[PATCH AUTOSEL 5.5 10/58] s390/zcrypt: fix card and queue total counter wrap

Sasha Levin
2020-02-23T02:37:34Z

From: Harald Freudenberger <freude@linux.ibm.com>

[ Upstream commit fcd98d4002539f1e381916fc1b6648938c1eac76 ]

The internal statistic counters for the total number of
requests processed per card and per queue used integers. So they do
wrap after a rather huge amount of crypto requests processed. This
patch introduces uint64 counters which should hold much longer but
still may wrap. The sysfs attributes request_count for card and queue
also used only %ld and now display the counter value with %llu.

This is not a security relevant fix. The int overflow which happened
is not in any way exploitable as a security breach.

Signed-off-by: Harald Freudenberger <freude@linux.ibm.com>
Signed-off-by: Vasily Gorbik <gor@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/s390/crypto/ap_bus.h | 4 ++--
drivers/s390/crypto/ap_card.c | 8 ++++----
drivers/s390/crypto/ap_queue.c | 6 +++---
drivers/s390/crypto/zcrypt_api.c | 16 +++++++++-------
4 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/drivers/s390/crypto/ap_bus.h b/drivers/s390/crypto/ap_bus.h
index bb35ba4a8d243..4348fdff1c61e 100644
--- a/drivers/s390/crypto/ap_bus.h
+++ b/drivers/s390/crypto/ap_bus.h
@@ -162,7 +162,7 @@ struct ap_card {
unsigned int functions; /* AP device function bitfield. */
int queue_depth; /* AP queue depth.*/
int id; /* AP card number. */
- atomic_t total_request_count; /* # requests ever for this AP device.*/
+ atomic64_t total_request_count; /* # requests ever for this AP device.*/
};

#define to_ap_card(x) container_of((x), struct ap_card, ap_dev.device)
@@ -179,7 +179,7 @@ struct ap_queue {
enum ap_state state; /* State of the AP device. */
int pendingq_count; /* # requests on pendingq list. */
int requestq_count; /* # requests on requestq list. */
- int total_request_count; /* # requests ever for this AP device.*/
+ u64 total_request_count; /* # requests ever for this AP device.*/
int request_timeout; /* Request timeout in jiffies. */
struct timer_list timeout; /* Timer for request timeouts. */
struct list_head pendingq; /* List of message sent to AP queue. */
diff --git a/drivers/s390/crypto/ap_card.c b/drivers/s390/crypto/ap_card.c
index 63b4cc6cd7e59..e85bfca1ed163 100644
--- a/drivers/s390/crypto/ap_card.c
+++ b/drivers/s390/crypto/ap_card.c
@@ -63,13 +63,13 @@ static ssize_t request_count_show(struct device *dev,
char *buf)
{
struct ap_card *ac = to_ap_card(dev);
- unsigned int req_cnt;
+ u64 req_cnt;

req_cnt = 0;
spin_lock_bh(&ap_list_lock);
- req_cnt = atomic_read(&ac->total_request_count);
+ req_cnt = atomic64_read(&ac->total_request_count);
spin_unlock_bh(&ap_list_lock);
- return snprintf(buf, PAGE_SIZE, "%d\n", req_cnt);
+ return snprintf(buf, PAGE_SIZE, "%llu\n", req_cnt);
}

static ssize_t request_count_store(struct device *dev,
@@ -83,7 +83,7 @@ static ssize_t request_count_store(struct device *dev,
for_each_ap_queue(aq, ac)
aq->total_request_count = 0;
spin_unlock_bh(&ap_list_lock);
- atomic_set(&ac->total_request_count, 0);
+ atomic64_set(&ac->total_request_count, 0);

return count;
}
diff --git a/drivers/s390/crypto/ap_queue.c b/drivers/s390/crypto/ap_queue.c
index 37c3bdc3642dc..a317ab4849320 100644
--- a/drivers/s390/crypto/ap_queue.c
+++ b/drivers/s390/crypto/ap_queue.c
@@ -479,12 +479,12 @@ static ssize_t request_count_show(struct device *dev,
char *buf)
{
struct ap_queue *aq = to_ap_queue(dev);
- unsigned int req_cnt;
+ u64 req_cnt;

spin_lock_bh(&aq->lock);
req_cnt = aq->total_request_count;
spin_unlock_bh(&aq->lock);
- return snprintf(buf, PAGE_SIZE, "%d\n", req_cnt);
+ return snprintf(buf, PAGE_SIZE, "%llu\n", req_cnt);
}

static ssize_t request_count_store(struct device *dev,
@@ -676,7 +676,7 @@ void ap_queue_message(struct ap_queue *aq, struct ap_message *ap_msg)
list_add_tail(&ap_msg->list, &aq->requestq);
aq->requestq_count++;
aq->total_request_count++;
- atomic_inc(&aq->card->total_request_count);
+ atomic64_inc(&aq->card->total_request_count);
/* Send/receive as many request from the queue as possible. */
ap_wait(ap_sm_event_loop(aq, AP_EVENT_POLL));
spin_unlock_bh(&aq->lock);
diff --git a/drivers/s390/crypto/zcrypt_api.c b/drivers/s390/crypto/zcrypt_api.c
index 9157e728a362d..7fa0262e91af0 100644
--- a/drivers/s390/crypto/zcrypt_api.c
+++ b/drivers/s390/crypto/zcrypt_api.c
@@ -605,8 +605,8 @@ static inline bool zcrypt_card_compare(struct zcrypt_card *zc,
weight += atomic_read(&zc->load);
pref_weight += atomic_read(&pref_zc->load);
if (weight == pref_weight)
- return atomic_read(&zc->card->total_request_count) >
- atomic_read(&pref_zc->card->total_request_count);
+ return atomic64_read(&zc->card->total_request_count) >
+ atomic64_read(&pref_zc->card->total_request_count);
return weight > pref_weight;
}

@@ -1216,11 +1216,12 @@ static void zcrypt_qdepth_mask(char qdepth[], size_t max_adapters)
spin_unlock(&zcrypt_list_lock);
}

-static void zcrypt_perdev_reqcnt(int reqcnt[], size_t max_adapters)
+static void zcrypt_perdev_reqcnt(u32 reqcnt[], size_t max_adapters)
{
struct zcrypt_card *zc;
struct zcrypt_queue *zq;
int card;
+ u64 cnt;

memset(reqcnt, 0, sizeof(int) * max_adapters);
spin_lock(&zcrypt_list_lock);
@@ -1232,8 +1233,9 @@ static void zcrypt_perdev_reqcnt(int reqcnt[], size_t max_adapters)
|| card >= max_adapters)
continue;
spin_lock(&zq->queue->lock);
- reqcnt[card] = zq->queue->total_request_count;
+ cnt = zq->queue->total_request_count;
spin_unlock(&zq->queue->lock);
+ reqcnt[card] = (cnt < UINT_MAX) ? (u32) cnt : UINT_MAX;
}
}
local_bh_enable();
@@ -1411,9 +1413,9 @@ static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
return 0;
}
case ZCRYPT_PERDEV_REQCNT: {
- int *reqcnt;
+ u32 *reqcnt;

- reqcnt = kcalloc(AP_DEVICES, sizeof(int), GFP_KERNEL);
+ reqcnt = kcalloc(AP_DEVICES, sizeof(u32), GFP_KERNEL);
if (!reqcnt)
return -ENOMEM;
zcrypt_perdev_reqcnt(reqcnt, AP_DEVICES);
@@ -1470,7 +1472,7 @@ static long zcrypt_unlocked_ioctl(struct file *filp, unsigned int cmd,
}
case Z90STAT_PERDEV_REQCNT: {
/* the old ioctl supports only 64 adapters */
- int reqcnt[MAX_ZDEV_CARDIDS];
+ u32 reqcnt[MAX_ZDEV_CARDIDS];

zcrypt_perdev_reqcnt(reqcnt, MAX_ZDEV_CARDIDS);
if (copy_to_user((int __user *) arg, reqcnt, sizeof(reqcnt)))
--
2.20.1