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2017-10-16net: enable interface alias removal via rtnlNicolas Dichtel1-1/+4
IFLA_IFALIAS is defined as NLA_STRING. It means that the minimal length of the attribute is 1 ("\0"). However, to remove an alias, the attribute length must be 0 (see dev_set_alias()). Let's define the type to NLA_BINARY to allow 0-length string, so that the alias can be removed. Example: $ ip l s dummy0 alias foo $ ip l l dev dummy0 5: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether ae:20:30:4f:a7:f3 brd ff:ff:ff:ff:ff:ff alias foo Before the patch: $ ip l s dummy0 alias "" RTNETLINK answers: Numerical result out of range After the patch: $ ip l s dummy0 alias "" $ ip l l dev dummy0 5: dummy0: <BROADCAST,NOARP> mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000 link/ether ae:20:30:4f:a7:f3 brd ff:ff:ff:ff:ff:ff CC: Oliver Hartkopp <oliver@hartkopp.net> CC: Stephen Hemminger <stephen@networkplumber.org> Fixes: 96ca4a2cc145 ("net: remove ifalias on empty given alias") Reported-by: Julien FLoret <julien.floret@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: do not set notification for tx_queue_len in do_setlinkXin Long1-1/+1
NETDEV_CHANGE_TX_QUEUE_LEN event process in rtnetlink_event would send a notification for userspace and tx_queue_len's setting in do_setlink would trigger NETDEV_CHANGE_TX_QUEUE_LEN. So it shouldn't set DO_SETLINK_NOTIFY status for this change to send a notification any more. Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlinkXin Long1-1/+1
The check 'status & DO_SETLINK_NOTIFY' in do_setlink doesn't really work after status & DO_SETLINK_MODIFIED, as: DO_SETLINK_MODIFIED 0x1 DO_SETLINK_NOTIFY 0x3 Considering that notifications are suppposed to be sent only when status have the flag DO_SETLINK_NOTIFY, the right check would be: (status & DO_SETLINK_NOTIFY) == DO_SETLINK_NOTIFY This would avoid lots of duplicated notifications when setting some properties of a link. Fixes: ba9989069f4e ("rtnl/do_setlink(): notify when a netdev is modified") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Acked-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_CHANGEUPPER event process back in rtnetlink_eventXin Long1-0/+1
libteam needs this event notification in userspace when dev's master dev has been changed. After this, the redundant notifications issue would be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink'. Fixes: b6b36eb23a46 ("rtnetlink: Do not generate notifications for NETDEV_CHANGEUPPER event") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_POST_TYPE_CHANGE event process back in rtnetlink_eventXin Long1-0/+1
As I said in patch 'rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_event', removing NETDEV_POST_TYPE_CHANGE event was not the right fix for the redundant notifications issue. So bring this event process back to rtnetlink_event and the old redundant notifications issue would be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink'. Fixes: aef091ae58aa ("rtnetlink: Do not generate notifications for POST_TYPE_CHANGE event") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_CHANGE_TX_QUEUE_LEN event process back in ↵Xin Long1-0/+1
rtnetlink_event The same fix for changing mtu in the patch 'rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_event' is needed for changing tx_queue_len. Note that the redundant notifications issue for tx_queue_len will be fixed in the later patch 'rtnetlink: do not send notification for tx_queue_len in do_setlink'. Fixes: 27b3b551d8a7 ("rtnetlink: Do not generate notifications for NETDEV_CHANGE_TX_QUEUE_LEN event") Signed-off-by: Xin Long <lucien.xin@gmail.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-16rtnetlink: bring NETDEV_CHANGEMTU event process back in rtnetlink_eventXin Long1-0/+1
Commit 085e1a65f04f ("rtnetlink: Do not generate notifications for MTU events") tried to fix the redundant notifications issue when ip link set mtu by removing NETDEV_CHANGEMTU event process in rtnetlink_event. But it also resulted in no notification generated when dev's mtu is changed via other methods, like: 'ifconfig eth1 mtu 1400' or 'echo 1400 > /sys/class/net/eth1/mtu' It would cause users not to be notified by this change. This patch is to fix it by bringing NETDEV_CHANGEMTU event back into rtnetlink_event, and the redundant notifications issue will be fixed in the later patch 'rtnetlink: check DO_SETLINK_NOTIFY correctly in do_setlink'. Fixes: 085e1a65f04f ("rtnetlink: Do not generate notifications for MTU events") Signed-off-by: Xin Long <lucien.xin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-10-03net: rtnetlink: fix info leak in RTM_GETSTATS callNikolay Aleksandrov1-0/+3
When RTM_GETSTATS was added the fields of its header struct were not all initialized when returning the result thus leaking 4 bytes of information to user-space per rtnl_fill_statsinfo call, so initialize them now. Thanks to Alexander Potapenko for the detailed report and bisection. Reported-by: Alexander Potapenko <glider@google.com> Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats") Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Acked-by: Roopa Prabhu <roopa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-14rtnelink: Move link dump consistency check out of the loopJakub Sitnicki1-4/+2
Calls to rtnl_dump_ifinfo() are protected by RTNL lock. So are the {list,unlist}_netdevice() calls where we bump the net->dev_base_seq number. For this reason net->dev_base_seq can't change under out feet while we're looping over links in rtnl_dump_ifinfo(). So move the check for net->dev_base_seq change (since the last time we were called) out of the loop. This way we avoid giving a wrong impression that there are concurrent updates to the link list going on while we're iterating over them. Signed-off-by: Jakub Sitnicki <jkbs@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: fallback to UNSPEC if current family has no doit callbackFlorian Westphal1-0/+6
We need to use PF_UNSPEC in case the requested family has no doit callback, otherwise this now fails with EOPNOTSUPP instead of running the unspec doit callback, as before. Fixes: 6853dd488119 ("rtnetlink: protect handler table with rcu") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: init handler refcounts to 1Florian Westphal1-1/+6
If using CONFIG_REFCOUNT_FULL=y we get following splat: refcount_t: increment on 0; use-after-free. WARNING: CPU: 0 PID: 304 at lib/refcount.c:152 refcount_inc+0x47/0x50 Call Trace: rtnetlink_rcv_msg+0x191/0x260 ... This warning is harmless (0 is "no callback running", not "memory was freed"). Use '1' as the new 'no handler is running' base instead of 0 to avoid this. Fixes: 019a316992ee ("rtnetlink: add reference counting to prevent module unload while dump is in progress") Reported-by: Sabrina Dubroca <sdubroca@redhat.com> Reported-by: kernel test robot <fengguang.wu@intel.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: switch rtnl_link_get_slave_info_data_size to rcuFlorian Westphal1-4/+12
David Ahern reports following splat: RTNL: assertion failed at net/core/dev.c (5717) netdev_master_upper_dev_get+0x5f/0x70 if_nlmsg_size+0x158/0x240 rtnl_calcit.isra.26+0xa3/0xf0 rtnl_link_get_slave_info_data_size currently assumes RTNL protection, but there appears to be no hard requirement for this, so use rcu instead. At the time of this writing, there are three 'get_slave_size' callbacks (now invoked under rcu): bond_get_slave_size, vrf_get_slave_size and br_port_get_slave_size, all return constant only (i.e. they don't sleep). Fixes: 6853dd488119 ("rtnetlink: protect handler table with rcu") Reported-by: David Ahern <dsahern@gmail.com> Signed-off-by: Florian Westphal <fw@strlen.de> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: do not use RTM_GETLINK directlyFlorian Westphal1-2/+2
Userspace sends RTM_GETLINK type, but the kernel substracts RTM_BASE from this, i.e. 'type' doesn't contain RTM_GETLINK anymore but instead RTM_GETLINK - RTM_BASE. This caused the calcit callback to not be invoked when it should have been (and vice versa). While at it, also fix a off-by one when checking family index. vs handler array size. Fixes: e1fa6d216dd ("rtnetlink: call rtnl_calcit directly") Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: use rcu_dereference_raw to silence rcu splatFlorian Westphal1-1/+1
Ido reports a rcu splat in __rtnl_register. The splat is correct; as rtnl_register doesn't grab any logs and doesn't use rcu locks either. It has always been like this. handler families are not registered in parallel so there are no races wrt. the kmalloc ordering. The only reason to use rcu_dereference in the first place was to avoid sparse from complaining about this. Thus this switches to _raw() to not have rcu checks here. The alternative is to add rtnl locking to register/unregister, however, I don't see a compelling reason to do so as this has been lockless for the past twenty years or so. Fixes: 6853dd4881 ("rtnetlink: protect handler table with rcu") Reported-by: Ido Schimmel <idosch@idosch.org> Signed-off-by: Florian Westphal <fw@strlen.de> Tested-by: Ido Schimmel <idosch@mellanox.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: add RTNL_FLAG_DOIT_UNLOCKEDFlorian Westphal1-0/+15
Allow callers to tell rtnetlink core that its doit callback should be invoked without holding rtnl mutex. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: protect handler table with rcuFlorian Westphal1-56/+65
Note that netlink dumps still acquire rtnl mutex via the netlink dump infrastructure. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: small rtnl lock pushdownFlorian Westphal1-6/+13
instead of rtnl lock/unload at the top level, push it down to the called function. This is just an intermediate step, next commit switches protection of the rtnl_link ops table to rcu, in which case (for dumps) the rtnl lock is acquired only by the netlink dumper infrastructure (current lock/unlock/dump/lock/unlock rtnl sequence becomes rcu lock/rcu unlock/dump). Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: add reference counting to prevent module unload while dump is in ↵Florian Westphal1-1/+13
progress I don't see what prevents rmmod (unregister_all is called) while a dump is active. Even if we'd add rtnl lock/unlock pair to unregister_all (as done here), thats not enough either as rtnl_lock is released right before the dump process starts. So this adds a refcount: * acquire rtnl mutex * bump refcount * release mutex * start the dump ... and make unregister_all remove the callbacks (no new dumps possible) and then wait until refcount is 0. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: make rtnl_register accept a flags parameterFlorian Westphal1-18/+18
This change allows us to later indicate to rtnetlink core that certain doit functions should be called without acquiring rtnl_mutex. This change should have no effect, we simply replace the last (now unused) calcit argument with the new flag. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-08-10rtnetlink: call rtnl_calcit directlyFlorian Westphal1-25/+4
There is only a single place in the kernel that regisers the "calcit" callback (to determine min allocation for dumps). This is in rtnetlink.c for PF_UNSPEC RTM_GETLINK. The function that checks for calcit presence at run time will first check the requested family (which will always fail for !PF_UNSPEC as no callsite registers this), then falls back to checking PF_UNSPEC. Therefore we can just check if type is RTM_GETLINK and then do a direct call. Because of fallback to PF_UNSPEC all RTM_GETLINK types used this regardless of family. This has the advantage that we don't need to allocate space for the function pointer for all the other families. A followup patch will drop the calcit function pointer from the rtnl_link callback structure. Signed-off-by: Florian Westphal <fw@strlen.de> Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-21rtnetlink: allocate more memory for dev_set_mac_address()WANG Cong1-1/+2
virtnet_set_mac_address() interprets mac address as struct sockaddr, but upper layer only allocates dev->addr_len which is ETH_ALEN + sizeof(sa_family_t) in this case. We lack a unified definition for mac address, so just fix the upper layer, this also allows drivers to interpret it to struct sockaddr freely. Reported-by: David Ahern <dsahern@gmail.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-20Revert "rtnetlink: Do not generate notifications for CHANGEADDR event"David Ahern1-0/+1
This reverts commit cd8966e75ed3c6b41a37047a904617bc44fa481f. The duplicate CHANGEADDR event message is sent regardless of link status whereas the setlink changes only generate a notification when the link is up. Not sending a notification when the link is down breaks dhcpcd which only processes hwaddr changes when the link is down. Fixes reported regression: https://bugzilla.kernel.org/show_bug.cgi?id=196355 Reported-by: Yaroslav Isakov <yaroslav.isakov@gmail.com> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-07-01net: convert sk_buff.users from atomic_t to refcount_tReshetova, Elena1-1/+1
refcount_t type and corresponding API should be used instead of atomic_t when the variable is used as a reference counter. This allows to avoid accidental refcounter overflows that might lead to use-after-free situations. Signed-off-by: Elena Reshetova <elena.reshetova@intel.com> Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Signed-off-by: David Windsor <dwindsor@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-27net: add netlink_ext_ack argument to rtnl_link_ops.slave_validateMatthias Schiffer1-1/+2
Add support for extended error reporting. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-27net: add netlink_ext_ack argument to rtnl_link_ops.slave_changelinkMatthias Schiffer1-1/+2
Add support for extended error reporting. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-27net: add netlink_ext_ack argument to rtnl_link_ops.validateMatthias Schiffer1-1/+1
Add support for extended error reporting. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-27net: add netlink_ext_ack argument to rtnl_link_ops.changelinkMatthias Schiffer1-1/+1
Add support for extended error reporting. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-27net: add netlink_ext_ack argument to rtnl_link_ops.newlinkMatthias Schiffer1-1/+2
Add support for extended error reporting. Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23xdp: add reporting of offload modeJakub Kicinski1-3/+3
Extend the XDP_ATTACHED_* values to include offloaded mode. Let drivers report whether program is installed in the driver or the HW by changing the prog_attached field from bool to u8 (type of the netlink attribute). Exploit the fact that the value of XDP_ATTACHED_DRV is 1, therefore since all drivers currently assign the mode with double negation: mode = !!xdp_prog; no drivers have to be modified. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-23xdp: add HW offload mode flag for installing programsJakub Kicinski1-2/+2
Add an installation-time flag for requesting that the program be installed only if it can be offloaded to HW. Internally new command for ndo_xdp is added, this way we avoid putting checks into drivers since they all return -EINVAL on an unknown command. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-22Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-0/+2
Two entries being added at the same time to the IFLA policy table, whilst parallel bug fixes to decnet routing dst handling overlapping with the dst gc removal in net-next. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-21rtnetlink: add restricted rtnl groups for ipv4 and ipv6 mrouteJulien Gomes1-0/+13
Add RTNLGRP_{IPV4,IPV6}_MROUTE_R as two new restricted groups for the NETLINK_ROUTE family. Binding to these groups specifically requires CAP_NET_ADMIN to allow multicast of sensitive messages (e.g. mroute cache reports). Suggested-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: Julien Gomes <julien@arista.com> Signed-off-by: Nikolay Aleksandrov <nikolay@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-20rtnetlink: add IFLA_GROUP to ifla_policySerhey Popovych1-0/+2
Network interface groups support added while ago, however there is no IFLA_GROUP attribute description in policy and netlink message size calculations until now. Add IFLA_GROUP attribute to the policy. Fixes: cbda10fa97d7 ("net_device: add support for network device groups") Signed-off-by: Serhey Popovych <serhe.popovych@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-16net: Add IFLA_XDP_PROG_IDMartin KaFai Lau1-6/+21
Expose prog_id through IFLA_XDP_PROG_ID. This patch makes modification to generic_xdp. The later patches will modify other xdp-supported drivers. prog_id is added to struct net_dev_xdp. iproute2 patch will be followed. Here is how the 'ip link' will look like: > ip link show eth0 3: eth0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 xdp(prog_id:1) qdisc fq_codel state UP mode DEFAULT group default qlen 1000 Signed-off-by: Martin KaFai Lau <kafai@fb.com> Acked-by: Alexei Starovoitov <ast@fb.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-15Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-1/+2
The conflicts were two cases of overlapping changes in batman-adv and the qed driver. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-06-08net: Zero ifla_vf_info in rtnl_fill_vfinfo()Mintz, Yuval1-1/+2
Some of the structure's fields are not initialized by the rtnetlink. If driver doesn't set those in ndo_get_vf_config(), they'd leak memory to user. Signed-off-by: Yuval Mintz <Yuval.Mintz@cavium.com> CC: Michal Schmidt <mschmidt@redhat.com> Reviewed-by: Greg Rose <gvrose8192@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-31rtnetlink: use the new rtnl_get_event() interfaceVlad Yasevich1-1/+1
Small clean-up to rtmsg_ifinfo() to use the rtnl_get_event() interface instead of using 'internal' values directly. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-28rtnl: Add support for netdev event to link messagesVlad Yasevich1-9/+56
When netdev events happen, a rtnetlink_event() handler will send messages for every event in it's white list. These messages contain current information about a particular device, but they do not include the iformation about which event just happened. So, it is impossible to tell what just happend for these events. This patch adds a new extension to RTM_NEWLINK message called IFLA_EVENT that would have an encoding of event that triggered this message. This would allow the the message consumer to easily determine if it needs to perform certain actions. Signed-off-by: Vladislav Yasevich <vyasevic@redhat.com> Acked-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-27Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-2/+5
Overlapping changes in drivers/net/phy/marvell.c, bug fix in 'net' restricting a HW workaround alongside cleanups in 'net-next'. Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-24net: rtnetlink: bail out from rtnl_fdb_dump() on parse errorAlexander Potapenko1-2/+5
rtnl_fdb_dump() failed to check the result of nlmsg_parse(), which led to contents of |ifm| being uninitialized because nlh->nlmsglen was too small to accommodate |ifm|. The uninitialized data may affect some branches and result in unwanted effects, although kernel data doesn't seem to leak to the userspace directly. The bug has been detected with KMSAN and syzkaller. For the record, here is the KMSAN report: ================================================================== BUG: KMSAN: use of unitialized memory in rtnl_fdb_dump+0x5dc/0x1000 CPU: 0 PID: 1039 Comm: probe Not tainted 4.11.0-rc5+ #2727 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x143/0x1b0 lib/dump_stack.c:52 kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:1007 __kmsan_warning_32+0x66/0xb0 mm/kmsan/kmsan_instr.c:491 rtnl_fdb_dump+0x5dc/0x1000 net/core/rtnetlink.c:3230 netlink_dump+0x84f/0x1190 net/netlink/af_netlink.c:2168 __netlink_dump_start+0xc97/0xe50 net/netlink/af_netlink.c:2258 netlink_dump_start ./include/linux/netlink.h:165 rtnetlink_rcv_msg+0xae9/0xb40 net/core/rtnetlink.c:4094 netlink_rcv_skb+0x339/0x5a0 net/netlink/af_netlink.c:2339 rtnetlink_rcv+0x83/0xa0 net/core/rtnetlink.c:4110 netlink_unicast_kernel net/netlink/af_netlink.c:1272 netlink_unicast+0x13b7/0x1480 net/netlink/af_netlink.c:1298 netlink_sendmsg+0x10b8/0x10f0 net/netlink/af_netlink.c:1844 sock_sendmsg_nosec net/socket.c:633 sock_sendmsg net/socket.c:643 ___sys_sendmsg+0xd4b/0x10f0 net/socket.c:1997 __sys_sendmsg net/socket.c:2031 SYSC_sendmsg+0x2c6/0x3f0 net/socket.c:2042 SyS_sendmsg+0x87/0xb0 net/socket.c:2038 do_syscall_64+0x102/0x150 arch/x86/entry/common.c:285 entry_SYSCALL64_slow_path+0x25/0x25 arch/x86/entry/entry_64.S:246 RIP: 0033:0x401300 RSP: 002b:00007ffc3b0e6d58 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00000000004002b0 RCX: 0000000000401300 RDX: 0000000000000000 RSI: 00007ffc3b0e6d80 RDI: 0000000000000003 RBP: 00007ffc3b0e6e00 R08: 000000000000000b R09: 0000000000000004 R10: 000000000000000d R11: 0000000000000246 R12: 0000000000000000 R13: 00000000004065a0 R14: 0000000000406630 R15: 0000000000000000 origin: 000000008fe00056 save_stack_trace+0x59/0x60 arch/x86/kernel/stacktrace.c:59 kmsan_save_stack_with_flags mm/kmsan/kmsan.c:352 kmsan_internal_poison_shadow+0xb1/0x1a0 mm/kmsan/kmsan.c:247 kmsan_poison_shadow+0x6d/0xc0 mm/kmsan/kmsan.c:260 slab_alloc_node mm/slub.c:2743 __kmalloc_node_track_caller+0x1f4/0x390 mm/slub.c:4349 __kmalloc_reserve net/core/skbuff.c:138 __alloc_skb+0x2cd/0x740 net/core/skbuff.c:231 alloc_skb ./include/linux/skbuff.h:933 netlink_alloc_large_skb net/netlink/af_netlink.c:1144 netlink_sendmsg+0x934/0x10f0 net/netlink/af_netlink.c:1819 sock_sendmsg_nosec net/socket.c:633 sock_sendmsg net/socket.c:643 ___sys_sendmsg+0xd4b/0x10f0 net/socket.c:1997 __sys_sendmsg net/socket.c:2031 SYSC_sendmsg+0x2c6/0x3f0 net/socket.c:2042 SyS_sendmsg+0x87/0xb0 net/socket.c:2038 do_syscall_64+0x102/0x150 arch/x86/entry/common.c:285 return_from_SYSCALL_64+0x0/0x6a arch/x86/entry/entry_64.S:246 ================================================================== and the reproducer: ================================================================== #include <sys/socket.h> #include <net/if_arp.h> #include <linux/netlink.h> #include <stdint.h> int main() { int sock = socket(PF_NETLINK, SOCK_DGRAM | SOCK_NONBLOCK, 0); struct msghdr msg; memset(&msg, 0, sizeof(msg)); char nlmsg_buf[32]; memset(nlmsg_buf, 0, sizeof(nlmsg_buf)); struct nlmsghdr *nlmsg = nlmsg_buf; nlmsg->nlmsg_len = 0x11; nlmsg->nlmsg_type = 0x1e; // RTM_NEWROUTE = RTM_BASE + 0x0e // type = 0x0e = 1110b // kind = 2 nlmsg->nlmsg_flags = 0x101; // NLM_F_ROOT | NLM_F_REQUEST nlmsg->nlmsg_seq = 0; nlmsg->nlmsg_pid = 0; nlmsg_buf[16] = (char)7; struct iovec iov; iov.iov_base = nlmsg_buf; iov.iov_len = 17; msg.msg_iov = &iov; msg.msg_iovlen = 1; sendmsg(sock, &msg, 0); return 0; } ================================================================== Signed-off-by: Alexander Potapenko <glider@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-18Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/netDavid S. Miller1-12/+24
2017-05-18net: make struct net_device::tx_queue_len unsigned intAlexey Dobriyan1-2/+2
4 billion packet queue is something unthinkable so use 32-bit value for now. Space savings on x86_64: add/remove: 0/0 grow/shrink: 3/70 up/down: 16/-131 (-115) function old new delta change_tx_queue_len 94 108 +14 qdisc_create 1176 1177 +1 alloc_netdev_mqs 1124 1125 +1 xenvif_alloc 533 532 -1 x25_asy_setup 167 166 -1 ... tun_queue_resize 945 940 -5 pfifo_fast_enqueue 167 162 -5 qfq_init_qdisc 168 158 -10 tap_queue_resize 810 799 -11 transmit 719 698 -21 Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-16net: Improve handling of failures on link and route dumpsDavid Ahern1-12/+24
In general, rtnetlink dumps do not anticipate failure to dump a single object (e.g., link or route) on a single pass. As both route and link objects have grown via more attributes, that is no longer a given. netlink dumps can handle a failure if the dump function returns an error; specifically, netlink_dump adds the return code to the response if it is <= 0 so userspace is notified of the failure. The missing piece is the rtnetlink dump functions returning the error. Fix route and link dump functions to return the errors if no object is added to an skb (detected by skb->len != 0). IPv6 route dumps (rt6_dump_route) already return the error; this patch updates IPv4 and link dumps. Other dump functions may need to be ajusted as well. Reported-by: Jan Moskyto Matejka <mq@ucw.cz> Signed-off-by: David Ahern <dsahern@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-12xdp: refine xdp api with regards to generic xdpDaniel Borkmann1-22/+18
While working on the iproute2 generic XDP frontend, I noticed that as of right now it's possible to have native *and* generic XDP programs loaded both at the same time for the case when a driver supports native XDP. The intended model for generic XDP from b5cdae3291f7 ("net: Generic XDP") is, however, that only one out of the two can be present at once which is also indicated as such in the XDP netlink dump part. The main rationale for generic XDP is to ease accessibility (in case a driver does not yet have XDP support) and to generically provide a semantical model as an example for driver developers wanting to add XDP support. The generic XDP option for an XDP aware driver can still be useful for comparing and testing both implementations. However, it is not intended to have a second XDP processing stage or layer with exactly the same functionality of the first native stage. Only reason could be to have a partial fallback for future XDP features that are not supported yet in the native implementation and we probably also shouldn't strive for such fallback and instead encourage native feature support in the first place. Given there's currently no such fallback issue or use case, lets not go there yet if we don't need to. Therefore, change semantics for loading XDP and bail out if the user tries to load a generic XDP program when a native one is present and vice versa. Another alternative to bailing out would be to handle the transition from one flavor to another gracefully, but that would require to bring the device down, exchange both types of programs, and bring it up again in order to avoid a tiny window where a packet could hit both hooks. Given this complicates the logic for just a debugging feature in the native case, I went with the simpler variant. For the dump, remove IFLA_XDP_FLAGS that was added with b5cdae3291f7 and reuse IFLA_XDP_ATTACHED for indicating the mode. Dumping all or just a subset of flags that were used for loading the XDP prog is suboptimal in the long run since not all flags are useful for dumping and if we start to reuse the same flag definitions for load and dump, then we'll waste bit space. What we really just want is to dump the mode for now. Current IFLA_XDP_ATTACHED semantics are: nothing was installed (0), a program is running at the native driver layer (1). Thus, add a mode that says that a program is running at generic XDP layer (2). Applications will handle this fine in that older binaries will just indicate that something is attached at XDP layer, effectively this is similar to IFLA_XDP_FLAGS attr that we would have had modulo the redundancy. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-12xdp: add flag to enforce driver modeDaniel Borkmann1-0/+5
After commit b5cdae3291f7 ("net: Generic XDP") we automatically fall back to a generic XDP variant if the driver does not support native XDP. Allow for an option where the user can specify that always the native XDP variant should be selected and in case it's not supported by a driver, just bail out. Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Alexei Starovoitov <ast@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-04rtnetlink: NUL-terminate IFLA_PHYS_PORT_NAME stringMichal Schmidt1-1/+1
IFLA_PHYS_PORT_NAME is a string attribute, so terminate it with \0. Otherwise libnl3 fails to validate netlink messages with this attribute. "ip -detail a" assumes too that the attribute is NUL-terminated when printing it. It often was, due to padding. I noticed this as libvirtd failing to start on a system with sfc driver after upgrading it to Linux 4.11, i.e. when sfc added support for phys_port_name. Signed-off-by: Michal Schmidt <mschmidt@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-05-01xdp: propagate extended ack to XDP setupJakub Kicinski1-5/+8
Drivers usually have a number of restrictions for running XDP - most common being buffer sizes, LRO and number of rings. Even though some drivers try to be helpful and print error messages experience shows that users don't often consult kernel logs on netlink errors. Try to use the new extended ack mechanism to carry the message back to user space. Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com> Acked-by: Daniel Borkmann <daniel@iogearbox.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-25net: Generic XDPDavid S. Miller1-15/+25
This provides a generic SKB based non-optimized XDP path which is used if either the driver lacks a specific XDP implementation, or the user requests it via a new IFLA_XDP_FLAGS value named XDP_FLAGS_SKB_MODE. It is arguable that perhaps I should have required something like this as part of the initial XDP feature merge. I believe this is critical for two reasons: 1) Accessibility. More people can play with XDP with less dependencies. Yes I know we have XDP support in virtio_net, but that just creates another depedency for learning how to use this facility. I wrote this to make life easier for the XDP newbies. 2) As a model for what the expected semantics are. If there is a pure generic core implementation, it serves as a semantic example for driver folks adding XDP support. One thing I have not tried to address here is the issue of XDP_PACKET_HEADROOM, thanks to Daniel for spotting that. It seems incredibly expensive to do a skb_cow(skb, XDP_PACKET_HEADROOM) or whatever even if the XDP program doesn't try to push headers at all. I think we really need the verifier to somehow propagate whether certain XDP helpers are used or not. v5: - Handle both negative and positive offset after running prog - Fix mac length in XDP_TX case (Alexei) - Use rcu_dereference_protected() in free_netdev (kbuild test robot) v4: - Fix MAC header adjustmnet before calling prog (David Ahern) - Disable LRO when generic XDP is installed (Michael Chan) - Bypass qdisc et al. on XDP_TX and record the event (Alexei) - Do not perform generic XDP on reinjected packets (DaveM) v3: - Make sure XDP program sees packet at MAC header, push back MAC header if we do XDP_TX. (Alexei) - Elide GRO when generic XDP is in use. (Alexei) - Add XDP_FLAG_SKB_MODE flag which the user can use to request generic XDP even if the driver has an XDP implementation. (Alexei) - Report whether SKB mode is in use in rtnl_xdp_fill() via XDP_FLAGS attribute. (Daniel) v2: - Add some "fall through" comments in switch statements based upon feedback from Andrew Lunn - Use RCU for generic xdp_prog, thanks to Johannes Berg. Tested-by: Andy Gospodarek <andy@greyhouse.net> Tested-by: Jesper Dangaard Brouer <brouer@redhat.com> Tested-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-17net: rtnetlink: plumb extended ack to doit functionDavid Ahern1-16/+26
Add netlink_ext_ack arg to rtnl_doit_func. Pass extack arg to nlmsg_parse for doit functions that call it directly. This is the first step to using extended error reporting in rtnetlink. >From here individual subsystems can be updated to set netlink_ext_ack as needed. Signed-off-by: David Ahern <dsa@cumulusnetworks.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2017-04-13netlink: pass extended ACK struct to parsing functionsJohannes Berg1-21/+26
Pass the new extended ACK reporting struct to all of the generic netlink parsing functions. For now, pass NULL in almost all callers (except for some in the core.) Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>