[PATCH 5.15 185/279] s390/kexec: fix return code handling

Greg Kroah-Hartman
2021-11-24T13:57:44Z

From: Heiko Carstens <hca@linux.ibm.com>

[ Upstream commit 20c76e242e7025bd355619ba67beb243ba1a1e95 ]

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@linux.ibm.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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 e2cc35775b996..5ad1dde23dc59 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 f9e4baa64b675..c1090f0b1f6a6 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,
--
2.33.0