Messages in this thread Patch in this message | | | Subject | Re: [PATCH] x86: eas should not be NULL when it is referenced | From | "Liang, Kan" <> | Date | Thu, 24 Jun 2021 15:03:50 -0400 |
| |
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; -- 2.7.4 Thanks, Kan
| |