From 2d0abe36cf13fb7b577949fd1539326adddcc9bc Mon Sep 17 00:00:00 2001 From: Chuck Lever Date: Wed, 19 Jun 2019 10:32:38 -0400 Subject: [PATCH] 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: 7c8d9e7c8863 ("xprtrdma: Move Receive posting to ... ") Signed-off-by: Chuck Lever Signed-off-by: Anna Schumaker --- net/sunrpc/xprtrdma/verbs.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/net/sunrpc/xprtrdma/verbs.c b/net/sunrpc/xprtrdma/verbs.c index 84bb37924540..e71315e9dca2 100644 --- a/net/sunrpc/xprtrdma/verbs.c +++ b/net/sunrpc/xprtrdma/verbs.c @@ -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; } -- 2.30.2