diff options
author | Daniel Borkmann <daniel@iogearbox.net> | 2016-04-13 00:10:52 +0200 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2016-04-14 21:40:41 -0400 |
commit | 074f528eed408b467516e142fa4c45e5b0d2ba16 (patch) | |
tree | e42352604c4f0db159881faff4b7cef49393d878 /net/core | |
parent | 435faee1aae9c1ac231f89e4faf0437bfe29f425 (diff) |
bpf: convert relevant helper args to ARG_PTR_TO_RAW_STACK
This patch converts all helpers that can use ARG_PTR_TO_RAW_STACK as argument
type. For tc programs this is bpf_skb_load_bytes(), bpf_skb_get_tunnel_key(),
bpf_skb_get_tunnel_opt(). For tracing, this optimizes bpf_get_current_comm()
and bpf_probe_read(). The check in bpf_skb_load_bytes() for MAX_BPF_STACK can
also be removed since the verifier already makes sure we stay within bounds
on stack buffers.
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Alexei Starovoitov <ast@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core')
-rw-r--r-- | net/core/filter.c | 57 |
1 files changed, 40 insertions, 17 deletions
diff --git a/net/core/filter.c b/net/core/filter.c index e8486ba601ea..5d2ac2b9d1c4 100644 --- a/net/core/filter.c +++ b/net/core/filter.c @@ -1409,16 +1409,19 @@ static u64 bpf_skb_load_bytes(u64 r1, u64 r2, u64 r3, u64 r4, u64 r5) unsigned int len = (unsigned int) r4; void *ptr; - if (unlikely((u32) offset > 0xffff || len > MAX_BPF_STACK)) - return -EFAULT; + if (unlikely((u32) offset > 0xffff)) + goto err_clear; ptr = skb_header_pointer(skb, offset, len, to); if (unlikely(!ptr)) - return -EFAULT; + goto err_clear; if (ptr != to) memcpy(to, ptr, len); return 0; +err_clear: + memset(to, 0, len); + return -EFAULT; } static const struct bpf_func_proto bpf_skb_load_bytes_proto = { @@ -1427,7 +1430,7 @@ static const struct bpf_func_proto bpf_skb_load_bytes_proto = { .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, .arg2_type = ARG_ANYTHING, - .arg3_type = ARG_PTR_TO_STACK, + .arg3_type = ARG_PTR_TO_RAW_STACK, .arg4_type = ARG_CONST_STACK_SIZE, }; @@ -1756,12 +1759,19 @@ static u64 bpf_skb_get_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5) struct bpf_tunnel_key *to = (struct bpf_tunnel_key *) (long) r2; const struct ip_tunnel_info *info = skb_tunnel_info(skb); u8 compat[sizeof(struct bpf_tunnel_key)]; + void *to_orig = to; + int err; - if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) - return -EINVAL; - if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) - return -EPROTO; + if (unlikely(!info || (flags & ~(BPF_F_TUNINFO_IPV6)))) { + err = -EINVAL; + goto err_clear; + } + if (ip_tunnel_info_af(info) != bpf_tunnel_key_af(flags)) { + err = -EPROTO; + goto err_clear; + } if (unlikely(size != sizeof(struct bpf_tunnel_key))) { + err = -EINVAL; switch (size) { case offsetof(struct bpf_tunnel_key, tunnel_label): case offsetof(struct bpf_tunnel_key, tunnel_ext): @@ -1771,12 +1781,12 @@ static u64 bpf_skb_get_tunnel_key(u64 r1, u64 r2, u64 size, u64 flags, u64 r5) * a common path later on. */ if (ip_tunnel_info_af(info) != AF_INET) - return -EINVAL; + goto err_clear; set_compat: to = (struct bpf_tunnel_key *)compat; break; default: - return -EINVAL; + goto err_clear; } } @@ -1793,9 +1803,12 @@ set_compat: } if (unlikely(size != sizeof(struct bpf_tunnel_key))) - memcpy((void *)(long) r2, to, size); + memcpy(to_orig, to, size); return 0; +err_clear: + memset(to_orig, 0, size); + return err; } static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = { @@ -1803,7 +1816,7 @@ static const struct bpf_func_proto bpf_skb_get_tunnel_key_proto = { .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, - .arg2_type = ARG_PTR_TO_STACK, + .arg2_type = ARG_PTR_TO_RAW_STACK, .arg3_type = ARG_CONST_STACK_SIZE, .arg4_type = ARG_ANYTHING, }; @@ -1813,16 +1826,26 @@ static u64 bpf_skb_get_tunnel_opt(u64 r1, u64 r2, u64 size, u64 r4, u64 r5) struct sk_buff *skb = (struct sk_buff *) (long) r1; u8 *to = (u8 *) (long) r2; const struct ip_tunnel_info *info = skb_tunnel_info(skb); + int err; if (unlikely(!info || - !(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))) - return -ENOENT; - if (unlikely(size < info->options_len)) - return -ENOMEM; + !(info->key.tun_flags & TUNNEL_OPTIONS_PRESENT))) { + err = -ENOENT; + goto err_clear; + } + if (unlikely(size < info->options_len)) { + err = -ENOMEM; + goto err_clear; + } ip_tunnel_info_opts_get(to, info); + if (size > info->options_len) + memset(to + info->options_len, 0, size - info->options_len); return info->options_len; +err_clear: + memset(to, 0, size); + return err; } static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto = { @@ -1830,7 +1853,7 @@ static const struct bpf_func_proto bpf_skb_get_tunnel_opt_proto = { .gpl_only = false, .ret_type = RET_INTEGER, .arg1_type = ARG_PTR_TO_CTX, - .arg2_type = ARG_PTR_TO_STACK, + .arg2_type = ARG_PTR_TO_RAW_STACK, .arg3_type = ARG_CONST_STACK_SIZE, }; |