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authorMichael Kinney <michael.d.kinney@intel.com>2016-10-04 10:55:24 -0700
committerMichael Kinney <michael.d.kinney@intel.com>2016-10-07 14:56:37 -0700
commit5f82e02a4b40f25462f0d592e85071bdeb80a2bd (patch)
tree3c27a70efee02b08b6948706e2e865124b17df69 /QuarkSocPkg
parent29f169d17a0f09cd1e05c984da5965e08f2b696e (diff)
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QuarkSocPkg/QncSmmDispatcher: Fix use after free issue
Update Quark North Cluster SMM dispatcher logic to handle case where an SMI handler unregisters itself. https://bugzilla.tianocore.org/show_bug.cgi?id=51 This issue was reproduced using the unit test at: https://github.com/mdkinney/edk2/tree/Bug51/Reproduce An ASSERT() is generated the 4th time the periodic SMI handler is triggered when the periodic SMI handler unregisters itself. After applying this patch, the DEBUG() message from the periodic SMI handler in this unit test is generated 4 times, the periodic SMI handler is unregistered, and the UEFI Shell works as expected. Cc: Kelly Steele <kelly.steele@intel.com> Contributed-under: TianoCore Contribution Agreement 1.0 Signed-off-by: Michael Kinney <michael.d.kinney@intel.com> Reviewed-by: Kelly Steele <kelly.steele@intel.com>
Diffstat (limited to 'QuarkSocPkg')
-rw-r--r--QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmm.h2
-rw-r--r--QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmmCore.c41
2 files changed, 38 insertions, 5 deletions
diff --git a/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmm.h b/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmm.h
index 797be16f79..ccf9dae1c5 100644
--- a/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmm.h
+++ b/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmm.h
@@ -387,6 +387,8 @@ struct _DATABASE_RECORD {
UINT32 Signature;
LIST_ENTRY Link;
+ BOOLEAN Processed;
+
//
// Status and Enable bit description
//
diff --git a/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmmCore.c b/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmmCore.c
index 47834064ff..c2f75f8664 100644
--- a/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmmCore.c
+++ b/QuarkSocPkg/QuarkNorthCluster/Smm/DxeSmm/QncSmmDispatcher/QNCSmmCore.c
@@ -592,6 +592,7 @@ QNCSmmCoreDispatcher (
BOOLEAN ChildWasDispatched;
DATABASE_RECORD *RecordInDb;
+ DATABASE_RECORD ActiveRecordInDb;
LIST_ENTRY *LinkInDb;
DATABASE_RECORD *RecordToExhaust;
LIST_ENTRY *LinkToExhaust;
@@ -614,6 +615,16 @@ QNCSmmCoreDispatcher (
ChildWasDispatched = FALSE;
//
+ // Mark all child handlers as not processed
+ //
+ LinkInDb = GetFirstNode (&mPrivateData.CallbackDataBase);
+ while (!IsNull (&mPrivateData.CallbackDataBase, LinkInDb)) {
+ RecordInDb = DATABASE_RECORD_FROM_LINK (LinkInDb);
+ RecordInDb->Processed = FALSE;
+ LinkInDb = GetNextNode (&mPrivateData.CallbackDataBase, LinkInDb);
+ }
+
+ //
// Preserve Index registers
//
SaveState ();
@@ -634,6 +645,12 @@ QNCSmmCoreDispatcher (
while ((!IsNull (&mPrivateData.CallbackDataBase, LinkInDb)) && (ResetListSearch == FALSE)) {
RecordInDb = DATABASE_RECORD_FROM_LINK (LinkInDb);
+ //
+ // Make a copy of the record that contains an active SMI source,
+ // because un-register maybe invoked in callback function and
+ // RecordInDb maybe released
+ //
+ CopyMem (&ActiveRecordInDb, RecordInDb, sizeof (ActiveRecordInDb));
//
// look for the first active source
@@ -663,6 +680,13 @@ QNCSmmCoreDispatcher (
//
while (!IsNull (&mPrivateData.CallbackDataBase, LinkToExhaust)) {
RecordToExhaust = DATABASE_RECORD_FROM_LINK (LinkToExhaust);
+ LinkToExhaust = GetNextNode (&mPrivateData.CallbackDataBase, LinkToExhaust);
+ if (RecordToExhaust->Processed) {
+ //
+ // Record has already been processed. Continue with next child handler.
+ //
+ continue;
+ }
if (CompareSources (&RecordToExhaust->SrcDesc, &ActiveSource)) {
//
@@ -692,6 +716,11 @@ QNCSmmCoreDispatcher (
ContextsMatch = TRUE;
}
+ //
+ // Mark this child handler so it will not be processed again
+ //
+ RecordToExhaust->Processed = TRUE;
+
if (ContextsMatch) {
if (RecordToExhaust->BufferSize != 0) {
@@ -720,11 +749,13 @@ QNCSmmCoreDispatcher (
SxChildWasDispatched = TRUE;
}
}
+ //
+ // Can not use RecordInDb after this point because Callback may have unregistered RecordInDb
+ // Restart processing of SMI handlers from the begining of the linked list because the
+ // state of the linked listed may have been modified due to unregister actions in the Callback.
+ //
+ LinkToExhaust = GetFirstNode (&mPrivateData.CallbackDataBase);
}
- //
- // Get next record in DB
- //
- LinkToExhaust = GetNextNode (&mPrivateData.CallbackDataBase, &RecordToExhaust->Link);
}
if (RecordInDb->ClearSource == NULL) {
@@ -736,7 +767,7 @@ QNCSmmCoreDispatcher (
//
// This source requires special handling to clear
//
- RecordInDb->ClearSource (&ActiveSource);
+ ActiveRecordInDb.ClearSource (&ActiveSource);
}
if (ChildWasDispatched) {