From 5a27594a16307d0b9ab626d7b51514f92e4b7bdd Mon Sep 17 00:00:00 2001
From: N Balachandran <nbalacha@redhat.com>
Date: Thu, 18 May 2017 10:08:43 +0530
Subject: [PATCH 451/473] cluster/dht: Fix crash in dht rmdir

Using local->call_cnt to check STACK_WINDs can
cause dht_rmdir_do to be called erroneously if
dht_rmdir_readdirp_cbk unwinds before we check if
local->call_cnt is zero in dht_rmdir_opendir_cbk.
This can cause frame corruptions and crashes.

Thanks to Shyam (srangana@redhat.com) for the
analysis.

> BUG: 1451083
> Signed-off-by: N Balachandran <nbalacha@redhat.com>
> Reviewed-on: https://review.gluster.org/17305
> Smoke: Gluster Build System <jenkins@build.gluster.org>
> NetBSD-regression: NetBSD Build System <jenkins@build.gluster.org>
> CentOS-regression: Gluster Build System <jenkins@build.gluster.org>
> Reviewed-by: Shyamsundar Ranganathan <srangana@redhat.com>

Change-Id: I116dbbffca83a4547b71d922ca99a42f3cf6e009
BUG: 1451086
Signed-off-by: N Balachandran <nbalacha@redhat.com>
Reviewed-on: https://code.engineering.redhat.com/gerrit/106511
Reviewed-by: Atin Mukherjee <amukherj@redhat.com>
---
 xlators/cluster/dht/src/dht-common.c | 14 ++++++++++----
 1 file changed, 10 insertions(+), 4 deletions(-)

diff --git a/xlators/cluster/dht/src/dht-common.c b/xlators/cluster/dht/src/dht-common.c
index 962282a..264ca65 100644
--- a/xlators/cluster/dht/src/dht-common.c
+++ b/xlators/cluster/dht/src/dht-common.c
@@ -8646,6 +8646,7 @@ dht_rmdir_opendir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
         char          gfid[GF_UUID_BUF_SIZE] = {0};
         dht_local_t  *readdirp_local = NULL;
         call_frame_t *readdirp_frame = NULL;
+        int           cnt           = 0;
 
         local = frame->local;
         prev  = cookie;
@@ -8688,7 +8689,7 @@ dht_rmdir_opendir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                         "%s: Failed to set dictionary value:key = %s",
                         local->loc.path, conf->link_xattr_name);
 
-        local->call_cnt = conf->subvolume_cnt;
+        cnt = local->call_cnt = conf->subvolume_cnt;
 
 
         /* Create a separate frame per subvol as we might need
@@ -8701,7 +8702,9 @@ dht_rmdir_opendir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 readdirp_frame = copy_frame (frame);
 
                 if (!readdirp_frame) {
-                        local->call_cnt--;
+                        cnt--;
+                        /* Reduce the local->call_cnt as well */
+                        dht_frame_return (frame);
                         continue;
                 }
 
@@ -8710,7 +8713,9 @@ dht_rmdir_opendir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
 
                 if (!readdirp_local) {
                         DHT_STACK_DESTROY (readdirp_frame);
-                        local->call_cnt--;
+                        cnt--;
+                        /* Reduce the local->call_cnt as well */
+                        dht_frame_return (frame);
                         continue;
                 }
                 readdirp_local->main_frame = frame;
@@ -8730,7 +8735,8 @@ dht_rmdir_opendir_cbk (call_frame_t *frame, void *cookie, xlator_t *this,
                 dict_unref (dict);
 
         /* Could not wind readdirp to any subvol */
-        if (!local->call_cnt)
+
+        if (!cnt)
                 goto err;
 
         return 0;
-- 
1.8.3.1