Re: [PATCH] x86/kprobes: Fix 1 byte conditional jump target

[Google]

On Sun, 5 Feb 2023 09:49:56 +0200
Nadav Amit <nadav.amit@xxxxxxxxx> wrote:

> 
> 
> > On Feb 4, 2023, at 11:08 PM, Nadav Amit <nadav.amit@xxxxxxxxx> wrote:
> > 
> > From: Nadav Amit <namit@xxxxxxxxxx>
> > 
> > Commit 3bc753c06dd0 ("kbuild: treat char as always unsigned") broke
> > kprobes.  Setting a probe-point on 1 byte conditional jump can cause the
> > kernel to crash, as the branch target is not sign extended.
> > 
> > Fix by using s8 instead of char and use immediate.value instead of
> > immediate.bytes for consistency.
> 
> I guess I forgot to put a “Fixes” tag, since it is still not a real
> regression. (The bug was introduced in 6.2).
> 
> Still, this fix should not fall between the cracks… Please let me know
> whether v2 is needed with a “fixes” tag.

No problem, I added Fixed tag with my Ack :)

Thank you!

> 


-- 
Masami Hiramatsu (Google) <mhiramat@xxxxxxxxxx>