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2020-10-14net_sched: defer tcf_idr_insert() in tcf_action_init_1()Cong Wang
commit e49d8c22f1261c43a986a7fdbf677ac309682a07 upstream. All TC actions call tcf_idr_insert() for new action at the end of their ->init(), so we can actually move it to a central place in tcf_action_init_1(). And once the action is inserted into the global IDR, other parallel process could free it immediately as its refcnt is still 1, so we can not fail after this, we need to move it after the goto action validation to avoid handling the failure case after insertion. This is found during code review, is not directly triggered by syzbot. And this prepares for the next patch. Cc: Vlad Buslov <vladbu@mellanox.com> Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-07-22sched: consistently handle layer3 header accesses in the presence of VLANsToke Høiland-Jørgensen
[ Upstream commit d7bf2ebebc2bd61ab95e2a8e33541ef282f303d4 ] There are a couple of places in net/sched/ that check skb->protocol and act on the value there. However, in the presence of VLAN tags, the value stored in skb->protocol can be inconsistent based on whether VLAN acceleration is enabled. The commit quoted in the Fixes tag below fixed the users of skb->protocol to use a helper that will always see the VLAN ethertype. However, most of the callers don't actually handle the VLAN ethertype, but expect to find the IP header type in the protocol field. This means that things like changing the ECN field, or parsing diffserv values, stops working if there's a VLAN tag, or if there are multiple nested VLAN tags (QinQ). To fix this, change the helper to take an argument that indicates whether the caller wants to skip the VLAN tags or not. When skipping VLAN tags, we make sure to skip all of them, so behaviour is consistent even in QinQ mode. To make the helper usable from the ECN code, move it to if_vlan.h instead of pkt_sched.h. v3: - Remove empty lines - Move vlan variable definitions inside loop in skb_protocol() - Also use skb_protocol() helper in IP{,6}_ECN_decapsulate() and bpf_skb_ecn_set_ce() v2: - Use eth_type_vlan() helper in skb_protocol() - Also fix code that reads skb->protocol directly - Change a couple of 'if/else if' statements to switch constructs to avoid calling the helper twice Reported-by: Ilya Ponetayev <i.ponetaev@ndmsystems.com> Fixes: d8b9605d2697 ("net: sched: fix skb->protocol use in case of accelerated vlan path") Signed-off-by: Toke Høiland-Jørgensen <toke@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2020-01-23net: sched: act_ctinfo: fix memory leakEric Dumazet
[ Upstream commit 09d4f10a5e78d76a53e3e584f1e6a701b6d24108 ] Implement a cleanup method to properly free ci->params BUG: memory leak unreferenced object 0xffff88811746e2c0 (size 64): comm "syz-executor617", pid 7106, jiffies 4294943055 (age 14.250s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ c0 34 60 84 ff ff ff ff 00 00 00 00 00 00 00 00 .4`............. backtrace: [<0000000015aa236f>] kmemleak_alloc_recursive include/linux/kmemleak.h:43 [inline] [<0000000015aa236f>] slab_post_alloc_hook mm/slab.h:586 [inline] [<0000000015aa236f>] slab_alloc mm/slab.c:3320 [inline] [<0000000015aa236f>] kmem_cache_alloc_trace+0x145/0x2c0 mm/slab.c:3549 [<000000002c946bd1>] kmalloc include/linux/slab.h:556 [inline] [<000000002c946bd1>] kzalloc include/linux/slab.h:670 [inline] [<000000002c946bd1>] tcf_ctinfo_init+0x21a/0x530 net/sched/act_ctinfo.c:236 [<0000000086952cca>] tcf_action_init_1+0x400/0x5b0 net/sched/act_api.c:944 [<000000005ab29bf8>] tcf_action_init+0x135/0x1c0 net/sched/act_api.c:1000 [<00000000392f56f9>] tcf_action_add+0x9a/0x200 net/sched/act_api.c:1410 [<0000000088f3c5dd>] tc_ctl_action+0x14d/0x1bb net/sched/act_api.c:1465 [<000000006b39d986>] rtnetlink_rcv_msg+0x178/0x4b0 net/core/rtnetlink.c:5424 [<00000000fd6ecace>] netlink_rcv_skb+0x61/0x170 net/netlink/af_netlink.c:2477 [<0000000047493d02>] rtnetlink_rcv+0x1d/0x30 net/core/rtnetlink.c:5442 [<00000000bdcf8286>] netlink_unicast_kernel net/netlink/af_netlink.c:1302 [inline] [<00000000bdcf8286>] netlink_unicast+0x223/0x310 net/netlink/af_netlink.c:1328 [<00000000fc5b92d9>] netlink_sendmsg+0x2c0/0x570 net/netlink/af_netlink.c:1917 [<00000000da84d076>] sock_sendmsg_nosec net/socket.c:639 [inline] [<00000000da84d076>] sock_sendmsg+0x54/0x70 net/socket.c:659 [<0000000042fb2eee>] ____sys_sendmsg+0x2d0/0x300 net/socket.c:2330 [<000000008f23f67e>] ___sys_sendmsg+0x8a/0xd0 net/socket.c:2384 [<00000000d838e4f6>] __sys_sendmsg+0x80/0xf0 net/socket.c:2417 [<00000000289a9cb1>] __do_sys_sendmsg net/socket.c:2426 [inline] [<00000000289a9cb1>] __se_sys_sendmsg net/socket.c:2424 [inline] [<00000000289a9cb1>] __x64_sys_sendmsg+0x23/0x30 net/socket.c:2424 Fixes: 24ec483cec98 ("net: sched: Introduce act_ctinfo action") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Cc: Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Kevin 'ldir' Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-08-27net_sched: fix a NULL pointer deref in ipt actionCong Wang
The net pointer in struct xt_tgdtor_param is not explicitly initialized therefore is still NULL when dereferencing it. So we have to find a way to pass the correct net pointer to ipt_destroy_target(). The best way I find is just saving the net pointer inside the per netns struct tcf_idrinfo, which could make this patch smaller. Fixes: 0c66dc1ea3f0 ("netfilter: conntrack: register hooks in netns when needed by ruleset") Reported-and-tested-by: itugrok@yahoo.com Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Jiri Pirko <jiri@resnulli.us> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-08-05net: sched: use temporary variable for actions indexesDmytro Linkin
Currently init call of all actions (except ipt) init their 'parm' structure as a direct pointer to nla data in skb. This leads to race condition when some of the filter actions were initialized successfully (and were assigned with idr action index that was written directly into nla data), but then were deleted and retried (due to following action module missing or classifier-initiated retry), in which case action init code tries to insert action to idr with index that was assigned on previous iteration. During retry the index can be reused by another action that was inserted concurrently, which causes unintended action sharing between filters. To fix described race condition, save action idr index to temporary stack-allocated variable instead on nla data. Fixes: 0190c1d452a9 ("net: sched: atomically check-allocate action") Signed-off-by: Dmytro Linkin <dmitrolin@mellanox.com> Signed-off-by: Vlad Buslov <vladbu@mellanox.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17net: sched: act_ctinfo: fix policy validationKevin Darbyshire-Bryant
Fix nla_policy definition by specifying an exact length type attribute to CTINFO action paraneter block structure. Without this change, netlink parsing will fail validation and the action will not be instantiated. 8cb081746c03 ("netlink: make validation more configurable for future") introduced much stricter checking to attributes being passed via netlink. Existing actions were updated to use less restrictive deprecated versions of nla_parse_nested. As a new module, act_ctinfo should be designed to use the strict checking model otherwise, well, what was the point of implementing it. Confession time: Until very recently, development of this module has been done on 'net-next' tree to 'clean compile' level with run-time testing on backports to 4.14 & 4.19 kernels under openwrt. This is how I managed to miss the run-time impacts of the new strict nla_parse_nested function. I hopefully have learned something from this (glances toward laptop running a net-next kernel) There is however a still outstanding implication on iproute2 user space in that it needs to be told to pass nested netlink messages with the nested attribute actually set. So even with this kernel fix to do things correctly you still cannot instantiate a new 'strict' nla_parse_nested based action such as act_ctinfo with iproute2's tc. Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-17net: sched: act_ctinfo: fix action creationKevin Darbyshire-Bryant
Use correct return value on action creation: ACT_P_CREATED. The use of incorrect return value could result in a situation where the system thought a ctinfo module was listening but actually wasn't instantiated correctly leading to an OOPS in tcf_generic_walker(). Confession time: Until very recently, development of this module has been done on 'net-next' tree to 'clean compile' level with run-time testing on backports to 4.14 & 4.19 kernels under openwrt. During the back & forward porting during development & testing, the critical ACT_P_CREATED return code got missed despite being in the 4.14 & 4.19 backports. I have now gone through the init functions, using act_csum as reference with a fine toothed comb. Bonus, no more OOPSes. I managed to also miss this issue till now due to the new strict nla_parse_nested function failing validation before action creation. As an inexperienced developer I've learned that copy/pasting/backporting/forward porting code correctly is hard. If I ever get to a developer conference I shall don the cone of shame. Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-06-14sched: act_ctinfo: use extack error reportingKevin Darbyshire-Bryant
Use extack error reporting mechanism in addition to returning -EINVAL NL_SET_ERR_* code shamelessy copy/paste/adjusted from act_pedit & sch_cake and used as reference as to what I should have done in the first place. Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-30net: sched: act_ctinfo: minor size optimisationKevin 'ldir' Darbyshire-Bryant
Since the new parameter block is initialised to 0 by kzmalloc we don't need to mask & clear unused operational mode bits, they are already unset. Drop the pointless code. Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
2019-05-29net: sched: Introduce act_ctinfo actionKevin 'ldir' Darbyshire-Bryant
ctinfo is a new tc filter action module. It is designed to restore information contained in firewall conntrack marks to other packet fields and is typically used on packet ingress paths. At present it has two independent sub-functions or operating modes, DSCP restoration mode & skb mark restoration mode. The DSCP restore mode: This mode copies DSCP values that have been placed in the firewall conntrack mark back into the IPv4/v6 diffserv fields of relevant packets. The DSCP restoration is intended for use and has been found useful for restoring ingress classifications based on egress classifications across links that bleach or otherwise change DSCP, typically home ISP Internet links. Restoring DSCP on ingress on the WAN link allows qdiscs such as but by no means limited to CAKE to shape inbound packets according to policies that are easier to set & mark on egress. Ingress classification is traditionally a challenging task since iptables rules haven't yet run and tc filter/eBPF programs are pre-NAT lookups, hence are unable to see internal IPv4 addresses as used on the typical home masquerading gateway. Thus marking the connection in some manner on egress for later restoration of classification on ingress is easier to implement. Parameters related to DSCP restore mode: dscpmask - a 32 bit mask of 6 contiguous bits and indicate bits of the conntrack mark field contain the DSCP value to be restored. statemask - a 32 bit mask of (usually) 1 bit length, outside the area specified by dscpmask. This represents a conditional operation flag whereby the DSCP is only restored if the flag is set. This is useful to implement a 'one shot' iptables based classification where the 'complicated' iptables rules are only run once to classify the connection on initial (egress) packet and subsequent packets are all marked/restored with the same DSCP. A mask of zero disables the conditional behaviour ie. the conntrack mark DSCP bits are always restored to the ip diffserv field (assuming the conntrack entry is found & the skb is an ipv4/ipv6 type) e.g. dscpmask 0xfc000000 statemask 0x01000000 |----0xFC----conntrack mark----000000---| | Bits 31-26 | bit 25 | bit24 |~~~ Bit 0| | DSCP | unused | flag |unused | |-----------------------0x01---000000---| | | | | ---| Conditional flag v only restore if set |-ip diffserv-| | 6 bits | |-------------| The skb mark restore mode (cpmark): This mode copies the firewall conntrack mark to the skb's mark field. It is completely the functional equivalent of the existing act_connmark action with the additional feature of being able to apply a mask to the restored value. Parameters related to skb mark restore mode: mask - a 32 bit mask applied to the firewall conntrack mark to mask out bits unwanted for restoration. This can be useful where the conntrack mark is being used for different purposes by different applications. If not specified and by default the whole mark field is copied (i.e. default mask of 0xffffffff) e.g. mask 0x00ffffff to mask out the top 8 bits being used by the aforementioned DSCP restore mode. |----0x00----conntrack mark----ffffff---| | Bits 31-24 | | | DSCP & flag| some value here | |---------------------------------------| | | v |------------skb mark-------------------| | | | | zeroed | | |---------------------------------------| Overall parameters: zone - conntrack zone control - action related control (reclassify | pipe | drop | continue | ok | goto chain <CHAIN_INDEX>) Signed-off-by: Kevin Darbyshire-Bryant <ldir@darbyshire-bryant.me.uk> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Acked-by: Cong Wang <xiyou.wangcong@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net>