[edk2-devel] [PATCH v1 1/1] UefiCpuPkg: PiSmmCpuDxeSmm: Check buffer size before accessing
Kun Qin
kuqin12 at gmail.com
Fri Mar 26 23:41:42 UTC 2021
REF: https://bugzilla.tianocore.org/show_bug.cgi?id=3283
Current SMM Save State routine does not check the number of bytes to be
read, when it comse to read IO_INFO, before casting the incoming buffer
to EFI_SMM_SAVE_STATE_IO_INFO. This could potentially cause memory
corruption due to extra bytes are written out of buffer boundary.
This change adds a width check before copying IoInfo into output buffer.
Cc: Eric Dong <eric.dong at intel.com>
Cc: Ray Ni <ray.ni at intel.com>
Cc: Laszlo Ersek <lersek at redhat.com>
Cc: Rahul Kumar <rahul1.kumar at intel.com>
Signed-off-by: Kun Qin <kuqin12 at gmail.com>
---
UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c | 7 +++++++
1 file changed, 7 insertions(+)
diff --git a/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c b/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
index 661cc51f361a..ec760e4c37ca 100644
--- a/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
+++ b/UefiCpuPkg/PiSmmCpuDxeSmm/SmramSaveState.c
@@ -418,6 +418,13 @@ ReadSaveStateRegister (
return EFI_NOT_FOUND;
}
+ //
+ // Make sure the incoming buffer is large enough to hold IoInfo before accessing
+ //
+ if (Width < sizeof (EFI_SMM_SAVE_STATE_IO_INFO)) {
+ return EFI_INVALID_PARAMETER;
+ }
+
//
// Zero the IoInfo structure that will be returned in Buffer
//
--
2.31.0.windows.1
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