[PATCH] fb: omap2: dsi: do not copy isr table

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.

Suggested-by: [email protected]
Signed-off-by: Andreas Kemnade <[email protected]>
---
Fix for drm variant fo driver:
https://lore.kernel.org/lkml/[email protected]/
---
 drivers/video/fbdev/omap2/omapfb/dss/dsi.c | 9 +--------
 1 file changed, 1 insertion(+), 8 deletions(-)

diff --git a/drivers/video/fbdev/omap2/omapfb/dss/dsi.c b/drivers/video/fbdev/omap2/omapfb/dss/dsi.c
index 330d9fb7d2b0..d98db01fdd39 100644
--- a/drivers/video/fbdev/omap2/omapfb/dss/dsi.c
+++ b/drivers/video/fbdev/omap2/omapfb/dss/dsi.c
@@ -326,8 +326,6 @@ struct dsi_data {
 
 	spinlock_t irq_lock;
 	struct dsi_isr_tables isr_tables;
-	/* space for a copy used by the interrupt handler */
-	struct dsi_isr_tables isr_tables_copy;
 
 	int update_channel;
 #ifdef DSI_PERF_MEASURE
@@ -838,15 +836,10 @@ 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(dsidev, irqstatus, vcstatus, ciostatus);
 
 	dsi_collect_irq_stats(dsidev, irqstatus, vcstatus, ciostatus);

---
base-commit: dc59e4fea9d83f03bad6bddf3fa2e52491777482
change-id: 20260702-fbomap-uaf-fix-167ed8a8bf38

Best regards,
--  
Andreas Kemnade <[email protected]>