| From 8792d0c90a7952d7677cf197bbd504028352361e Mon Sep 17 00:00:00 2001 |
| From: Mathias Krause <minipli@googlemail.com> |
| Date: Sun, 29 Jul 2012 19:45:14 +0000 |
| Subject: net/tun: fix ioctl() based info leaks |
| |
| |
| From: Mathias Krause <minipli@googlemail.com> |
| |
| [ Upstream commits a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc |
| and 8bbb181308bc348e02bfdbebdedd4e4ec9d452ce ] |
| |
| The tun module leaks up to 36 bytes of memory by not fully initializing |
| a structure located on the stack that gets copied to user memory by the |
| TUNGETIFF and SIOCGIFHWADDR ioctl()s. |
| |
| Signed-off-by: Mathias Krause <minipli@googlemail.com> |
| Signed-off-by: David S. Miller <davem@davemloft.net> |
| Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> |
| --- |
| drivers/net/tun.c | 6 ++++-- |
| 1 file changed, 4 insertions(+), 2 deletions(-) |
| |
| --- a/drivers/net/tun.c |
| +++ b/drivers/net/tun.c |
| @@ -1255,10 +1255,12 @@ static long __tun_chr_ioctl(struct file |
| int vnet_hdr_sz; |
| int ret; |
| |
| - if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) |
| + if (cmd == TUNSETIFF || _IOC_TYPE(cmd) == 0x89) { |
| if (copy_from_user(&ifr, argp, ifreq_len)) |
| return -EFAULT; |
| - |
| + } else { |
| + memset(&ifr, 0, sizeof(ifr)); |
| + } |
| if (cmd == TUNGETFEATURES) { |
| /* Currently this just means: "what IFF flags are valid?". |
| * This is needed because we never checked for invalid flags on |
