Re: [PATCH] kobject: fix suppressing modalias in uevents delivered over netlink

[Eric Dumazet]

On Tue, Dec 19, 2017 at 12:48 AM, Greg Kroah-Hartman
<gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> On Wed, Dec 13, 2017 at 03:21:22PM -0800, Dmitry Torokhov wrote:
>> The commit 4a336a23d619 ("kobject: copy env blob in one go") optimized
>> constructing uevent data for delivery over netlink by using the raw
>> environment buffer, instead of reconstructing it from individual
>> environment pointers. Unfortunately in doing so it broke suppressing
>> MODALIAS attribute for KOBJ_UNBIND events, as the code that suppressed this
>> attribute only adjusted the environment pointers, but left the buffer
>> itself alone. Let's fix it by making sure the offending attribute is
>> obliterated form the buffer as well.
>>
>> Reported-by: Tariq Toukan <tariqt@xxxxxxxxxxxx>
>> Reported-by: Casey Leedom <leedom@xxxxxxxxxxx>
>> Fixes: 4a336a23d619 ("kobject: copy env blob in one go")
>> Signed-off-by: Dmitry Torokhov <dmitry.torokhov@xxxxxxxxx>
>> ---
>>  lib/kobject_uevent.c | 16 ++++++++++++----
>>  1 file changed, 12 insertions(+), 4 deletions(-)
>
> Ok, I'm lost here, is this patch still needed for 4.15-final?
>
> And am I supposed to be taking it through my tree as the offending patch
> didn't come from me?  :)

Sorry for that, I sent a patch series (
8ca712c373a462cfa1b62272870b6c2c74aa83f9 )
that was mostly network related stuff (dealing with skbs and all rtnl batching),
and sent it to David before Dmitry patch was visible in David tree.

Yes, we believe fix in zap_modalias_env() is needed.

Thanks.