From: Ranbir Singh <ranbir.sin...@dell.com>
The functions FatGetDirEntInfo and FatOpenDirEnt contains the code
statements
Cluster = (Entry->FileClusterHigh << 16) | Entry->FileCluster;
and
OFile->FileCluster = ((DirEnt->Entry.FileClusterHigh) << 16) |
(DirEnt->Entry.FileCluster);
respectively. As per Coverity report, in both these statements, there is
an "Operand1" with type "UINT16" (16 bits, unsigned) which is promoted in
"(Operand1 << 16) | Operand2" to type "int" (32 bits, signed), then sign-
extended to type "unsigned long long" (64 bits, unsigned). If the result
of "(Operand1 << 16) | Operand2" is greater than 0x7FFFFFFF, the upper
bits of the result will all be 1.
So to avoid sign-extension, typecast the Operand1 and then the inter-
-mediate result after << 16 operation with UINTN. Note - UINTN is the
data type of the variable on the LHS of the assignment.
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4249
Cc: Ray Ni <ray...@intel.com>
Co-authored-by: Veeresh Sangolli <veeresh.sango...@dellteam.com>
Signed-off-by: Ranbir Singh <ranbir.sin...@dell.com>
Signed-off-by: Ranbir Singh <rsi...@ventanamicro.com>
---
FatPkg/EnhancedFatDxe/DirectoryManage.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/FatPkg/EnhancedFatDxe/DirectoryManage.c
b/FatPkg/EnhancedFatDxe/DirectoryManage.c
index 723fc35f38db..a21b7973cd21 100644
--- a/FatPkg/EnhancedFatDxe/DirectoryManage.c
+++ b/FatPkg/EnhancedFatDxe/DirectoryManage.c
@@ -474,7 +474,7 @@ FatGetDirEntInfo (
Info = Buffer;
Info->Size = ResultSize;
if ((Entry->Attributes & FAT_ATTRIBUTE_DIRECTORY) != 0) {
- Cluster = (Entry->FileClusterHigh << 16) | Entry->FileCluster;
+ Cluster = (UINTN)((UINTN)(Entry->FileClusterHigh) << 16) |
Entry->FileCluster;
Info->PhysicalSize = FatPhysicalDirSize (Volume, Cluster);
Info->FileSize = Info->PhysicalSize;
} else {
@@ -1167,7 +1167,7 @@ FatOpenDirEnt (
//
Volume = Parent->Volume;
OFile->FullPathLen = Parent->FullPathLen + 1 + StrLen
(DirEnt->FileString);
- OFile->FileCluster = ((DirEnt->Entry.FileClusterHigh) << 16) |
(DirEnt->Entry.FileCluster);
+ OFile->FileCluster = (UINTN)((UINTN)(DirEnt->Entry.FileClusterHigh) <<
16) | (DirEnt->Entry.FileCluster);
InsertTailList (&Parent->ChildHead, &OFile->ChildLink);
} else {
//
--
2.34.1
-=-=-=-=-=-=-=-=-=-=-=-
Groups.io Links: You receive all messages sent to this group.
View/Reply Online (#109139): https://edk2.groups.io/g/devel/message/109139
Mute This Topic: https://groups.io/mt/101633788/21656
Group Owner: devel+ow...@edk2.groups.io
Unsubscribe: https://edk2.groups.io/g/devel/unsub [arch...@mail-archive.com]
-=-=-=-=-=-=-=-=-=-=-=-
