On Fri, 05 Feb 2021 11:36:30 +1100 NeilBrown <neilb@xxxxxxx> wrote:
> A recent change to seq_file broke some users which were using seq_file
> in a non-"standard" way ... though the "standard" isn't documented, so
> they can be excused. The result is a possible leak - of memory in one
> case, of references to a 'transport' in the other.
>
> These three patches:
> 1/ document and explain the problem
> 2/ fix the problem user in x86
> 3/ fix the problem user in net/sctp
>
1f4aace60b0e ("fs/seq_file.c: simplify seq_file iteration code and
interface") was August 2018, so I don't think "recent" applies here?
I didn't look closely, but it appears that the sctp procfs file is
world-readable. So we gave unprivileged userspace the ability to leak
kernel memory?
So I'm thinking that we aim for 5.12-rc1 on all three patches with a cc:stable?
