6.1-stable review patch. If anyone has any objections, please let me know.
------------------
From: Andreas Kemnade <andreas@kemnade.info>
[ Upstream commit 97c03b32b28a9f7f13f768f2b06e1eaafe850e66 ]
To be 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@kemnade.info>
Link: https://patch.msgid.link/20260702-dsi-uaf-v2-1-dbb4aa0f0b8e@kemnade.info (local)
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/omapdrm/dss/dsi.c | 7 +------
drivers/gpu/drm/omapdrm/dss/dsi.h | 2 --
2 files changed, 1 insertion(+), 8 deletions(-)
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.c b/drivers/gpu/drm/omapdrm/dss/dsi.c
index 4c1084eb01759..708520e5d4525 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)
del_timer(&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);
diff --git a/drivers/gpu/drm/omapdrm/dss/dsi.h b/drivers/gpu/drm/omapdrm/dss/dsi.h
index 601707c0ecc4e..2b25247ea8935 100644
--- a/drivers/gpu/drm/omapdrm/dss/dsi.h
+++ b/drivers/gpu/drm/omapdrm/dss/dsi.h
@@ -379,8 +379,6 @@ 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_vc;
#ifdef DSI_PERF_MEASURE--
2.53.0