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Commit e6e9bcef authored by Arnd Bergmann's avatar Arnd Bergmann Committed by Greg Kroah-Hartman
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compat_ioctl: pppoe: fix PPPOEIOCSFWD handling 



[ Upstream commit 055d88242a6046a1ceac3167290f054c72571cd9 ]

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>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 473430ed

drivers/net/ppp/pppoe.c

+3 −0
Original line number Diff line number Diff line
@@ -1120,6 +1120,9 @@ 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 = {

drivers/net/ppp/pppox.c

+13 −0
Original line number Diff line number Diff line
@@ -22,6 +22,7 @@ 
#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>
@@ -103,6 +104,18 @@ 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)

{

drivers/net/ppp/pptp.c

+3 −0
Original line number Diff line number Diff line
@@ -633,6 +633,9 @@ 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 = {

fs/compat_ioctl.c

+0 −3
Original line number Diff line number Diff line
@@ -894,9 +894,6 @@ 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 */

include/linux/if_pppox.h

+3 −0
Original line number Diff line number Diff line
@@ -84,6 +84,9 @@ 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 {