On 10/06/2017 08:19 PM, Matt Fleming wrote:
On Sat, 30 Sep, at 11:17:32AM, Dan Carpenter wrote:
If "qcaps.capsule_count" is ULONG_MAX then "qcaps.capsule_count + 1"
will overflow to zero and kcalloc() will return the ZERO_SIZE_PTR. We
try to dereference it inside the loop and crash.
Fixes: ff6301dabc3c ("efi: Add efi_test driver for exporting UEFI runtime service interfaces")
Signed-off-by: Dan Carpenter <dan.carpenter@xxxxxxxxxx>
diff --git a/drivers/firmware/efi/test/efi_test.c b/drivers/firmware/efi/test/efi_test.c
index 08129b7b80ab..41c48a1e8baa 100644
--- a/drivers/firmware/efi/test/efi_test.c
+++ b/drivers/firmware/efi/test/efi_test.c
@@ -593,6 +593,9 @@ static long efi_runtime_query_capsulecaps(unsigned long arg)
if (copy_from_user(&qcaps, qcaps_user, sizeof(qcaps)))
return -EFAULT;
+ if (qcaps.capsule_count == ULONG_MAX)
+ return -EINVAL;
+
capsules = kcalloc(qcaps.capsule_count + 1,
sizeof(efi_capsule_header_t), GFP_KERNEL);
if (!capsules)
This looks OK to me. Ivan?
Acked-by: Ivan Hu <ivan.hu@xxxxxxxxxxxxx>
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