From 9a4e7849b5e4e8742d71fa90fbf0722dd0710a56 Mon Sep 17 00:00:00 2001 From: Russell King Date: Tue, 26 Jan 2016 14:49:22 +0000 Subject: component: fix crash on x86_64 with hda audio drivers Maarten reports that the addition of releasing match data to the component helper results in a general protection fault on x86_64. This is caused by the devm resources being freed in reverse order to their allocation, which caused a use-after-free of the match array. Switch the match array to be a more conventional kmalloc/kfree() affair, explicitly freeing it along with the parent match data structure. Reported-by: Maarten Lankhorst Fixes: ce657b1cddf1 ("component: add support for releasing match data") Signed-off-by: Russell King --- drivers/base/component.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'drivers/base/component.c') diff --git a/drivers/base/component.c b/drivers/base/component.c index 89f5cf68d80a..05cd26c02449 100644 --- a/drivers/base/component.c +++ b/drivers/base/component.c @@ -206,6 +206,8 @@ static void component_match_release(struct device *master, if (mc->release) mc->release(master, mc->data); } + + kfree(match->compare); } static void devm_component_match_release(struct device *dev, void *res) @@ -221,14 +223,14 @@ static int component_match_realloc(struct device *dev, if (match->alloc == num) return 0; - new = devm_kmalloc_array(dev, num, sizeof(*new), GFP_KERNEL); + new = kmalloc_array(num, sizeof(*new), GFP_KERNEL); if (!new) return -ENOMEM; if (match->compare) { memcpy(new, match->compare, sizeof(*new) * min(match->num, num)); - devm_kfree(dev, match->compare); + kfree(match->compare); } match->compare = new; match->alloc = num; -- cgit v1.2.3-59-g8ed1b