From 29a0c843973bc385918158c6976e4dbe891df969 Mon Sep 17 00:00:00 2001 From: Robert Richter Date: Tue, 14 May 2019 10:49:09 +0000 Subject: [PATCH] EDAC/mc: Fix edac_mc_find() in case no device is found 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 Signed-off-by: Borislav Petkov Cc: "linux-edac@vger.kernel.org" Cc: James Morse Cc: Mauro Carvalho Chehab Link: https://lkml.kernel.org/r/20190514104838.15065-1-rrichter@marvell.com --- drivers/edac/edac_mc.c | 12 ++++-------- 1 file changed, 4 insertions(+), 8 deletions(-) diff --git a/drivers/edac/edac_mc.c b/drivers/edac/edac_mc.c index 13594ffadcb3..64922c8fa7e3 100644 --- a/drivers/edac/edac_mc.c +++ b/drivers/edac/edac_mc.c @@ -679,22 +679,18 @@ 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;