Messages in this thread | | | Subject | Re: [PATCH] x86: eas should not be NULL when it is referenced | From | "Liang, Kan" <> | Date | Thu, 24 Jun 2021 15:06:02 -0400 |
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Oops, forgot to add Peter.
On 6/24/2021 3:03 PM, Liang, Kan wrote: > > Hi Shengxian, > > Thanks for the patch. > > On 6/24/2021 3:04 AM, 13145886936@163.com wrote: >> From: gushengxian <gushengxian@yulong.com> >> >> "eas" should not be NULL when it is referenced. >> > > I think the NULL pointer dereference of eas should not happen, because > die is -1 if eas is NULL. But the whole error handling path looks fragile. > > We already fixed one issue caused by it in commit ID f797f05d917f > ("perf/x86/intel/uncore: Fix for iio mapping on Skylake Server") > https://lore.kernel.org/lkml/160149233331.7002.10919231011379055356.tip-bot2@tip-bot2/ > > > Maybe something as below? > > From 3de81ba3b04262ef3346297d82f6c4ffb4af7029 Mon Sep 17 00:00:00 2001 > From: Kan Liang <kan.liang@linux.intel.com> > Date: Thu, 24 Jun 2021 11:17:57 -0700 > Subject: [PATCH] perf/x86/intel/uncore: Clean up error handling path of > iio mapping > > The error handling path of iio mapping looks fragile. We already fixed > one issue caused by it, commit ID f797f05d917f ("perf/x86/intel/uncore: > Fix for iio mapping on Skylake Server"). Clean up the error handling > path and make the code robust. > > Reported-by: gushengxian <gushengxian@yulong.com> > Signed-off-by: Kan Liang <kan.liang@linux.intel.com> > --- > arch/x86/events/intel/uncore_snbep.c | 6 ++++-- > 1 file changed, 4 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/events/intel/uncore_snbep.c > b/arch/x86/events/intel/uncore_snbep.c > index 7622762..6d4a5a9 100644 > --- a/arch/x86/events/intel/uncore_snbep.c > +++ b/arch/x86/events/intel/uncore_snbep.c > @@ -3802,11 +3802,11 @@ pmu_iio_set_mapping(struct intel_uncore_type > *type, struct attribute_group *ag) > /* One more for NULL. */ > attrs = kcalloc((uncore_max_dies() + 1), sizeof(*attrs), GFP_KERNEL); > if (!attrs) > - goto err; > + goto clear_topology; > > eas = kcalloc(uncore_max_dies(), sizeof(*eas), GFP_KERNEL); > if (!eas) > - goto err; > + goto clear_attrs; > > for (die = 0; die < uncore_max_dies(); die++) { > sprintf(buf, "die%ld", die); > @@ -3827,7 +3827,9 @@ pmu_iio_set_mapping(struct intel_uncore_type > *type, struct attribute_group *ag) > for (; die >= 0; die--) > kfree(eas[die].attr.attr.name); > kfree(eas); > +clear_attrs: > kfree(attrs); > +clear_topology: > kfree(type->topology); > clear_attr_update: > type->attr_update = NULL;
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