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path: root/net/sunrpc/auth_gss/gss_rpc_upcall.c
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2017-05-15sunrpc: mark all struct rpc_procinfo instances as constChristoph Hellwig
struct rpc_procinfo contains function pointers, and marking it as constant avoids it being able to be used as an attach vector for code injections. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-15sunrpc: move p_count out of struct rpc_procinfoChristoph Hellwig
p_count is the only writeable memeber of struct rpc_procinfo, which is a good candidate to be const-ified as it contains function pointers. This patch moves it into out out struct rpc_procinfo, and into a separate writable array that is pointed to by struct rpc_version and indexed by p_statidx. Signed-off-by: Christoph Hellwig <hch@lst.de>
2017-05-15sunrpc/auth_gss: fix decoder callback prototypesChristoph Hellwig
Declare the p_decode callbacks with the proper prototype instead of casting to kxdrdproc_t and losing all type safety. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2017-05-15sunrpc/auth_gss: nfsd: fix encoder callback prototypesChristoph Hellwig
Declare the p_encode callbacks with the proper prototype instead of casting to kxdreproc_t and losing all type safety. Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jeff Layton <jlayton@redhat.com> Acked-by: Trond Myklebust <trond.myklebust@primarydata.com>
2015-11-24nfsd4: fix gss-proxy 4.1 mounts for some AD principalsJ. Bruce Fields
The principal name on a gss cred is used to setup the NFSv4.0 callback, which has to have a client principal name to authenticate to. That code wants the name to be in the form servicetype@hostname. rpc.svcgssd passes down such names (and passes down no principal name at all in the case the principal isn't a service principal). gss-proxy always passes down the principal name, and passes it down in the form servicetype/hostname@REALM. So we've been munging the name gss-proxy passes down into the format the NFSv4.0 callback code expects, or throwing away the name if we can't. Since the introduction of the MACH_CRED enforcement in NFSv4.1, we've also been using the principal name to verify that certain operations are done as the same principal as was used on the original EXCHANGE_ID call. For that application, the original name passed down by gss-proxy is also useful. Lack of that name in some cases was causing some kerberized NFSv4.1 mount failures in an Active Directory environment. This fix only works in the gss-proxy case. The fix for legacy rpc.svcgssd would be more involved, and rpc.svcgssd already has other problems in the AD case. Reported-and-tested-by: James Ralston <ralston@pobox.com> Acked-by: Simo Sorce <simo@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2015-02-17svcrpc: fix memory leak in gssp_accept_sec_context_upcallDavid Ramos
Our UC-KLEE tool found a kernel memory leak of 512 bytes (on x86_64) for each call to gssp_accept_sec_context_upcall() (net/sunrpc/auth_gss/gss_rpc_upcall.c). Since it appears that this call can be triggered by remote connections (at least, from a cursory a glance at the call chain), it may be exploitable to cause kernel memory exhaustion. We found the bug in kernel 3.16.3, but it appears to date back to commit 9dfd87da1aeb0fd364167ad199f40fe96a6a87be (2013-08-20). The gssp_accept_sec_context_upcall() function performs a pair of calls to gssp_alloc_receive_pages() and gssp_free_receive_pages(). The first allocates memory for arg->pages. The second then frees the pages pointed to by the arg->pages array, but not the array itself. Reported-by: David A. Ramos <daramos@stanford.edu> Fixes: 9dfd87da1aeb ("rpc: fix huge kmalloc's in gss-proxy”) Signed-off-by: David A. Ramos <daramos@stanford.edu> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2014-01-06sunrpc: don't wait for write before allowing reads from use-gss-proxy fileJeff Layton
It doesn't make much sense to make reads from this procfile hang. As far as I can tell, only gssproxy itself will open this file and it never reads from it. Change it to just give the present setting of sn->use_gss_proxy without waiting for anything. Note that we do not want to call use_gss_proxy() in this codepath since an inopportune read of this file could cause it to be disabled prematurely. Cc: stable@vger.kernel.org Signed-off-by: Jeff Layton <jlayton@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-10-08svcrpc: fix gss-proxy NULL dereference in some error casesJ. Bruce Fields
We depend on the xdr decoder to set this pointer, but if we error out before we decode this piece it could be left NULL. I think this is probably tough to hit without a buggy gss-proxy. Reported-by: Andi Kleen <andi@firstfloor.org> Cc: Simo Sorce <simo@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-09-06rpc: let xdr layer allocate gssproxy receieve pagesJ. Bruce Fields
In theory the linux cred in a gssproxy reply can include up to NGROUPS_MAX data, 256K of data. In the common case we expect it to be shorter. So do as the nfsv3 ACL code does and let the xdr code allocate the pages as they come in, instead of allocating a lot of pages that won't typically be used. Tested-by: Simo Sorce <simo@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-09-06rpc: fix huge kmalloc's in gss-proxyJ. Bruce Fields
The reply to a gssproxy can include up to NGROUPS_MAX gid's, which will take up more than a page. We therefore need to allocate an array of pages to hold the reply instead of trying to allocate a single huge buffer. Tested-by: Simo Sorce <simo@redhat.com> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-08-01svcrpc: fix kfree oops in gss-proxy codeJ. Bruce Fields
mech_oid.data is an array, not kmalloc()'d memory. Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-08-01svcrpc: fix gss_rpc_upcall create errorJ. Bruce Fields
Cc: stable@vger.kernel.org Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-29SUNRPC: gssp_procedures[] can be staticFengguang Wu
Cc: Simo Sorce <simo@redhat.com> Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
2013-04-29Merge branch 'nfs-for-next' of git://linux-nfs.org/~trondmy/nfs-2.6 into ↵J. Bruce Fields
for-3.10 Note conflict: Chuck's patches modified (and made static) gss_mech_get_by_OID, which is still needed by gss-proxy patches. The conflict resolution is a bit minimal; we may want some more cleanup.
2013-04-26SUNRPC: Use gssproxy upcall for server RPCGSS authentication.Simo Sorce
The main advantge of this new upcall mechanism is that it can handle big tickets as seen in Kerberos implementations where tickets carry authorization data like the MS-PAC buffer with AD or the Posix Authorization Data being discussed in IETF on the krbwg working group. The Gssproxy program is used to perform the accept_sec_context call on the kernel's behalf. The code is changed to also pass the input buffer straight to upcall mechanism to avoid allocating and copying many pages as tokens can be as big (potentially more in future) as 64KiB. Signed-off-by: Simo Sorce <simo@redhat.com> [bfields: containerization, negotiation api] Signed-off-by: J. Bruce Fields <bfields@redhat.com>
2013-04-26SUNRPC: Add RPC based upcall mechanism for RPCGSS authSimo Sorce
This patch implements a sunrpc client to use the services of the gssproxy userspace daemon. In particular it allows to perform calls in user space using an RPC call instead of custom hand-coded upcall/downcall messages. Currently only accept_sec_context is implemented as that is all is needed for the server case. File server modules like NFS and CIFS can use full gssapi services this way, once init_sec_context is also implemented. For the NFS server case this code allow to lift the limit of max 2k krb5 tickets. This limit is prevents legitimate kerberos deployments from using krb5 authentication with the Linux NFS server as they have normally ticket that are many kilobytes large. It will also allow to lift the limitation on the size of the credential set (uid,gid,gids) passed down from user space for users that have very many groups associated. Currently the downcall mechanism used by rpc.svcgssd is limited to around 2k secondary groups of the 65k allowed by kernel structures. Signed-off-by: Simo Sorce <simo@redhat.com> [bfields: containerization, concurrent upcalls, misc. fixes and cleanup] Signed-off-by: J. Bruce Fields <bfields@redhat.com>