sravan/system76-edk2
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

NetworkPkg/SnpDxe: Prevent invalid PCI BAR access

Browse Source 
REF:https://bugzilla.tianocore.org/show_bug.cgi?id=1563

SnpDxe initializes values for MemoryBarIndex and IoBarIndex to 0 and 1
respectively even if calls to PciIo->GetBarAttributes never return
success.

Later, if the BAR is used to perform IO/Mem reads/writes, a potentially
non-existent BAR index may be accessed. This change initializes the
values
to an invalid BAR index (PCI_MAX_BAR) so the condition can be explicitly
checked to avoid an invalid BAR access.

Cc: Siyuan Fu <siyuan.fu@intel.com>
Cc: Maciej Rabeda <maciej.rabeda@linux.intel.com>
Cc: Jiaxin Wu <jiaxin.wu@intel.com>
Signed-off-by: Michael Kubacki <michael.kubacki@microsoft.com>
Reviewed-by: Siyuan Fu <siyuan.fu@intel.com>
Reviewed-by: Maciej Rabeda <maciej.rabeda@linux.intel.com>
This commit is contained in:
Michael Kubacki
2020-04-08 20:02:05 -07:00
committed by mergify[bot]
parent ca08f3d453
commit df4f154da9
2 changed files with 47 additions and 34 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
NetworkPkg/SnpDxe/Snp.c
View File

@@ -466,8 +466,8 @@ SimpleNetworkDriverStart (
// the IO BAR. Save the index of the BAR into the adapter info structure.
// for regular 32bit BARs, 0 is memory mapped, 1 is io mapped
//
Snp->MemoryBarIndex = 0;
Snp->IoBarIndex = 1;
Snp->MemoryBarIndex = PCI_MAX_BAR;
Snp->IoBarIndex = PCI_MAX_BAR;
FoundMemoryBar = FALSE;
FoundIoBar = FALSE;
for (BarIndex = 0; BarIndex < PCI_MAX_BAR; BarIndex++) {