6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Karl Mehltretter <redacted>
[ Upstream commit 8c3afcf27fa4582c1ab912503dc8a4ebb8dc0f82 ]
imx6_soc_volt is allocated fresh on every probe, sized to the number of
ARM OPPs:
imx6_soc_volt = devm_kcalloc(cpu_dev, num, sizeof(*imx6_soc_volt),
GFP_KERNEL);
but it is filled through soc_opp_count, which has static storage and is
never reset. A second bind after an unbind keeps indexing from where the
first one stopped, and writes past the end of the new array.
Unbinding and rebinding the driver on qemu's mcimx6ul-evk, under KASAN:
BUG: KASAN: slab-out-of-bounds in imx6q_cpufreq_probe+0x3b0/0xa34
Write of size 4 at addr c5e90480 by task binder/73
imx6q_cpufreq_probe from platform_probe+0x88/0xe4
platform_probe from really_probe+0x108/0x384
bind_store from kernfs_fop_write_iter+0x1b4/0x28c
The write lands one u32 past the end of the allocation.
soc_opp_count is only read a few lines below the loop that fills it, so it
never needed static storage. Make it a local.
Fixes: b4573d1d657a ("cpufreq: imx6q: correct VDDSOC/PU voltage scaling when cpufreq is changed")
Assisted-by: Claude:claude-opus-5
Signed-off-by: Karl Mehltretter <redacted>
Signed-off-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/cpufreq/imx6q-cpufreq.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/drivers/cpufreq/imx6q-cpufreq.c b/drivers/cpufreq/imx6q-cpufreq.c
index 7115f713ba6a1..7f5f1f5c1edbd 100644
--- a/drivers/cpufreq/imx6q-cpufreq.c
+++ b/drivers/cpufreq/imx6q-cpufreq.c
@@ -53,7 +53,6 @@ static unsigned int max_freq;
static unsigned int transition_latency;
static u32 *imx6_soc_volt;
-static u32 soc_opp_count;
static int imx6q_set_target(struct cpufreq_policy *policy, unsigned int index)
{@@ -346,6 +345,7 @@ static int imx6q_cpufreq_probe(struct platform_device *pdev)
const struct property *prop;
const __be32 *val;
u32 nr, i, j;
+ u32 soc_opp_count = 0;
cpu_dev = get_cpu_device(0);
if (!cpu_dev) {--
2.53.0