xprtrdma: Fix use-after-free in rpcrdma_post_recvs

Dereference wr->next /before/ the memory backing wr has been
released. This issue was found by code inspection. It is not
expected to be a significant problem because it is in an error
path that is almost never executed.

Fixes: 7c8d9e7c88 ("xprtrdma: Move Receive posting to ... ")
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Anna Schumaker <Anna.Schumaker@Netapp.com>
This commit is contained in:
Chuck Lever 2019-06-19 10:32:38 -04:00 committed by Anna Schumaker
parent 10694ac92c
commit 2d0abe36cf

View File

@ -1553,10 +1553,11 @@ rpcrdma_post_recvs(struct rpcrdma_xprt *r_xprt, bool temp)
rc = ib_post_recv(r_xprt->rx_ia.ri_id->qp, wr,
(const struct ib_recv_wr **)&bad_wr);
if (rc) {
for (wr = bad_wr; wr; wr = wr->next) {
for (wr = bad_wr; wr;) {
struct rpcrdma_rep *rep;
rep = container_of(wr, struct rpcrdma_rep, rr_recv_wr);
wr = wr->next;
rpcrdma_recv_buffer_put(rep);
--count;
}