2022-09-21 09:46:10

by Adam Guerin

Subject: [RESEND] crypto: qat - add limit to linked list parsing

adf_copy_key_value_data() copies data from userland to kernel, based on
a linked link provided by userland. If userland provides a circular
list (or just a very long one) then it would drive a long loop where
allocation occurs in every loop. This could lead to low memory conditions.
Adding a limit to stop endless loop.

Signed-off-by: Adam Guerin <[email protected]>
Co-developed-by: Ciunas Bennett <[email protected]>
Signed-off-by: Ciunas Bennett <[email protected]>
Reviewed-by: Giovanni Cabiddu <[email protected]>
---
drivers/crypto/qat/qat_common/adf_ctl_drv.c | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)

diff --git a/drivers/crypto/qat/qat_common/adf_ctl_drv.c b/drivers/crypto/qat/qat_common/adf_ctl_drv.c
index 508c18edd692..82b69e1f725b 100644
--- a/drivers/crypto/qat/qat_common/adf_ctl_drv.c
+++ b/drivers/crypto/qat/qat_common/adf_ctl_drv.c
@@ -16,6 +16,9 @@
#include "adf_cfg_common.h"
#include "adf_cfg_user.h"

+#define ADF_CFG_MAX_SECTION 512
+#define ADF_CFG_MAX_KEY_VAL 256
+
#define DEVICE_NAME "qat_adf_ctl"

static DEFINE_MUTEX(adf_ctl_lock);
@@ -137,10 +140,11 @@ static int adf_copy_key_value_data(struct adf_accel_dev *accel_dev,
struct adf_user_cfg_key_val key_val;
struct adf_user_cfg_key_val *params_head;
struct adf_user_cfg_section section, *section_head;
+ int i, j;

section_head = ctl_data->config_section;

- while (section_head) {
+ for (i = 0; section_head && i < ADF_CFG_MAX_SECTION; i++) {
if (copy_from_user(&section, (void __user *)section_head,
sizeof(*section_head))) {
dev_err(&GET_DEV(accel_dev),
@@ -156,7 +160,7 @@ static int adf_copy_key_value_data(struct adf_accel_dev *accel_dev,

params_head = section.params;

- while (params_head) {
+ for (j = 0; params_head && j < ADF_CFG_MAX_KEY_VAL; j++) {
if (copy_from_user(&key_val, (void __user *)params_head,
sizeof(key_val))) {
dev_err(&GET_DEV(accel_dev),
--
2.37.3