* [PATCH] nfc: Ensure presence of required attributes in the activate_target netlink handler
@ 2017-05-24 10:42 Mateusz Jurczyk
[not found] ` <20170524104226.14841-1-mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-06-22 22:29 ` Samuel Ortiz
0 siblings, 2 replies; 3+ messages in thread
From: Mateusz Jurczyk @ 2017-05-24 10:42 UTC (permalink / raw)
To: Samuel Ortiz, David S. Miller
Cc: linux-wireless-u79uwXL29TY76Z2rM5mHXA,
netdev-u79uwXL29TY76Z2rM5mHXA,
linux-kernel-u79uwXL29TY76Z2rM5mHXA,
security-DgEjT+Ai2ygdnm+yROfE0A
Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS attributes (in
addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client
prior to accessing them. This prevents potential unhandled NULL pointer
dereference exceptions which can be triggered by malicious user-mode
programs, if they omit one or both of these attributes.
Signed-off-by: Mateusz Jurczyk <mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
---
net/nfc/netlink.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)
diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
index 6b0850e63e09..b251fb936a27 100644
--- a/net/nfc/netlink.c
+++ b/net/nfc/netlink.c
@@ -907,7 +907,9 @@ static int nfc_genl_activate_target(struct sk_buff *skb, struct genl_info *info)
u32 device_idx, target_idx, protocol;
int rc;
- if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
+ if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
+ !info->attrs[NFC_ATTR_TARGET_INDEX] ||
+ !info->attrs[NFC_ATTR_PROTOCOLS])
return -EINVAL;
device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
--
2.13.0.219.gdb65acc882-goog
^ permalink raw reply related [flat|nested] 3+ messages in thread[parent not found: <20170524104226.14841-1-mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>]
* Re: [PATCH] nfc: Ensure presence of required attributes in the activate_target netlink handler
[not found] ` <20170524104226.14841-1-mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
@ 2017-05-24 17:05 ` Kees Cook
0 siblings, 0 replies; 3+ messages in thread
From: Kees Cook @ 2017-05-24 17:05 UTC (permalink / raw)
To: Mateusz Jurczyk
Cc: Samuel Ortiz, David S. Miller, linux-wireless,
Network Development, LKML,
security-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org
On Wed, May 24, 2017 at 3:42 AM, Mateusz Jurczyk <mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org> wrote:
> Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS attributes (in
> addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client
> prior to accessing them. This prevents potential unhandled NULL pointer
> dereference exceptions which can be triggered by malicious user-mode
> programs, if they omit one or both of these attributes.
>
> Signed-off-by: Mateusz Jurczyk <mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
Acked-by: Kees Cook <keescook-F7+t8E8rja9g9hUCZPvPmw@public.gmane.org>
-Kees
> ---
> net/nfc/netlink.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
>
> diff --git a/net/nfc/netlink.c b/net/nfc/netlink.c
> index 6b0850e63e09..b251fb936a27 100644
> --- a/net/nfc/netlink.c
> +++ b/net/nfc/netlink.c
> @@ -907,7 +907,9 @@ static int nfc_genl_activate_target(struct sk_buff *skb, struct genl_info *info)
> u32 device_idx, target_idx, protocol;
> int rc;
>
> - if (!info->attrs[NFC_ATTR_DEVICE_INDEX])
> + if (!info->attrs[NFC_ATTR_DEVICE_INDEX] ||
> + !info->attrs[NFC_ATTR_TARGET_INDEX] ||
> + !info->attrs[NFC_ATTR_PROTOCOLS])
> return -EINVAL;
>
> device_idx = nla_get_u32(info->attrs[NFC_ATTR_DEVICE_INDEX]);
> --
> 2.13.0.219.gdb65acc882-goog
>
--
Kees Cook
Pixel Security
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] nfc: Ensure presence of required attributes in the activate_target netlink handler
2017-05-24 10:42 [PATCH] nfc: Ensure presence of required attributes in the activate_target netlink handler Mateusz Jurczyk
[not found] ` <20170524104226.14841-1-mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
@ 2017-06-22 22:29 ` Samuel Ortiz
1 sibling, 0 replies; 3+ messages in thread
From: Samuel Ortiz @ 2017-06-22 22:29 UTC (permalink / raw)
To: Mateusz Jurczyk
Cc: David S. Miller, linux-wireless, netdev, linux-kernel, security
Hi Mateusz,
On Wed, May 24, 2017 at 12:42:26PM +0200, Mateusz Jurczyk wrote:
> Check that the NFC_ATTR_TARGET_INDEX and NFC_ATTR_PROTOCOLS attributes (in
> addition to NFC_ATTR_DEVICE_INDEX) are provided by the netlink client
> prior to accessing them. This prevents potential unhandled NULL pointer
> dereference exceptions which can be triggered by malicious user-mode
> programs, if they omit one or both of these attributes.
>
> Signed-off-by: Mateusz Jurczyk <mjurczyk@google.com>
> ---
> net/nfc/netlink.c | 4 +++-
> 1 file changed, 3 insertions(+), 1 deletion(-)
Applied, thanks.
Cheers,
Samuel.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2017-05-24 10:42 [PATCH] nfc: Ensure presence of required attributes in the activate_target netlink handler Mateusz Jurczyk
[not found] ` <20170524104226.14841-1-mjurczyk-hpIqsD4AKlfQT0dZR+AlfA@public.gmane.org>
2017-05-24 17:05 ` Kees Cook
2017-06-22 22:29 ` Samuel Ortiz
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