From 51c739d1f484b2562040a3e496dc8e1670d4e279 Mon Sep 17 00:00:00 2001 From: "David S. Miller" Date: Tue, 30 Oct 2007 21:29:29 -0700 Subject: [PATCH] [NET]: Fix incorrect sg_mark_end() calls. This fixes scatterlist corruptions added by commit 68e3f5dd4db62619fdbe520d36c9ebf62e672256 [CRYPTO] users: Fix up scatterlist conversion errors The issue is that the code calls sg_mark_end() which clobbers the sg_page() pointer of the final scatterlist entry. The first part fo the fix makes skb_to_sgvec() do __sg_mark_end(). After considering all skb_to_sgvec() call sites the most correct solution is to call __sg_mark_end() in skb_to_sgvec() since that is what all of the callers would end up doing anyways. I suspect this might have fixed some problems in virtio_net which is the sole non-crypto user of skb_to_sgvec(). Other similar sg_mark_end() cases were converted over to __sg_mark_end() as well. Arguably sg_mark_end() is a poorly named function because it doesn't just "mark", it clears out the page pointer as a side effect, which is what led to these bugs in the first place. The one remaining plain sg_mark_end() call is in scsi_alloc_sgtable() and arguably it could be converted to __sg_mark_end() if only so that we can delete this confusing interface from linux/scatterlist.h Signed-off-by: David S. Miller --- net/core/skbuff.c | 16 +++++++++++++--- net/ipv4/esp4.c | 12 +++++++----- net/ipv4/tcp_ipv4.c | 2 +- net/ipv6/esp6.c | 13 +++++++------ net/ipv6/tcp_ipv6.c | 2 +- net/rxrpc/rxkad.c | 9 +++++---- net/sunrpc/auth_gss/gss_krb5_crypto.c | 6 +++--- 7 files changed, 37 insertions(+), 23 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 573e172..64b50ff 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -2028,8 +2028,8 @@ void __init skb_init(void) * Fill the specified scatter-gather list with mappings/pointers into a * region of the buffer space attached to a socket buffer. */ -int -skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) +static int +__skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) { int start = skb_headlen(skb); int i, copy = start - offset; @@ -2078,7 +2078,8 @@ skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) if ((copy = end - offset) > 0) { if (copy > len) copy = len; - elt += skb_to_sgvec(list, sg+elt, offset - start, copy); + elt += __skb_to_sgvec(list, sg+elt, offset - start, + copy); if ((len -= copy) == 0) return elt; offset += copy; @@ -2090,6 +2091,15 @@ skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) return elt; } +int skb_to_sgvec(struct sk_buff *skb, struct scatterlist *sg, int offset, int len) +{ + int nsg = __skb_to_sgvec(skb, sg, offset, len); + + __sg_mark_end(&sg[nsg - 1]); + + return nsg; +} + /** * skb_cow_data - Check that a socket buffer's data buffers are writable * @skb: The socket buffer to check. diff --git a/net/ipv4/esp4.c b/net/ipv4/esp4.c index cad4278..c31bccb 100644 --- a/net/ipv4/esp4.c +++ b/net/ipv4/esp4.c @@ -111,9 +111,10 @@ static int esp_output(struct xfrm_state *x, struct sk_buff *skb) goto unlock; } sg_init_table(sg, nfrags); - sg_mark_end(sg, skb_to_sgvec(skb, sg, esph->enc_data + - esp->conf.ivlen - - skb->data, clen)); + skb_to_sgvec(skb, sg, + esph->enc_data + + esp->conf.ivlen - + skb->data, clen); err = crypto_blkcipher_encrypt(&desc, sg, sg, clen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); @@ -205,8 +206,9 @@ static int esp_input(struct xfrm_state *x, struct sk_buff *skb) goto out; } sg_init_table(sg, nfrags); - sg_mark_end(sg, skb_to_sgvec(skb, sg, sizeof(*esph) + esp->conf.ivlen, - elen)); + skb_to_sgvec(skb, sg, + sizeof(*esph) + esp->conf.ivlen, + elen); err = crypto_blkcipher_decrypt(&desc, sg, sg, elen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); diff --git a/net/ipv4/tcp_ipv4.c b/net/ipv4/tcp_ipv4.c index d3d8d5d..eec02b2 100644 --- a/net/ipv4/tcp_ipv4.c +++ b/net/ipv4/tcp_ipv4.c @@ -1083,7 +1083,7 @@ static int tcp_v4_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key, sg_set_buf(&sg[block++], key->key, key->keylen); nbytes += key->keylen; - sg_mark_end(sg, block); + __sg_mark_end(&sg[block - 1]); /* Now store the Hash into the packet */ err = crypto_hash_init(desc); diff --git a/net/ipv6/esp6.c b/net/ipv6/esp6.c index ab17b5e..7db66f1 100644 --- a/net/ipv6/esp6.c +++ b/net/ipv6/esp6.c @@ -110,9 +110,10 @@ static int esp6_output(struct xfrm_state *x, struct sk_buff *skb) goto unlock; } sg_init_table(sg, nfrags); - sg_mark_end(sg, skb_to_sgvec(skb, sg, esph->enc_data + - esp->conf.ivlen - - skb->data, clen)); + skb_to_sgvec(skb, sg, + esph->enc_data + + esp->conf.ivlen - + skb->data, clen); err = crypto_blkcipher_encrypt(&desc, sg, sg, clen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); @@ -209,9 +210,9 @@ static int esp6_input(struct xfrm_state *x, struct sk_buff *skb) } } sg_init_table(sg, nfrags); - sg_mark_end(sg, skb_to_sgvec(skb, sg, - sizeof(*esph) + esp->conf.ivlen, - elen)); + skb_to_sgvec(skb, sg, + sizeof(*esph) + esp->conf.ivlen, + elen); ret = crypto_blkcipher_decrypt(&desc, sg, sg, elen); if (unlikely(sg != &esp->sgbuf[0])) kfree(sg); diff --git a/net/ipv6/tcp_ipv6.c b/net/ipv6/tcp_ipv6.c index f1523b8..4b90328 100644 --- a/net/ipv6/tcp_ipv6.c +++ b/net/ipv6/tcp_ipv6.c @@ -781,7 +781,7 @@ static int tcp_v6_do_calc_md5_hash(char *md5_hash, struct tcp_md5sig_key *key, sg_set_buf(&sg[block++], key->key, key->keylen); nbytes += key->keylen; - sg_mark_end(sg, block); + __sg_mark_end(&sg[block - 1]); /* Now store the hash into the packet */ err = crypto_hash_init(desc); diff --git a/net/rxrpc/rxkad.c b/net/rxrpc/rxkad.c index eebefb6e..c387cf6 100644 --- a/net/rxrpc/rxkad.c +++ b/net/rxrpc/rxkad.c @@ -237,7 +237,8 @@ static int rxkad_secure_packet_encrypt(const struct rxrpc_call *call, len = data_size + call->conn->size_align - 1; len &= ~(call->conn->size_align - 1); - sg_init_table(sg, skb_to_sgvec(skb, sg, 0, len)); + sg_init_table(sg, nsg); + skb_to_sgvec(skb, sg, 0, len); crypto_blkcipher_encrypt_iv(&desc, sg, sg, len); _leave(" = 0"); @@ -344,7 +345,7 @@ static int rxkad_verify_packet_auth(const struct rxrpc_call *call, goto nomem; sg_init_table(sg, nsg); - sg_mark_end(sg, skb_to_sgvec(skb, sg, 0, 8)); + skb_to_sgvec(skb, sg, 0, 8); /* start the decryption afresh */ memset(&iv, 0, sizeof(iv)); @@ -426,7 +427,7 @@ static int rxkad_verify_packet_encrypt(const struct rxrpc_call *call, } sg_init_table(sg, nsg); - sg_mark_end(sg, skb_to_sgvec(skb, sg, 0, skb->len)); + skb_to_sgvec(skb, sg, 0, skb->len); /* decrypt from the session key */ payload = call->conn->key->payload.data; @@ -701,7 +702,7 @@ static void rxkad_sg_set_buf2(struct scatterlist sg[2], nsg++; } - sg_mark_end(sg, nsg); + __sg_mark_end(&sg[nsg - 1]); ASSERTCMP(sg[0].length + sg[1].length, ==, buflen); } diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c b/net/sunrpc/auth_gss/gss_krb5_crypto.c index 91cd8f0..ab7cbd6 100644 --- a/net/sunrpc/auth_gss/gss_krb5_crypto.c +++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c @@ -211,8 +211,8 @@ encryptor(struct scatterlist *sg, void *data) if (thislen == 0) return 0; - sg_mark_end(desc->infrags, desc->fragno); - sg_mark_end(desc->outfrags, desc->fragno); + __sg_mark_end(&desc->infrags[desc->fragno - 1]); + __sg_mark_end(&desc->outfrags[desc->fragno - 1]); ret = crypto_blkcipher_encrypt_iv(&desc->desc, desc->outfrags, desc->infrags, thislen); @@ -293,7 +293,7 @@ decryptor(struct scatterlist *sg, void *data) if (thislen == 0) return 0; - sg_mark_end(desc->frags, desc->fragno); + __sg_mark_end(&desc->frags[desc->fragno - 1]); ret = crypto_blkcipher_decrypt_iv(&desc->desc, desc->frags, desc->frags, thislen); -- 2.7.4