diff options
Diffstat (limited to 'kernel/bpf/verifier.c')
| -rw-r--r-- | kernel/bpf/verifier.c | 17 |
1 files changed, 16 insertions, 1 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index a8d67d097b0d..f72f23b8fdab 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -653,6 +653,16 @@ static int check_map_access(struct verifier_env *env, u32 regno, int off, #define MAX_PACKET_OFF 0xffff +static bool may_write_pkt_data(enum bpf_prog_type type) +{ + switch (type) { + case BPF_PROG_TYPE_XDP: + return true; + default: + return false; + } +} + static int check_packet_access(struct verifier_env *env, u32 regno, int off, int size) { @@ -806,10 +816,15 @@ static int check_mem_access(struct verifier_env *env, u32 regno, int off, err = check_stack_read(state, off, size, value_regno); } } else if (state->regs[regno].type == PTR_TO_PACKET) { - if (t == BPF_WRITE) { + if (t == BPF_WRITE && !may_write_pkt_data(env->prog->type)) { verbose("cannot write into packet\n"); return -EACCES; } + if (t == BPF_WRITE && value_regno >= 0 && + is_pointer_value(env, value_regno)) { + verbose("R%d leaks addr into packet\n", value_regno); + return -EACCES; + } err = check_packet_access(env, regno, off, size); if (!err && t == BPF_READ && value_regno >= 0) mark_reg_unknown_value(state->regs, value_regno); |