Re: [PATCH 00/29] Crypto keys and module signing [ver #4]

[Tetsuo Handa]

+static int pgp_calc_pkey_keyid(struct shash_desc *digest,
+			       struct pgp_parse_pubkey *pgp,
+			       struct public_key *key)
+{
+	unsigned nb[ARRAY_SIZE(key->mpi)];
+	unsigned nn[ARRAY_SIZE(key->mpi)];
+	unsigned n;
+	u8 *pp[ARRAY_SIZE(key->mpi)];
+	u32 a32;
+	int npkey = key->algo->n_pub_mpi;
+	int i, ret = -ENOMEM;
+
+	kenter("");
+
+	n = (pgp->version < PGP_KEY_VERSION_4) ? 8 : 6;
+	for (i = 0; i < npkey; i++) {
+		nb[i] = mpi_get_nbits(key->mpi[i]);

Is key->algo->n_pub_mpi < ARRAY_SIZE(key->mpi) guaranteed?

+		pp[i] = mpi_get_buffer(key->mpi[i], nn + i, NULL);
+		if (!pp[i])
+			goto error;
+		n += 2 + nn[i];
+	}
+
+	digest_putc(digest, 0x99);     /* ctb */
+	digest_putc(digest, n >> 8);   /* 16-bit header length */
+	digest_putc(digest, n);
+	digest_putc(digest, pgp->version);
+
+	a32 = pgp->creation_time;
+	digest_putc(digest, a32 >> 24);
+	digest_putc(digest, a32 >> 16);
+	digest_putc(digest, a32 >>  8);
+	digest_putc(digest, a32 >>  0);
+
+	if (pgp->version < PGP_KEY_VERSION_4) {
+		u16 a16;
+
+		if( pgp->expires_at)

checkpatch.pl

+			a16 = (pgp->expires_at - pgp->creation_time) / 86400UL;
+		else
+			a16 = 0;
+		digest_putc(digest, a16 >> 8);
+		digest_putc(digest, a16 >> 0);
+	}
+
+	digest_putc(digest, pgp->pubkey_algo);
+
+	for (i = 0; i < npkey; i++) {
+		digest_putc(digest, nb[i] >> 8);
+		digest_putc(digest, nb[i]);
+		crypto_shash_update(digest, pp[i], nn[i]);
+	}
+	ret = 0;
+
+error:
+	for (i = 0; i < npkey; i++)
+		kfree(pp[i]);

Stack memory may not be initialized.

+	kleave(" = %d", ret);
+	return ret;
+}



+static int pgp_pkey_digest_signature(struct pgp_parse_context *context,
+				     enum pgp_packet_tag type,
+				     u8 headerlen,
+				     const u8 *data,
+				     size_t datalen)
+{
+	struct pgp_pkey_sig_digest_context *ctx =
+		container_of(context, struct pgp_pkey_sig_digest_context, pgp);
+	enum pgp_signature_version version;
+	int i;
+
+	kenter(",%u,%u,,%zu", type, headerlen, datalen);
+
+	version = *data;
+	if (version == PGP_SIG_VERSION_3) {
+		/* We just include an excerpt of the metadata from a V3
+		 * signature.
+		 */
+		crypto_shash_update(&ctx->sig->hash, data + 1, 5);
+		data += sizeof(struct pgp_signature_v3_packet);
+		datalen -= sizeof(struct pgp_signature_v3_packet);
+	} else if (version == PGP_SIG_VERSION_4) {
+		/* We add the whole metadata header and some of the hashed data
+		 * for a V4 signature, plus a trailer.
+		 */
+		size_t hashedsz, unhashedsz;
+		u8 trailer[6];
+
+		hashedsz = 4 + 2 + (data[4] << 8) + data[5];

Given the (datalen <= 2) check below, can we trust data[4,5] here?

+		crypto_shash_update(&ctx->sig->hash, data, hashedsz);
+
+		trailer[0] = version;
+		trailer[1] = 0xffU;
+		trailer[2] = hashedsz >> 24;
+		trailer[3] = hashedsz >> 16;
+		trailer[4] = hashedsz >> 8;
+		trailer[5] = hashedsz;
+
+		crypto_shash_update(&ctx->sig->hash, trailer, 6);
+		data += hashedsz;
+		datalen -= hashedsz;
+
+		unhashedsz = 2 + (data[0] << 8) + data[1];
+		data += unhashedsz;
+		datalen -= unhashedsz;
+	}
+
+	if (datalen <= 2) {
+		kleave(" = -EBADMSG");
+		return -EBADMSG;
+	}



+static int module_verify_canonicalise(struct module_verify_data *mvdata)
+{
+	const Elf_Shdr *sechdrs = mvdata->sections;
+	unsigned *canonlist, canon, loop, tmp;
+	bool changed;
+
+	canonlist = kmalloc(sizeof(unsigned) * mvdata->nsects * 2, GFP_KERNEL);
+	if (!canonlist)
+		return -ENOMEM;

Can mvdata->nsects == (UINT_MAX + 1) / (sizeof(unsigned) * 2) due to size_t?
I think we want kmalloc() variant that does not return ZERO_SIZE_PTR.
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