On 3/17/21 13:57, Jann Horn wrote:
>>>> diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
>>>> b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
>>>> index 62ddb452f862..bff3dc1af702 100644
>>>> --- a/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
>>>> +++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_common.c
>>>> @@ -3679,7 +3679,7 @@ s32 ixgbe_host_interface_command(struct ixgbe_hw
>>>> *hw, void *buffer,
>>>> u32 hdr_size = sizeof(struct ixgbe_hic_hdr);
>>>> union {
>>>> struct ixgbe_hic_hdr hdr;
>>>> - u32 u32arr[1];
>>>> + u32 *u32arr;
>>>> } *bp = buffer;
>>>> u16 buf_len, dword_len;
>>>> s32 status;
>>>
>>> This looks bogus. An array is inline, a pointer points elsewhere -
>>> they're not interchangeable.
>>
>> Yep; but in this case these are the only places in the code where _u32arr_ is
>> being used:
>>
>> 3707 /* first pull in the header so we know the buffer length */
>> 3708 for (bi = 0; bi < dword_len; bi++) {
>> 3709 bp->u32arr[bi] = IXGBE_READ_REG_ARRAY(hw,
>> IXGBE_FLEX_MNG, bi);
>> 3710 le32_to_cpus(&bp->u32arr[bi]);
>> 3711 }
>
> So now line 3709 means: Read a pointer from bp->u32arr (the value
> being read from there is not actually a valid pointer), and write to
> that pointer at offset `bi`. I don't see how that line could execute
> without crashing.
Yeah; you're right. I see my confusion now. Apparently, there is no escape
from allocating heap memory to fix this issue, as I was proposing in my
last email.
I really appreciate the feedback. Thanks!
--
Gustavo
