Unverified Commit 26b4309a authored by Xiao Kan's avatar Xiao Kan Committed by Maxime Ripard
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drm: Account property blob allocations to memcg 



DRM_IOCTL_MODE_CREATEPROPBLOB allows userspace to allocate arbitrary-sized
property blobs backed by kernel memory.

Currently, the blob data allocation is not accounted to the allocating
process's memory cgroup, allowing unprivileged users to trigger unbounded
kernel memory consumption and potentially cause system-wide OOM.

Mark the property blob data allocation with GFP_KERNEL_ACCOUNT so that the memory
is properly charged to the caller's memcg. This ensures existing cgroup
memory limits apply and prevents uncontrolled kernel memory growth without
introducing additional policy or per-file limits.

Signed-off-by: default avatarXiao Kan <814091656@qq.com>
Signed-off-by: default avatarXiao Kan <xiao.kan@samsung.com>
Link: https://patch.msgid.link/tencent_D12AA2DEDE6F359E1AF59405242FB7A5FD05@qq.com


Signed-off-by: default avatarMaxime Ripard <mripard@kernel.org>
parent 64aa8b3a

drivers/gpu/drm/drm_property.c

+1 −1
Original line number Diff line number Diff line
@@ -562,7 +562,7 @@ drm_property_create_blob(struct drm_device *dev, size_t length, 
	if (!length || length > INT_MAX - sizeof(struct drm_property_blob))

		return ERR_PTR(-EINVAL);



	blob = kvzalloc(sizeof(struct drm_property_blob)+length, GFP_KERNEL);

	blob = kvzalloc(sizeof(struct drm_property_blob) + length, GFP_KERNEL_ACCOUNT);

	if (!blob)

		return ERR_PTR(-ENOMEM);