socket: fix struct ifreq size in compat ioctl
As reported by Reobert O'Callahan, since Viro's commit to kill
dev_ifsioc() we attempt to copy too much data in compat mode,
which may lead to EFAULT when the 32-bit version of struct ifreq
sits at/near the end of a page boundary, and the next page isn't
mapped.
Fix this by passing the approprate compat/non-compat size to copy
and using that, as before the dev_ifsioc() removal. This works
because only the embedded "struct ifmap" has different size, and
this is only used in SIOCGIFMAP/SIOCSIFMAP which has a different
handler. All other parts of the union are naturally compatible.
This fixes https://bugzilla.kernel.org/show_bug.cgi?id=199469.
Fixes: bf4405737f
("kill dev_ifsioc()")
Reported-by: Robert O'Callahan <robert@ocallahan.org>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
parent
c56cae23c6
commit
1cebf8f143
22
net/socket.c
22
net/socket.c
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@ -941,7 +941,8 @@ void dlci_ioctl_set(int (*hook) (unsigned int, void __user *))
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EXPORT_SYMBOL(dlci_ioctl_set);
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static long sock_do_ioctl(struct net *net, struct socket *sock,
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unsigned int cmd, unsigned long arg)
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unsigned int cmd, unsigned long arg,
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unsigned int ifreq_size)
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{
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int err;
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void __user *argp = (void __user *)arg;
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@ -967,11 +968,11 @@ static long sock_do_ioctl(struct net *net, struct socket *sock,
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} else {
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struct ifreq ifr;
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bool need_copyout;
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if (copy_from_user(&ifr, argp, sizeof(struct ifreq)))
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if (copy_from_user(&ifr, argp, ifreq_size))
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return -EFAULT;
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err = dev_ioctl(net, cmd, &ifr, &need_copyout);
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if (!err && need_copyout)
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if (copy_to_user(argp, &ifr, sizeof(struct ifreq)))
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if (copy_to_user(argp, &ifr, ifreq_size))
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return -EFAULT;
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}
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return err;
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@ -1070,7 +1071,8 @@ static long sock_ioctl(struct file *file, unsigned cmd, unsigned long arg)
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err = open_related_ns(&net->ns, get_net_ns);
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break;
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default:
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err = sock_do_ioctl(net, sock, cmd, arg);
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err = sock_do_ioctl(net, sock, cmd, arg,
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sizeof(struct ifreq));
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break;
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}
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return err;
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@ -2750,7 +2752,8 @@ static int do_siocgstamp(struct net *net, struct socket *sock,
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int err;
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set_fs(KERNEL_DS);
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err = sock_do_ioctl(net, sock, cmd, (unsigned long)&ktv);
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err = sock_do_ioctl(net, sock, cmd, (unsigned long)&ktv,
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sizeof(struct compat_ifreq));
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set_fs(old_fs);
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if (!err)
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err = compat_put_timeval(&ktv, up);
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@ -2766,7 +2769,8 @@ static int do_siocgstampns(struct net *net, struct socket *sock,
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int err;
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set_fs(KERNEL_DS);
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err = sock_do_ioctl(net, sock, cmd, (unsigned long)&kts);
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err = sock_do_ioctl(net, sock, cmd, (unsigned long)&kts,
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sizeof(struct compat_ifreq));
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set_fs(old_fs);
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if (!err)
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err = compat_put_timespec(&kts, up);
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@ -3072,7 +3076,8 @@ static int routing_ioctl(struct net *net, struct socket *sock,
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}
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set_fs(KERNEL_DS);
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ret = sock_do_ioctl(net, sock, cmd, (unsigned long) r);
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ret = sock_do_ioctl(net, sock, cmd, (unsigned long) r,
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sizeof(struct compat_ifreq));
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set_fs(old_fs);
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out:
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@ -3185,7 +3190,8 @@ static int compat_sock_ioctl_trans(struct file *file, struct socket *sock,
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case SIOCBONDSETHWADDR:
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case SIOCBONDCHANGEACTIVE:
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case SIOCGIFNAME:
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return sock_do_ioctl(net, sock, cmd, arg);
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return sock_do_ioctl(net, sock, cmd, arg,
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sizeof(struct compat_ifreq));
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}
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return -ENOIOCTLCMD;
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