Messages in this thread Patch in this message |  | | Date | Fri, 17 Aug 2012 04:02:55 +0100 | | From | Ben Hutchings <> | | Subject | [ 12/37] net/tun: fix ioctl() based info leaks |
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3.2-stable review patch. If anyone has any objections, please let me know.
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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: Ben Hutchings <ben@decadent.org.uk> --- drivers/net/tun.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index 7bea9c6..a12c9bf 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -1243,10 +1243,12 @@ static long __tun_chr_ioctl(struct file *file, unsigned int cmd, 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
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