From: Nathan Chancellor nathan@kernel.org
[ Upstream commit 58606220a2f1407a7516c547f09a1ba7b4350a73 ]
When an attribute group is created with sysfs_create_group(), the ->sysfs_ops() callback is set to kobj_sysfs_ops, which sets the ->show() callback to kobj_attr_show(). kobj_attr_show() uses container_of() to get the ->show() callback from the attribute it was passed, meaning the ->show() callback needs to be the same type as the ->show() callback in 'struct kobj_attribute'.
However, show_dynamic_id() has the type of the ->show() callback in 'struct device_attribute', which causes a CFI violation when opening the 'id' sysfs node under drm/card0/metrics. This happens to work because the layout of 'struct kobj_attribute' and 'struct device_attribute' are the same, so the container_of() cast happens to allow the ->show() callback to still work.
Change the type of show_dynamic_id() to match the ->show() callback in 'struct kobj_attributes' and update the type of sysfs_metric_id to match, which resolves the CFI violation.
Fixes: f89823c21224 ("drm/i915/perf: Implement I915_PERF_ADD/REMOVE_CONFIG interface") Signed-off-by: Nathan Chancellor nathan@kernel.org Reviewed-by: Kees Cook keescook@chromium.org Reviewed-by: Sami Tolvanen samitolvanen@google.com Signed-off-by: Tvrtko Ursulin tvrtko.ursulin@intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20220513075136.1027007-1-tvrtk... (cherry picked from commit 18fb42db05a0b93ab5dd5eab5315e50eaa3ca620) Signed-off-by: Jani Nikula jani.nikula@intel.com Signed-off-by: Sasha Levin sashal@kernel.org --- drivers/gpu/drm/i915/i915_perf.c | 4 ++-- drivers/gpu/drm/i915/i915_perf_types.h | 2 +- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/gpu/drm/i915/i915_perf.c b/drivers/gpu/drm/i915/i915_perf.c index e27f3b7cf094..abcf7e66fe6a 100644 --- a/drivers/gpu/drm/i915/i915_perf.c +++ b/drivers/gpu/drm/i915/i915_perf.c @@ -4008,8 +4008,8 @@ static struct i915_oa_reg *alloc_oa_regs(struct i915_perf *perf, return ERR_PTR(err); }
-static ssize_t show_dynamic_id(struct device *dev, - struct device_attribute *attr, +static ssize_t show_dynamic_id(struct kobject *kobj, + struct kobj_attribute *attr, char *buf) { struct i915_oa_config *oa_config = diff --git a/drivers/gpu/drm/i915/i915_perf_types.h b/drivers/gpu/drm/i915/i915_perf_types.h index aa14354a5120..f682c7a6474d 100644 --- a/drivers/gpu/drm/i915/i915_perf_types.h +++ b/drivers/gpu/drm/i915/i915_perf_types.h @@ -55,7 +55,7 @@ struct i915_oa_config {
struct attribute_group sysfs_metric; struct attribute *attrs[2]; - struct device_attribute sysfs_metric_id; + struct kobj_attribute sysfs_metric_id;
struct kref ref; struct rcu_head rcu;