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| author | Scott Mayhew <smayhew@redhat.com> | 2015-04-28 16:29:53 -0400 |
|---|---|---|
| committer | J. Bruce Fields <bfields@redhat.com> | 2015-05-04 12:02:40 -0400 |
| commit | 9507271d960a1911a51683888837d75c171cd91f (patch) | |
| tree | 51ae70d0b2257ec9e32c78ade5e953dca00acdc2 /net/sunrpc/auth_gss | |
| parent | 8287f009bd95a5e548059dba62a67727bb9549cd (diff) | |
| download | linux-9507271d960a1911a51683888837d75c171cd91f.tar.gz | |
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>
Diffstat (limited to 'net/sunrpc/auth_gss')
| -rw-r--r-- | net/sunrpc/auth_gss/gss_rpc_xdr.c | 23 |
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; } |