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.
We don't need this anyway. The comment says it can't fail, so why
bother checking for a condition which will never happen?
> + return -ENOMEM;
> +
> p = bios_signature(bios);
> if (p) {
> /* just use the first address */
--
Jean Delvare
SUSE L3 Support
