Re: [RFC PATCH 1/1] net: kcm: Use sk_psock size for kcm_psock_cache
From: Khalid Masum
Date: Wed Jul 13 2022 - 14:26:11 EST
On Thu, Jul 14, 2022 at 12:16 AM Jakub Kicinski <kuba@xxxxxxxxxx> wrote:
> On Wed, 13 Jul 2022 12:32:04 +0600 Khalid Masum wrote:
> > `struct sock` has a member `sk_user_data`, which got its memory allocated
> > in `kcm_attach` by `kcm_psock_cache` with the size of `kcm_psock`. Which
> > is not enough when the member is used as `sk_psock` causing out of bound
> > read.
> > Use `sk_psock` size to allocate memory instead for `sk_user_data`.
> > Reported-by: syzbot+1fa91bcd05206ff8cbb5@xxxxxxxxxxxxxxxxxxxxxxxxx
> > Signed-off-by: Khalid Masum <khalid.masum.92@xxxxxxxxx>
> Odd CC list, it looks like a netdev problem but netdev@ is not copied.
I am sorry for the inconvenience. I resent the patch with netdev in CC here:
> We had an other parson looking at this on netdev. Is this happening
> when legit kernel socket gets mixed with BPF sockmap?
> Does this fix work?
I will take a look at it.