[PATCH AUTOSEL 4.14 32/37] s390/qeth: use vzalloc for QUERY OAT buffer

[Sasha Levin]

From: Wenjia Zhang <wenjia@xxxxxxxxxxxxx>

[ Upstream commit aec45e857c5538664edb76a60dd452e3265f37d1 ]

qeth_query_oat_command() currently allocates the kernel buffer for
the SIOC_QETH_QUERY_OAT ioctl with kzalloc. So on systems with
fragmented memory, large allocations may fail (eg. the qethqoat tool by
default uses 132KB).

Solve this issue by using vzalloc, backing the allocation with
non-contiguous memory.

Signed-off-by: Wenjia Zhang <wenjia@xxxxxxxxxxxxx>
Reviewed-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx>
Signed-off-by: Julian Wiedmann <jwi@xxxxxxxxxxxxx>
Signed-off-by: David S. Miller <davem@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
---
 drivers/s390/net/qeth_core_main.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/s390/net/qeth_core_main.c b/drivers/s390/net/qeth_core_main.c
index 0a6afd4b283d..4f2747cd15a6 100644
--- a/drivers/s390/net/qeth_core_main.c
+++ b/drivers/s390/net/qeth_core_main.c
@@ -23,6 +23,7 @@
 #include <linux/netdevice.h>
 #include <linux/netdev_features.h>
 #include <linux/skbuff.h>
+#include <linux/vmalloc.h>
 
 #include <net/iucv/af_iucv.h>
 #include <net/dsfield.h>
@@ -4728,7 +4729,7 @@ static int qeth_query_oat_command(struct qeth_card *card, char __user *udata)
 
 	priv.buffer_len = oat_data.buffer_len;
 	priv.response_len = 0;
-	priv.buffer =  kzalloc(oat_data.buffer_len, GFP_KERNEL);
+	priv.buffer = vzalloc(oat_data.buffer_len);
 	if (!priv.buffer) {
 		rc = -ENOMEM;
 		goto out;
@@ -4769,7 +4770,7 @@ static int qeth_query_oat_command(struct qeth_card *card, char __user *udata)
 			rc = -EFAULT;
 
 out_free:
-	kfree(priv.buffer);
+	vfree(priv.buffer);
 out:
 	return rc;
 }
-- 
2.17.1