[PATCH AUTOSEL 5.15 03/65] backlight: Propagate errors from get_brightness()

[PATCH AUTOSEL 5.15 03/65] backlight: Propagate errors from get_brightness()

[Sasha Levin]

From: Thomas Weißschuh <linux@weissschuh.net>

[ Upstream commit 563edf85ce18a90dd0a7b39e279a691d937205f6 ]

backlight.h documents "struct backlight_ops->get_brightness()" to return
a negative errno on failure.

So far these errors have not been handled in the backlight core.
This leads to negative values being exposed through sysfs although only
positive values are documented to be reported.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/backlight/backlight.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 537fe1b376ad7..4658cfb75aa28 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -292,10 +292,13 @@ static ssize_t actual_brightness_show(struct device *dev,
 	struct backlight_device *bd = to_backlight_device(dev);
 
 	mutex_lock(&bd->ops_lock);
-	if (bd->ops && bd->ops->get_brightness)
-		rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
-	else
+	if (bd->ops && bd->ops->get_brightness) {
+		rc = bd->ops->get_brightness(bd);
+		if (rc >= 0)
+			rc = sprintf(buf, "%d\n", rc);
+	} else {
 		rc = sprintf(buf, "%d\n", bd->props.brightness);
+	}
 	mutex_unlock(&bd->ops_lock);
 
 	return rc;
@@ -381,9 +384,18 @@ ATTRIBUTE_GROUPS(bl_device);
 void backlight_force_update(struct backlight_device *bd,
 			    enum backlight_update_reason reason)
 {
+	int brightness;
+
 	mutex_lock(&bd->ops_lock);
-	if (bd->ops && bd->ops->get_brightness)
-		bd->props.brightness = bd->ops->get_brightness(bd);
+	if (bd->ops && bd->ops->get_brightness) {
+		brightness = bd->ops->get_brightness(bd);
+		if (brightness >= 0)
+			bd->props.brightness = brightness;
+		else
+			dev_err(&bd->dev,
+				"Could not update brightness from device: %pe\n",
+				ERR_PTR(brightness));
+	}
 	mutex_unlock(&bd->ops_lock);
 	backlight_generate_event(bd, reason);
 }
-- 
2.33.0

[PATCH AUTOSEL 5.15 03/65] backlight: Propagate errors from get_brightness()

[Sasha Levin]

From: Thomas Weißschuh <linux@weissschuh.net>

[ Upstream commit 563edf85ce18a90dd0a7b39e279a691d937205f6 ]

backlight.h documents "struct backlight_ops->get_brightness()" to return
a negative errno on failure.

So far these errors have not been handled in the backlight core.
This leads to negative values being exposed through sysfs although only
positive values are documented to be reported.

Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Reviewed-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/backlight/backlight.c | 22 +++++++++++++++++-----
 1 file changed, 17 insertions(+), 5 deletions(-)

diff --git a/drivers/video/backlight/backlight.c b/drivers/video/backlight/backlight.c
index 537fe1b376ad7..4658cfb75aa28 100644
--- a/drivers/video/backlight/backlight.c
+++ b/drivers/video/backlight/backlight.c
@@ -292,10 +292,13 @@ static ssize_t actual_brightness_show(struct device *dev,
 	struct backlight_device *bd = to_backlight_device(dev);
 
 	mutex_lock(&bd->ops_lock);
-	if (bd->ops && bd->ops->get_brightness)
-		rc = sprintf(buf, "%d\n", bd->ops->get_brightness(bd));
-	else
+	if (bd->ops && bd->ops->get_brightness) {
+		rc = bd->ops->get_brightness(bd);
+		if (rc >= 0)
+			rc = sprintf(buf, "%d\n", rc);
+	} else {
 		rc = sprintf(buf, "%d\n", bd->props.brightness);
+	}
 	mutex_unlock(&bd->ops_lock);
 
 	return rc;
@@ -381,9 +384,18 @@ ATTRIBUTE_GROUPS(bl_device);
 void backlight_force_update(struct backlight_device *bd,
 			    enum backlight_update_reason reason)
 {
+	int brightness;
+
 	mutex_lock(&bd->ops_lock);
-	if (bd->ops && bd->ops->get_brightness)
-		bd->props.brightness = bd->ops->get_brightness(bd);
+	if (bd->ops && bd->ops->get_brightness) {
+		brightness = bd->ops->get_brightness(bd);
+		if (brightness >= 0)
+			bd->props.brightness = brightness;
+		else
+			dev_err(&bd->dev,
+				"Could not update brightness from device: %pe\n",
+				ERR_PTR(brightness));
+	}
 	mutex_unlock(&bd->ops_lock);
 	backlight_generate_event(bd, reason);
 }
-- 
2.33.0

[PATCH AUTOSEL 5.15 07/65] fbdev: fbmem: Fix double free of 'fb_info->pixmap.addr'

[Sasha Levin]

From: Zheyu Ma <zheyuma97@gmail.com>

[ Upstream commit 2c0c19b681d5a331b53aab0d170f72a87c7bff12 ]

savagefb and some other drivers call kfree to free 'info->pixmap.addr'
even after calling unregister_framebuffer, which may cause double free.

Fix this by setting 'fb_info->pixmap.addr' to NULL after kfree in
unregister_framebuffer.

The following log reveals it:

[   37.318872] BUG: KASAN: double-free or invalid-free in kfree+0x13e/0x290
[   37.319369]
[   37.320803] Call Trace:
[   37.320992]  dump_stack_lvl+0xa8/0xd1
[   37.321274]  print_address_description+0x87/0x3b0
[   37.321632]  ? kfree+0x13e/0x290
[   37.321879]  ? kfree+0x13e/0x290
[   37.322126]  ? kfree+0x13e/0x290
[   37.322374]  kasan_report_invalid_free+0x58/0x90
[   37.322724]  ____kasan_slab_free+0x123/0x140
[   37.323049]  __kasan_slab_free+0x11/0x20
[   37.323347]  slab_free_freelist_hook+0x81/0x150
[   37.323689]  ? savagefb_remove+0xa1/0xc0 [savagefb]
[   37.324066]  kfree+0x13e/0x290
[   37.324304]  savagefb_remove+0xa1/0xc0 [savagefb]
[   37.324655]  pci_device_remove+0xa9/0x250
[   37.324959]  ? pci_device_probe+0x7d0/0x7d0
[   37.325273]  device_release_driver_internal+0x4f7/0x7a0
[   37.325666]  driver_detach+0x1e8/0x2c0
[   37.325952]  bus_remove_driver+0x134/0x290
[   37.326262]  ? sysfs_remove_groups+0x97/0xb0
[   37.326584]  driver_unregister+0x77/0xa0
[   37.326883]  pci_unregister_driver+0x2c/0x1c0
[   37.336124]
[   37.336245] Allocated by task 5465:
[   37.336507]  ____kasan_kmalloc+0xb5/0xe0
[   37.336801]  __kasan_kmalloc+0x9/0x10
[   37.337069]  kmem_cache_alloc_trace+0x12b/0x220
[   37.337405]  register_framebuffer+0x3f3/0xa00
[   37.337731]  foo_register_framebuffer+0x3b/0x50 [savagefb]
[   37.338136]
[   37.338255] Freed by task 5475:
[   37.338492]  kasan_set_track+0x3d/0x70
[   37.338774]  kasan_set_free_info+0x23/0x40
[   37.339081]  ____kasan_slab_free+0x10b/0x140
[   37.339399]  __kasan_slab_free+0x11/0x20
[   37.339694]  slab_free_freelist_hook+0x81/0x150
[   37.340034]  kfree+0x13e/0x290
[   37.340267]  do_unregister_framebuffer+0x21c/0x3d0
[   37.340624]  unregister_framebuffer+0x23/0x40
[   37.340950]  savagefb_remove+0x45/0xc0 [savagefb]
[   37.341302]  pci_device_remove+0xa9/0x250
[   37.341603]  device_release_driver_internal+0x4f7/0x7a0
[   37.341990]  driver_detach+0x1e8/0x2c0
[   37.342272]  bus_remove_driver+0x134/0x290
[   37.342577]  driver_unregister+0x77/0xa0
[   37.342873]  pci_unregister_driver+0x2c/0x1c0
[   37.343196]  cleanup_module+0x15/0x1c [savagefb]
[   37.343543]  __se_sys_delete_module+0x398/0x490
[   37.343881]  __x64_sys_delete_module+0x56/0x60
[   37.344221]  do_syscall_64+0x4d/0xc0
[   37.344492]  entry_SYSCALL_64_after_hwframe+0x44/0xae

Signed-off-by: Zheyu Ma <zheyuma97@gmail.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/1633848148-29747-1-git-send-email-zheyuma97@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/video/fbdev/core/fbmem.c | 5 ++++-
 1 file changed, 4 insertions(+), 1 deletion(-)

diff --git a/drivers/video/fbdev/core/fbmem.c b/drivers/video/fbdev/core/fbmem.c
index 7420d2c16e47e..826175ad88a2f 100644
--- a/drivers/video/fbdev/core/fbmem.c
+++ b/drivers/video/fbdev/core/fbmem.c
@@ -1702,8 +1702,11 @@ static void do_unregister_framebuffer(struct fb_info *fb_info)
 {
 	unlink_framebuffer(fb_info);
 	if (fb_info->pixmap.addr &&
-	    (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT))
+	    (fb_info->pixmap.flags & FB_PIXMAP_DEFAULT)) {
 		kfree(fb_info->pixmap.addr);
+		fb_info->pixmap.addr = NULL;
+	}
+
 	fb_destroy_modelist(&fb_info->modelist);
 	registered_fb[fb_info->node] = NULL;
 	num_registered_fb--;
-- 
2.33.0

[PATCH AUTOSEL 5.15 08/65] drm/virtio: fix the missed drm_gem_object_put() in virtio_gpu_user_framebuffer_create()

[Sasha Levin]

From: Jing Xiangfeng <jingxiangfeng@huawei.com>

[ Upstream commit a63f393dd7e1ebee707c9dee1d197fdc33d6486b ]

virtio_gpu_user_framebuffer_create() misses to call drm_gem_object_put()
in an error path. Add the missed function call to fix it.

Signed-off-by: Jing Xiangfeng <jingxiangfeng@huawei.com>
Link: http://patchwork.freedesktop.org/patch/msgid/1633770560-11658-1-git-send-email-jingxiangfeng@huawei.com
Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/gpu/drm/virtio/virtgpu_display.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/virtio/virtgpu_display.c b/drivers/gpu/drm/virtio/virtgpu_display.c
index a6caebd4a0dd6..5b00310ac4cd4 100644
--- a/drivers/gpu/drm/virtio/virtgpu_display.c
+++ b/drivers/gpu/drm/virtio/virtgpu_display.c
@@ -308,8 +308,10 @@ virtio_gpu_user_framebuffer_create(struct drm_device *dev,
 		return ERR_PTR(-EINVAL);
 
 	virtio_gpu_fb = kzalloc(sizeof(*virtio_gpu_fb), GFP_KERNEL);
-	if (virtio_gpu_fb == NULL)
+	if (virtio_gpu_fb == NULL) {
+		drm_gem_object_put(obj);
 		return ERR_PTR(-ENOMEM);
+	}
 
 	ret = virtio_gpu_framebuffer_init(dev, virtio_gpu_fb, mode_cmd, obj);
 	if (ret) {
-- 
2.33.0