linux-kernel - [PATCH 05/11] RAS/CEC: Do not set decay value on error

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Date:   Thu,  9 May 2019 20:09:20 +0200
From:   Borislav Petkov <bp@...en8.de>
To:     Tony Luck <tony.luck@...el.com>
Cc:     linux-edac <linux-edac@...r.kernel.org>,
        LKML <linux-kernel@...r.kernel.org>
Subject: [PATCH 05/11] RAS/CEC: Do not set decay value on error

From: Borislav Petkov <bp@...e.de>

When the value requested doesn't match the allowed (min,max) range,
the @data buffer should not be modified with the invalid value because
reading "decay_interval" shows it otherwise.

Move the data write after the check.

Signed-off-by: Borislav Petkov <bp@...e.de>
Cc: Tony Luck <tony.luck@...el.com>
Cc: linux-edac <linux-edac@...r.kernel.org>
---
 drivers/ras/cec.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/ras/cec.c b/drivers/ras/cec.c
index 73216b7f67be..667a126f39f1 100644
--- a/drivers/ras/cec.c
+++ b/drivers/ras/cec.c
@@ -371,17 +371,17 @@ DEFINE_DEBUGFS_ATTRIBUTE(pfn_ops, pfn_get, pfn_set, "0x%llx\n");
 
 static int decay_interval_set(void *data, u64 val)
 {
-	*(u64 *)data = val;
-
 	if (val < CEC_DECAY_MIN_INTERVAL)
 		return -EINVAL;
 
 	if (val > CEC_DECAY_MAX_INTERVAL)
 		return -EINVAL;
 
+	*(u64 *)data   = val;
 	decay_interval = val;
 
 	cec_mod_work(decay_interval);
+
 	return 0;
 }
 DEFINE_DEBUGFS_ATTRIBUTE(decay_interval_ops, pfn_get, decay_interval_set, "%lld\n");
-- 
2.21.0