From: Dan Carpenter <dan.carpen...@oracle.com>

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.carpen...@oracle.com>
Acked-by: Ivan Hu <ivan...@canonical.com>
Cc: Ard Biesheuvel <ard.biesheu...@linaro.org>
Signed-off-by: Matt Fleming <m...@codeblueprint.co.uk>
Signed-off-by: Ard Biesheuvel <ard.biesheu...@linaro.org>
---
 drivers/firmware/efi/test/efi_test.c | 3 +++
 1 file changed, 3 insertions(+)

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)
-- 
2.11.0

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