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authorSusant Palai <spalai@redhat.com>2018-11-02 09:23:42 +0530
committerAmar Tumballi <amarts@redhat.com>2018-11-06 05:39:44 +0000
commitc2c70552188ee1b15bb748b4f2272062505c7696 (patch)
tree929566938f72805aae9b2797464b8e0089d2dff4
parent4c6b063463ae48b3509ff8e66cd391f8637a86af (diff)
lock: Do not allow meta-lock count to be more than one
In the current scheme of glusterfs where lock migration is experimental, (ideally) the rebalance process which is migrating the file should request for a metalock. Hence, the metalock count should not be more than one for an inode. In future, if there is a need for meta-lock from other clients, this patch can be reverted. Since pl_metalk is called as part of setxattr operation, any client process(non-rebalance) residing outside trusted network can exhaust memory of the server node by issuing setxattr repetitively on the metalock key. The current patch makes sure that more than one metalock cannot be granted on an inode. Fixes CVE-2018-14660 updates: bz#1644758 Change-Id: Ie1e697766388718804a9551bc58351808fe71069 Signed-off-by: Susant Palai <spalai@redhat.com>
-rw-r--r--xlators/features/locks/src/posix.c35
1 files changed, 34 insertions, 1 deletions
diff --git a/xlators/features/locks/src/posix.c b/xlators/features/locks/src/posix.c
index 17f733a..40191263 100644
--- a/xlators/features/locks/src/posix.c
+++ b/xlators/features/locks/src/posix.c
@@ -2922,6 +2922,39 @@ pl_metalk(call_frame_t *frame, xlator_t *this, inode_t *inode)
goto out;
}
+ /* Non rebalance process trying to do metalock */
+ if (frame->root->pid != GF_CLIENT_PID_DEFRAG) {
+ ret = -1;
+ goto out;
+ }
+
+ /* Note: In the current scheme of glusterfs where lock migration is
+ * experimental, (ideally) the rebalance process which is migrating
+ * the file should request for a metalock. Hence, the metalock count
+ * should not be more than one for an inode. In future, if there is a
+ * need for meta-lock from other clients, the following block can be
+ * removed.
+ *
+ * Since pl_metalk is called as part of setxattr operation, any client
+ * process(non-rebalance) residing outside trusted network can exhaust
+ * memory of the server node by issuing setxattr repetitively on the
+ * metalock key. The following code makes sure that more than
+ * one metalock cannot be granted on an inode*/
+ pthread_mutex_lock(&pl_inode->mutex);
+ {
+ if (pl_metalock_is_active(pl_inode)) {
+ gf_msg(this->name, GF_LOG_WARNING, EINVAL, 0,
+ "More than one meta-lock can not be granted on"
+ "the inode");
+ ret = -1;
+ }
+ }
+ pthread_mutex_lock(&pl_inode->mutex);
+
+ if (ret == -1) {
+ goto out;
+ }
+
if (frame->root->client) {
ctx = pl_ctx_get(frame->root->client, this);
if (!ctx) {
@@ -3095,7 +3128,7 @@ pl_setxattr(call_frame_t *frame, xlator_t *this, loc_t *loc, dict_t *dict,
int flags, dict_t *xdata)
{
int op_ret = 0;
- int op_errno = 0;
+ int op_errno = EINVAL;
dict_t *xdata_rsp = NULL;
PL_LOCAL_GET_REQUESTS(frame, this, xdata, NULL, loc, NULL);