diff options
-rw-r--r-- | kernel/bpf/verifier.c | 58 |
1 files changed, 38 insertions, 20 deletions
diff --git a/kernel/bpf/verifier.c b/kernel/bpf/verifier.c index 86deddecff25..a834068a400e 100644 --- a/kernel/bpf/verifier.c +++ b/kernel/bpf/verifier.c @@ -765,38 +765,56 @@ static bool is_pointer_value(struct bpf_verifier_env *env, int regno) } } -static int check_ptr_alignment(struct bpf_verifier_env *env, - struct bpf_reg_state *reg, int off, int size) +static int check_pkt_ptr_alignment(const struct bpf_reg_state *reg, + int off, int size) { - if (reg->type != PTR_TO_PACKET && reg->type != PTR_TO_MAP_VALUE_ADJ) { - if (off % size != 0) { - verbose("misaligned access off %d size %d\n", - off, size); - return -EACCES; - } else { - return 0; - } - } - - if (IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS)) - /* misaligned access to packet is ok on x86,arm,arm64 */ - return 0; - if (reg->id && size != 1) { - verbose("Unknown packet alignment. Only byte-sized access allowed\n"); + verbose("Unknown alignment. Only byte-sized access allowed in packet access.\n"); return -EACCES; } /* skb->data is NET_IP_ALIGN-ed */ - if (reg->type == PTR_TO_PACKET && - (NET_IP_ALIGN + reg->off + off) % size != 0) { + if ((NET_IP_ALIGN + reg->off + off) % size != 0) { verbose("misaligned packet access off %d+%d+%d size %d\n", NET_IP_ALIGN, reg->off, off, size); return -EACCES; } + return 0; } +static int check_val_ptr_alignment(const struct bpf_reg_state *reg, + int size) +{ + if (size != 1) { + verbose("Unknown alignment. Only byte-sized access allowed in value access.\n"); + return -EACCES; + } + + return 0; +} + +static int check_ptr_alignment(const struct bpf_reg_state *reg, + int off, int size) +{ + switch (reg->type) { + case PTR_TO_PACKET: + return IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ? 0 : + check_pkt_ptr_alignment(reg, off, size); + case PTR_TO_MAP_VALUE_ADJ: + return IS_ENABLED(CONFIG_HAVE_EFFICIENT_UNALIGNED_ACCESS) ? 0 : + check_val_ptr_alignment(reg, size); + default: + if (off % size != 0) { + verbose("misaligned access off %d size %d\n", + off, size); + return -EACCES; + } + + return 0; + } +} + /* check whether memory at (regno + off) is accessible for t = (read | write) * if t==write, value_regno is a register which value is stored into memory * if t==read, value_regno is a register which will receive the value from memory @@ -818,7 +836,7 @@ static int check_mem_access(struct bpf_verifier_env *env, u32 regno, int off, if (size < 0) return size; - err = check_ptr_alignment(env, reg, off, size); + err = check_ptr_alignment(reg, off, size); if (err) return err; |