nfs/nlm: use refcounting for nfs3_call_state_t

In order to track down a potential use-after-free of the
nfs3_call_state_t structure in the NLM component, add reference counting
where teh structure is used. This should prevent premature free'ing of
the structure.

Cherry picked from commit 01bfdd4d1759423681d311da33f4ac2346ace445:
> Change-Id: Ib1f13b0463ab1e012b7b49a623c91f0f3e73e1fb
> BUG: 1467313
> Signed-off-by: Niels de Vos <ndevos@redhat.com>
> Reviewed-on: https://review.gluster.org/17699
> Reviewed-by: jiffin tony Thottan <jthottan@redhat.com>
> Smoke: Gluster Build System <jenkins@build.gluster.org>
> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>

Change-Id: Ib1f13b0463ab1e012b7b49a623c91f0f3e73e1fb
BUG: 1471869
Signed-off-by: Niels de Vos <ndevos@redhat.com>
Reviewed-on: https://review.gluster.org/17800
CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
Smoke: Gluster Build System <jenkins@build.gluster.org>
Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>

1 files changed, 35 insertions, 11 deletions

diff --git a/xlators/nfs/server/src/nlm4.c b/xlators/nfs/server/src/nlm4.c
index fab9e62cb3a..f237f1a29ab 100644
--- a/xlators/nfs/server/src/nlm4.c
+++ b/xlators/nfs/server/src/nlm4.c
@@ -528,8 +528,11 @@ nlm4_file_open_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 fd_bind (cs->fd);
         cs->resolve_ret = op_ret;
         cs->resume_fn (cs);
+
         frame->local = NULL;
         STACK_DESTROY (frame->root);
+        GF_REF_PUT (cs);
+
         return 0;
 }
 
@@ -669,7 +672,7 @@ nlm4_file_open_and_resume(nfs3_call_state_t *cs, nlm4_resume_fn_t resume)
         frame->root->pid = NFS_PID;
         frame->root->uid = rpcsvc_request_uid (cs->req);
         frame->root->gid = rpcsvc_request_gid (cs->req);
-        frame->local = cs;
+        frame->local = GF_REF_GET (cs);
         nfs_fix_groups (cs->nfsx, frame->root);
 
         STACK_WIND_COOKIE (frame, nlm4_file_open_cbk, cs->vol, cs->vol,
@@ -806,7 +809,7 @@ nlm4_test_fd_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nfs_request_user_init (&nfu, cs->req);
         nlm4_lock_to_gf_flock (&flock, &cs->args.nlm4_testargs.alock,
                                cs->args.nlm4_testargs.exclusive);
@@ -814,6 +817,8 @@ nlm4_test_fd_resume (void *carg)
         ret = nfs_lk (cs->nfsx, cs->vol, &nfu, cs->fd, F_GETLK, &flock,
                       nlm4svc_test_cbk, cs);
 
+        GF_REF_PUT (cs);
+
         return ret;
 }
 
@@ -829,7 +834,7 @@ nlm4_test_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nlm4_check_fh_resolve_status (cs, stat, nlm4err);
         fd = fd_anonymous (cs->resolvedloc.inode);
         if (!fd)
@@ -846,6 +851,8 @@ nlm4err:
                 nfs3_call_state_wipe (cs);
         }
 
+        GF_REF_PUT (cs);
+
         return ret;
 }
 
@@ -1371,7 +1378,7 @@ nlm4_lock_fd_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nlm4_check_fh_resolve_status (cs, stat, nlm4err);
         (void) nlm_search_and_add (cs->fd,
                                    cs->args.nlm4_lockargs.alock.caller_name);
@@ -1402,6 +1409,8 @@ nlm4err:
                 nfs3_call_state_wipe (cs);
         }
 
+        GF_REF_PUT (cs);
+
         return ret;
 }
 
@@ -1416,7 +1425,7 @@ nlm4_lock_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nlm4_check_fh_resolve_status (cs, stat, nlm4err);
         ret = nlm4_file_open_and_resume (cs, nlm4_lock_fd_resume);
 
@@ -1430,6 +1439,8 @@ nlm4err:
                 nfs3_call_state_wipe (cs);
         }
 
+        GF_REF_PUT (cs);
+
         return ret;
 }
 
@@ -1549,7 +1560,7 @@ nlm4_cancel_fd_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nfs_request_user_init (&nfu, cs->req);
         nlm4_lock_to_gf_flock (&flock, &cs->args.nlm4_cancargs.alock,
                                 cs->args.nlm4_cancargs.exclusive);
@@ -1558,6 +1569,8 @@ nlm4_cancel_fd_resume (void *carg)
         ret = nfs_lk (cs->nfsx, cs->vol, &nfu, cs->fd, F_SETLK,
                       &flock, nlm4svc_cancel_cbk, cs);
 
+        GF_REF_PUT (cs);
+
         return ret;
 }
 
@@ -1572,7 +1585,7 @@ nlm4_cancel_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nlm4_check_fh_resolve_status (cs, stat, nlm4err);
 
         nlmclnt = nlm_get_uniq (cs->args.nlm4_cancargs.alock.caller_name);
@@ -1599,6 +1612,9 @@ nlm4err:
 
                 nfs3_call_state_wipe (cs);
         }
+
+        GF_REF_PUT (cs);
+
         /* clean up is taken care of */
         return 0;
 }
@@ -1674,7 +1690,7 @@ nlm4svc_unlock_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         nlm4_stats                      stat = nlm4_denied;
         nfs3_call_state_t              *cs = NULL;
 
-        cs = frame->local;
+        cs = GF_REF_GET ((nfs3_call_state_t*) frame->local);
         if (op_ret == -1) {
                 stat = nlm4_errno_to_nlm4stat (op_errno);
                 goto err;
@@ -1687,7 +1703,7 @@ nlm4svc_unlock_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 
 err:
         nlm4_generic_reply (cs->req, cs->args.nlm4_unlockargs.cookie, stat);
-        nfs3_call_state_wipe (cs);
+        GF_REF_PUT (cs);
         return 0;
 }
 
@@ -1701,7 +1717,7 @@ nlm4_unlock_fd_resume (void *carg)
 
         if (!carg)
                 return ret;
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nfs_request_user_init (&nfu, cs->req);
         nlm4_lock_to_gf_flock (&flock, &cs->args.nlm4_unlockargs.alock, 0);
         nlm_copy_lkowner (&nfu.lk_owner, &cs->args.nlm4_unlockargs.alock.oh);
@@ -1709,6 +1725,8 @@ nlm4_unlock_fd_resume (void *carg)
         ret = nfs_lk (cs->nfsx, cs->vol, &nfu, cs->fd, F_SETLK,
                       &flock, nlm4svc_unlock_cbk, cs);
 
+        GF_REF_PUT (cs);
+
         return ret;
 }
 
@@ -1724,7 +1742,7 @@ nlm4_unlock_resume (void *carg)
         if (!carg)
                 return ret;
 
-        cs = (nfs3_call_state_t *)carg;
+        cs = GF_REF_GET ((nfs3_call_state_t *)carg);
         nlm4_check_fh_resolve_status (cs, stat, nlm4err);
         caller_name = cs->args.nlm4_unlockargs.alock.caller_name;
 
@@ -1754,6 +1772,9 @@ nlm4err:
 
                 nfs3_call_state_wipe (cs);
         }
+
+        GF_REF_PUT (cs);
+
         /* we have already taken care of cleanup */
         return 0;
 }
@@ -2421,6 +2442,9 @@ nlm_handle_connect (struct rpc_clnt *rpc_clnt, nfs3_call_state_t *cs)
         }
 
 out:
+        if (cs)
+                GF_REF_PUT (cs);
+
         return ret;
 }