> -----Original Message----- > From: Chuck Ebbert [mailto:cebbert.l...@gmail.com] > Sent: Friday, September 26, 2014 3:01 PM > To: Anish Bhatt > Cc: linux-kernel@vger.kernel.org; x...@kernel.org; t...@linutronix.de; > mi...@redhat.com; h...@zytor.com; sebast...@fds-team.de; Linus > Torvalds > Subject: Re: [PATCH] x86 : Ensure X86_FLAGS_NT is cleared on syscall entry > > On Thu, 25 Sep 2014 12:42:51 -0700 > Anish Bhatt <an...@chelsio.com> wrote: > > > The MSR_SYSCALL_MASK, which is responsible for clearing specific > > EFLAGS on syscall entry, should also clear the nested task (NT) flag > > to be safe from userspace injection. Without this fix the application > > segmentation faults on syscall return because of the changed meaning > > of the IRET instruction. > > > > Further details can be seen here > > https://bugs.winehq.org/show_bug.cgi?id=33275 > > > > Signed-off-by: Anish Bhatt <an...@chelsio.com> > > Signed-off-by: Sebastian Lackner <sebast...@fds-team.de> > > --- > > arch/x86/kernel/cpu/common.c | 2 +- > > 1 file changed, 1 insertion(+), 1 deletion(-) > > > > diff --git a/arch/x86/kernel/cpu/common.c > > b/arch/x86/kernel/cpu/common.c index e4ab2b4..3126558 100644 > > --- a/arch/x86/kernel/cpu/common.c > > +++ b/arch/x86/kernel/cpu/common.c > > @@ -1184,7 +1184,7 @@ void syscall_init(void) > > /* Flags to clear on syscall */ > > wrmsrl(MSR_SYSCALL_MASK, > > X86_EFLAGS_TF|X86_EFLAGS_DF|X86_EFLAGS_IF| > > - X86_EFLAGS_IOPL|X86_EFLAGS_AC); > > + X86_EFLAGS_IOPL|X86_EFLAGS_AC|X86_EFLAGS_NT); > > } > > > > /* > > I don't get it. Why isn't this patch acceptable, at least on x86-64 where NT > is > never valid? > > Bueller?
Chuck, I don't think anyone has gotten around to reviewing, accepting or rejecting this patch yet. -Anish -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
