hi Greg,

Please apply upstream 8ab49526b53d to all stable kernels containing 07e1d88adaae, which should be v4.20 and higher stable kernels.

Thanks,

Ingo

----- Forwarded message from Eric Dumazet edumazet@google.com -----

Date: Sat, 15 Aug 2020 10:38:58 -0700 From: Eric Dumazet edumazet@google.com To: Ingo Molnar mingo@kernel.org Cc: linux-kernel linux-kernel@vger.kernel.org, Eric Dumazet eric.dumazet@gmail.com, Jann Horn jannh@google.com, syzbot syzkaller@googlegroups.com, Andy Lutomirski luto@kernel.org, "Chang S . Bae" chang.seok.bae@intel.com, Andy Lutomirski luto@amacapital.net, Borislav Petkov bp@alien8.de, Brian Gerst brgerst@gmail.com, Dave Hansen dave.hansen@linux.intel.com, Denys Vlasenko dvlasenk@redhat.com, "H . Peter Anvin" hpa@zytor.com, Linus Torvalds torvalds@linux-foundation.org, Markus T Metzger markus.t.metzger@intel.com, Peter Zijlstra peterz@infradead.org, Ravi Shankar ravi.v.shankar@intel.com, Rik van Riel riel@surriel.com, Thomas Gleixner tglx@linutronix.de Subject: Re: [PATCH] x86/fsgsbase/64: Fix NULL deref in 86_fsgsbase_read_task

On Sat, Aug 15, 2020 at 4:48 AM Ingo Molnar mingo@kernel.org wrote:

• Eric Dumazet edumazet@google.com wrote:

...

syzbot found its way in 86_fsgsbase_read_task() [1]

Fix is to make sure ldt pointer is not NULL.

Thanks for this fix. Linus has picked it up (inclusive the typos to the x86_fsgsbase_read_task() function name ;-), it's now upstream under:

8ab49526b53d: ("x86/fsgsbase/64: Fix NULL deref in 86_fsgsbase_read_task")

By the fixes tag it looks like this should probably be backported all the way back to ~v4.20 or so?

This is absolutely right, sorry about the lack of a stable tag.

Most of my patches usually land into David Miller trees, where the stable tag is not welcomed. We use Fixes: tags to convey the exact information needed for stable backports.

Thanks.

----- End forwarded message -----