* [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam
@ 2016-06-01 14:39 Kangjie Lu
2016-06-01 14:57 ` Edward Cree
2016-06-01 17:14 ` Ben Hutchings
0 siblings, 2 replies; 3+ messages in thread
From: Kangjie Lu @ 2016-06-01 14:39 UTC (permalink / raw)
To: davem; +Cc: ben, kan.liang, netdev, linux-kernel, taesoo, csong84, Kangjie Lu
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 <kjlu@gatech.edu>
---
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 };
+ struct ethtool_pauseparam pauseparam;
+
+ memset(&pauseparam, 0, sizeof(pauseparam));
+ pauseparam.cmd = ETHTOOL_GPAUSEPARAM;
if (!dev->ethtool_ops->get_pauseparam)
return -EOPNOTSUPP;
--
1.9.1
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam
2016-06-01 14:39 [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam Kangjie Lu
@ 2016-06-01 14:57 ` Edward Cree
2016-06-01 17:14 ` Ben Hutchings
1 sibling, 0 replies; 3+ messages in thread
From: Edward Cree @ 2016-06-01 14:57 UTC (permalink / raw)
To: Kangjie Lu, davem
Cc: ben, kan.liang, netdev, linux-kernel, taesoo, csong84, Kangjie Lu
On 01/06/16 15:39, Kangjie Lu wrote:
> 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 <kjlu@gatech.edu>
> ---
> 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;
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam
2016-06-01 14:39 [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam Kangjie Lu
2016-06-01 14:57 ` Edward Cree
@ 2016-06-01 17:14 ` Ben Hutchings
1 sibling, 0 replies; 3+ messages in thread
From: Ben Hutchings @ 2016-06-01 17:14 UTC (permalink / raw)
To: Kangjie Lu, davem
Cc: kan.liang, netdev, linux-kernel, taesoo, csong84, Kangjie Lu
[-- Attachment #1: Type: text/plain, Size: 1295 bytes --]
On Wed, 2016-06-01 at 16:39 +0200, Kangjie Lu wrote:
> The field autoneg of pauseparam is not initialized in some
> implementations of get_pauseparam(),
Nonsense. The current implementation initialises all fields. (If
there was padding in the structure, this change would be needed to
guarantee that the padding was initialised. But there isn't.)
Ben.
> but the whole object is
> copied to userland.
>
> Signed-off-by: Kangjie Lu <kjlu@gatech.edu>
> ---
> 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
> };
> + struct ethtool_pauseparam pauseparam;
> +
> + memset(&pauseparam, 0, sizeof(pauseparam));
> + pauseparam.cmd = ETHTOOL_GPAUSEPARAM;
>
> if (!dev->ethtool_ops->get_pauseparam)
> return -EOPNOTSUPP;
--
Ben Hutchings
To err is human; to really foul things up requires a computer.
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^ permalink raw reply [flat|nested] 3+ messages in thread
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2016-06-01 14:39 [PATCH] ethtool: fix a kernel infoleak in ethtool_get_pauseparam Kangjie Lu
2016-06-01 14:57 ` Edward Cree
2016-06-01 17:14 ` Ben Hutchings
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