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authorArnd Bergmann <arnd@arndb.de>2019-07-30 21:25:20 +0200
committerDavid S. Miller <davem@davemloft.net>2019-07-30 14:42:13 -0700
commit055d88242a6046a1ceac3167290f054c72571cd9 (patch)
tree476499d967c08a870cb07d8885941922e6fd7c21 /drivers/net/ppp/pppox.c
parenttipc: fix unitilized skb list crash (diff)
downloadlinux-dev-055d88242a6046a1ceac3167290f054c72571cd9.tar.xz
linux-dev-055d88242a6046a1ceac3167290f054c72571cd9.zip
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 <g.nault@alphalink.fr> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/ppp/pppox.c')
-rw-r--r--drivers/net/ppp/pppox.c13
1 files changed, 13 insertions, 0 deletions
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 <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)
{