From 68599525d8bbd7a3d6a631a5f57cb040c4595ba4 Mon Sep 17 00:00:00 2001 From: Ruiyu Ni Date: Thu, 25 Jan 2018 17:44:16 +0800 Subject: [PATCH] MdeModulePkg/Partition: Fix media probe The call in ProbeMediaStatusEx() to the ReadDisk() function of the EFI_DISK_IO_PROTOCOL interface implemented in DiskIoDxe/DiskIo.c crashed in DiskIo2ReadWriteDisk() because of the NULL value of the destination buffer pointer. Pass the address of a buffer in the stack instead of a NULL pointer. The similar fix was applied to ProbeMediaStatus in commit df473cc1fc9acd1a623ec7e05276f2f0635c19d2 * MdeModulePkg/PartitionDxe: Fix media probe Somehow ProbeMediaStatusEx() wasn't changed together. Contributed-under: TianoCore Contribution Agreement 1.1 Signed-off-by: Ruiyu Ni Reviewed-by: Jian J Wang Tested-by: Jian J Wang --- MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c index bb9d0b70ce..46c0877cee 100644 --- a/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c +++ b/MdeModulePkg/Universal/Disk/PartitionDxe/Partition.c @@ -4,7 +4,7 @@ of the raw block devices media. Currently "El Torito CD-ROM", UDF, Legacy MBR, and GPT partition schemes are supported. -Copyright (c) 2006 - 2017, Intel Corporation. All rights reserved.
+Copyright (c) 2006 - 2018, Intel Corporation. All rights reserved.
This program and the accompanying materials are licensed and made available under the terms and conditions of the BSD License which accompanies this distribution. The full text of the license may be found at @@ -777,11 +777,15 @@ ProbeMediaStatusEx ( ) { EFI_STATUS Status; + UINT8 Buffer[1]; // - // Read 1 byte from offset 0 but passing NULL as buffer pointer + // Read 1 byte from offset 0 to check if the MediaId is still valid. + // The reading operation is synchronious thus it is not worth it to + // allocate a buffer from the pool. The destination buffer for the + // data is in the stack. // - Status = DiskIo2->ReadDiskEx (DiskIo2, MediaId, 0, NULL, 1, NULL); + Status = DiskIo2->ReadDiskEx (DiskIo2, MediaId, 0, NULL, 1, (VOID*)Buffer); if ((Status == EFI_NO_MEDIA) || (Status == EFI_MEDIA_CHANGED)) { return Status; } -- 2.39.2