[xen staging] vtpmmgr: Remove bogus cast from TPM2_GetRandom

[patchbot@xxxxxxx]

commit 7f4276fad8f0bfba5bb3fd012bf2df51c05fcf02
Author:     Jason Andryuk <jandryuk@xxxxxxxxx>
AuthorDate: Thu May 6 09:59:20 2021 -0400
Commit:     Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
CommitDate: Mon May 10 14:50:33 2021 +0100

    vtpmmgr: Remove bogus cast from TPM2_GetRandom
    
    The UINT32 <-> UINT16 casting in TPM2_GetRandom is incorrect.  Use a
    local UINT16 as needed for the TPM hardware command and assign the
    result.
    
    Suggested-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
    Signed-off-by: Jason Andryuk <jandryuk@xxxxxxxxx>
    Reviewed-by: Samuel Thibault <samuel.thibault@xxxxxxxxxxxx>
    Reviewed-by: Daniel P. Smith <dpsmith@xxxxxxxxxxxxxxxxxxxx>
---
 stubdom/vtpmmgr/tpm2.c | 13 ++++++++++---
 1 file changed, 10 insertions(+), 3 deletions(-)

diff --git a/stubdom/vtpmmgr/tpm2.c b/stubdom/vtpmmgr/tpm2.c
index 655e6d164c..ebd06eac74 100644
--- a/stubdom/vtpmmgr/tpm2.c
+++ b/stubdom/vtpmmgr/tpm2.c
@@ -427,15 +427,22 @@ abort_egress:
 
 TPM_RC TPM2_GetRandom(UINT32 * bytesRequested, BYTE * randomBytes)
 {
+    UINT16 bytesReq;
     TPM_BEGIN(TPM_ST_NO_SESSIONS, TPM_CC_GetRandom);
 
-    ptr = pack_UINT16(ptr, (UINT16)*bytesRequested);
+    if (*bytesRequested > UINT16_MAX)
+        bytesReq = UINT16_MAX;
+    else
+        bytesReq = *bytesRequested;
+
+    ptr = pack_UINT16(ptr, bytesReq);
 
     TPM_TRANSMIT();
     TPM_UNPACK_VERIFY();
 
-    ptr = unpack_UINT16(ptr, (UINT16 *)bytesRequested);
-    ptr = unpack_TPM_BUFFER(ptr, randomBytes, *bytesRequested);
+    ptr = unpack_UINT16(ptr, &bytesReq);
+    *bytesRequested = bytesReq;
+    ptr = unpack_TPM_BUFFER(ptr, randomBytes, bytesReq);
 
 abort_egress:
     return status;
--
generated by git-patchbot for /home/xen/git/xen.git#staging