This is a note to let you know that I've just added the patch titled
drm/amdgpu: Fix init ordering in amdgpu_vram_mgr_init()
to the 7.2-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
drm-amdgpu-fix-init-ordering-in-amdgpu_vram_mgr_init.patch
and it can be found in the queue-7.2 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From e773798e14ac0aea54ca9676083b91f445e5bc59 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Thomas=20Hellstr=C3=B6m?= <[email protected]>
Date: Sat, 25 Jul 2026 12:00:31 +0200
Subject: drm/amdgpu: Fix init ordering in amdgpu_vram_mgr_init()
MIME-Version: 1.0
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From: Thomas Hellström <[email protected]>
commit e773798e14ac0aea54ca9676083b91f445e5bc59 upstream.
drmm_cgroup_register_region() is called before INIT_LIST_HEAD() and
gpu_buddy_init() in amdgpu_vram_mgr_init(). If it fails, the function
returns early and bypasses those initializations.
Since adev->mman.initialized is set to true before amdgpu_vram_mgr_init()
is called, a failure triggers amdgpu_ttm_fini(), which calls
amdgpu_vram_mgr_fini(), which then:
- Calls list_for_each_entry_safe() on reservations_pending and
reserved_pages, whose list_head::next pointers are zero-initialized
(NULL). The loop does not recognize them as empty and dereferences NULL.
- Calls gpu_buddy_fini(), which iterates free_trees[] unconditionally
via for_each_free_tree(). Since mm->free_trees is NULL
(never allocated), this dereferences NULL.
Both result in a kernel panic on the module load error path.
Fix by moving drmm_cgroup_register_region() to after the list and buddy
allocator are fully initialized, so the teardown path is safe to run.
Reported-by: Sashiko-bot <[email protected]>
Closes:
https://sashiko.dev/#/patchset/[email protected]?part=4
Fixes: 2b624a2c1865 ("drm/ttm: Handle cgroup based eviction in TTM")
Cc: Friedrich Vock <[email protected]>
Cc: Maarten Lankhorst <[email protected]>
Cc: Tejun Heo <[email protected]>
Cc: Maxime Ripard <[email protected]>
Cc: Christian König <[email protected]>
Cc: Alex Deucher <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected] # v6.14+
Assisted-by: GitHub_Copilot:claude-sonnet-4.6
Signed-off-by: Thomas Hellström <[email protected]>
Reviewed-by: Arunpravin Paneer Selvam <[email protected]>
Reviewed-By: Maarten Lankhorst <[email protected]>
Tested-by: Thadeu Lima de Souza Cascardo <[email protected]>
Link:
https://patch.msgid.link/[email protected]
Acked-by: Christian König <[email protected]>
Signed-off-by: Maarten Lankhorst <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c | 7 ++++---
1 file changed, 4 insertions(+), 3 deletions(-)
--- a/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
+++ b/drivers/gpu/drm/amd/amdgpu/amdgpu_vram_mgr.c
@@ -918,9 +918,6 @@ int amdgpu_vram_mgr_init(struct amdgpu_d
struct ttm_resource_manager *man = &mgr->manager;
int err;
- man->cg = drmm_cgroup_register_region(adev_to_drm(adev), "vram",
adev->gmc.real_vram_size);
- if (IS_ERR(man->cg))
- return PTR_ERR(man->cg);
ttm_resource_manager_init(man, &adev->mman.bdev,
adev->gmc.real_vram_size);
@@ -935,6 +932,10 @@ int amdgpu_vram_mgr_init(struct amdgpu_d
if (err)
return err;
+ man->cg = drmm_cgroup_register_region(adev_to_drm(adev), "vram",
adev->gmc.real_vram_size);
+ if (IS_ERR(man->cg))
+ return PTR_ERR(man->cg);
+
ttm_set_driver_manager(&adev->mman.bdev, TTM_PL_VRAM, &mgr->manager);
ttm_resource_manager_set_used(man, true);
return 0;
Patches currently in stable-queue which might be from
[email protected] are
queue-7.2/drm-amdgpu-fix-init-ordering-in-amdgpu_vram_mgr_init.patch
