Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 2876a344 authored by J. Bruce Fields's avatar J. Bruce Fields
Browse files

sunrpc: don't pass on-stack memory to sg_set_buf 



As of ac4e97ab "scatterlist: sg_set_buf() argument must be in linear
mapping", sg_set_buf hits a BUG when make_checksum_v2->xdr_process_buf,
among other callers, passes it memory on the stack.

We only need a scatterlist to pass this to the crypto code, and it seems
like overkill to require kmalloc'd memory just to encrypt a few bytes,
but for now this seems the best fix.

Many of these callers are in the NFS write paths, so we allocate with
GFP_NOFS.  It might be possible to do without allocations here entirely,
but that would probably be a bigger project.

Cc: Rusty Russell <rusty@rustcorp.com.au>
Signed-off-by: default avatarJ. Bruce Fields <bfields@redhat.com>
parent 0cc11a61

net/sunrpc/auth_gss/auth_gss.c

+9 −4
Original line number Diff line number Diff line
@@ -1616,7 +1616,7 @@ gss_validate(struct rpc_task *task, __be32 *p) 
{

	struct rpc_cred *cred = task->tk_rqstp->rq_cred;

	struct gss_cl_ctx *ctx = gss_cred_get_ctx(cred);

	__be32		seq;

	__be32		*seq = NULL;

	struct kvec	iov;

	struct xdr_buf	verf_buf;

	struct xdr_netobj mic;
@@ -1631,9 +1631,12 @@ gss_validate(struct rpc_task *task, __be32 *p) 
		goto out_bad;

	if (flav != RPC_AUTH_GSS)

		goto out_bad;

	seq = htonl(task->tk_rqstp->rq_seqno);

	iov.iov_base = &seq;

	iov.iov_len = sizeof(seq);

	seq = kmalloc(4, GFP_NOFS);

	if (!seq)

		goto out_bad;

	*seq = htonl(task->tk_rqstp->rq_seqno);

	iov.iov_base = seq;

	iov.iov_len = 4;

	xdr_buf_from_iov(&iov, &verf_buf);

	mic.data = (u8 *)p;

	mic.len = len;
@@ -1653,11 +1656,13 @@ gss_validate(struct rpc_task *task, __be32 *p) 
	gss_put_ctx(ctx);

	dprintk("RPC: %5u %s: gss_verify_mic succeeded.\n",

			task->tk_pid, __func__);

	kfree(seq);

	return p + XDR_QUADLEN(len);

out_bad:

	gss_put_ctx(ctx);

	dprintk("RPC: %5u %s failed ret %ld.\n", task->tk_pid, __func__,

		PTR_ERR(ret));

	kfree(seq);

	return ret;

}

net/sunrpc/auth_gss/gss_krb5_crypto.c

+48 −34
Original line number Diff line number Diff line
@@ -166,8 +166,8 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, 
		       unsigned int usage, struct xdr_netobj *cksumout)

{

	struct scatterlist              sg[1];

	int err;

	u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];

	int err = -1;

	u8 *checksumdata;

	u8 rc4salt[4];

	struct crypto_ahash *md5;

	struct crypto_ahash *hmac_md5;
@@ -187,23 +187,22 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, 
		return GSS_S_FAILURE;

	}



	checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS);

	if (!checksumdata)

		return GSS_S_FAILURE;



	md5 = crypto_alloc_ahash("md5", 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(md5))

		return GSS_S_FAILURE;

		goto out_free_cksum;



	hmac_md5 = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0,

				      CRYPTO_ALG_ASYNC);

	if (IS_ERR(hmac_md5)) {

		crypto_free_ahash(md5);

		return GSS_S_FAILURE;

	}

	if (IS_ERR(hmac_md5))

		goto out_free_md5;



	req = ahash_request_alloc(md5, GFP_KERNEL);

	if (!req) {

		crypto_free_ahash(hmac_md5);

		crypto_free_ahash(md5);

		return GSS_S_FAILURE;

	}

	if (!req)

		goto out_free_hmac_md5;



	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
@@ -232,11 +231,8 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, 


	ahash_request_free(req);

	req = ahash_request_alloc(hmac_md5, GFP_KERNEL);

	if (!req) {

		crypto_free_ahash(hmac_md5);

		crypto_free_ahash(md5);

		return GSS_S_FAILURE;

	}

	if (!req)

		goto out_free_hmac_md5;



	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
@@ -258,8 +254,12 @@ make_checksum_hmac_md5(struct krb5_ctx *kctx, char *header, int hdrlen, 
	cksumout->len = kctx->gk5e->cksumlength;

out:

	ahash_request_free(req);

	crypto_free_ahash(md5);

out_free_hmac_md5:

	crypto_free_ahash(hmac_md5);

out_free_md5:

	crypto_free_ahash(md5);

out_free_cksum:

	kfree(checksumdata);

	return err ? GSS_S_FAILURE : 0;

}
@@ -276,8 +276,8 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen, 
	struct crypto_ahash *tfm;

	struct ahash_request *req;

	struct scatterlist              sg[1];

	int err;

	u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];

	int err = -1;

	u8 *checksumdata;

	unsigned int checksumlen;



	if (kctx->gk5e->ctype == CKSUMTYPE_HMAC_MD5_ARCFOUR)
@@ -291,15 +291,17 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen, 
		return GSS_S_FAILURE;

	}



	checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS);

	if (checksumdata == NULL)

		return GSS_S_FAILURE;



	tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm))

		return GSS_S_FAILURE;

		goto out_free_cksum;



	req = ahash_request_alloc(tfm, GFP_KERNEL);

	if (!req) {

		crypto_free_ahash(tfm);

		return GSS_S_FAILURE;

	}

	if (!req)

		goto out_free_ahash;



	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
@@ -349,7 +351,10 @@ make_checksum(struct krb5_ctx *kctx, char *header, int hdrlen, 
	cksumout->len = kctx->gk5e->cksumlength;

out:

	ahash_request_free(req);

out_free_ahash:

	crypto_free_ahash(tfm);

out_free_cksum:

	kfree(checksumdata);

	return err ? GSS_S_FAILURE : 0;

}
@@ -368,8 +373,8 @@ make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen, 
	struct crypto_ahash *tfm;

	struct ahash_request *req;

	struct scatterlist sg[1];

	int err;

	u8 checksumdata[GSS_KRB5_MAX_CKSUM_LEN];

	int err = -1;

	u8 *checksumdata;

	unsigned int checksumlen;



	if (kctx->gk5e->keyed_cksum == 0) {
@@ -383,16 +388,18 @@ make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen, 
		return GSS_S_FAILURE;

	}



	checksumdata = kmalloc(GSS_KRB5_MAX_CKSUM_LEN, GFP_NOFS);

	if (!checksumdata)

		return GSS_S_FAILURE;



	tfm = crypto_alloc_ahash(kctx->gk5e->cksum_name, 0, CRYPTO_ALG_ASYNC);

	if (IS_ERR(tfm))

		return GSS_S_FAILURE;

		goto out_free_cksum;

	checksumlen = crypto_ahash_digestsize(tfm);



	req = ahash_request_alloc(tfm, GFP_KERNEL);

	if (!req) {

		crypto_free_ahash(tfm);

		return GSS_S_FAILURE;

	}

	if (!req)

		goto out_free_ahash;



	ahash_request_set_callback(req, CRYPTO_TFM_REQ_MAY_SLEEP, NULL, NULL);
@@ -433,7 +440,10 @@ make_checksum_v2(struct krb5_ctx *kctx, char *header, int hdrlen, 
	}

out:

	ahash_request_free(req);

out_free_ahash:

	crypto_free_ahash(tfm);

out_free_cksum:

	kfree(checksumdata);

	return err ? GSS_S_FAILURE : 0;

}
@@ -666,14 +676,17 @@ gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf, 
	u32 ret;

	struct scatterlist sg[1];

	SKCIPHER_REQUEST_ON_STACK(req, cipher);

	u8 data[GSS_KRB5_MAX_BLOCKSIZE * 2];

	u8 *data;

	struct page **save_pages;

	u32 len = buf->len - offset;



	if (len > ARRAY_SIZE(data)) {

	if (len > GSS_KRB5_MAX_BLOCKSIZE * 2) {

		WARN_ON(0);

		return -ENOMEM;

	}

	data = kmalloc(GSS_KRB5_MAX_BLOCKSIZE * 2, GFP_NOFS);

	if (!data)

		return -ENOMEM;



	/*

	 * For encryption, we want to read from the cleartext
@@ -708,6 +721,7 @@ gss_krb5_cts_crypt(struct crypto_skcipher *cipher, struct xdr_buf *buf, 
	ret = write_bytes_to_xdr_buf(buf, offset, data, len);



out:

	kfree(data);

	return ret;

}

net/sunrpc/auth_gss/svcauth_gss.c

+14 −7
Original line number Diff line number Diff line
@@ -718,30 +718,37 @@ gss_write_null_verf(struct svc_rqst *rqstp) 
static int

gss_write_verf(struct svc_rqst *rqstp, struct gss_ctx *ctx_id, u32 seq)

{

	__be32			xdr_seq;

	__be32			*xdr_seq;

	u32			maj_stat;

	struct xdr_buf		verf_data;

	struct xdr_netobj	mic;

	__be32			*p;

	struct kvec		iov;

	int err = -1;



	svc_putnl(rqstp->rq_res.head, RPC_AUTH_GSS);

	xdr_seq = htonl(seq);

	xdr_seq = kmalloc(4, GFP_KERNEL);

	if (!xdr_seq)

		return -1;

	*xdr_seq = htonl(seq);



	iov.iov_base = &xdr_seq;

	iov.iov_len = sizeof(xdr_seq);

	iov.iov_base = xdr_seq;

	iov.iov_len = 4;

	xdr_buf_from_iov(&iov, &verf_data);

	p = rqstp->rq_res.head->iov_base + rqstp->rq_res.head->iov_len;

	mic.data = (u8 *)(p + 1);

	maj_stat = gss_get_mic(ctx_id, &verf_data, &mic);

	if (maj_stat != GSS_S_COMPLETE)

		return -1;

		goto out;

	*p++ = htonl(mic.len);

	memset((u8 *)p + mic.len, 0, round_up_to_quad(mic.len) - mic.len);

	p += XDR_QUADLEN(mic.len);

	if (!xdr_ressize_check(rqstp, p))

		return -1;

	return 0;

		goto out;

	err = 0;

out:

	kfree(xdr_seq);

	return err;

}



struct gss_domain {