diff options
| author | Jian J Wang <jian.j.wang@intel.com> | 2018-10-24 10:26:07 +0800 |
|---|---|---|
| committer | Jian J Wang <jian.j.wang@intel.com> | 2018-10-26 10:27:20 +0800 |
| commit | 5323e918c39a04a872149737096db6ac9408f322 (patch) | |
| tree | ca96fff0c536b7bca6bdff6a01ef2139edd1cc15 | |
| parent | a6bde8a644694a69b66c0a2168fd7702176bbd46 (diff) | |
| download | edk2-5323e918c39a04a872149737096db6ac9408f322.tar.gz | |
MdeModulePkg: introduce UEFI freed-memory guard bit in HeapGuard PCD
UAF (Use-After-Free) memory issue is kind of illegal access to memory
which has been freed. It can be detected by a new freed-memory guard
enforced onto freed memory.
BIT4 of following PCD is used to enable the freed-memory guard feature.
gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPropertyMask
Please note this feature is for debug purpose and should not be enabled
in product BIOS, and cannot be enabled with pool/page heap guard at the
same time. It's disabled by default.
Cc: Star Zeng <star.zeng@intel.com>
Cc: Michael D Kinney <michael.d.kinney@intel.com>
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Ruiyu Ni <ruiyu.ni@intel.com>
Cc: Laszlo Ersek <lersek@redhat.com>
Contributed-under: TianoCore Contribution Agreement 1.1
Signed-off-by: Jian J Wang <jian.j.wang@intel.com>
Reviewed-by: Star Zeng <star.zeng@intel.com>
Reviewed-by: Laszlo Ersek <lersek@redhat.com>
| -rw-r--r-- | MdeModulePkg/MdeModulePkg.dec | 16 | ||||
| -rw-r--r-- | MdeModulePkg/MdeModulePkg.uni | 14 |
2 files changed, 22 insertions, 8 deletions
diff --git a/MdeModulePkg/MdeModulePkg.dec b/MdeModulePkg/MdeModulePkg.dec index 2009dbc5fd..428eeeb670 100644 --- a/MdeModulePkg/MdeModulePkg.dec +++ b/MdeModulePkg/MdeModulePkg.dec @@ -1011,14 +1011,22 @@ gEfiMdeModulePkgTokenSpaceGuid.PcdHeapGuardPoolType|0x0|UINT64|0x30001053
## This mask is to control Heap Guard behavior.
- # Note that due to the limit of pool memory implementation and the alignment
- # requirement of UEFI spec, BIT7 is a try-best setting which cannot guarantee
- # that the returned pool is exactly adjacent to head guard page or tail guard
- # page.
+ #
+ # Note:
+ # a) Heap Guard is for debug purpose and should not be enabled in product
+ # BIOS.
+ # b) Due to the limit of pool memory implementation and the alignment
+ # requirement of UEFI spec, BIT7 is a try-best setting which cannot
+ # guarantee that the returned pool is exactly adjacent to head guard
+ # page or tail guard page.
+ # c) UEFI freed-memory guard and UEFI pool/page guard cannot be enabled
+ # at the same time.
+ #
# BIT0 - Enable UEFI page guard.<BR>
# BIT1 - Enable UEFI pool guard.<BR>
# BIT2 - Enable SMM page guard.<BR>
# BIT3 - Enable SMM pool guard.<BR>
+ # BIT4 - Enable UEFI freed-memory guard (Use-After-Free memory detection).<BR>
# BIT6 - Enable non-stop mode.<BR>
# BIT7 - The direction of Guard Page for Pool Guard.
# 0 - The returned pool is near the tail guard page.<BR>
diff --git a/MdeModulePkg/MdeModulePkg.uni b/MdeModulePkg/MdeModulePkg.uni index 9d2e473fa9..5fa7a6ae30 100644 --- a/MdeModulePkg/MdeModulePkg.uni +++ b/MdeModulePkg/MdeModulePkg.uni @@ -1224,14 +1224,20 @@ #string STR_gEfiMdeModulePkgTokenSpaceGuid_PcdHeapGuardPropertyMask_PROMPT #language en-US "The Heap Guard feature mask"
#string STR_gEfiMdeModulePkgTokenSpaceGuid_PcdHeapGuardPropertyMask_HELP #language en-US "This mask is to control Heap Guard behavior.\n"
- "Note that due to the limit of pool memory implementation and the alignment\n"
- "requirement of UEFI spec, BIT7 is a try-best setting which cannot guarantee\n"
- "that the returned pool is exactly adjacent to head guard page or tail guard\n"
- "page.\n"
+ " Note:\n"
+ " a) Heap Guard is for debug purpose and should not be enabled in product"
+ " BIOS.\n"
+ " b) Due to the limit of pool memory implementation and the alignment"
+ " requirement of UEFI spec, BIT7 is a try-best setting which cannot"
+ " guarantee that the returned pool is exactly adjacent to head guard"
+ " page or tail guard page.\n"
+ " c) UEFI freed-memory guard and UEFI pool/page guard cannot be enabled"
+ " at the same time.\n"
" BIT0 - Enable UEFI page guard.<BR>\n"
" BIT1 - Enable UEFI pool guard.<BR>\n"
" BIT2 - Enable SMM page guard.<BR>\n"
" BIT3 - Enable SMM pool guard.<BR>\n"
+ " BIT4 - Enable UEFI freed-memory guard (Use-After-Free memory detection).<BR>\n"
" BIT7 - The direction of Guard Page for Pool Guard.\n"
" 0 - The returned pool is near the tail guard page.<BR>\n"
" 1 - The returned pool is near the head guard page.<BR>"
|