[PATCH] usbip: Fix unsafe unaligned pointer usage

From: Shuah Khan
Date: Wed Jan 08 2020 - 20:24:24 EST


Fix unsafe unaligned pointer usage in usbip network interfaces. usbip tool
build fails with new gcc -Werror=address-of-packed-member checks.

usbip_network.c: In function âusbip_net_pack_usb_deviceâ:
usbip_network.c:79:32: error: taking address of packed member of âstruct usbip_usb_deviceâ may result in an unaligned pointer value [-Werror=address-of-packed-member]
79 | usbip_net_pack_uint32_t(pack, &udev->busnum);

Fix with minor changes to pass by value instead of by address.

Signed-off-by: Shuah Khan <skhan@xxxxxxxxxxxxxxxxxxx>
---
tools/usb/usbip/src/usbip_network.c | 40 +++++++++++++++++------------
tools/usb/usbip/src/usbip_network.h | 12 +++------
2 files changed, 27 insertions(+), 25 deletions(-)

diff --git a/tools/usb/usbip/src/usbip_network.c b/tools/usb/usbip/src/usbip_network.c
index d595d72693fb..ed4dc8c14269 100644
--- a/tools/usb/usbip/src/usbip_network.c
+++ b/tools/usb/usbip/src/usbip_network.c
@@ -50,39 +50,39 @@ void usbip_setup_port_number(char *arg)
info("using port %d (\"%s\")", usbip_port, usbip_port_string);
}

-void usbip_net_pack_uint32_t(int pack, uint32_t *num)
+uint32_t usbip_net_pack_uint32_t(int pack, uint32_t num)
{
uint32_t i;

if (pack)
- i = htonl(*num);
+ i = htonl(num);
else
- i = ntohl(*num);
+ i = ntohl(num);

- *num = i;
+ return i;
}

-void usbip_net_pack_uint16_t(int pack, uint16_t *num)
+uint16_t usbip_net_pack_uint16_t(int pack, uint16_t num)
{
uint16_t i;

if (pack)
- i = htons(*num);
+ i = htons(num);
else
- i = ntohs(*num);
+ i = ntohs(num);

- *num = i;
+ return i;
}

void usbip_net_pack_usb_device(int pack, struct usbip_usb_device *udev)
{
- usbip_net_pack_uint32_t(pack, &udev->busnum);
- usbip_net_pack_uint32_t(pack, &udev->devnum);
- usbip_net_pack_uint32_t(pack, &udev->speed);
+ udev->busnum = usbip_net_pack_uint32_t(pack, udev->busnum);
+ udev->devnum = usbip_net_pack_uint32_t(pack, udev->devnum);
+ udev->speed = usbip_net_pack_uint32_t(pack, udev->speed);

- usbip_net_pack_uint16_t(pack, &udev->idVendor);
- usbip_net_pack_uint16_t(pack, &udev->idProduct);
- usbip_net_pack_uint16_t(pack, &udev->bcdDevice);
+ udev->idVendor = usbip_net_pack_uint16_t(pack, udev->idVendor);
+ udev->idProduct = usbip_net_pack_uint16_t(pack, udev->idProduct);
+ udev->bcdDevice = usbip_net_pack_uint16_t(pack, udev->bcdDevice);
}

void usbip_net_pack_usb_interface(int pack __attribute__((unused)),
@@ -129,6 +129,14 @@ ssize_t usbip_net_send(int sockfd, void *buff, size_t bufflen)
return usbip_net_xmit(sockfd, buff, bufflen, 1);
}

+static inline void usbip_net_pack_op_common(int pack,
+ struct op_common *op_common)
+{
+ op_common->version = usbip_net_pack_uint16_t(pack, op_common->version);
+ op_common->code = usbip_net_pack_uint16_t(pack, op_common->code);
+ op_common->status = usbip_net_pack_uint32_t(pack, op_common->status);
+}
+
int usbip_net_send_op_common(int sockfd, uint32_t code, uint32_t status)
{
struct op_common op_common;
@@ -140,7 +148,7 @@ int usbip_net_send_op_common(int sockfd, uint32_t code, uint32_t status)
op_common.code = code;
op_common.status = status;

- PACK_OP_COMMON(1, &op_common);
+ usbip_net_pack_op_common(1, &op_common);

rc = usbip_net_send(sockfd, &op_common, sizeof(op_common));
if (rc < 0) {
@@ -164,7 +172,7 @@ int usbip_net_recv_op_common(int sockfd, uint16_t *code, int *status)
goto err;
}

- PACK_OP_COMMON(0, &op_common);
+ usbip_net_pack_op_common(0, &op_common);

if (op_common.version != USBIP_VERSION) {
err("USBIP Kernel and tool version mismatch: %d %d:",
diff --git a/tools/usb/usbip/src/usbip_network.h b/tools/usb/usbip/src/usbip_network.h
index 555215eae43e..83b4c5344f72 100644
--- a/tools/usb/usbip/src/usbip_network.h
+++ b/tools/usb/usbip/src/usbip_network.h
@@ -32,12 +32,6 @@ struct op_common {

} __attribute__((packed));

-#define PACK_OP_COMMON(pack, op_common) do {\
- usbip_net_pack_uint16_t(pack, &(op_common)->version);\
- usbip_net_pack_uint16_t(pack, &(op_common)->code);\
- usbip_net_pack_uint32_t(pack, &(op_common)->status);\
-} while (0)
-
/* ---------------------------------------------------------------------- */
/* Dummy Code */
#define OP_UNSPEC 0x00
@@ -163,11 +157,11 @@ struct op_devlist_reply_extra {
} while (0)

#define PACK_OP_DEVLIST_REPLY(pack, reply) do {\
- usbip_net_pack_uint32_t(pack, &(reply)->ndev);\
+ (reply)->ndev = usbip_net_pack_uint32_t(pack, (reply)->ndev);\
} while (0)

-void usbip_net_pack_uint32_t(int pack, uint32_t *num);
-void usbip_net_pack_uint16_t(int pack, uint16_t *num);
+uint32_t usbip_net_pack_uint32_t(int pack, uint32_t num);
+uint16_t usbip_net_pack_uint16_t(int pack, uint16_t num);
void usbip_net_pack_usb_device(int pack, struct usbip_usb_device *udev);
void usbip_net_pack_usb_interface(int pack, struct usbip_usb_interface *uinf);

--
2.20.1