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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tomi Valkeinen <tomi.valkeinen@ti.com>,
        Tony Lindgren <tony@atomide.com>,
        Peter Ujfalusi <peter.ujfalusi@ti.com>,
        Stephen Boyd <sboyd@kernel.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.19 08/47] clk: ti: clkctrl: Fix returning uninitialized data
Date:   Thu, 18 Jul 2019 12:01:22 +0900
Message-Id: <20190718030049.197902316@linuxfoundation.org>
In-Reply-To: <20190718030045.780672747@linuxfoundation.org>
References: <20190718030045.780672747@linuxfoundation.org>
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[ Upstream commit 41b3588dba6ef4b7995735a97e47ff0aeea6c276 ]

If we do a clk_get() for a clock that does not exists, we have
_ti_omap4_clkctrl_xlate() return uninitialized data if no match
is found. This can be seen in some cases with SLAB_DEBUG enabled:

Unable to handle kernel paging request at virtual address 5a5a5a5a
...
clk_hw_create_clk.part.33
sysc_notifier_call
notifier_call_chain
blocking_notifier_call_chain
device_add

Let's fix this by setting a found flag only when we find a match.

Reported-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Fixes: 88a172526c32 ("clk: ti: add support for clkctrl clocks")
Signed-off-by: Tony Lindgren <tony@atomide.com>
Tested-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/clk/ti/clkctrl.c | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/drivers/clk/ti/clkctrl.c b/drivers/clk/ti/clkctrl.c
index ca3218337fd7..dfaa5aad0692 100644
--- a/drivers/clk/ti/clkctrl.c
+++ b/drivers/clk/ti/clkctrl.c
@@ -229,6 +229,7 @@ static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
 {
 	struct omap_clkctrl_provider *provider = data;
 	struct omap_clkctrl_clk *entry;
+	bool found = false;
 
 	if (clkspec->args_count != 2)
 		return ERR_PTR(-EINVAL);
@@ -238,11 +239,13 @@ static struct clk_hw *_ti_omap4_clkctrl_xlate(struct of_phandle_args *clkspec,
 
 	list_for_each_entry(entry, &provider->clocks, node) {
 		if (entry->reg_offset == clkspec->args[0] &&
-		    entry->bit_offset == clkspec->args[1])
+		    entry->bit_offset == clkspec->args[1]) {
+			found = true;
 			break;
+		}
 	}
 
-	if (!entry)
+	if (!found)
 		return ERR_PTR(-EINVAL);
 
 	return entry->clk;
-- 
2.20.1