); - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; count = *bs->cur++; count <<= 8; count += *bs->cur++; break; case SEMI: BYTE_ALIGN(bs); - CHECK_BOUND(bs, 2); + if (nf_h323_error_boundary(bs, 2)) + return H323_ERROR_BOUND; count = get_len(bs); break; default: @@ -659,7 +692,8 @@ static int decode_seqof(struct bitstr *bs, const struct field_t *f, if (son->attr & OPEN) { BYTE_ALIGN(bs); len = get_len(bs); - CHECK_BOUND(bs, len); + if (nf_h323_error_boundary(bs, len)) + return H323_ERROR_BOUND; if (!base || !(son->attr & DECODE)) { PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name); @@ -728,7 +762,8 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f, if (type >= f->ub) { /* Newer version? */ BYTE_ALIGN(bs); len = get_len(bs); - CHECK_BOUND(bs, len); + if (nf_h323_error_boundary(bs, len)) + return H323_ERROR_BOUND; bs->cur += len; return H323_ERROR_NONE; } @@ -743,7 +778,8 @@ static int decode_choice(struct bitstr *bs, const struct field_t *f, if (ext || (son->attr & OPEN)) { BYTE_ALIGN(bs); len = get_len(bs); - CHECK_BOUND(bs, len); + if (nf_h323_error_boundary(bs, len)) + return H323_ERROR_BOUND; if (!base || !(son->attr & DECODE)) { PRINT("%*.s%s\n", (level + 1) * TAB_SIZE, " ", son->name); -- 2.7.4