features/locks: error-out {inode,entry}lk fops with all-zero lk-owner

Problem:
Sometimes we find that developers forget to assign lk-owner for an
inodelk/entrylk/lk before writing code to wind these fops. locks
xlator at the moment allows this operation. This leads to multiple
threads in the same client being able to get locks on the inode
because lk-owner is same and transport is same. So isolation
with locks can't be achieved.

Fix:
Disallow locks with lk-owner zero.

fixes bz#1624701
Change-Id: I1c816280cffd150ebb392e3dcd4d21007cdd767f
Signed-off-by: Pranith Kumar K <pkarampu@redhat.com>

1 files changed, 11 insertions, 5 deletions

diff --git a/xlators/features/locks/src/inodelk.c b/xlators/features/locks/src/inodelk.c
index df00ede242d..95afc902ffa 100644
--- a/xlators/features/locks/src/inodelk.c
+++ b/xlators/features/locks/src/inodelk.c
@@ -873,17 +873,23 @@ pl_inode_setlk(xlator_t *this, pl_ctx_t *ctx, pl_inode_t *pl_inode,
 }
 
 /* Create a new inode_lock_t */
-pl_inode_lock_t *
+static pl_inode_lock_t *
 new_inode_lock(struct gf_flock *flock, client_t *client, pid_t client_pid,
                call_frame_t *frame, xlator_t *this, const char *volume,
-               char *conn_id)
+               char *conn_id, int32_t *op_errno)
 
 {
     pl_inode_lock_t *lock = NULL;
 
+    if (!pl_is_lk_owner_valid(&frame->root->lk_owner, frame->root->client)) {
+        *op_errno = EINVAL;
+        goto out;
+    }
+
     lock = GF_CALLOC(1, sizeof(*lock), gf_locks_mt_pl_inode_lock_t);
     if (!lock) {
-        return NULL;
+        *op_errno = ENOMEM;
+        goto out;
     }
 
     lock->fl_start = flock->l_start;
@@ -911,6 +917,7 @@ new_inode_lock(struct gf_flock *flock, client_t *client, pid_t client_pid,
     INIT_LIST_HEAD(&lock->contend);
     __pl_inodelk_ref(lock);
 
+out:
     return lock;
 }
 
@@ -1005,11 +1012,10 @@ pl_common_inodelk(call_frame_t *frame, xlator_t *this, const char *volume,
     }
 
     reqlock = new_inode_lock(flock, frame->root->client, frame->root->pid,
-                             frame, this, dom->domain, conn_id);
+                             frame, this, dom->domain, conn_id, &op_errno);
 
     if (!reqlock) {
         op_ret = -1;
-        op_errno = ENOMEM;
         goto unwind;
     }