diff options
| author | Kirill A. Shutemov <[email protected]> | 2024-08-26 15:53:04 +0300 |
|---|---|---|
| committer | Dave Hansen <[email protected]> | 2024-08-26 12:45:19 -0700 |
| commit | b6fb565a2d15277896583d471b21bc14a0c99661 (patch) | |
| tree | 74e3447334816fe6d0705334cb02de25d98e631f | |
| parent | ea72ce5da22806d5713f3ffb39a6d5ae73841f93 (diff) | |
x86/tdx: Fix data leak in mmio_read()
The mmio_read() function makes a TDVMCALL to retrieve MMIO data for an
address from the VMM.
Sean noticed that mmio_read() unintentionally exposes the value of an
initialized variable (val) on the stack to the VMM.
This variable is only needed as an output value. It did not need to be
passed to the VMM in the first place.
Do not send the original value of *val to the VMM.
[ dhansen: clarify what 'val' is used for. ]
Fixes: 31d58c4e557d ("x86/tdx: Handle in-kernel MMIO")
Reported-by: Sean Christopherson <[email protected]>
Signed-off-by: Kirill A. Shutemov <[email protected]>
Signed-off-by: Dave Hansen <[email protected]>
Cc:[email protected]
Link: https://lore.kernel.org/all/20240826125304.1566719-1-kirill.shutemov%40linux.intel.com
| -rw-r--r-- | arch/x86/coco/tdx/tdx.c | 1 |
1 files changed, 0 insertions, 1 deletions
diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index 078e2bac2553..da8b66dce0da 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -389,7 +389,6 @@ static bool mmio_read(int size, unsigned long addr, unsigned long *val) .r12 = size, .r13 = EPT_READ, .r14 = addr, - .r15 = *val, }; if (__tdx_hypercall(&args)) |