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authorTrond Myklebust <trond.myklebust@hammerspace.com>2019-05-29 19:49:52 +0300
committerAnna Schumaker <Anna.Schumaker@Netapp.com>2019-05-30 22:29:41 +0300
commit7987b694ade8cc465ce10fb3dceaa614f13ceaf3 (patch)
tree5c71e423c301bd079f8bcf7f298ffd6688600d1d /net/sunrpc
parentec6017d9035986a36de064f48a63245930bfad6f (diff)
downloadlinux-7987b694ade8cc465ce10fb3dceaa614f13ceaf3.tar.xz
SUNRPC: Fix a use after free when a server rejects the RPCSEC_GSS credential
The addition of rpc_check_timeout() to call_decode causes an Oops when the RPCSEC_GSS credential is rejected. The reason is that rpc_decode_header() will call xprt_release() in order to free task->tk_rqstp, which is needed by rpc_check_timeout() to check whether or not we should exit due to a soft timeout. The fix is to move the call to xprt_release() into call_decode() so we can perform it after rpc_check_timeout(). Reported-by: Olga Kornievskaia <olga.kornievskaia@gmail.com> Reported-by: Nick Bowler <nbowler@draconx.ca> Fixes: cea57789e408 ("SUNRPC: Clean up") Cc: stable@vger.kernel.org # v5.1+ Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com> Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
Diffstat (limited to 'net/sunrpc')
-rw-r--r--net/sunrpc/clnt.c28
1 files changed, 14 insertions, 14 deletions
diff --git a/net/sunrpc/clnt.c b/net/sunrpc/clnt.c
index 94a653be8e25..627a87a71f8b 100644
--- a/net/sunrpc/clnt.c
+++ b/net/sunrpc/clnt.c
@@ -2426,17 +2426,21 @@ call_decode(struct rpc_task *task)
return;
case -EAGAIN:
task->tk_status = 0;
- /* Note: rpc_decode_header() may have freed the RPC slot */
- if (task->tk_rqstp == req) {
- xdr_free_bvec(&req->rq_rcv_buf);
- req->rq_reply_bytes_recvd = 0;
- req->rq_rcv_buf.len = 0;
- if (task->tk_client->cl_discrtry)
- xprt_conditional_disconnect(req->rq_xprt,
- req->rq_connect_cookie);
- }
+ xdr_free_bvec(&req->rq_rcv_buf);
+ req->rq_reply_bytes_recvd = 0;
+ req->rq_rcv_buf.len = 0;
+ if (task->tk_client->cl_discrtry)
+ xprt_conditional_disconnect(req->rq_xprt,
+ req->rq_connect_cookie);
task->tk_action = call_encode;
rpc_check_timeout(task);
+ break;
+ case -EKEYREJECTED:
+ task->tk_action = call_reserve;
+ rpc_check_timeout(task);
+ rpcauth_invalcred(task);
+ /* Ensure we obtain a new XID if we retry! */
+ xprt_release(task);
}
}
@@ -2572,11 +2576,7 @@ out_msg_denied:
break;
task->tk_cred_retry--;
trace_rpc__stale_creds(task);
- rpcauth_invalcred(task);
- /* Ensure we obtain a new XID! */
- xprt_release(task);
- task->tk_action = call_reserve;
- return -EAGAIN;
+ return -EKEYREJECTED;
case rpc_autherr_badcred:
case rpc_autherr_badverf:
/* possibly garbled cred/verf? */