Commit 055d8824 authored by Arnd Bergmann's avatar Arnd Bergmann Committed by David S. Miller

compat_ioctl: pppoe: fix PPPOEIOCSFWD handling

Support for handling the PPPOEIOCSFWD ioctl in compat mode was added in
linux-2.5.69 along with hundreds of other commands, but was always broken
sincen only the structure is compatible, but the command number is not,
due to the size being sizeof(size_t), or at first sizeof(sizeof((struct
sockaddr_pppox)), which is different on 64-bit architectures.

Guillaume Nault adds:

  And the implementation was broken until 2016 (see 29e73269 ("pppoe:
  fix reference counting in PPPoE proxy")), and nobody ever noticed. I
  should probably have removed this ioctl entirely instead of fixing it.
  Clearly, it has never been used.

Fix it by adding a compat_ioctl handler for all pppoe variants that
translates the command number and then calls the regular ioctl function.

All other ioctl commands handled by pppoe are compatible between 32-bit
and 64-bit, and require compat_ptr() conversion.

This should apply to all stable kernels.
Acked-by: default avatarGuillaume Nault <g.nault@alphalink.fr>
Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 2948a1fc
......@@ -1115,6 +1115,9 @@ static const struct proto_ops pppoe_ops = {
.recvmsg = pppoe_recvmsg,
.mmap = sock_no_mmap,
.ioctl = pppox_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = pppox_compat_ioctl,
#endif
};
static const struct pppox_proto pppoe_proto = {
......
......@@ -17,6 +17,7 @@
#include <linux/string.h>
#include <linux/module.h>
#include <linux/kernel.h>
#include <linux/compat.h>
#include <linux/errno.h>
#include <linux/netdevice.h>
#include <linux/net.h>
......@@ -98,6 +99,18 @@ int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
EXPORT_SYMBOL(pppox_ioctl);
#ifdef CONFIG_COMPAT
int pppox_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg)
{
if (cmd == PPPOEIOCSFWD32)
cmd = PPPOEIOCSFWD;
return pppox_ioctl(sock, cmd, (unsigned long)compat_ptr(arg));
}
EXPORT_SYMBOL(pppox_compat_ioctl);
#endif
static int pppox_create(struct net *net, struct socket *sock, int protocol,
int kern)
{
......
......@@ -623,6 +623,9 @@ static const struct proto_ops pptp_ops = {
.recvmsg = sock_no_recvmsg,
.mmap = sock_no_mmap,
.ioctl = pppox_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = pppox_compat_ioctl,
#endif
};
static const struct pppox_proto pppox_pptp_proto = {
......
......@@ -638,9 +638,6 @@ COMPATIBLE_IOCTL(PPPIOCDISCONN)
COMPATIBLE_IOCTL(PPPIOCATTCHAN)
COMPATIBLE_IOCTL(PPPIOCGCHAN)
COMPATIBLE_IOCTL(PPPIOCGL2TPSTATS)
/* PPPOX */
COMPATIBLE_IOCTL(PPPOEIOCSFWD)
COMPATIBLE_IOCTL(PPPOEIOCDFWD)
/* Big A */
/* sparc only */
/* Big Q for sound/OSS */
......
......@@ -80,6 +80,9 @@ extern int register_pppox_proto(int proto_num, const struct pppox_proto *pp);
extern void unregister_pppox_proto(int proto_num);
extern void pppox_unbind_sock(struct sock *sk);/* delete ppp-channel binding */
extern int pppox_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
extern int pppox_compat_ioctl(struct socket *sock, unsigned int cmd, unsigned long arg);
#define PPPOEIOCSFWD32 _IOW(0xB1 ,0, compat_size_t)
/* PPPoX socket states */
enum {
......
......@@ -1681,6 +1681,9 @@ static const struct proto_ops pppol2tp_ops = {
.recvmsg = pppol2tp_recvmsg,
.mmap = sock_no_mmap,
.ioctl = pppox_ioctl,
#ifdef CONFIG_COMPAT
.compat_ioctl = pppox_compat_ioctl,
#endif
};
static const struct pppox_proto pppol2tp_proto = {
......
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