Re: [PATCH] kexec: Fix uninitialized struct kimage *image pointer

[Qiang Ma]

在 2025/12/15 16:50, Baoquan He 写道:
> On 12/15/25 at 12:41pm, Qiang Ma wrote:
> > 在 2025/12/15 09:18, Baoquan He 写道:
> > > On 12/14/25 at 07:35pm, Qiang Ma wrote:
> > > > 在 2025/12/12 18:53, Baoquan He 写道:
> > > > > On 12/12/25 at 03:16pm, Qiang Ma wrote:
> > > > > > The image is initialized to NULL. Then, after calling kimage_alloc_init,
> > > > > > we can directly goto 'out' because at this time, the kimage_free will
> > > > > > determine whether image is a NULL pointer.
> > > > > Rechecked the code flow, in kimage_alloc_init(), if anything wrong, the
> > > > > allocated memory are all freed via out_free_control_pages and
> > > > > out_free_image accordingly, any place missed? If no, I think the current
> > > > > code is correctly handled.
> > > > I rechecked the code and found no omissions.
> > > Hmm, my bad, I didn't say my question clearly. I checked code, didn't
> > > find anything wrong in the current code. In kimage_alloc_init(), the
> > > allocated memory are all freed on failure, no memory leaked. Means you
> > > are fixing correct code.
> > Oh, I see. I recalled that this fix was in preparation for patch
> > "kexec: add kexec flag to control debug printing" for kexec_dbg_print
> > to be reset to false in kimage_free.
> >
> > In that case, I don't think this patch should be posted separately.
> If it's prepared for later patch, it should not be saying it's fixing
> issue. People may be confused and try to add it to stable kernel.
That makes sense. I renamed it: "kexec: Replace the goto out_unlock with 
out" in v2.
> > > > > > Signed-off-by: Qiang Ma <maqianga@xxxxxxxxxxxxx>
> > > > > > ---
> > > > > >     kernel/kexec.c | 4 +++-
> > > > > >     1 file changed, 3 insertions(+), 1 deletion(-)
> > > > > Acked-by: Baoquan He <bhe@xxxxxxxxxx>
> > > > >
> > > > > > diff --git a/kernel/kexec.c b/kernel/kexec.c
> > > > > > index 28008e3d462e..9bb1f2b6b268 100644
> > > > > > --- a/kernel/kexec.c
> > > > > > +++ b/kernel/kexec.c
> > > > > > @@ -95,6 +95,8 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
> > > > > >     	unsigned long i;
> > > > > >     	int ret;
> > > > > > +	image = NULL;
> > > > > > +
> > > > > >     	/*
> > > > > >     	 * Because we write directly to the reserved memory region when loading
> > > > > >     	 * crash kernels we need a serialization here to prevent multiple crash
> > > > > > @@ -129,7 +131,7 @@ static int do_kexec_load(unsigned long entry, unsigned long nr_segments,
> > > > > >     	ret = kimage_alloc_init(&image, entry, nr_segments, segments, flags);
> > > > > >     	if (ret)
> > > > > > -		goto out_unlock;
> > > > > > +		goto out;
> > > > > >     	if (flags & KEXEC_PRESERVE_CONTEXT)
> > > > > >     		image->preserve_context = 1;
> > > > > > --
> > > > > > 2.20.1