Re: [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam
From: Edward Cree <hidden>
Date: 2016-06-01 15:05:57
Also in:
lkml
On 01/06/16 15:39, Kangjie Lu wrote:
quoted hunk ↗ jump to hunk
The field autoneg of pauseparam is not initialized in some implementations of get_pauseparam(), but the whole object is copied to userland. Signed-off-by: Kangjie Lu <redacted> --- net/core/ethtool.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)diff --git a/net/core/ethtool.c b/net/core/ethtool.c index f426c5a..84544bd 100644 --- a/net/core/ethtool.c +++ b/net/core/ethtool.c@@ -1723,7 +1723,10 @@ static noinline_for_stack int ethtool_set_channels(struct net_device *dev, static int ethtool_get_pauseparam(struct net_device *dev, void __user *useraddr) { - struct ethtool_pauseparam pauseparam = { ETHTOOL_GPAUSEPARAM };
AIUI an incomplete compound initialiser will fill all unspecified fields with zeroes of the appropriate type. So this patch is unnecessary. Per C99, §6.7.8.21:
If there are fewer initializers in a brace-enclosed list than there are elements or members of an aggregate [...] the remainder of the aggregate shall be initialized implicitly the same as objects that have static storage duration.
-Ed
+ struct ethtool_pauseparam pauseparam; + + memset(&pauseparam, 0, sizeof(pauseparam)); + pauseparam.cmd = ETHTOOL_GPAUSEPARAM; if (!dev->ethtool_ops->get_pauseparam) return -EOPNOTSUPP;