From: Arnd Bergmann arnd@arndb.de
[ 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 29e73269aa4d ("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: Guillaume Nault g.nault@alphalink.fr Signed-off-by: Arnd Bergmann arnd@arndb.de Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/net/ppp/pppoe.c | 3 +++ drivers/net/ppp/pppox.c | 13 +++++++++++++ drivers/net/ppp/pptp.c | 3 +++ fs/compat_ioctl.c | 3 --- include/linux/if_pppox.h | 3 +++ net/l2tp/l2tp_ppp.c | 3 +++ 6 files changed, 25 insertions(+), 3 deletions(-)
--- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -1134,6 +1134,9 @@ 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 = { --- a/drivers/net/ppp/pppox.c +++ b/drivers/net/ppp/pppox.c @@ -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, uns
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) { --- a/drivers/net/ppp/pptp.c +++ b/drivers/net/ppp/pptp.c @@ -638,6 +638,9 @@ 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 = { --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -1038,9 +1038,6 @@ 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 */ --- a/include/linux/if_pppox.h +++ b/include/linux/if_pppox.h @@ -84,6 +84,9 @@ extern int register_pppox_proto(int prot 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 { --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -1790,6 +1790,9 @@ static const struct proto_ops pppol2tp_o .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 = {