From: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> stable inclusion from stable-v6.6.131 commit e23602eb0779760544314ed3905fa6a89a4e4070 category: bugfix bugzilla: https://atomgit.com/src-openeuler/kernel/issues/14312 CVE: CVE-2026-31566 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=... -------------------------------- [ Upstream commit 7150850146ebfa4ca998f653f264b8df6f7f85be ] amdgpu_amdkfd_submit_ib() submits a GPU job and gets a fence from amdgpu_ib_schedule(). This fence is used to wait for job completion. Currently, the code drops the fence reference using dma_fence_put() before calling dma_fence_wait(). If dma_fence_put() releases the last reference, the fence may be freed before dma_fence_wait() is called. This can lead to a use-after-free. Fix this by waiting on the fence first and releasing the reference only after dma_fence_wait() completes. Fixes the below: drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c:697 amdgpu_amdkfd_submit_ib() warn: passing freed memory 'f' (line 696) Fixes: 9ae55f030dc5 ("drm/amdgpu: Follow up change to previous drm scheduler change.") Cc: Felix Kuehling <Felix.Kuehling@amd.com> Cc: Dan Carpenter <dan.carpenter@linaro.org> Cc: Christian König <christian.koenig@amd.com> Cc: Alex Deucher <alexander.deucher@amd.com> Signed-off-by: Srinivasan Shanmugam <srinivasan.shanmugam@amd.com> Reviewed-by: Christian König <christian.koenig@amd.com> Signed-off-by: Alex Deucher <alexander.deucher@amd.com> (cherry picked from commit 8b9e5259adc385b61a6590a13b82ae0ac2bd3482) Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Jiacheng Yu <yujiacheng3@huawei.com> --- drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c index ce9602cb6e9c0..9d677bf10a01f 100644 --- a/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c +++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_amdkfd.c @@ -694,9 +694,9 @@ int amdgpu_amdkfd_submit_ib(struct amdgpu_device *adev, goto err_ib_sched; } - /* Drop the initial kref_init count (see drm_sched_main as example) */ - dma_fence_put(f); ret = dma_fence_wait(f, false); + /* Drop the returned fence reference after the wait completes */ + dma_fence_put(f); err_ib_sched: amdgpu_job_free(job); -- 2.43.0