From 055d88242a6046a1ceac3167290f054c72571cd9 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 30 Jul 2019 21:25:20 +0200 Subject: [PATCH] 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 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 Signed-off-by: Arnd Bergmann Signed-off-by: David S. Miller --- 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(-) diff --git a/drivers/net/ppp/pppoe.c b/drivers/net/ppp/pppoe.c index 1d902ecb4aa8..a44dd3c8af63 100644 --- a/drivers/net/ppp/pppoe.c +++ b/drivers/net/ppp/pppoe.c @@ -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 = { diff --git a/drivers/net/ppp/pppox.c b/drivers/net/ppp/pppox.c index 5ef422a43d70..08364f10a43f 100644 --- a/drivers/net/ppp/pppox.c +++ b/drivers/net/ppp/pppox.c @@ -17,6 +17,7 @@ #include #include #include +#include #include #include #include @@ -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) { diff --git a/drivers/net/ppp/pptp.c b/drivers/net/ppp/pptp.c index a8e52c8e4128..734de7de03f7 100644 --- a/drivers/net/ppp/pptp.c +++ b/drivers/net/ppp/pptp.c @@ -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 = { diff --git a/fs/compat_ioctl.c b/fs/compat_ioctl.c index 6e30949d9f77..a7ec2d3dff92 100644 --- a/fs/compat_ioctl.c +++ b/fs/compat_ioctl.c @@ -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 */ diff --git a/include/linux/if_pppox.h b/include/linux/if_pppox.h index 8b728750a625..69e813bcb947 100644 --- a/include/linux/if_pppox.h +++ b/include/linux/if_pppox.h @@ -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 { diff --git a/net/l2tp/l2tp_ppp.c b/net/l2tp/l2tp_ppp.c index 1d0e5904dedf..c54cb59593ef 100644 --- a/net/l2tp/l2tp_ppp.c +++ b/net/l2tp/l2tp_ppp.c @@ -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 = { -- 2.30.2