system/posix-acl: prevent NULL pointer dereference of group_ce

Thanks Amar Tumballi.

Change-Id: I3ac9b46d4c3fcd12d1eec779317a03c47d267556
BUG: 887098
Signed-off-by: Varun Shastry <vshastry@redhat.com>
Reviewed-on: http://review.gluster.org/4351
Reviewed-by: Amar Tumballi <amarts@redhat.com>
Tested-by: Gluster Build System <jenkins@build.gluster.com>
Reviewed-by: Vijay Bellur <vbellur@redhat.com>

2 files changed, 49 insertions, 1 deletions

diff --git a/tests/bugs/bug-887098-gmount-crash.t b/tests/bugs/bug-887098-gmount-crash.t
new file mode 100644
index 00000000..54e52d4d
--- /dev/null
+++ b/tests/bugs/bug-887098-gmount-crash.t
@@ -0,0 +1,48 @@
+#!/bin/bash
+
+. $(dirname $0)/../include.rc
+. $(dirname $0)/../volume.rc
+
+cleanup;
+
+## Start and create a volume
+TEST glusterd;
+TEST pidof glusterd;
+TEST $CLI volume info;
+
+TEST $CLI volume create $V0 replica 2 $H0:$B0/${V0}{1,2,3,4};
+
+## Verify volume is is created
+EXPECT "$V0" volinfo_field $V0 'Volume Name';
+EXPECT 'Created' volinfo_field $V0 'Status';
+
+function pidgrep()
+{
+    ps ax | grep "$1" | awk '{print $1}' | head -1
+}
+
+
+## Start volume and verify
+TEST $CLI volume start $V0;
+EXPECT 'Started' volinfo_field $V0 'Status';
+
+TEST glusterfs -s $H0 --volfile-id=$V0 --acl $M0
+MOUNT_PID=`ps ax |grep "glusterfs -s $H0 --volfile-id=$V0 --acl $M0" | awk '{print $1}' | head -1`
+
+for i in {1..25};
+do
+    mkdir $M0/tmp_$i && cat /etc/hosts > $M0/tmp_$i/file
+    cp -RPp $M0/tmp_$i $M0/newtmp_$i && cat /etc/hosts > $M0/newtmp_$i/newfile
+done
+
+EXPECT "$MOUNT_PID" pidgrep $MOUNT_PID
+TEST rm -rf $M0/*
+umount $M0
+
+## Finish up
+TEST $CLI volume stop $V0;
+EXPECT 'Stopped' volinfo_field $V0 'Status';
+
+TEST $CLI volume delete $V0;
+
+cleanup;
diff --git a/xlators/system/posix-acl/src/posix-acl.c b/xlators/system/posix-acl/src/posix-acl.c
index 3928a56a..a3570c0b 100644
--- a/xlators/system/posix-acl/src/posix-acl.c
+++ b/xlators/system/posix-acl/src/posix-acl.c
@@ -516,7 +516,7 @@ posix_acl_inherit_mode (struct posix_acl *acl, mode_t modein)
         if (mask_ce) {
                 mask_ce->perm &= (mode >> 3) | ~S_IRWXO;
                 mode &= (mask_ce->perm << 3) | ~S_IRWXG;
-        } else {
+        } else if (group_ce) {
                 group_ce->perm &= (mode >> 3) | ~S_IRWXO;
                 mode &= (group_ce->perm << 3) | ~S_IRWXG;
         }