Messages in this thread | | | Date | Thu, 23 Mar 2023 12:43:54 +0100 | Subject | Re: [PATCH] cpufreq: mediatek: guard error paths to avoid kernel panic | From | AngeloGioacchino Del Regno <> |
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Il 23/03/23 12:04, Daniel Golle ha scritto: > Guard pointer access in error path of mtk_cpu_dvfs_info_init() to > make sure info->proc_reg and info->sram_reg are valid pointers before > accessing them, which would result in kernel panic e.g. in case of > them being set to -EPROBE_DEFER. > > Fixes: 4b9ceb757bbb ("cpufreq: mediatek: Enable clocks and regulators") > Reported-by: Sam Shih <sam.shih@mediatek.com> > Suggested-by: Sam Shih <sam.shih@mediatek.com> > Signed-off-by: Daniel Golle <daniel@makrotopia.org> > --- > drivers/cpufreq/mediatek-cpufreq.c | 10 ++++++---- > 1 file changed, 6 insertions(+), 4 deletions(-) > > diff --git a/drivers/cpufreq/mediatek-cpufreq.c b/drivers/cpufreq/mediatek-cpufreq.c > index 4466d0c91a6a..980a31ddd0f2 100644 > --- a/drivers/cpufreq/mediatek-cpufreq.c > +++ b/drivers/cpufreq/mediatek-cpufreq.c > @@ -579,10 +579,12 @@ static int mtk_cpu_dvfs_info_init(struct mtk_cpu_dvfs_info *info, int cpu) > dev_pm_opp_of_cpumask_remove_table(&info->cpus); > > out_free_resources: > - if (regulator_is_enabled(info->proc_reg)) > - regulator_disable(info->proc_reg); > - if (info->sram_reg && regulator_is_enabled(info->sram_reg)) > - regulator_disable(info->sram_reg); > + if (!IS_ERR(info->proc_reg)) > + if (regulator_is_enabled(info->proc_reg)) > + regulator_disable(info->proc_reg); > + if (!IS_ERR(info->sram_reg))
For both, actually, if you suspect that (xxxx)_reg may be NULL, then you should use IS_ERR_OR_NULL() instead...
> + if (info->sram_reg && regulator_is_enabled(info->sram_reg))
...otherwise, here it's useless to check if it's not NULL?
Regards, Angelo
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