crypto: iaa - Fix nr_cpus < nr_iaa case

If nr_cpus < nr_iaa, the calculated cpus_per_iaa will be 0, which
causes a divide-by-0 in rebalance_wq_table().

Make sure cpus_per_iaa is 1 in that case, and also in the nr_iaa == 0
case, even though cpus_per_iaa is never used if nr_iaa == 0, for
paranoia.

Cc: <stable@vger.kernel.org> # v6.8+
Reported-by: Jerry Snitselaar <jsnitsel@redhat.com>
Signed-off-by: Tom Zanussi <tom.zanussi@linux.intel.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>

diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index 1cd304de53881562cdbf7b116a0e54c9c66082a0..b2191ade9011c683145b115158a1fe1a3694d1a4 100644 (file)
--- a/drivers/crypto/intel/iaa/iaa_crypto_main.c
+++ b/drivers/crypto/intel/iaa/iaa_crypto_main.c
@@ -806,6 +806,8 @@ static int save_iaa_wq(struct idxd_wq *wq)
                return -EINVAL;
 
        cpus_per_iaa = (nr_nodes * nr_cpus_per_node) / nr_iaa;
+       if (!cpus_per_iaa)
+               cpus_per_iaa = 1;
 out:
        return 0;
 }
@@ -821,10 +823,12 @@ static void remove_iaa_wq(struct idxd_wq *wq)
                }
        }
 
-       if (nr_iaa)
+       if (nr_iaa) {
                cpus_per_iaa = (nr_nodes * nr_cpus_per_node) / nr_iaa;
-       else
-               cpus_per_iaa = 0;
+               if (!cpus_per_iaa)
+                       cpus_per_iaa = 1;
+       } else
+               cpus_per_iaa = 1;
 }
 
 static int wq_table_add_wqs(int iaa, int cpu)