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Message-Id: <20200717062331.691152-5-hch@lst.de>
Date: Fri, 17 Jul 2020 08:23:13 +0200
From: Christoph Hellwig <hch@....de>
To: "David S. Miller" <davem@...emloft.net>
Cc: Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Chas Williams <3chas3@...il.com>,
Pablo Neira Ayuso <pablo@...filter.org>,
Jozsef Kadlecsik <kadlec@...filter.org>,
Florian Westphal <fw@...len.de>,
Alexey Kuznetsov <kuznet@....inr.ac.ru>,
Hideaki YOSHIFUJI <yoshfuji@...ux-ipv6.org>,
linux-kernel@...r.kernel.org, netdev@...r.kernel.org,
bpf@...r.kernel.org, netfilter-devel@...r.kernel.org,
linux-sctp@...r.kernel.org, linux-arch@...r.kernel.org,
linux-bluetooth@...r.kernel.org, bridge@...ts.linux-foundation.org,
linux-can@...r.kernel.org, dccp@...r.kernel.org,
linux-wpan@...r.kernel.org, mptcp@...ts.01.org
Subject: [PATCH 04/22] net: simplify cBPF setsockopt compat handling
Add a helper that copies either a native or compat bpf_fprog from
userspace after verifying the length, and remove the compat setsockopt
handlers that now aren't required.
Signed-off-by: Christoph Hellwig <hch@....de>
---
include/linux/filter.h | 4 ++--
include/net/compat.h | 1 -
net/compat.c | 45 +-----------------------------------------
net/core/filter.c | 23 +++++++++++++++++++++
net/core/sock.c | 30 ++++++++++------------------
net/packet/af_packet.c | 33 ++++---------------------------
6 files changed, 40 insertions(+), 96 deletions(-)
diff --git a/include/linux/filter.h b/include/linux/filter.h
index 0b0144752d780a..4d049c8e1fbeaa 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -502,13 +502,11 @@ static inline bool insn_is_zext(const struct bpf_insn *insn)
offsetof(TYPE, MEMBER); \
})
-#ifdef CONFIG_COMPAT
/* A struct sock_filter is architecture independent. */
struct compat_sock_fprog {
u16 len;
compat_uptr_t filter; /* struct sock_filter * */
};
-#endif
struct sock_fprog_kern {
u16 len;
@@ -1278,4 +1276,6 @@ struct bpf_sockopt_kern {
s32 retval;
};
+int copy_bpf_fprog_from_user(struct sock_fprog *dst, void __user *src, int len);
+
#endif /* __LINUX_FILTER_H__ */
diff --git a/include/net/compat.h b/include/net/compat.h
index f241666117d88c..745db0d605b62b 100644
--- a/include/net/compat.h
+++ b/include/net/compat.h
@@ -61,7 +61,6 @@ int __get_compat_msghdr(struct msghdr *kmsg, struct compat_msghdr __user *umsg,
compat_size_t *len);
int get_compat_msghdr(struct msghdr *, struct compat_msghdr __user *,
struct sockaddr __user **, struct iovec **);
-struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval);
int put_cmsg_compat(struct msghdr*, int, int, int, void *);
int cmsghdr_from_user_compat_to_kern(struct msghdr *, struct sock *,
diff --git a/net/compat.c b/net/compat.c
index 5e3041a2c37d4d..3e6c2c5ff2609c 100644
--- a/net/compat.c
+++ b/net/compat.c
@@ -335,49 +335,6 @@ void scm_detach_fds_compat(struct msghdr *kmsg, struct scm_cookie *scm)
__scm_destroy(scm);
}
-/* allocate a 64-bit sock_fprog on the user stack for duration of syscall. */
-struct sock_fprog __user *get_compat_bpf_fprog(char __user *optval)
-{
- struct compat_sock_fprog __user *fprog32 = (struct compat_sock_fprog __user *)optval;
- struct sock_fprog __user *kfprog = compat_alloc_user_space(sizeof(struct sock_fprog));
- struct compat_sock_fprog f32;
- struct sock_fprog f;
-
- if (copy_from_user(&f32, fprog32, sizeof(*fprog32)))
- return NULL;
- memset(&f, 0, sizeof(f));
- f.len = f32.len;
- f.filter = compat_ptr(f32.filter);
- if (copy_to_user(kfprog, &f, sizeof(struct sock_fprog)))
- return NULL;
-
- return kfprog;
-}
-EXPORT_SYMBOL_GPL(get_compat_bpf_fprog);
-
-static int do_set_attach_filter(struct socket *sock, int level, int optname,
- char __user *optval, unsigned int optlen)
-{
- struct sock_fprog __user *kfprog;
-
- kfprog = get_compat_bpf_fprog(optval);
- if (!kfprog)
- return -EFAULT;
-
- return sock_setsockopt(sock, level, optname, (char __user *)kfprog,
- sizeof(struct sock_fprog));
-}
-
-static int compat_sock_setsockopt(struct socket *sock, int level, int optname,
- char __user *optval, unsigned int optlen)
-{
- if (optname == SO_ATTACH_FILTER ||
- optname == SO_ATTACH_REUSEPORT_CBPF)
- return do_set_attach_filter(sock, level, optname,
- optval, optlen);
- return sock_setsockopt(sock, level, optname, optval, optlen);
-}
-
static int __compat_sys_setsockopt(int fd, int level, int optname,
char __user *optval, unsigned int optlen)
{
@@ -396,7 +353,7 @@ static int __compat_sys_setsockopt(int fd, int level, int optname,
}
if (level == SOL_SOCKET)
- err = compat_sock_setsockopt(sock, level,
+ err = sock_setsockopt(sock, level,
optname, optval, optlen);
else if (sock->ops->compat_setsockopt)
err = sock->ops->compat_setsockopt(sock, level,
diff --git a/net/core/filter.c b/net/core/filter.c
index bdd2382e655d85..2bf6624796d86f 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -77,6 +77,29 @@
#include <net/transp_v6.h>
#include <linux/btf_ids.h>
+int copy_bpf_fprog_from_user(struct sock_fprog *dst, void __user *src, int len)
+{
+ if (in_compat_syscall()) {
+ struct compat_sock_fprog f32;
+
+ if (len != sizeof(f32))
+ return -EINVAL;
+ if (copy_from_user(&f32, src, sizeof(f32)))
+ return -EFAULT;
+ memset(dst, 0, sizeof(*dst));
+ dst->len = f32.len;
+ dst->filter = compat_ptr(f32.filter);
+ } else {
+ if (len != sizeof(*dst))
+ return -EINVAL;
+ if (copy_from_user(dst, src, sizeof(*dst)))
+ return -EFAULT;
+ }
+
+ return 0;
+}
+EXPORT_SYMBOL_GPL(copy_bpf_fprog_from_user);
+
/**
* sk_filter_trim_cap - run a packet through a socket filter
* @sk: sock associated with &sk_buff
diff --git a/net/core/sock.c b/net/core/sock.c
index 11d6f77dd56207..e085df79482520 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -1059,19 +1059,14 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
ret = sock_set_timeout(&sk->sk_sndtimeo, optval, optlen, optname == SO_SNDTIMEO_OLD);
break;
- case SO_ATTACH_FILTER:
- ret = -EINVAL;
- if (optlen == sizeof(struct sock_fprog)) {
- struct sock_fprog fprog;
-
- ret = -EFAULT;
- if (copy_from_user(&fprog, optval, sizeof(fprog)))
- break;
+ case SO_ATTACH_FILTER: {
+ struct sock_fprog fprog;
+ ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
+ if (!ret)
ret = sk_attach_filter(&fprog, sk);
- }
break;
-
+ }
case SO_ATTACH_BPF:
ret = -EINVAL;
if (optlen == sizeof(u32)) {
@@ -1085,19 +1080,14 @@ int sock_setsockopt(struct socket *sock, int level, int optname,
}
break;
- case SO_ATTACH_REUSEPORT_CBPF:
- ret = -EINVAL;
- if (optlen == sizeof(struct sock_fprog)) {
- struct sock_fprog fprog;
-
- ret = -EFAULT;
- if (copy_from_user(&fprog, optval, sizeof(fprog)))
- break;
+ case SO_ATTACH_REUSEPORT_CBPF: {
+ struct sock_fprog fprog;
+ ret = copy_bpf_fprog_from_user(&fprog, optval, optlen);
+ if (!ret)
ret = sk_reuseport_attach_filter(&fprog, sk);
- }
break;
-
+ }
case SO_ATTACH_REUSEPORT_EBPF:
ret = -EINVAL;
if (optlen == sizeof(u32)) {
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c
index 781fee93b7d5e3..35aee9e980536d 100644
--- a/net/packet/af_packet.c
+++ b/net/packet/af_packet.c
@@ -1545,10 +1545,10 @@ static int fanout_set_data_cbpf(struct packet_sock *po, char __user *data,
if (sock_flag(&po->sk, SOCK_FILTER_LOCKED))
return -EPERM;
- if (len != sizeof(fprog))
- return -EINVAL;
- if (copy_from_user(&fprog, data, len))
- return -EFAULT;
+
+ ret = copy_bpf_fprog_from_user(&fprog, data, len);
+ if (ret)
+ return ret;
ret = bpf_prog_create_from_user(&new, &fprog, NULL, false);
if (ret)
@@ -4040,28 +4040,6 @@ static int packet_getsockopt(struct socket *sock, int level, int optname,
return 0;
}
-
-#ifdef CONFIG_COMPAT
-static int compat_packet_setsockopt(struct socket *sock, int level, int optname,
- char __user *optval, unsigned int optlen)
-{
- struct packet_sock *po = pkt_sk(sock->sk);
-
- if (level != SOL_PACKET)
- return -ENOPROTOOPT;
-
- if (optname == PACKET_FANOUT_DATA &&
- po->fanout && po->fanout->type == PACKET_FANOUT_CBPF) {
- optval = (char __user *)get_compat_bpf_fprog(optval);
- if (!optval)
- return -EFAULT;
- optlen = sizeof(struct sock_fprog);
- }
-
- return packet_setsockopt(sock, level, optname, optval, optlen);
-}
-#endif
-
static int packet_notifier(struct notifier_block *this,
unsigned long msg, void *ptr)
{
@@ -4549,9 +4527,6 @@ static const struct proto_ops packet_ops = {
.shutdown = sock_no_shutdown,
.setsockopt = packet_setsockopt,
.getsockopt = packet_getsockopt,
-#ifdef CONFIG_COMPAT
- .compat_setsockopt = compat_packet_setsockopt,
-#endif
.sendmsg = packet_sendmsg,
.recvmsg = packet_recvmsg,
.mmap = packet_mmap,
--
2.27.0
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