The patch below does not apply to the 4.20-stable tree.
If someone wants it applied there, or to any other stable or longterm
tree, then please email the backport, including the original git commit
id to <stable@xxxxxxxxxxxxxxx>.
thanks,
greg k-h
------------------ original commit in Linus's tree ------------------
>From 227ad6d957898a88b1746e30234ece64d305f066 Mon Sep 17 00:00:00 2001
From: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Date: Sun, 30 Dec 2018 12:28:42 +0000
Subject: [PATCH] drm: Reorder set_property_atomic to avoid returning with an
active ww_ctx
Delay the drm_modeset_acquire_init() until after we check for an
allocation failure so that we can return immediately upon error without
having to unwind.
WARNING: lock held when returning to user space!
4.20.0+ #174 Not tainted
------------------------------------------------
syz-executor556/8153 is leaving the kernel with locks still held!
1 lock held by syz-executor556/8153:
#0: 000000005100c85c (crtc_ww_class_acquire){+.+.}, at:
set_property_atomic+0xb3/0x330 drivers/gpu/drm/drm_mode_object.c:462
Reported-by: syzbot+6ea337c427f5083ebdf2@xxxxxxxxxxxxxxxxxxxxxxxxx
Fixes: 144a7999d633 ("drm: Handle properties in the core for atomic drivers")
Signed-off-by: Chris Wilson <chris@xxxxxxxxxxxxxxxxxx>
Cc: Daniel Vetter <daniel.vetter@xxxxxxxx>
Cc: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Cc: Sean Paul <sean@xxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: <stable@xxxxxxxxxxxxxxx> # v4.14+
Reviewed-by: Maarten Lankhorst <maarten.lankhorst@xxxxxxxxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20181230122842.21917-1-chris@xxxxxxxxxxxxxxxxxx
diff --git a/drivers/gpu/drm/drm_mode_object.c b/drivers/gpu/drm/drm_mode_object.c
index bb1dd46496cd..a9005c1c2384 100644
--- a/drivers/gpu/drm/drm_mode_object.c
+++ b/drivers/gpu/drm/drm_mode_object.c
@@ -459,12 +459,13 @@ static int set_property_atomic(struct drm_mode_object *obj,
struct drm_modeset_acquire_ctx ctx;
int ret;
- drm_modeset_acquire_init(&ctx, 0);
-
state = drm_atomic_state_alloc(dev);
if (!state)
return -ENOMEM;
+
+ drm_modeset_acquire_init(&ctx, 0);
state->acquire_ctx = &ctx;
+
retry:
if (prop == state->dev->mode_config.dpms_property) {
if (obj->type != DRM_MODE_OBJECT_CONNECTOR) {
