From: Chuck Lever <chuck.le...@oracle.com>

[ Upstream commit 31c9590ae468478fe47dc0f5f0d3562b2f69450e ]

Refactor: This is a pre-requisite to fixing the client-side ralign
computation in gss_unwrap_resp_priv().

The length value is passed in explicitly rather that as the value
of buf->len. This will subsequently allow gss_unwrap_kerberos_v1()
to compute a slack and align value, instead of computing it in
gss_unwrap_resp_priv().

Fixes: 35e77d21baa0 ("SUNRPC: Add rpc_auth::au_ralign field")
Signed-off-by: Chuck Lever <chuck.le...@oracle.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 include/linux/sunrpc/gss_api.h        |  2 ++
 include/linux/sunrpc/gss_krb5.h       |  6 +++---
 net/sunrpc/auth_gss/auth_gss.c        |  4 ++--
 net/sunrpc/auth_gss/gss_krb5_crypto.c |  8 ++++----
 net/sunrpc/auth_gss/gss_krb5_wrap.c   | 26 +++++++++++++++-----------
 net/sunrpc/auth_gss/gss_mech_switch.c |  3 ++-
 net/sunrpc/auth_gss/svcauth_gss.c     |  8 ++------
 7 files changed, 30 insertions(+), 27 deletions(-)

diff --git a/include/linux/sunrpc/gss_api.h b/include/linux/sunrpc/gss_api.h
index 5ac5db4d295f9..d1c6f65de76e7 100644
--- a/include/linux/sunrpc/gss_api.h
+++ b/include/linux/sunrpc/gss_api.h
@@ -67,6 +67,7 @@ u32 gss_wrap(
 u32 gss_unwrap(
                struct gss_ctx          *ctx_id,
                int                     offset,
+               int                     len,
                struct xdr_buf          *inbuf);
 u32 gss_delete_sec_context(
                struct gss_ctx          **ctx_id);
@@ -127,6 +128,7 @@ struct gss_api_ops {
        u32 (*gss_unwrap)(
                        struct gss_ctx          *ctx_id,
                        int                     offset,
+                       int                     len,
                        struct xdr_buf          *buf);
        void (*gss_delete_sec_context)(
                        void                    *internal_ctx_id);
diff --git a/include/linux/sunrpc/gss_krb5.h b/include/linux/sunrpc/gss_krb5.h
index 02c0412e368cc..07930bc9ad604 100644
--- a/include/linux/sunrpc/gss_krb5.h
+++ b/include/linux/sunrpc/gss_krb5.h
@@ -83,7 +83,7 @@ struct gss_krb5_enctype {
        u32 (*encrypt_v2) (struct krb5_ctx *kctx, u32 offset,
                           struct xdr_buf *buf,
                           struct page **pages); /* v2 encryption function */
-       u32 (*decrypt_v2) (struct krb5_ctx *kctx, u32 offset,
+       u32 (*decrypt_v2) (struct krb5_ctx *kctx, u32 offset, u32 len,
                           struct xdr_buf *buf, u32 *headskip,
                           u32 *tailskip);      /* v2 decryption function */
 };
@@ -255,7 +255,7 @@ gss_wrap_kerberos(struct gss_ctx *ctx_id, int offset,
                struct xdr_buf *outbuf, struct page **pages);
 
 u32
-gss_unwrap_kerberos(struct gss_ctx *ctx_id, int offset,
+gss_unwrap_kerberos(struct gss_ctx *ctx_id, int offset, int len,
                struct xdr_buf *buf);
 
 
@@ -312,7 +312,7 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
                     struct page **pages);
 
 u32
-gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset,
+gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
                     struct xdr_buf *buf, u32 *plainoffset,
                     u32 *plainlen);
 
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c
index ff5fcb3e12084..c8782f4e20ec2 100644
--- a/net/sunrpc/auth_gss/auth_gss.c
+++ b/net/sunrpc/auth_gss/auth_gss.c
@@ -2041,9 +2041,9 @@ gss_unwrap_resp_priv(struct rpc_task *task, struct 
rpc_cred *cred,
        offset = (u8 *)(p) - (u8 *)head->iov_base;
        if (offset + opaque_len > rcv_buf->len)
                goto unwrap_failed;
-       rcv_buf->len = offset + opaque_len;
 
-       maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset, rcv_buf);
+       maj_stat = gss_unwrap(ctx->gc_gss_ctx, offset,
+                             offset + opaque_len, rcv_buf);
        if (maj_stat == GSS_S_CONTEXT_EXPIRED)
                clear_bit(RPCAUTH_CRED_UPTODATE, &cred->cr_flags);
        if (maj_stat != GSS_S_COMPLETE)
diff --git a/net/sunrpc/auth_gss/gss_krb5_crypto.c 
b/net/sunrpc/auth_gss/gss_krb5_crypto.c
index 6f2d30d7b766d..e7180da1fc6a1 100644
--- a/net/sunrpc/auth_gss/gss_krb5_crypto.c
+++ b/net/sunrpc/auth_gss/gss_krb5_crypto.c
@@ -851,8 +851,8 @@ gss_krb5_aes_encrypt(struct krb5_ctx *kctx, u32 offset,
 }
 
 u32
-gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, struct xdr_buf *buf,
-                    u32 *headskip, u32 *tailskip)
+gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, u32 len,
+                    struct xdr_buf *buf, u32 *headskip, u32 *tailskip)
 {
        struct xdr_buf subbuf;
        u32 ret = 0;
@@ -881,7 +881,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, 
struct xdr_buf *buf,
 
        /* create a segment skipping the header and leaving out the checksum */
        xdr_buf_subsegment(buf, &subbuf, offset + GSS_KRB5_TOK_HDR_LEN,
-                                   (buf->len - offset - GSS_KRB5_TOK_HDR_LEN -
+                                   (len - offset - GSS_KRB5_TOK_HDR_LEN -
                                     kctx->gk5e->cksumlength));
 
        nblocks = (subbuf.len + blocksize - 1) / blocksize;
@@ -926,7 +926,7 @@ gss_krb5_aes_decrypt(struct krb5_ctx *kctx, u32 offset, 
struct xdr_buf *buf,
                goto out_err;
 
        /* Get the packet's hmac value */
-       ret = read_bytes_from_xdr_buf(buf, buf->len - kctx->gk5e->cksumlength,
+       ret = read_bytes_from_xdr_buf(buf, len - kctx->gk5e->cksumlength,
                                      pkt_hmac, kctx->gk5e->cksumlength);
        if (ret)
                goto out_err;
diff --git a/net/sunrpc/auth_gss/gss_krb5_wrap.c 
b/net/sunrpc/auth_gss/gss_krb5_wrap.c
index 14a0aff0cd84c..a7cafc29d61ee 100644
--- a/net/sunrpc/auth_gss/gss_krb5_wrap.c
+++ b/net/sunrpc/auth_gss/gss_krb5_wrap.c
@@ -261,7 +261,8 @@ gss_wrap_kerberos_v1(struct krb5_ctx *kctx, int offset,
 }
 
 static u32
-gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, int len,
+                      struct xdr_buf *buf)
 {
        int                     signalg;
        int                     sealalg;
@@ -284,7 +285,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, 
struct xdr_buf *buf)
 
        ptr = (u8 *)buf->head[0].iov_base + offset;
        if (g_verify_token_header(&kctx->mech_used, &bodysize, &ptr,
-                                       buf->len - offset))
+                                       len - offset))
                return GSS_S_DEFECTIVE_TOKEN;
 
        if ((ptr[0] != ((KG_TOK_WRAP_MSG >> 8) & 0xff)) ||
@@ -324,6 +325,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, 
struct xdr_buf *buf)
            (!kctx->initiate && direction != 0))
                return GSS_S_BAD_SIG;
 
+       buf->len = len;
        if (kctx->enctype == ENCTYPE_ARCFOUR_HMAC) {
                struct crypto_sync_skcipher *cipher;
                int err;
@@ -376,7 +378,7 @@ gss_unwrap_kerberos_v1(struct krb5_ctx *kctx, int offset, 
struct xdr_buf *buf)
        data_len = (buf->head[0].iov_base + buf->head[0].iov_len) - data_start;
        memmove(orig_start, data_start, data_len);
        buf->head[0].iov_len -= (data_start - orig_start);
-       buf->len -= (data_start - orig_start);
+       buf->len = len - (data_start - orig_start);
 
        if (gss_krb5_remove_padding(buf, blocksize))
                return GSS_S_DEFECTIVE_TOKEN;
@@ -486,7 +488,8 @@ gss_wrap_kerberos_v2(struct krb5_ctx *kctx, u32 offset,
 }
 
 static u32
-gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, struct xdr_buf *buf)
+gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, int len,
+                      struct xdr_buf *buf)
 {
        s32             now;
        u8              *ptr;
@@ -532,7 +535,7 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, 
struct xdr_buf *buf)
        if (rrc != 0)
                rotate_left(offset + 16, buf, rrc);
 
-       err = (*kctx->gk5e->decrypt_v2)(kctx, offset, buf,
+       err = (*kctx->gk5e->decrypt_v2)(kctx, offset, len, buf,
                                        &headskip, &tailskip);
        if (err)
                return GSS_S_FAILURE;
@@ -542,7 +545,7 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, 
struct xdr_buf *buf)
         * it against the original
         */
        err = read_bytes_from_xdr_buf(buf,
-                               buf->len - GSS_KRB5_TOK_HDR_LEN - tailskip,
+                               len - GSS_KRB5_TOK_HDR_LEN - tailskip,
                                decrypted_hdr, GSS_KRB5_TOK_HDR_LEN);
        if (err) {
                dprintk("%s: error %u getting decrypted_hdr\n", __func__, err);
@@ -568,14 +571,14 @@ gss_unwrap_kerberos_v2(struct krb5_ctx *kctx, int offset, 
struct xdr_buf *buf)
         * Note that buf->head[0].iov_len may indicate the available
         * head buffer space rather than that actually occupied.
         */
-       movelen = min_t(unsigned int, buf->head[0].iov_len, buf->len);
+       movelen = min_t(unsigned int, buf->head[0].iov_len, len);
        movelen -= offset + GSS_KRB5_TOK_HDR_LEN + headskip;
        if (offset + GSS_KRB5_TOK_HDR_LEN + headskip + movelen >
            buf->head[0].iov_len)
                return GSS_S_FAILURE;
        memmove(ptr, ptr + GSS_KRB5_TOK_HDR_LEN + headskip, movelen);
        buf->head[0].iov_len -= GSS_KRB5_TOK_HDR_LEN + headskip;
-       buf->len -= GSS_KRB5_TOK_HDR_LEN + headskip;
+       buf->len = len - GSS_KRB5_TOK_HDR_LEN + headskip;
 
        /* Trim off the trailing "extra count" and checksum blob */
        buf->len -= ec + GSS_KRB5_TOK_HDR_LEN + tailskip;
@@ -603,7 +606,8 @@ gss_wrap_kerberos(struct gss_ctx *gctx, int offset,
 }
 
 u32
-gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, struct xdr_buf *buf)
+gss_unwrap_kerberos(struct gss_ctx *gctx, int offset,
+                   int len, struct xdr_buf *buf)
 {
        struct krb5_ctx *kctx = gctx->internal_ctx_id;
 
@@ -613,9 +617,9 @@ gss_unwrap_kerberos(struct gss_ctx *gctx, int offset, 
struct xdr_buf *buf)
        case ENCTYPE_DES_CBC_RAW:
        case ENCTYPE_DES3_CBC_RAW:
        case ENCTYPE_ARCFOUR_HMAC:
-               return gss_unwrap_kerberos_v1(kctx, offset, buf);
+               return gss_unwrap_kerberos_v1(kctx, offset, len, buf);
        case ENCTYPE_AES128_CTS_HMAC_SHA1_96:
        case ENCTYPE_AES256_CTS_HMAC_SHA1_96:
-               return gss_unwrap_kerberos_v2(kctx, offset, buf);
+               return gss_unwrap_kerberos_v2(kctx, offset, len, buf);
        }
 }
diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c 
b/net/sunrpc/auth_gss/gss_mech_switch.c
index 82060099a4291..8fa924c8e282c 100644
--- a/net/sunrpc/auth_gss/gss_mech_switch.c
+++ b/net/sunrpc/auth_gss/gss_mech_switch.c
@@ -438,10 +438,11 @@ gss_wrap(struct gss_ctx   *ctx_id,
 u32
 gss_unwrap(struct gss_ctx      *ctx_id,
           int                  offset,
+          int                  len,
           struct xdr_buf       *buf)
 {
        return ctx_id->mech_type->gm_ops
-               ->gss_unwrap(ctx_id, offset, buf);
+               ->gss_unwrap(ctx_id, offset, len, buf);
 }
 
 
diff --git a/net/sunrpc/auth_gss/svcauth_gss.c 
b/net/sunrpc/auth_gss/svcauth_gss.c
index ed20fa8a6f707..ab3a9c49a859a 100644
--- a/net/sunrpc/auth_gss/svcauth_gss.c
+++ b/net/sunrpc/auth_gss/svcauth_gss.c
@@ -925,7 +925,7 @@ static int
 unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf *buf, u32 seq, struct 
gss_ctx *ctx)
 {
        u32 priv_len, maj_stat;
-       int pad, saved_len, remaining_len, offset;
+       int pad, remaining_len, offset;
 
        clear_bit(RQ_SPLICE_OK, &rqstp->rq_flags);
 
@@ -945,12 +945,8 @@ unwrap_priv_data(struct svc_rqst *rqstp, struct xdr_buf 
*buf, u32 seq, struct gs
        buf->len -= pad;
        fix_priv_head(buf, pad);
 
-       /* Maybe it would be better to give gss_unwrap a length parameter: */
-       saved_len = buf->len;
-       buf->len = priv_len;
-       maj_stat = gss_unwrap(ctx, 0, buf);
+       maj_stat = gss_unwrap(ctx, 0, priv_len, buf);
        pad = priv_len - buf->len;
-       buf->len = saved_len;
        buf->len -= pad;
        /* The upper layers assume the buffer is aligned on 4-byte boundaries.
         * In the krb5p case, at least, the data ends up offset, so we need to
-- 
2.20.1



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