[PATCH] drm/omap: dsi: do not copy isr table

[Andreas Kemnade]

To te able to unregister stuff from isrs, the corresponding table was
copied.  Nobody seems to unregister stuff that way, so it does not help.
But there are stack-allocated objects passed to these isrs giving chances
of UAF of these objects if irqs are unregistered while they are handled,
so better do not copy that table.

Fixes: 4ae2ddddf44cd ("OMAP: DSS2: DSI: Add ISR support")
Signed-off-by: Andreas Kemnade <andreas@xxxxxxxxxxxx>
---
If this gets backported, it should be re-checked that
no isr unregisters itself in older kernel versions`.
---
 drivers/gpu/drm/omapdrm/dss/dsi.c | 7 +------
 1 file changed, 1 insertion(+), 6 deletions(-)

diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index 27fe7bca9e2c..70cfb779d6ae 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.c
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.c
@@ -455,15 +455,10 @@ static irqreturn_t omap_dsi_irq_handler(int irq, void *arg)
 		timer_delete(&dsi->te_timer);
 #endif
 
-	/* make a copy and unlock, so that isrs can unregister
-	 * themselves */
-	memcpy(&dsi->isr_tables_copy, &dsi->isr_tables,
-		sizeof(dsi->isr_tables));
+	dsi_handle_isrs(&dsi->isr_tables, irqstatus, vcstatus, ciostatus);
 
 	spin_unlock(&dsi->irq_lock);
 
-	dsi_handle_isrs(&dsi->isr_tables_copy, irqstatus, vcstatus, ciostatus);
-
 	dsi_handle_irq_errors(dsi, irqstatus, vcstatus, ciostatus);
 
 	dsi_collect_irq_stats(dsi, irqstatus, vcstatus, ciostatus);

---
base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
change-id: 20260629-dsi-uaf-71bfbf3553bf

Best regards,
--  
Andreas Kemnade <andreas@xxxxxxxxxxxx>