| From | Paul Gortmaker <> | Subject | [v2.6.34-stable 059/213] net/tun: fix ioctl() based info leaks | Date | Wed, 5 Feb 2014 15:00:14 -0500 |
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From: Mathias Krause <minipli@googlemail.com>
------------------- This is a commit scheduled for the next v2.6.34 longterm release. http://git.kernel.org/?p=linux/kernel/git/paulg/longterm-queue-2.6.34.git If you see a problem with using this for longterm, please comment. -------------------
commit a117dacde0288f3ec60b6e5bcedae8fa37ee0dfc upstream.
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: Paul Gortmaker <paul.gortmaker@windriver.com> --- drivers/net/tun.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 7b4a88b2f696..c777d8ebdaa8 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1177,9 +1177,11 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, int sndbuf; 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?". -- 1.8.5.2
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