RDMA/mlx5: Fix error path fall-through in mlx5_ib_dev_res_srq_init()

commit c488df06bd552bb8b6e14fa0cfd5ad986c6e9525 upstream.

mlx5_ib_dev_res_srq_init() allocates two SRQs, s0 and s1. When
ib_create_srq() fails for s1, the error branch destroys s0 but falls
through and unconditionally assigns the freed s0 and the ERR_PTR s1 to
devr->s0 and devr->s1.

This leads to several problems: the lock-free fast path checks
"if (devr->s1) return 0;" and treats the ERR_PTR as already initialised;
users in mlx5_ib_create_qp() dereference the freed SRQ or ERR_PTR via
to_msrq(devr->s0)->msrq.srqn; and mlx5_ib_dev_res_cleanup() dereferences
the ERR_PTR and double-frees s0 on teardown.

Fix by adding the same `goto unlock` in the s1 failure path.

Cc: stable@vger.kernel.org
Fixes: 5895e70f2e6e ("IB/mlx5: Allocate resources just before first QP/SRQ is created")
Link: https://patch.msgid.link/r/SYBPR01MB7881E1E0970268BD69C0BA75AF2B2@SYBPR01MB7881.ausprd01.prod.outlook.com
Reported-by: Yuhao Jiang <danisjiang@gmail.com>
Signed-off-by: Junrui Luo <moonafterrain@outlook.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/infiniband/hw/mlx5/main.c b/drivers/infiniband/hw/mlx5/main.c
index 635002e684a55fcc2f6c42127f67abba38809b08..356a7c7856e7b97b121c7165aba1c0e961591eb2 100644 (file)
--- a/drivers/infiniband/hw/mlx5/main.c
+++ b/drivers/infiniband/hw/mlx5/main.c
@@ -3380,6 +3380,7 @@ int mlx5_ib_dev_res_srq_init(struct mlx5_ib_dev *dev)
                            "Couldn't create SRQ 1 for res init, err=%pe\n",
                            s1);
                ib_destroy_srq(s0);
+               goto unlock;
        }
 
        devr->s0 = s0;