diff options
| author | Bob Pearson | 2023-05-17 16:15:10 -0500 |
|---|---|---|
| committer | Greg Kroah-Hartman | 2023-06-21 16:00:57 +0200 |
| commit | 2906e0d75b50c987379cd10e0092f167b8145f2e (patch) | |
| tree | a9dae618709dc702903b710a3562fc786994251d | |
| parent | 7617a59f00568b931f7fa50756219300cf77e93e (diff) | |
RDMA/rxe: Fix ref count error in check_rkey()
[ Upstream commit b00683422fd79dd07c9b75efdce1660e5e19150e ]
There is a reference count error in error path code and a potential race
in check_rkey() in rxe_resp.c. When looking up the rkey for a memory
window the reference to the mw from rxe_lookup_mw() is dropped before a
reference is taken on the mr referenced by the mw. If the mr is destroyed
immediately after the call to rxe_put(mw) the mr pointer is unprotected
and may end up pointing at freed memory. The rxe_get(mr) call should take
place before the rxe_put(mw) call.
All errors in check_rkey() call rxe_put(mw) if mw is not NULL but it was
already called after the above. The mw pointer should be set to NULL after
the rxe_put(mw) call to prevent this from happening.
Fixes: cdd0b85675ae ("RDMA/rxe: Implement memory access through MWs")
Link: https://lore.kernel.org/r/20230517211509.1819998-1-rpearsonhpe@gmail.com
Signed-off-by: Bob Pearson <rpearsonhpe@gmail.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/infiniband/sw/rxe/rxe_resp.c | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/drivers/infiniband/sw/rxe/rxe_resp.c b/drivers/infiniband/sw/rxe/rxe_resp.c index 693081e813ec..9f65c346d843 100644 --- a/drivers/infiniband/sw/rxe/rxe_resp.c +++ b/drivers/infiniband/sw/rxe/rxe_resp.c @@ -466,8 +466,9 @@ static enum resp_states check_rkey(struct rxe_qp *qp, if (mw->access & IB_ZERO_BASED) qp->resp.offset = mw->addr; - rxe_put(mw); rxe_get(mr); + rxe_put(mw); + mw = NULL; } else { mr = lookup_mr(qp->pd, access, rkey, RXE_LOOKUP_REMOTE); if (!mr) { |