From 055d88242a6046a1ceac3167290f054c72571cd9 Mon Sep 17 00:00:00 2001 From: Arnd Bergmann Date: Tue, 30 Jul 2019 21:25:20 +0200 Subject: 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/pptp.c | 3 +++ 1 file changed, 3 insertions(+) (limited to 'drivers/net/ppp/pptp.c') 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 = { -- cgit v1.2.3