linux-kernel - [PATCH] drm/sched: Fix UB pointer dereference

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20240827074521.12828-2-pstanner@redhat.com>
Date: Tue, 27 Aug 2024 09:45:22 +0200
From: Philipp Stanner <pstanner@...hat.com>
To: Luben Tuikov <ltuikov89@...il.com>,
	Matthew Brost <matthew.brost@...el.com>,
	Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
	Maxime Ripard <mripard@...nel.org>,
	Thomas Zimmermann <tzimmermann@...e.de>,
	David Airlie <airlied@...il.com>,
	Daniel Vetter <daniel@...ll.ch>,
	Christian König <christian.koenig@....com>
Cc: dri-devel@...ts.freedesktop.org,
	linux-kernel@...r.kernel.org,
	Philipp Stanner <pstanner@...hat.com>,
	stable@...r.kernel.org,
	Danilo Krummrich <dakr@...hat.com>
Subject: [PATCH] drm/sched: Fix UB pointer dereference

In drm_sched_job_init(), commit 56e449603f0a ("drm/sched: Convert the
GPU scheduler to variable number of run-queues") implemented a call to
drm_err(), which uses the job's scheduler pointer as a parameter.
job->sched, however, is not yet valid as it gets set by
drm_sched_job_arm(), which is always called after drm_sched_job_init().

Since the scheduler code has no control over how the API-User has
allocated or set 'job', the pointer's dereference is undefined behavior.

Fix the UB by replacing drm_err() with pr_err().

Cc: <stable@...r.kernel.org>	# 6.7+
Fixes: 56e449603f0a ("drm/sched: Convert the GPU scheduler to variable number of run-queues")
Reported-by: Danilo Krummrich <dakr@...hat.com>
Closes: https://lore.kernel.org/lkml/20231108022716.15250-1-dakr@redhat.com/
Signed-off-by: Philipp Stanner <pstanner@...hat.com>
---
 drivers/gpu/drm/scheduler/sched_main.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/scheduler/sched_main.c b/drivers/gpu/drm/scheduler/sched_main.c
index 7e90c9f95611..356c30fa24a8 100644
--- a/drivers/gpu/drm/scheduler/sched_main.c
+++ b/drivers/gpu/drm/scheduler/sched_main.c
@@ -797,7 +797,7 @@ int drm_sched_job_init(struct drm_sched_job *job,
 		 * or worse--a blank screen--leave a trail in the
 		 * logs, so this can be debugged easier.
 		 */
-		drm_err(job->sched, "%s: entity has no rq!\n", __func__);
+		pr_err("*ERROR* %s: entity has no rq!\n", __func__);
 		return -ENOENT;
 	}
 
-- 
2.46.0