On 2019/5/10 16:09, Jean Delvare wrote:
> Hi Kefeng,
>
> On Fri, 10 May 2019 11:03:20 +0800, Kefeng Wang wrote:
>> If ioremap fails, NULL pointer dereference will happen and
>> leading to a kernel panic when access the virtual address
>> in check_signature().
>>
>> Fix it by check the return value of ioremap.
>>
>> Cc: Jean Delvare <jdelvare@xxxxxxxx>
>> Cc: Wolfram Sang <wsa@xxxxxxxxxxxxx>
>> Cc: linux-i2c@xxxxxxxxxxxxxxx
>> Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
>> Signed-off-by: Kefeng Wang <wangkefeng.wang@xxxxxxxxxx>
>> ---
>> drivers/i2c/busses/i2c-i801.c | 5 ++++-
>> 1 file changed, 4 insertions(+), 1 deletion(-)
>>
>> diff --git a/drivers/i2c/busses/i2c-i801.c b/drivers/i2c/busses/i2c-i801.c
>> index 679c6c41f64b..fc6ccb8aba17 100644
>> --- a/drivers/i2c/busses/i2c-i801.c
>> +++ b/drivers/i2c/busses/i2c-i801.c
>> @@ -1068,7 +1068,10 @@ static void __init input_apanel_init(void)
>> void __iomem *bios;
>> const void __iomem *p;
>>
>> - bios = ioremap(0xF0000, 0x10000); /* Can't fail */
>> + bios = ioremap(0xF0000, 0x10000);
>> + if (!base)
> That would be "if (!bios)". Please don't send patches without at least
> test-building the result.
sorry, copy error.
> We don't need this anyway. The comment says it can't fail, so why
> bother checking for a condition which will never happen?
The ioremap could fails due to no memory, our inner test robot(enable FAULT_INJECTION)
find this issue.
>
>> + return -ENOMEM;
>> +
>> p = bios_signature(bios);
>> if (p) {
>> /* just use the first address */
>
