lkml.org 
[lkml]   [2021]   [Nov]   [10]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] s390/kexec: fix memory leak of ipl report buffer
On 11/10/21 at 04:18pm, Heiko Carstens wrote:
> On Fri, Oct 29, 2021 at 06:31:32PM +0200, Philipp Rudo wrote:
> > Hi Baoquan,
> >
> > On Fri, 29 Oct 2021 17:26:35 +0800
> > Baoquan He <bhe@redhat.com> wrote:
> >
> > > A memory leak is reported by kmemleak scanning:
> ...
> > > The ipl report buffer is allocated via vmalloc, while has no chance to free
> > > if the kexe loading is unloaded. This will cause obvious memory leak
> > > when kexec/kdump kernel is reloaded, manually, or triggered, e.g by
> > > memory hotplug.
> > >
> > > Here, add struct kimage_arch to s390 to pass out the ipl report buffer
> > > address, and introduce arch dependent function
> > > arch_kimage_file_post_load_cleanup() to free it when unloaded.
> > >
> > > Signed-off-by: Baoquan He <bhe@redhat.com>
> >
> > other than a missing
> >
> > Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to
> > next kernel")
> >
> > the patch looks good to me.
> >
> > Reviewed-by: Philipp Rudo <prudo@redhat.com>
> ...
> > > buf.buffer = ipl_report_finish(data->report);
> > > buf.bufsz = data->report->size;
> > > buf.memsz = buf.bufsz;
> > > + image->arch.ipl_buf = buf.buffer;
>
> This seems (still) to be incorrect: ipl_report_finish() may return
> -ENOMEN, but there is no error checking anywhere, as far as I can
> tell, which would make this:
>
> > > +int arch_kimage_file_post_load_cleanup(struct kimage *image)
> > > +{
> > > + kvfree(image->arch.ipl_buf);
> > > + image->arch.ipl_buf = NULL;
> > > +
> > > + return kexec_image_post_load_cleanup_default(image);
> > > +}
>
> most likely not do what we want. That is: if this code is reached at
> all in such a case. I'll check and might add a patch before this to
> fix this also.

Right, we should check the returned value firstly. Thanks a lot for
reivewing, Heiko. I will post v2 to add a patch to check the returned
value as you suggested, and also update this patch to add missing Fixes tag.

\
 
 \ /
  Last update: 2021-11-11 01:23    [W:0.264 / U:0.112 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site