From 3b7951e3219385e336f09b282f03d705b9daef68 Mon Sep 17 00:00:00 2001
From: Ard Biesheuvel <ardb@kernel.org>
Date: Wed, 1 Sep 2021 08:33:19 +0200
Subject: [PATCH] efi/cper: use stack buffer for error record decoding
Git-commit: b3a72ca80351917cc23f9e24c35f3c3979d3c121
Patch-mainline: v5.15-rc6
References: stable-5.14.14
commit b3a72ca80351917cc23f9e24c35f3c3979d3c121 upstream.
Joe reports that using a statically allocated buffer for converting CPER
error records into human readable text is probably a bad idea. Even
though we are not aware of any actual issues, a stack buffer is clearly
a better choice here anyway, so let's move the buffer into the stack
frames of the two functions that refer to it.
Cc: <stable@vger.kernel.org>
Reported-by: Joe Perches <joe@perches.com>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Acked-by: Takashi Iwai <tiwai@suse.de>
---
drivers/firmware/efi/cper.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/drivers/firmware/efi/cper.c b/drivers/firmware/efi/cper.c
index ea7ca74fc173..232c092c4c97 100644
--- a/drivers/firmware/efi/cper.c
+++ b/drivers/firmware/efi/cper.c
@@ -25,8 +25,6 @@
#include <acpi/ghes.h>
#include <ras/ras_event.h>
-static char rcd_decode_str[CPER_REC_LEN];
-
/*
* CPER record ID need to be unique even after reboot, because record
* ID is used as index for ERST storage, while CPER records from
@@ -313,6 +311,7 @@ const char *cper_mem_err_unpack(struct trace_seq *p,
struct cper_mem_err_compact *cmem)
{
const char *ret = trace_seq_buffer_ptr(p);
+ char rcd_decode_str[CPER_REC_LEN];
if (cper_mem_err_location(cmem, rcd_decode_str))
trace_seq_printf(p, "%s", rcd_decode_str);
@@ -327,6 +326,7 @@ static void cper_print_mem(const char *pfx, const struct cper_sec_mem_err *mem,
int len)
{
struct cper_mem_err_compact cmem;
+ char rcd_decode_str[CPER_REC_LEN];
/* Don't trust UEFI 2.1/2.2 structure with bad validation bits */
if (len == sizeof(struct cper_sec_mem_err_old) &&
--
2.26.2