@@ -854,3 +854,50 @@
.errstr = "Unreleased reference",
.result = REJECT,
},
+{
+ "reference tracking: bpf_sk_release(btf_tcp_sock)",
+ .insns = {
+ BPF_SK_LOOKUP(sk_lookup_tcp),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_EMIT_CALL(BPF_FUNC_skc_to_tcp_sock),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 3),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = ACCEPT,
+ .result_unpriv = REJECT,
+ .errstr_unpriv = "unknown func",
+},
+{
+ "reference tracking: use ptr from bpf_skc_to_tcp_sock() after release",
+ .insns = {
+ BPF_SK_LOOKUP(sk_lookup_tcp),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 1),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_6, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_0),
+ BPF_EMIT_CALL(BPF_FUNC_skc_to_tcp_sock),
+ BPF_JMP_IMM(BPF_JNE, BPF_REG_0, 0, 3),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_EXIT_INSN(),
+ BPF_MOV64_REG(BPF_REG_7, BPF_REG_0),
+ BPF_MOV64_REG(BPF_REG_1, BPF_REG_6),
+ BPF_EMIT_CALL(BPF_FUNC_sk_release),
+ BPF_LDX_MEM(BPF_B, BPF_REG_0, BPF_REG_7, 0),
+ BPF_EXIT_INSN(),
+ },
+ .prog_type = BPF_PROG_TYPE_SCHED_CLS,
+ .result = REJECT,
+ .errstr = "invalid mem access",
+ .result_unpriv = REJECT,
+ .errstr_unpriv = "unknown func",
+},
The patch tests for: 1. bpf_sk_release() can be called on a tcp_sock btf_id ptr. 2. Ensure the tcp_sock btf_id pointer cannot be used after bpf_sk_release(). Signed-off-by: Martin KaFai Lau <kafai@fb.com> --- .../selftests/bpf/verifier/ref_tracking.c | 47 +++++++++++++++++++ 1 file changed, 47 insertions(+)