From: Harald Freudenberger <freude@xxxxxxxxxxxxx>
[ Upstream commit b43088f30db1a7bff61c8486238c195c77788d6d ]
This patch fixes the warning
memcpy: detected field-spanning write (size 60) of single field "to" at drivers/s390/crypto/zcrypt_api.h:173 (size 2)
WARNING: CPU: 1 PID: 2114 at drivers/s390/crypto/zcrypt_api.h:173 prep_ep11_ap_msg+0x2c6/0x2e0 [zcrypt]
The code has been rewritten to use a union in combination
with a flex array to clearly state which part of the buffer
the payload is to be copied in via z_copy_from_user
function (which may call memcpy() in case of in-kernel calls).
Signed-off-by: Harald Freudenberger <freude@xxxxxxxxxxxxx>
Suggested-by: Jürgen Christ <jchrist@xxxxxxxxxxxxx>
Reviewed-by: Jürgen Christ <jchrist@xxxxxxxxxxxxx>
Signed-off-by: Vasily Gorbik <gor@xxxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
drivers/s390/crypto/zcrypt_msgtype6.c | 21 +++++++++++++++------
1 file changed, 15 insertions(+), 6 deletions(-)
diff --git a/drivers/s390/crypto/zcrypt_msgtype6.c b/drivers/s390/crypto/zcrypt_msgtype6.c
index 8fb34b8eeb18..5ad251477593 100644
--- a/drivers/s390/crypto/zcrypt_msgtype6.c
+++ b/drivers/s390/crypto/zcrypt_msgtype6.c
@@ -342,7 +342,10 @@ static int xcrb_msg_to_type6cprb_msgx(bool userspace, struct ap_message *ap_msg,
};
struct {
struct type6_hdr hdr;
- struct CPRBX cprbx;
+ union {
+ struct CPRBX cprbx;
+ DECLARE_FLEX_ARRAY(u8, userdata);
+ };
} __packed * msg = ap_msg->msg;
int rcblen = CEIL4(xcrb->request_control_blk_length);
@@ -403,7 +406,8 @@ static int xcrb_msg_to_type6cprb_msgx(bool userspace, struct ap_message *ap_msg,
msg->hdr.fromcardlen2 = xcrb->reply_data_length;
/* prepare CPRB */
- if (z_copy_from_user(userspace, &msg->cprbx, xcrb->request_control_blk_addr,
+ if (z_copy_from_user(userspace, msg->userdata,
+ xcrb->request_control_blk_addr,
xcrb->request_control_blk_length))
return -EFAULT;
if (msg->cprbx.cprb_len + sizeof(msg->hdr.function_code) >
@@ -469,9 +473,14 @@ static int xcrb_msg_to_type6_ep11cprb_msgx(bool userspace, struct ap_message *ap
struct {
struct type6_hdr hdr;
- struct ep11_cprb cprbx;
- unsigned char pld_tag; /* fixed value 0x30 */
- unsigned char pld_lenfmt; /* payload length format */
+ union {
+ struct {
+ struct ep11_cprb cprbx;
+ unsigned char pld_tag; /* fixed value 0x30 */
+ unsigned char pld_lenfmt; /* length format */
+ } __packed;
+ DECLARE_FLEX_ARRAY(u8, userdata);
+ };
} __packed * msg = ap_msg->msg;
struct pld_hdr {
@@ -500,7 +509,7 @@ static int xcrb_msg_to_type6_ep11cprb_msgx(bool userspace, struct ap_message *ap
msg->hdr.fromcardlen1 = xcrb->resp_len;
/* Import CPRB data from the ioctl input parameter */
- if (z_copy_from_user(userspace, &msg->cprbx.cprb_len,
+ if (z_copy_from_user(userspace, msg->userdata,
(char __force __user *)xcrb->req, xcrb->req_len)) {
return -EFAULT;
}
--
2.35.1
