2024-02-19 20:22:07

by Alvin Šipraga

Subject: [PATCH v2] drm/bridge: adv7511: fix crash on irq during probe

From: Mads Bligaard Nielsen <[email protected]>

Moved IRQ registration down to end of adv7511_probe().

If an IRQ already is pending during adv7511_probe
(before adv7511_cec_init) then cec_received_msg_ts
could crash using uninitialized data:

Unable to handle kernel read from unreadable memory at virtual address 00000000000003d5
Internal error: Oops: 96000004 [#1] PREEMPT_RT SMP
Call trace:
cec_received_msg_ts+0x48/0x990 [cec]
adv7511_cec_irq_process+0x1cc/0x308 [adv7511]
adv7511_irq_process+0xd8/0x120 [adv7511]
adv7511_irq_handler+0x1c/0x30 [adv7511]
irq_thread_fn+0x30/0xa0
irq_thread+0x14c/0x238
kthread+0x190/0x1a8

Fixes: 3b1b975003e4 ("drm: adv7511/33: add HDMI CEC support")
Signed-off-by: Mads Bligaard Nielsen <[email protected]>
Signed-off-by: Alvin Šipraga <[email protected]>
---
Changes in v2:
- rebase on latest drm-misc-fixes
- no other changes
- RESEND
- Link to v1: https://lore.kernel.org/r/20231014-adv7511-cec-irq-crash-fix-v1-1-3389486c8373@bang-olufsen.dk
---
drivers/gpu/drm/bridge/adv7511/adv7511_drv.c | 22 +++++++++++-----------
1 file changed, 11 insertions(+), 11 deletions(-)

diff --git a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
index 8be235144f6d..6fc292393c67 100644
--- a/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
+++ b/drivers/gpu/drm/bridge/adv7511/adv7511_drv.c
@@ -1277,17 +1277,6 @@ static int adv7511_probe(struct i2c_client *i2c)

INIT_WORK(&adv7511->hpd_work, adv7511_hpd_work);

- if (i2c->irq) {
- init_waitqueue_head(&adv7511->wq);
-
- ret = devm_request_threaded_irq(dev, i2c->irq, NULL,
- adv7511_irq_handler,
- IRQF_ONESHOT, dev_name(dev),
- adv7511);
- if (ret)
- goto err_unregister_cec;
- }
-
adv7511_power_off(adv7511);

i2c_set_clientdata(i2c, adv7511);
@@ -1311,6 +1300,17 @@ static int adv7511_probe(struct i2c_client *i2c)

adv7511_audio_init(dev, adv7511);

+ if (i2c->irq) {
+ init_waitqueue_head(&adv7511->wq);
+
+ ret = devm_request_threaded_irq(dev, i2c->irq, NULL,
+ adv7511_irq_handler,
+ IRQF_ONESHOT, dev_name(dev),
+ adv7511);
+ if (ret)
+ goto err_unregister_audio;
+ }
+
if (adv7511->info->has_dsi) {
ret = adv7533_attach_dsi(adv7511);
if (ret)

---
base-commit: 335126937753844d36036984e96a8f343538a778
change-id: 20231014-adv7511-cec-irq-crash-fix-6fdd9093dc7a

2024-02-21 15:33:32

by Robert Foss

Subject: Re: [PATCH v2] drm/bridge: adv7511: fix crash on irq during probe

On Mon, 19 Feb 2024 21:21:47 +0100, Alvin Šipraga wrote:
> From: Mads Bligaard Nielsen <[email protected]>
>
> Moved IRQ registration down to end of adv7511_probe().
>
> If an IRQ already is pending during adv7511_probe
> (before adv7511_cec_init) then cec_received_msg_ts
> could crash using uninitialized data:
>
> [...]

Applied, thanks!

[1/1] drm/bridge: adv7511: fix crash on irq during probe
https://cgit.freedesktop.org/drm/drm-misc/commit/?id=aeedaee5ef54



Rob