[PATCH v6 mm-new 04/10] bpf: mark vma->vm_mm as trusted
From: Yafang Shao <hidden>
Date: 2025-08-26 07:20:59
Also in:
bpf, linux-mm
Subsystem:
bpf [core], bpf [general] (safe dynamic programs and tools), the rest · Maintainers:
Alexei Starovoitov, Daniel Borkmann, Andrii Nakryiko, Eduard Zingerman, Kumar Kartikeya Dwivedi, Linus Torvalds
Every VMA must have an associated mm_struct, and it is safe to access outside of RCU. Thus, we can mark it as trusted. With this change, BPF helpers can safely access vma->vm_mm to retrieve the associated task from the VMA. Signed-off-by: Yafang Shao <redacted> --- kernel/bpf/verifier.c | 5 +++++ 1 file changed, 5 insertions(+)
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c
index c4f69a9e9af6..984ffbca5cbe 100644
--- a/kernel/bpf/verifier.c
+++ b/kernel/bpf/verifier.c@@ -7154,6 +7154,10 @@ BTF_TYPE_SAFE_TRUSTED(struct file) { struct inode *f_inode; }; +BTF_TYPE_SAFE_TRUSTED(struct vm_area_struct) { + struct mm_struct *vm_mm; +}; + BTF_TYPE_SAFE_TRUSTED_OR_NULL(struct dentry) { struct inode *d_inode; };
@@ -7193,6 +7197,7 @@ static bool type_is_trusted(struct bpf_verifier_env *env, BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct bpf_iter__task)); BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct linux_binprm)); BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct file)); + BTF_TYPE_EMIT(BTF_TYPE_SAFE_TRUSTED(struct vm_area_struct)); return btf_nested_type_is_trusted(&env->log, reg, field_name, btf_id, "__safe_trusted"); }
--
2.47.3