On 2018/10/15 14:38, Ruiyu Ni wrote:
UsbBootReadWriteBlocks() and UsbBootReadWriteBlocks16() use a UINT16
local variable to hold the value of
USB_BOOT_MAX_CARRY_SIZE (=0x10000) / BlockSize.
When BlockSize is 1, the UINT16 local variable is set to 0x10000
Ray,
Thanks for the patch.
Is it possible that the BlockSize == 0 or > USB_BOOT_MAX_CARRY_SIZE?
Thanks,
Star
but the high-16 bits are truncated resulting the final value be 0.
It causes the while-loop in the two functions accesses 0 block in
each loop, resulting the loop never ends.
The patch fixes the two functions to make sure no integer overflow
happens.
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Ruiyu Ni <[email protected]>
Cc: Star Zeng <[email protected]>
Cc: Steven Shi <[email protected]>
---
.../Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c | 27 +++++++++++-----------
1 file changed, 14 insertions(+), 13 deletions(-)
diff --git a/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
b/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
index 581571ab45..37fbeedbeb 100644
--- a/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
+++ b/MdeModulePkg/Bus/Usb/UsbMassStorageDxe/UsbMassBoot.c
@@ -815,14 +815,14 @@ UsbBootReadWriteBlocks (
{
USB_BOOT_READ_WRITE_10_CMD Cmd;
EFI_STATUS Status;
- UINT16 Count;
- UINT16 CountMax;
+ UINT32 Count;
+ UINT32 CountMax;
UINT32 BlockSize;
UINT32 ByteSize;
UINT32 Timeout;
BlockSize = UsbMass->BlockIoMedia.BlockSize;
- CountMax = (UINT16)(USB_BOOT_MAX_CARRY_SIZE / BlockSize);
+ CountMax = USB_BOOT_MAX_CARRY_SIZE / BlockSize;
Status = EFI_SUCCESS;
while (TotalBlock > 0) {
@@ -831,8 +831,9 @@ UsbBootReadWriteBlocks (
// on the device. We must split the total block because the READ10
// command only has 16 bit transfer length (in the unit of block).
//
- Count = (UINT16)((TotalBlock < CountMax) ? TotalBlock : CountMax);
- ByteSize = (UINT32)Count * BlockSize;
+ Count = (UINT32)MIN (TotalBlock, CountMax);
+ Count = MIN (MAX_UINT16, Count);
+ ByteSize = Count * BlockSize;
//
// USB command's upper limit timeout is 5s. [USB2.0-9.2.6.1]
@@ -847,7 +848,7 @@ UsbBootReadWriteBlocks (
Cmd.OpCode = Write ? USB_BOOT_WRITE10_OPCODE : USB_BOOT_READ10_OPCODE;
Cmd.Lun = (UINT8) (USB_BOOT_LUN (UsbMass->Lun));
WriteUnaligned32 ((UINT32 *) Cmd.Lba, SwapBytes32 (Lba));
- WriteUnaligned16 ((UINT16 *) Cmd.TransferLen, SwapBytes16 (Count));
+ WriteUnaligned16 ((UINT16 *) Cmd.TransferLen, SwapBytes16 ((UINT16)Count));
Status = UsbBootExecCmdWithRetry (
UsbMass,
@@ -867,7 +868,7 @@ UsbBootReadWriteBlocks (
Lba, Count
));
Lba += Count;
- Buffer += Count * BlockSize;
+ Buffer += ByteSize;
TotalBlock -= Count;
}
@@ -897,22 +898,22 @@ UsbBootReadWriteBlocks16 (
{
UINT8 Cmd[16];
EFI_STATUS Status;
- UINT16 Count;
- UINT16 CountMax;
+ UINT32 Count;
+ UINT32 CountMax;
UINT32 BlockSize;
UINT32 ByteSize;
UINT32 Timeout;
BlockSize = UsbMass->BlockIoMedia.BlockSize;
- CountMax = (UINT16)(USB_BOOT_MAX_CARRY_SIZE / BlockSize);
+ CountMax = USB_BOOT_MAX_CARRY_SIZE / BlockSize;
Status = EFI_SUCCESS;
while (TotalBlock > 0) {
//
// Split the total blocks into smaller pieces.
//
- Count = (UINT16)((TotalBlock < CountMax) ? TotalBlock : CountMax);
- ByteSize = (UINT32)Count * BlockSize;
+ Count = (UINT32)MIN (TotalBlock, CountMax);
+ ByteSize = Count * BlockSize;
//
// USB command's upper limit timeout is 5s. [USB2.0-9.2.6.1]
@@ -947,7 +948,7 @@ UsbBootReadWriteBlocks16 (
Lba, Count
));
Lba += Count;
- Buffer += Count * BlockSize;
+ Buffer += ByteSize;
TotalBlock -= Count;
}
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