On 11/16/21 at 12:17pm, Heiko Carstens wrote:
> On Tue, Nov 16, 2021 at 11:25:56AM +0800, Baoquan He wrote:
> > In function ipl_report_finish(), it could fail by memory allocation
> > failure, so check the return value to handle the case.
> >
> > Signed-off-by: Baoquan He <bhe@xxxxxxxxxx>
> > ---
> > arch/s390/include/asm/ipl.h | 2 +-
> > arch/s390/kernel/ipl.c | 6 ++++--
> > arch/s390/kernel/machine_kexec_file.c | 5 ++++-
> > 3 files changed, 9 insertions(+), 4 deletions(-)
> >
> > diff --git a/arch/s390/include/asm/ipl.h b/arch/s390/include/asm/ipl.h
> > index 3f8ee257f9aa..864ab5d2890c 100644
> > --- a/arch/s390/include/asm/ipl.h
> > +++ b/arch/s390/include/asm/ipl.h
> > @@ -122,7 +122,7 @@ struct ipl_report_certificate {
> >
> > struct kexec_buf;
> > struct ipl_report *ipl_report_init(struct ipl_parameter_block *ipib);
> > -void *ipl_report_finish(struct ipl_report *report);
> > +int ipl_report_finish(struct ipl_report *report, void **ipl_buf);
> > int ipl_report_free(struct ipl_report *report);
> > int ipl_report_add_component(struct ipl_report *report, struct kexec_buf *kbuf,
> > unsigned char flags, unsigned short cert);
> > diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
> > index e2cc35775b99..a0af0b23148d 100644
> > --- a/arch/s390/kernel/ipl.c
> > +++ b/arch/s390/kernel/ipl.c
> > @@ -2144,7 +2144,7 @@ struct ipl_report *ipl_report_init(struct ipl_parameter_block *ipib)
> > return report;
> > }
> >
> > -void *ipl_report_finish(struct ipl_report *report)
> > +int ipl_report_finish(struct ipl_report *report, void **ipl_buf)
> > {
> > struct ipl_report_certificate *cert;
> > struct ipl_report_component *comp;
> > @@ -2195,7 +2195,9 @@ void *ipl_report_finish(struct ipl_report *report)
> > }
> >
> > BUG_ON(ptr > buf + report->size);
> > - return buf;
> > + *ipl_buf = buf;
> > +
> > + return 0;
>
> This does not compile:
>
> CC arch/s390/kernel/ipl.o
> arch/s390/kernel/ipl.c: In function ‘ipl_report_finish’:
> arch/s390/kernel/ipl.c:2159:24: warning: returning ‘void *’ from a function with return type ‘int’ makes integer from pointer without a cast [-Wint-conversion]
> 2159 | return ERR_PTR(-ENOMEM);
> | ^~~~~~~~~~~~~~~~
Oops, I forgot changing this place to "return -ENOMEM;". Thanks for
taking care of it with below patch.
>
> Anyway, before we are going to have more iterations I just applied the
> patch below instead before applying your memory leak fix.
>
> From 78e5f268d1be775354ab83c1e039dcfacaa5e258 Mon Sep 17 00:00:00 2001
> From: Heiko Carstens <hca@xxxxxxxxxxxxx>
> Date: Tue, 16 Nov 2021 11:06:38 +0100
> Subject: s390/kexec: fix return code handling
>
> kexec_file_add_ipl_report ignores that ipl_report_finish may fail and
> can return an error pointer instead of a valid pointer.
> Fix this and simplify by returning NULL in case of an error and let
> the only caller handle this case.
>
> Fixes: 99feaa717e55 ("s390/kexec_file: Create ipl report and pass to next kernel")
> Signed-off-by: Heiko Carstens <hca@xxxxxxxxxxxxx>
> ---
> arch/s390/kernel/ipl.c | 3 ++-
> arch/s390/kernel/machine_kexec_file.c | 8 +++++++-
> 2 files changed, 9 insertions(+), 2 deletions(-)
>
> diff --git a/arch/s390/kernel/ipl.c b/arch/s390/kernel/ipl.c
> index e2cc35775b99..5ad1dde23dc5 100644
> --- a/arch/s390/kernel/ipl.c
> +++ b/arch/s390/kernel/ipl.c
> @@ -2156,7 +2156,7 @@ void *ipl_report_finish(struct ipl_report *report)
>
> buf = vzalloc(report->size);
> if (!buf)
> - return ERR_PTR(-ENOMEM);
> + goto out;
> ptr = buf;
>
> memcpy(ptr, report->ipib, report->ipib->hdr.len);
> @@ -2195,6 +2195,7 @@ void *ipl_report_finish(struct ipl_report *report)
> }
>
> BUG_ON(ptr > buf + report->size);
> +out:
> return buf;
> }
>
> diff --git a/arch/s390/kernel/machine_kexec_file.c b/arch/s390/kernel/machine_kexec_file.c
> index 528edff085d9..f0200b503f94 100644
> --- a/arch/s390/kernel/machine_kexec_file.c
> +++ b/arch/s390/kernel/machine_kexec_file.c
> @@ -170,6 +170,7 @@ static int kexec_file_add_ipl_report(struct kimage *image,
> struct kexec_buf buf;
> unsigned long addr;
> void *ptr, *end;
> + int ret;
>
> buf.image = image;
>
> @@ -199,7 +200,10 @@ static int kexec_file_add_ipl_report(struct kimage *image,
> ptr += len;
> }
>
> + ret = -ENOMEM;
> buf.buffer = ipl_report_finish(data->report);
> + if (!buf.buffer)
> + goto out;
> buf.bufsz = data->report->size;
> buf.memsz = buf.bufsz;
>
> @@ -209,7 +213,9 @@ static int kexec_file_add_ipl_report(struct kimage *image,
> data->kernel_buf + offsetof(struct lowcore, ipl_parmblock_ptr);
> *lc_ipl_parmblock_ptr = (__u32)buf.mem;
>
> - return kexec_add_buffer(&buf);
> + ret = kexec_add_buffer(&buf);
> +out:
> + return ret;
> }
>
> void *kexec_file_add_components(struct kimage *image,
> --
> 2.31.1
>
