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authorHariprasad S2016-05-05 01:27:31 +0530
committerDoug Ledford2016-05-05 16:11:14 -0400
commit6e410d8f7175caf2316c515f1ea0bf80d33b3158 (patch)
tree06f9d18b62083f5cd0638daf72530b549b1b44a7 /drivers/infiniband/hw/cxgb4
parent88bc230dc614b8e19000022d0ae2c1dfd578a0b0 (diff)
RDMA/iw_cxgb4: ensure eps don't get freed while the mutex is held
In rx_data(), with the ep in FPDU_MODE, refcnt=2, if we get unexpected streaming data, we call c4iw_modify_rc_qp() and move the qp from RTS -> TERMINATE. In c4iw_modify_rc_qp(), if rdma_fini() returns an error, the ep will be dereferenced (refcnt=1). Then rx_data() calls c4iw_ep_disconnect() which starts the close operation. But if send_halfclose() fails in c4iw_ep_disconnect(), we will call release_ep_resources() derefing the ep which reduces the refcnt to 0 and and frees the ep. However we still has the ep mutex at that point, so we have a touch-after-free bug. There is a similar issue where peer_close() calls c4iw_ep_disconnect(). The solution is to add a reference to the ep in c4iw_ep_disconnect() after acquiring the mutex, and release it after releasing the mutex. Signed-off-by: Steve Wise <swise@opengridcomputing.com> Signed-off-by: Hariprasad Shenai <hariprasad@chelsio.com> Signed-off-by: Doug Ledford <dledford@redhat.com>
Diffstat (limited to 'drivers/infiniband/hw/cxgb4')
-rw-r--r--drivers/infiniband/hw/cxgb4/cm.c7
1 files changed, 7 insertions, 0 deletions
diff --git a/drivers/infiniband/hw/cxgb4/cm.c b/drivers/infiniband/hw/cxgb4/cm.c
index cc9836e46800..12eac98661c1 100644
--- a/drivers/infiniband/hw/cxgb4/cm.c
+++ b/drivers/infiniband/hw/cxgb4/cm.c
@@ -3416,6 +3416,12 @@ int c4iw_ep_disconnect(struct c4iw_ep *ep, int abrupt, gfp_t gfp)
PDBG("%s ep %p state %s, abrupt %d\n", __func__, ep,
states[ep->com.state], abrupt);
+ /*
+ * Ref the ep here in case we have fatal errors causing the
+ * ep to be released and freed.
+ */
+ c4iw_get_ep(&ep->com);
+
rdev = &ep->com.dev->rdev;
if (c4iw_fatal_error(rdev)) {
fatal = 1;
@@ -3476,6 +3482,7 @@ int c4iw_ep_disconnect(struct c4iw_ep *ep, int abrupt, gfp_t gfp)
}
}
mutex_unlock(&ep->com.mutex);
+ c4iw_put_ep(&ep->com);
if (fatal)
release_ep_resources(ep);
return ret;