bpf: fix off-by-one in class whitelisting

We would jump one insn too many, landing in the middle of the subsequent block.
2019-11-11 14:55:57 +01:00
parent 415fe5ec7d
commit a72a5326a4
1 changed files with 1 additions and 1 deletions
@@ -108,7 +108,7 @@ static int bpf_prog_whitelist_class(BPFProgram *prog, int type, const char *acc)
                return -EINVAL;

        const struct bpf_insn insn[] = {
-                BPF_JMP_IMM(BPF_JNE, BPF_REG_2, type, 5), /* compare device type */
+                BPF_JMP_IMM(BPF_JNE, BPF_REG_2, type, 4), /* compare device type */
                BPF_MOV32_REG(BPF_REG_1, BPF_REG_3), /* calculate access type */
                BPF_ALU32_IMM(BPF_AND, BPF_REG_1, access),
                BPF_JMP_REG(BPF_JNE, BPF_REG_1, BPF_REG_3, 1), /* compare access type */