[PATCH 5.10 45/73] bpf: net: Change sk_getsockopt() to take the sockptr_t argument

Sasha Levin
2024-03-13T16:47:31Z

From: Martin KaFai Lau <martin.lau@kernel.org>

[ Upstream commit 4ff09db1b79b98b4a2a7511571c640b76cab3beb ]

This patch changes sk_getsockopt() to take the sockptr_t argument
such that it can be used by bpf_getsockopt(SOL_SOCKET) in a
latter patch.

security_socket_getpeersec_stream() is not changed. It stays
with the __user ptr (optval.user and optlen.user) to avoid changes
to other security hooks. bpf_getsockopt(SOL_SOCKET) also does not
support SO_PEERSEC.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002802.2888419-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Stable-dep-of: 5a287d3d2b9d ("lsm: fix default return value of the socket_getpeersec_*() hooks")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
include/linux/filter.h | 3 +--
include/linux/sockptr.h | 5 +++++
net/core/filter.c | 5 ++---
net/core/sock.c | 43 +++++++++++++++++++++++------------------
4 files changed, 32 insertions(+), 24 deletions(-)

diff --git a/include/linux/filter.h b/include/linux/filter.h
index bc6ce4b202a80..cd56e53bd42e2 100644
--- a/include/linux/filter.h
+++ b/include/linux/filter.h
@@ -892,8 +892,7 @@ int sk_reuseport_attach_filter(struct sock_fprog *fprog, struct sock *sk);
int sk_reuseport_attach_bpf(u32 ufd, struct sock *sk);
void sk_reuseport_prog_free(struct bpf_prog *prog);
int sk_detach_filter(struct sock *sk);
-int sk_get_filter(struct sock *sk, struct sock_filter __user *filter,
- unsigned int len);
+int sk_get_filter(struct sock *sk, sockptr_t optval, unsigned int len);

bool sk_filter_charge(struct sock *sk, struct sk_filter *fp);
void sk_filter_uncharge(struct sock *sk, struct sk_filter *fp);
diff --git a/include/linux/sockptr.h b/include/linux/sockptr.h
index ea193414298b7..38862819e77a1 100644
--- a/include/linux/sockptr.h
+++ b/include/linux/sockptr.h
@@ -64,6 +64,11 @@ static inline int copy_to_sockptr_offset(sockptr_t dst, size_t offset,
return 0;
}

+static inline int copy_to_sockptr(sockptr_t dst, const void *src, size_t size)
+{
+ return copy_to_sockptr_offset(dst, 0, src, size);
+}
+
static inline void *memdup_sockptr(sockptr_t src, size_t len)
{
void *p = kmalloc_track_caller(len, GFP_USER | __GFP_NOWARN);
diff --git a/net/core/filter.c b/net/core/filter.c
index 6cfc8fb0562a2..49e4d1535cc82 100644
--- a/net/core/filter.c
+++ b/net/core/filter.c
@@ -9903,8 +9903,7 @@ int sk_detach_filter(struct sock *sk)
}
EXPORT_SYMBOL_GPL(sk_detach_filter);

-int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf,
- unsigned int len)
+int sk_get_filter(struct sock *sk, sockptr_t optval, unsigned int len)
{
struct sock_fprog_kern *fprog;
struct sk_filter *filter;
@@ -9935,7 +9934,7 @@ int sk_get_filter(struct sock *sk, struct sock_filter __user *ubuf,
goto out;

ret = -EFAULT;
- if (copy_to_user(ubuf, fprog->filter, bpf_classic_proglen(fprog)))
+ if (copy_to_sockptr(optval, fprog->filter, bpf_classic_proglen(fprog)))
goto out;

/* Instead of bytes, the API requests to return the number
diff --git a/net/core/sock.c b/net/core/sock.c
index 95559d088a169..42da46965b16f 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -644,8 +644,8 @@ static int sock_setbindtodevice(struct sock *sk, sockptr_t optval, int optlen)
return ret;
}

-static int sock_getbindtodevice(struct sock *sk, char __user *optval,
- int __user *optlen, int len)
+static int sock_getbindtodevice(struct sock *sk, sockptr_t optval,
+ sockptr_t optlen, int len)
{
int ret = -ENOPROTOOPT;
#ifdef CONFIG_NETDEVICES
@@ -668,12 +668,12 @@ static int sock_getbindtodevice(struct sock *sk, char __user *optval,
len = strlen(devname) + 1;

ret = -EFAULT;
- if (copy_to_user(optval, devname, len))
+ if (copy_to_sockptr(optval, devname, len))
goto out;

zero:
ret = -EFAULT;
- if (put_user(len, optlen))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
goto out;

ret = 0;
@@ -1281,20 +1281,23 @@ static void cred_to_ucred(struct pid *pid, const struct cred *cred,
}
}

-static int groups_to_user(gid_t __user *dst, const struct group_info *src)
+static int groups_to_user(sockptr_t dst, const struct group_info *src)
{
struct user_namespace *user_ns = current_user_ns();
int i;

- for (i = 0; i < src->ngroups; i++)
- if (put_user(from_kgid_munged(user_ns, src->gid[i]), dst + i))
+ for (i = 0; i < src->ngroups; i++) {
+ gid_t gid = from_kgid_munged(user_ns, src->gid[i]);
+
+ if (copy_to_sockptr_offset(dst, i * sizeof(gid), &gid, sizeof(gid)))
return -EFAULT;
+ }

return 0;
}

static int sk_getsockopt(struct sock *sk, int level, int optname,
- char __user *optval, int __user *optlen)
+ sockptr_t optval, sockptr_t optlen)
{
struct socket *sock = sk->sk_socket;

@@ -1312,7 +1315,7 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
int lv = sizeof(int);
int len;

- if (get_user(len, optlen))
+ if (copy_from_sockptr(&len, optlen, sizeof(int)))
return -EFAULT;
if (len < 0)
return -EINVAL;
@@ -1445,7 +1448,7 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
cred_to_ucred(sk->sk_peer_pid, sk->sk_peer_cred, &peercred);
spin_unlock(&sk->sk_peer_lock);

- if (copy_to_user(optval, &peercred, len))
+ if (copy_to_sockptr(optval, &peercred, len))
return -EFAULT;
goto lenout;
}
@@ -1463,11 +1466,11 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
if (len < n * sizeof(gid_t)) {
len = n * sizeof(gid_t);
put_cred(cred);
- return put_user(len, optlen) ? -EFAULT : -ERANGE;
+ return copy_to_sockptr(optlen, &len, sizeof(int)) ? -EFAULT : -ERANGE;
}
len = n * sizeof(gid_t);

- ret = groups_to_user((gid_t __user *)optval, cred->group_info);
+ ret = groups_to_user(optval, cred->group_info);
put_cred(cred);
if (ret)
return ret;
@@ -1483,7 +1486,7 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
return -ENOTCONN;
if (lv < len)
return -EINVAL;
- if (copy_to_user(optval, address, len))
+ if (copy_to_sockptr(optval, address, len))
return -EFAULT;
goto lenout;
}
@@ -1500,7 +1503,7 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
break;

case SO_PEERSEC:
- return security_socket_getpeersec_stream(sock, optval, optlen, len);
+ return security_socket_getpeersec_stream(sock, optval.user, optlen.user, len);

case SO_MARK:
v.val = sk->sk_mark;
@@ -1528,7 +1531,7 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
return sock_getbindtodevice(sk, optval, optlen, len);

case SO_GET_FILTER:
- len = sk_get_filter(sk, (struct sock_filter __user *)optval, len);
+ len = sk_get_filter(sk, optval, len);
if (len < 0)
return len;

@@ -1575,7 +1578,7 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
sk_get_meminfo(sk, meminfo);

len = min_t(unsigned int, len, sizeof(meminfo));
- if (copy_to_user(optval, &meminfo, len))
+ if (copy_to_sockptr(optval, &meminfo, len))
return -EFAULT;

goto lenout;
@@ -1625,10 +1628,10 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,

if (len > lv)
len = lv;
- if (copy_to_user(optval, &v, len))
+ if (copy_to_sockptr(optval, &v, len))
return -EFAULT;
lenout:
- if (put_user(len, optlen))
+ if (copy_to_sockptr(optlen, &len, sizeof(int)))
return -EFAULT;
return 0;
}
@@ -1636,7 +1639,9 @@ static int sk_getsockopt(struct sock *sk, int level, int optname,
int sock_getsockopt(struct socket *sock, int level, int optname,
char __user *optval, int __user *optlen)
{
- return sk_getsockopt(sock->sk, level, optname, optval, optlen);
+ return sk_getsockopt(sock->sk, level, optname,
+ USER_SOCKPTR(optval),
+ USER_SOCKPTR(optlen));
}

/*
--
2.43.0