diff options
| author | Michal Kubeček <mkubecek@suse.cz> | 2016-12-14 13:24:58 +0100 |
|---|---|---|
| committer | Sasha Levin <alexander.levin@verizon.com> | 2016-12-23 08:56:36 -0500 |
| commit | 016d02981cceb7b0f3436278b71fe3ea87542e20 (patch) | |
| tree | 1366ffc4b69769651fa3e9c9b2f4946da20bde12 /net/tipc/bearer.h | |
| parent | efcf38bd40200212ef3de3d38e11c42958f8afaa (diff) | |
tipc: check minimum bearer MTU
[ Upstream commit 3de81b758853f0b29c61e246679d20b513c4cfec ]
Qian Zhang (张谦) reported a potential socket buffer overflow in
tipc_msg_build() which is also known as CVE-2016-8632: due to
insufficient checks, a buffer overflow can occur if MTU is too short for
even tipc headers. As anyone can set device MTU in a user/net namespace,
this issue can be abused by a regular user.
As agreed in the discussion on Ben Hutchings' original patch, we should
check the MTU at the moment a bearer is attached rather than for each
processed packet. We also need to repeat the check when bearer MTU is
adjusted to new device MTU. UDP case also needs a check to avoid
overflow when calculating bearer MTU.
References: CVE-2016-8632
Fixes: b97bf3fd8f6a ("[TIPC] Initial merge")
Signed-off-by: Michal Kubecek <mkubecek@suse.cz>
Reported-by: Qian Zhang (张谦) <zhangqian-c@360.cn>
Acked-by: Ying Xue <ying.xue@windriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Conflicts:
net/tipc/bearer.c
net/tipc/bearer.h
due to 1a90632da8c17a27e0c93538ee987764adee43a5: tipc: eliminate remnants of hungarian notation
and b1c29f6b10d5981c89d3ea9b9991ca97141ed6d0 tipc: simplify resetting and disabling of bearers
Signed-off-by: Philipp Hahn <hahn@univention.de>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Diffstat (limited to 'net/tipc/bearer.h')
| -rw-r--r-- | net/tipc/bearer.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/net/tipc/bearer.h b/net/tipc/bearer.h index 5cad243ee8fc..b7302b012624 100644 --- a/net/tipc/bearer.h +++ b/net/tipc/bearer.h @@ -38,6 +38,7 @@ #define _TIPC_BEARER_H #include "netlink.h" +#include "msg.h" #include <net/genetlink.h> #define MAX_BEARERS 2 @@ -61,6 +62,9 @@ #define TIPC_MEDIA_TYPE_IB 2 #define TIPC_MEDIA_TYPE_UDP 3 +/* minimum bearer MTU */ +#define TIPC_MIN_BEARER_MTU (MAX_H_SIZE + INT_H_SIZE) + /** * struct tipc_node_map - set of node identifiers * @count: # of nodes in set @@ -218,4 +222,13 @@ void tipc_bearer_stop(struct net *net); void tipc_bearer_send(struct net *net, u32 bearer_id, struct sk_buff *buf, struct tipc_media_addr *dest); +/* check if device MTU is too low for tipc headers */ +static inline bool tipc_mtu_bad(struct net_device *dev, unsigned int reserve) +{ + if (dev->mtu >= TIPC_MIN_BEARER_MTU + reserve) + return false; + netdev_warn(dev, "MTU too low for tipc bearer\n"); + return true; +} + #endif /* _TIPC_BEARER_H */ |