Commit 4ff09db1 authored by Martin KaFai Lau's avatar Martin KaFai Lau Committed by Alexei Starovoitov
Browse files

bpf: net: Change sk_getsockopt() to take the sockptr_t argument 



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: default avatarMartin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002802.2888419-1-kafai@fb.com


Signed-off-by: default avatarAlexei Starovoitov <ast@kernel.org>
parent ba74a760

include/linux/filter.h

+1 −2
Original line number Diff line number Diff line
@@ -900,8 +900,7 @@ 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);

include/linux/sockptr.h

+5 −0
Original line number Diff line number Diff line
@@ -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);

net/core/filter.c

+2 −3
Original line number Diff line number Diff line
@@ -10716,8 +10716,7 @@ 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;
@@ -10748,7 +10747,7 @@ 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

net/core/sock.c

+24 −19
Original line number Diff line number Diff line
@@ -712,8 +712,8 @@ 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
@@ -737,12 +737,12 @@ 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;
@@ -1568,20 +1568,23 @@ 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;
@@ -1600,7 +1603,7 @@ 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;
@@ -1735,7 +1738,7 @@ 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;

	}
@@ -1753,11 +1756,11 @@ 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;
@@ -1773,7 +1776,7 @@ 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;

	}
@@ -1790,7 +1793,7 @@ 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;
@@ -1822,7 +1825,7 @@ 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;
@@ -1870,7 +1873,7 @@ 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;
@@ -1939,10 +1942,10 @@ 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;

}
@@ -1950,7 +1953,9 @@ 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));

}



/*