From: Greg KH <gregkh@linuxfoundation.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Xiang Yang <xiangyang3@huawei.com>,
mark.rutland@arm.com, catalin.marinas@arm.com, will@kernel.org,
keescook@chromium.org, linux-arm-kernel@lists.infradead.org,
stable@vger.kernel.org, xiujianfeng@huawei.com,
liaochang1@huawei.com
Subject: Re: [PATCH 5.10.y v2] Revert "arm64: Stash shadow stack pointer in the task struct on interrupt"
Date: Tue, 20 Feb 2024 16:31:57 +0100 [thread overview]
Message-ID: <2024022049-worst-dividable-0f1c@gregkh> (raw)
In-Reply-To: <CAMj1kXFwTLJ77MYy3Pm+S9WGgkMw0hAGdTKOF05xdqqBg8giMw@mail.gmail.com>
On Mon, Feb 19, 2024 at 05:57:07PM +0100, Ard Biesheuvel wrote:
> On Mon, 19 Feb 2024 at 14:24, Xiang Yang <xiangyang3@huawei.com> wrote:
> >
> > This reverts commit 3f225f29c69c13ce1cbdb1d607a42efeef080056.
> >
> > The shadow call stack for irq now is stored in current task's thread info
> > in irq_stack_entry. There is a possibility that we have some soft irqs
> > pending at the end of hard irq, and when we process softirq with the irq
> > enabled, irq_stack_entry will enter again and overwrite the shadow call
> > stack whitch stored in current task's thread info, leading to the
> > incorrect shadow call stack restoration for the first entry of the hard
> > IRQ, then the system end up with a panic.
> >
> > task A | task A
> > -------------------------------------+------------------------------------
> > el1_irq //irq1 enter |
> > irq_handler //save scs_sp1 |
> > gic_handle_irq |
> > irq_exit |
> > __do_softirq |
> > | el1_irq //irq2 enter
> > | irq_handler //save scs_sp2
> > | //overwrite scs_sp1
> > | ...
> > | irq_stack_exit //restore scs_sp2
> > irq_stack_exit //restore wrong |
> > //scs_sp2 |
> >
> > So revert this commit to fix it.
> >
> > Fixes: 3f225f29c69c ("arm64: Stash shadow stack pointer in the task struct on interrupt")
> >
> > Signed-off-by: Xiang Yang <xiangyang3@huawei.com>
>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
Now queued up, thanks.
greg k-h
WARNING: multiple messages have this Message-ID (diff)
From: Greg KH <gregkh@linuxfoundation.org>
To: Ard Biesheuvel <ardb@kernel.org>
Cc: Xiang Yang <xiangyang3@huawei.com>,
mark.rutland@arm.com, catalin.marinas@arm.com, will@kernel.org,
keescook@chromium.org, linux-arm-kernel@lists.infradead.org,
stable@vger.kernel.org, xiujianfeng@huawei.com,
liaochang1@huawei.com
Subject: Re: [PATCH 5.10.y v2] Revert "arm64: Stash shadow stack pointer in the task struct on interrupt"
Date: Tue, 20 Feb 2024 16:31:57 +0100 [thread overview]
Message-ID: <2024022049-worst-dividable-0f1c@gregkh> (raw)
In-Reply-To: <CAMj1kXFwTLJ77MYy3Pm+S9WGgkMw0hAGdTKOF05xdqqBg8giMw@mail.gmail.com>
On Mon, Feb 19, 2024 at 05:57:07PM +0100, Ard Biesheuvel wrote:
> On Mon, 19 Feb 2024 at 14:24, Xiang Yang <xiangyang3@huawei.com> wrote:
> >
> > This reverts commit 3f225f29c69c13ce1cbdb1d607a42efeef080056.
> >
> > The shadow call stack for irq now is stored in current task's thread info
> > in irq_stack_entry. There is a possibility that we have some soft irqs
> > pending at the end of hard irq, and when we process softirq with the irq
> > enabled, irq_stack_entry will enter again and overwrite the shadow call
> > stack whitch stored in current task's thread info, leading to the
> > incorrect shadow call stack restoration for the first entry of the hard
> > IRQ, then the system end up with a panic.
> >
> > task A | task A
> > -------------------------------------+------------------------------------
> > el1_irq //irq1 enter |
> > irq_handler //save scs_sp1 |
> > gic_handle_irq |
> > irq_exit |
> > __do_softirq |
> > | el1_irq //irq2 enter
> > | irq_handler //save scs_sp2
> > | //overwrite scs_sp1
> > | ...
> > | irq_stack_exit //restore scs_sp2
> > irq_stack_exit //restore wrong |
> > //scs_sp2 |
> >
> > So revert this commit to fix it.
> >
> > Fixes: 3f225f29c69c ("arm64: Stash shadow stack pointer in the task struct on interrupt")
> >
> > Signed-off-by: Xiang Yang <xiangyang3@huawei.com>
>
> Acked-by: Ard Biesheuvel <ardb@kernel.org>
Now queued up, thanks.
greg k-h
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next prev parent reply other threads:[~2024-02-20 15:32 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-02-19 13:21 [PATCH 5.10.y v2] Revert "arm64: Stash shadow stack pointer in the task struct on interrupt" Xiang Yang
2024-02-19 13:21 ` Xiang Yang
2024-02-19 16:57 ` Ard Biesheuvel
2024-02-19 16:57 ` Ard Biesheuvel
2024-02-20 15:31 ` Greg KH [this message]
2024-02-20 15:31 ` Greg KH
2024-02-20 15:31 ` Patch "Revert "arm64: Stash shadow stack pointer in the task struct on interrupt"" has been added to the 5.10-stable tree gregkh
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