2024-03-21 21:09:16

by Tom Zanussi

Subject: [PATCH 1/2] 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.

Reported-by: Jerry Snitselaar <[email protected]>
Signed-off-by: Tom Zanussi <[email protected]>
---
drivers/crypto/intel/iaa/iaa_crypto_main.c | 10 +++++++---
1 file changed, 7 insertions(+), 3 deletions(-)

diff --git a/drivers/crypto/intel/iaa/iaa_crypto_main.c b/drivers/crypto/intel/iaa/iaa_crypto_main.c
index 1cd304de5388..b2191ade9011 100644
--- 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)
--
2.34.1

2024-03-22 11:44:55

by Herbert Xu

Subject: Re: [PATCH 1/2] crypto: iaa - Fix nr_cpus < nr_iaa case

On Thu, Mar 21, 2024 at 04:08:45PM -0500, Tom Zanussi wrote:
> 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.
>
> Reported-by: Jerry Snitselaar <[email protected]>
> Signed-off-by: Tom Zanussi <[email protected]>
> ---
> drivers/crypto/intel/iaa/iaa_crypto_main.c | 10 +++++++---
> 1 file changed, 7 insertions(+), 3 deletions(-)

Patch applied. Thanks.
--
Email: Herbert Xu <[email protected]>
Home Page: http://gondor.apana.org.au/~herbert/
PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt