From: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Date: Fri, 6 Dec 2024 12:17:45 +0000 (+0100)
Subject: drm/amdgpu: don't access invalid sched
X-Git-Tag: v6.1.122~34
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=65501a4fd84ecdc0af863dbb37759242aab9f2dd;p=thirdparty%2Fkernel%2Fstable.git

drm/amdgpu: don't access invalid sched

[ Upstream commit a93b1020eb9386d7da11608477121b10079c076a ]

Since 2320c9e6a768 ("drm/sched: memset() 'job' in drm_sched_job_init()")
accessing job->base.sched can produce unexpected results as the initialisation
of (*job)->base.sched done in amdgpu_job_alloc is overwritten by the
memset.

This commit fixes an issue when a CS would fail validation and would
be rejected after job->num_ibs is incremented. In this case,
amdgpu_ib_free(ring->adev, ...) will be called, which would crash the
machine because the ring value is bogus.

To fix this, pass a NULL pointer to amdgpu_ib_free(): we can do this
because the device is actually not used in this function.

The next commit will remove the ring argument completely.

Fixes: 2320c9e6a768 ("drm/sched: memset() 'job' in drm_sched_job_init()")
Signed-off-by: Pierre-Eric Pelloux-Prayer <pierre-eric.pelloux-prayer@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>
(cherry picked from commit 2ae520cb12831d264ceb97c61f72c59d33c0dbd7)
Signed-off-by: Sasha Levin <sashal@kernel.org>
---

diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
index f34bc9bb7045a..7f1e92110dd1f 100644
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_job.c
@@ -150,7 +150,6 @@ void amdgpu_job_set_resources(struct amdgpu_job *job, struct amdgpu_bo *gds,
 
 void amdgpu_job_free_resources(struct amdgpu_job *job)
 {
-	struct amdgpu_ring *ring = to_amdgpu_ring(job->base.sched);
 	struct dma_fence *f;
 	unsigned i;
 
@@ -163,7 +162,7 @@ void amdgpu_job_free_resources(struct amdgpu_job *job)
 		f = NULL;
 
 	for (i = 0; i < job->num_ibs; ++i)
-		amdgpu_ib_free(ring->adev, &job->ibs[i], f);
+		amdgpu_ib_free(NULL, &job->ibs[i], f);
 }
 
 static void amdgpu_job_free_cb(struct drm_sched_job *s_job)