From 8c3afcf27fa4582c1ab912503dc8a4ebb8dc0f82 Mon Sep 17 00:00:00 2001 From: Karl Mehltretter Date: Thu, 6 Aug 2026 07:02:39 +0200 Subject: [PATCH] cpufreq: imx6q: fix out-of-bounds write when probed more than once 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 Signed-off-by: Viresh Kumar --- 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 8110c95059e0..731f5721ff1e 100644 --- a/drivers/cpufreq/imx6q-cpufreq.c +++ b/drivers/cpufreq/imx6q-cpufreq.c @@ -55,7 +55,6 @@ 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) { @@ -330,6 +329,7 @@ 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) {