Re: [PATCH -next v3 1/2] posix-timers: Check timespec64 before call clock_set()

[Jinjie Ruan <ruanjinjie@huawei.com>]

On 2024/9/10 20:05, Thomas Gleixner wrote:
> On Tue, Sep 10 2024 at 19:23, Jinjie Ruan wrote:
>> On 2024/9/9 23:19, Richard Cochran wrote:
>>> On Mon, Sep 09, 2024 at 03:41:23PM +0800, Jinjie Ruan wrote:
>>>> diff --git a/kernel/time/posix-timers.c b/kernel/time/posix-timers.c
>>>> index 1cc830ef93a7..34deec619e17 100644
>>>> --- a/kernel/time/posix-timers.c
>>>> +++ b/kernel/time/posix-timers.c
>>>> @@ -1137,6 +1137,9 @@ SYSCALL_DEFINE2(clock_settime, const clockid_t, which_clock,
>>>>  	if (get_timespec64(&new_tp, tp))
>>>>  		return -EFAULT;
>>>>  
>>>> +	if (!timespec64_valid(&new_tp))
>>>> +		return -ERANGE;
>>>
>>> Why not use timespec64_valid_settod()?
>>
>> It seems more limited and is only used in timekeeping or
>> do_sys_settimeofday64().
> 
> For a very good reason.
> 
>> And the timespec64_valid() is looser and wider used, which I think is
>> more appropriate here.
> 
> Can you please stop this handwaving and provide proper technical
> arguments?
> 
> Why would PTP have less strict requirements than settimeofday()?

I checked all the PTP driver, most of them use timespec64_to_ns()
convert them to ns which already have a check, but the others not check
them, and lan743x_ptp check them differently and more, so i think this
is a minimum check.

Use timespec64_to_ns()
- drivers/net/ethernet/amd/xgbe/xgbe-ptp.c
- drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c:
- drivers/net/ethernet/cavium/liquidio/lio_main.c:
- drivers/net/ethernet/engleder/tsnep_ptp.c
- drivers/net/ethernet/freescale/fec_ptp.c
- drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_ptp.c:
- drivers/net/ethernet/intel/i40e/i40e_ptp.c
- drivers/net/ethernet/intel/ice/ice_ptp.c
- drivers/net/ethernet/intel/igc/igc_ptp.c
- drivers/net/ethernet/intel/ixgbe/ixgbe_ptp.c
- drivers/net/ethernet/marvell/octeontx2/nic/otx2_ptp.c
- drivers/net/ethernet/qlogic/qede/qede_ptp.c
- drivers/ptp/ptp_idt82p33.c

Not check:
- drivers/net/ethernet/hisilicon/hns3/hns3pf/hclge_ptp.c
- drivers/net/ethernet/intel/igb/igb_ptp.c (only one igb_ptp_settime_i210())
- drivers/net/ethernet/marvell/mvpp2/mvpp2_tai.c
- drivers/net/ethernet/renesas/rcar_gen4_ptp.c
-
drivers/net/ethernet/stmicro/stmmac/stmmac_ptp.c/drivers/net/ethernet/stmicro/stmmac/stmmac_hwtstamp.c
- drivers/net/phy/micrel.c
- drivers/ptp/ptp_dfl_tod.c

Self check and check more:
- drivers/net/ethernet/microchip/lan743x_ptp.c

> 
> Thanks,
> 
>         tglx
> 
>