diff mbox series

[4.14,210/343] EDAC/mc: Fix edac_mc_find() in case no device is found

Message ID 20200124092947.711378247@linuxfoundation.org (mailing list archive)
State New, archived
Headers show
Series None | expand

Commit Message

Greg KH Jan. 24, 2020, 9:30 a.m. UTC 
From: Robert Richter <rrichter@marvell.com>

[ Upstream commit 29a0c843973bc385918158c6976e4dbe891df969 ]

The function should return NULL in case no device is found, but it
always returns the last checked mc device from the list even if the
index did not match. Fix that.

I did some analysis why this did not raise any issues for about 3 years
and the reason is that edac_mc_find() is mostly used to search for
existing devices. Thus, the bug is not triggered.

 [ bp: Drop the if (mci->mc_idx > idx) test in favor of readability. ]

Fixes: c73e8833bec5 ("EDAC, mc: Fix locking around mc_devices list")
Signed-off-by: Robert Richter <rrichter@marvell.com>
Signed-off-by: Borislav Petkov <bp@suse.de>
Cc: "linux-edac@vger.kernel.org" <linux-edac@vger.kernel.org>
Cc: James Morse <james.morse@arm.com>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Link: https://lkml.kernel.org/r/20190514104838.15065-1-rrichter@marvell.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/edac/edac_mc.c | 12 ++++--------
 1 file changed, 4 insertions(+), 8 deletions(-)
diff mbox series

Patch

diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c
index f7fa05fee45a1..329021189c38b 100644
--- a/drivers/edac/edac_mc.c
+++ b/drivers/edac/edac_mc.c
@@ -680,22 +680,18 @@  static int del_mc_from_global_list(struct mem_ctl_info *mci)
 
 struct mem_ctl_info *edac_mc_find(int idx)
 {
-	struct mem_ctl_info *mci = NULL;
+	struct mem_ctl_info *mci;
 	struct list_head *item;
 
 	mutex_lock(&mem_ctls_mutex);
 
 	list_for_each(item, &mc_devices) {
 		mci = list_entry(item, struct mem_ctl_info, link);
-
-		if (mci->mc_idx >= idx) {
-			if (mci->mc_idx == idx) {
-				goto unlock;
-			}
-			break;
-		}
+		if (mci->mc_idx == idx)
+			goto unlock;
 	}
 
+	mci = NULL;
 unlock:
 	mutex_unlock(&mem_ctls_mutex);
 	return mci;