diff options
Diffstat (limited to 'net/sunrpc')
| -rw-r--r-- | net/sunrpc/auth_gss/auth_gss.c | 12 | ||||
| -rw-r--r-- | net/sunrpc/auth_gss/gss_mech_switch.c | 14 | ||||
| -rw-r--r-- | net/sunrpc/auth_gss/svcauth_gss.c | 15 |
3 files changed, 38 insertions, 3 deletions
diff --git a/net/sunrpc/auth_gss/auth_gss.c b/net/sunrpc/auth_gss/auth_gss.c index 75602ece58eb..d64a58b8ed33 100644 --- a/net/sunrpc/auth_gss/auth_gss.c +++ b/net/sunrpc/auth_gss/auth_gss.c @@ -1316,15 +1316,21 @@ gss_wrap_req_priv(struct rpc_cred *cred, struct gss_cl_ctx *ctx, inpages = snd_buf->pages + first; snd_buf->pages = rqstp->rq_enc_pages; snd_buf->page_base -= first << PAGE_CACHE_SHIFT; - /* Give the tail its own page, in case we need extra space in the - * head when wrapping: */ + /* + * Give the tail its own page, in case we need extra space in the + * head when wrapping: + * + * call_allocate() allocates twice the slack space required + * by the authentication flavor to rq_callsize. + * For GSS, slack is GSS_CRED_SLACK. + */ if (snd_buf->page_len || snd_buf->tail[0].iov_len) { tmp = page_address(rqstp->rq_enc_pages[rqstp->rq_enc_pages_num - 1]); memcpy(tmp, snd_buf->tail[0].iov_base, snd_buf->tail[0].iov_len); snd_buf->tail[0].iov_base = tmp; } maj_stat = gss_wrap(ctx->gc_gss_ctx, offset, snd_buf, inpages); - /* RPC_SLACK_SPACE should prevent this ever happening: */ + /* slack space should prevent this ever happening: */ BUG_ON(snd_buf->len > snd_buf->buflen); status = -EIO; /* We're assuming that when GSS_S_CONTEXT_EXPIRED, the encryption was diff --git a/net/sunrpc/auth_gss/gss_mech_switch.c b/net/sunrpc/auth_gss/gss_mech_switch.c index 76e4c6f4ac3c..28a84ef41d13 100644 --- a/net/sunrpc/auth_gss/gss_mech_switch.c +++ b/net/sunrpc/auth_gss/gss_mech_switch.c @@ -285,6 +285,20 @@ gss_verify_mic(struct gss_ctx *context_handle, mic_token); } +/* + * This function is called from both the client and server code. + * Each makes guarantees about how much "slack" space is available + * for the underlying function in "buf"'s head and tail while + * performing the wrap. + * + * The client and server code allocate RPC_MAX_AUTH_SIZE extra + * space in both the head and tail which is available for use by + * the wrap function. + * + * Underlying functions should verify they do not use more than + * RPC_MAX_AUTH_SIZE of extra space in either the head or tail + * when performing the wrap. + */ u32 gss_wrap(struct gss_ctx *ctx_id, int offset, diff --git a/net/sunrpc/auth_gss/svcauth_gss.c b/net/sunrpc/auth_gss/svcauth_gss.c index b81e790ef9f4..1d9ac4ac818a 100644 --- a/net/sunrpc/auth_gss/svcauth_gss.c +++ b/net/sunrpc/auth_gss/svcauth_gss.c @@ -1315,6 +1315,14 @@ svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp) inpages = resbuf->pages; /* XXX: Would be better to write some xdr helper functions for * nfs{2,3,4}xdr.c that place the data right, instead of copying: */ + + /* + * If there is currently tail data, make sure there is + * room for the head, tail, and 2 * RPC_MAX_AUTH_SIZE in + * the page, and move the current tail data such that + * there is RPC_MAX_AUTH_SIZE slack space available in + * both the head and tail. + */ if (resbuf->tail[0].iov_base) { BUG_ON(resbuf->tail[0].iov_base >= resbuf->head[0].iov_base + PAGE_SIZE); @@ -1327,6 +1335,13 @@ svcauth_gss_wrap_resp_priv(struct svc_rqst *rqstp) resbuf->tail[0].iov_len); resbuf->tail[0].iov_base += RPC_MAX_AUTH_SIZE; } + /* + * If there is no current tail data, make sure there is + * room for the head data, and 2 * RPC_MAX_AUTH_SIZE in the + * allotted page, and set up tail information such that there + * is RPC_MAX_AUTH_SIZE slack space available in both the + * head and tail. + */ if (resbuf->tail[0].iov_base == NULL) { if (resbuf->head[0].iov_len + 2*RPC_MAX_AUTH_SIZE > PAGE_SIZE) return -ENOMEM; |