[PATCH 5.4 001/102] drm/i915: Fix pid leak with banned clients

Greg Kroah-Hartman
2020-01-24T09:33:22Z

From: Tvrtko Ursulin <tvrtko.ursulin@intel.com>

commit f0f3a6cecf3b98990985cd42f7bf5a0313894822 upstream.

Get_pid_task() needs to be paired with a put_pid or we leak a pid
reference every time a banned client tries to create a context.

v2:
* task_pid_nr helper exists! (Chris)

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Fixes: b083a0870c79 ("drm/i915: Add per client max context ban limit")
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Link: https://patchwork.freedesktop.org/patch/msgid/20191217170933.8108-1-tvrtko.ursulin@linux.intel.com
(cherry picked from commit ba16a48af797db124ac100417f9229b1650ce1fb)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
drivers/gpu/drm/i915/gem/i915_gem_context.c | 3 +--
1 file changed, 1 insertion(+), 2 deletions(-)

--- a/drivers/gpu/drm/i915/gem/i915_gem_context.c
+++ b/drivers/gpu/drm/i915/gem/i915_gem_context.c
@@ -2094,8 +2094,7 @@ int i915_gem_context_create_ioctl(struct
ext_data.fpriv = file->driver_priv;
if (client_is_banned(ext_data.fpriv)) {
DRM_DEBUG("client %s[%d] banned from creating ctx\n",
- current->comm,
- pid_nr(get_task_pid(current, PIDTYPE_PID)));
+ current->comm, task_pid_nr(current));
return -EIO;
}