| Message ID | 20230726075314.1059224-1-linma@zju.edu.cn (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | d73ef2d69c0dba5f5a1cb9600045c873bab1fb7f |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | [net,v3] rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length | expand |
On Wed, Jul 26, 2023 at 03:53:14PM +0800, Lin Ma wrote: > There are totally 9 ndo_bridge_setlink handlers in the current kernel, > which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3) > i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5) > ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7) > nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink. > > By investigating the code, we find that 1-7 parse and use nlattr > IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can > lead to an out-of-attribute read and allow a malformed nlattr (e.g., > length 0) to be viewed as a 2 byte integer. > > To avoid such issues, also for other ndo_bridge_setlink handlers in the > future. This patch adds the nla_len check in rtnl_bridge_setlink and > does an early error return if length mismatches. To make it works, the > break is removed from the parsing for IFLA_BRIDGE_FLAGS to make sure > this nla_for_each_nested iterates every attribute. > > Fixes: b1edc14a3fbf ("ice: Implement ice_bridge_getlink and ice_bridge_setlink") > Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops") > Suggested-by: Jakub Kicinski <kuba@kernel.org> > Signed-off-by: Lin Ma <linma@zju.edu.cn> > Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Hangbin Liu <liuhangbin@gmail.com>
On Wed, 26 Jul 2023 15:53:14 +0800 Lin Ma wrote:
> V2 -> V3: add net subject prefix and Acked-by tag
Because of the repost this patch didn't make it in time to today's
PR and you'll have to wait another week before posting the cleanup
of the drivers :(
Hello: This patch was applied to netdev/net.git (main) by Jakub Kicinski <kuba@kernel.org>: On Wed, 26 Jul 2023 15:53:14 +0800 you wrote: > There are totally 9 ndo_bridge_setlink handlers in the current kernel, > which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3) > i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5) > ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7) > nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink. > > By investigating the code, we find that 1-7 parse and use nlattr > IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can > lead to an out-of-attribute read and allow a malformed nlattr (e.g., > length 0) to be viewed as a 2 byte integer. > > [...] Here is the summary with links: - [net,v3] rtnetlink: let rtnl_bridge_setlink checks IFLA_BRIDGE_MODE length https://git.kernel.org/netdev/net/c/d73ef2d69c0d You are awesome, thank you!
Hello there, > > Because of the repost this patch didn't make it in time to today's > PR and you'll have to wait another week before posting the cleanup > of the drivers :( Gotcha :O I will remember to do that next week ;) Regards Lin
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index 3ad4e030846d..aef25aa5cf1d 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -5140,13 +5140,17 @@ static int rtnl_bridge_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, br_spec = nlmsg_find_attr(nlh, sizeof(struct ifinfomsg), IFLA_AF_SPEC); if (br_spec) { nla_for_each_nested(attr, br_spec, rem) { - if (nla_type(attr) == IFLA_BRIDGE_FLAGS) { + if (nla_type(attr) == IFLA_BRIDGE_FLAGS && !have_flags) { if (nla_len(attr) < sizeof(flags)) return -EINVAL; have_flags = true; flags = nla_get_u16(attr); - break; + } + + if (nla_type(attr) == IFLA_BRIDGE_MODE) { + if (nla_len(attr) < sizeof(u16)) + return -EINVAL; } } }
There are totally 9 ndo_bridge_setlink handlers in the current kernel, which are 1) bnxt_bridge_setlink, 2) be_ndo_bridge_setlink 3) i40e_ndo_bridge_setlink 4) ice_bridge_setlink 5) ixgbe_ndo_bridge_setlink 6) mlx5e_bridge_setlink 7) nfp_net_bridge_setlink 8) qeth_l2_bridge_setlink 9) br_setlink. By investigating the code, we find that 1-7 parse and use nlattr IFLA_BRIDGE_MODE but 3 and 4 forget to do the nla_len check. This can lead to an out-of-attribute read and allow a malformed nlattr (e.g., length 0) to be viewed as a 2 byte integer. To avoid such issues, also for other ndo_bridge_setlink handlers in the future. This patch adds the nla_len check in rtnl_bridge_setlink and does an early error return if length mismatches. To make it works, the break is removed from the parsing for IFLA_BRIDGE_FLAGS to make sure this nla_for_each_nested iterates every attribute. Fixes: b1edc14a3fbf ("ice: Implement ice_bridge_getlink and ice_bridge_setlink") Fixes: 51616018dd1b ("i40e: Add support for getlink, setlink ndo ops") Suggested-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Lin Ma <linma@zju.edu.cn> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> --- V1 -> V2: removes the break in parsing for IFLA_BRIDGE_FLAGS suggested by Hangbin Liu <liuhangbin@gmail.com> V2 -> V3: add net subject prefix and Acked-by tag net/core/rtnetlink.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-)