Re: [PATCH] getdelays: Fix netlink attribute length

From: Andrew Morton
Date: Sat Mar 28 2020 - 16:03:44 EST


On Fri, 27 Mar 2020 11:31:11 -0600 David Ahern <dsahern@xxxxxxxxxx> wrote:

> A recent change to the netlink code:
> 6e237d099fac ("netlink: Relax attr validation for fixed length types")
> logs a warning when programs send messages with invalid attributes
> (e.g., wrong length for a u32). Yafang reported this error message
> for tools/accounting/getdelays.c.
>
> send_cmd() is wrongly adding 1 to the attribute length. As noted in
> include/uapi/linux/netlink.h nla_len should be NLA_HDRLEN + payload
> length, so drop the +1.

Thanks.

> Fixes: 9e06d3f9f6b1 ("per task delay accounting taskstats interface: documentation fix")
> Signed-off-by: David Ahern <dsahern@xxxxxxxxxx>
> Tested-by: Yafang Shao <laoar.shao@xxxxxxxxx>

I'll add Reported-by: as well.

> Cc: Johannes Berg <johannes@xxxxxxxxxxxxxxxx>
> Cc: Shailabh Nagar <nagar@xxxxxxxxxxxxxx>

Is this worth a cc:stable?