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authorScott Mayhew <smayhew@redhat.com>2015-04-28 16:29:53 -0400
committerJ. Bruce Fields <bfields@redhat.com>2015-05-04 12:02:40 -0400
commit9507271d960a1911a51683888837d75c171cd91f (patch)
tree51ae70d0b2257ec9e32c78ade5e953dca00acdc2
parent8287f009bd95a5e548059dba62a67727bb9549cd (diff)
svcrpc: fix potential GSSX_ACCEPT_SEC_CONTEXT decoding failures
In an environment where the KDC is running Active Directory, the exported composite name field returned in the context could be large enough to span a page boundary. Attaching a scratch buffer to the decoding xdr_stream helps deal with those cases. The case where we saw this was actually due to behavior that's been fixed in newer gss-proxy versions, but we're fixing it here too. Signed-off-by: Scott Mayhew <smayhew@redhat.com> Cc: stable@vger.kernel.org Reviewed-by: Simo Sorce <simo@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
-rw-r--r--net/sunrpc/auth_gss/gss_rpc_xdr.c23
1 files changed, 16 insertions, 7 deletions
diff --git a/net/sunrpc/auth_gss/gss_rpc_xdr.c b/net/sunrpc/auth_gss/gss_rpc_xdr.c
index 1ec19f6f0c2b..eeeba5adee6d 100644
--- a/net/sunrpc/auth_gss/gss_rpc_xdr.c
+++ b/net/sunrpc/auth_gss/gss_rpc_xdr.c
@@ -793,20 +793,26 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
{
u32 value_follows;
int err;
+ struct page *scratch;
+
+ scratch = alloc_page(GFP_KERNEL);
+ if (!scratch)
+ return -ENOMEM;
+ xdr_set_scratch_buffer(xdr, page_address(scratch), PAGE_SIZE);
/* res->status */
err = gssx_dec_status(xdr, &res->status);
if (err)
- return err;
+ goto out_free;
/* res->context_handle */
err = gssx_dec_bool(xdr, &value_follows);
if (err)
- return err;
+ goto out_free;
if (value_follows) {
err = gssx_dec_ctx(xdr, res->context_handle);
if (err)
- return err;
+ goto out_free;
} else {
res->context_handle = NULL;
}
@@ -814,11 +820,11 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
/* res->output_token */
err = gssx_dec_bool(xdr, &value_follows);
if (err)
- return err;
+ goto out_free;
if (value_follows) {
err = gssx_dec_buffer(xdr, res->output_token);
if (err)
- return err;
+ goto out_free;
} else {
res->output_token = NULL;
}
@@ -826,14 +832,17 @@ int gssx_dec_accept_sec_context(struct rpc_rqst *rqstp,
/* res->delegated_cred_handle */
err = gssx_dec_bool(xdr, &value_follows);
if (err)
- return err;
+ goto out_free;
if (value_follows) {
/* we do not support upcall servers sending this data. */
- return -EINVAL;
+ err = -EINVAL;
+ goto out_free;
}
/* res->options */
err = gssx_dec_option_array(xdr, &res->options);
+out_free:
+ __free_page(scratch);
return err;
}