linux/net/core, branch v5.7

neigh: fix ARP retransmit timer guard

2020-05-29T23:56:53Z

In commit 19e16d220f0a ("neigh: support smaller retrans_time settting") we add more accurate control for ARP and NS. But for ARP I forgot to update the latest guard in neigh_timer_handler(), then the next retransmit would be reset to jiffies + HZ/2 if we set the retrans_time less than 500ms. Fix it by setting the time_before() check to HZ/100. IPv6 does not have this issue. Reported-by: Jianwen Ji Fixes: 19e16d220f0a ("neigh: support smaller retrans_time settting") Signed-off-by: Hangbin Liu Signed-off-by: David S. Miller

flow_dissector: Drop BPF flow dissector prog ref on netns cleanup

2020-05-22T00:52:45Z

When attaching a flow dissector program to a network namespace with bpf(BPF_PROG_ATTACH, ...) we grab a reference to bpf_prog. If netns gets destroyed while a flow dissector is still attached, and there are no other references to the prog, we leak the reference and the program remains loaded. Leak can be reproduced by running flow dissector tests from selftests/bpf: # bpftool prog list # ./test_flow_dissector.sh ... selftests: test_flow_dissector [PASS] # bpftool prog list 4: flow_dissector name _dissect tag e314084d332a5338 gpl loaded_at 2020-05-20T18:50:53+0200 uid 0 xlated 552B jited 355B memlock 4096B map_ids 3,4 btf_id 4 # Fix it by detaching the flow dissector program when netns is going away. Fixes: d58e468b1112 ("flow_dissector: implements flow dissector BPF hook") Signed-off-by: Jakub Sitnicki Signed-off-by: Alexei Starovoitov Reviewed-by: Stanislav Fomichev Link: https://lore.kernel.org/bpf/20200521083435.560256-1-jakub@cloudflare.com

__netif_receive_skb_core: pass skb by reference

2020-05-19T22:38:00Z

__netif_receive_skb_core may change the skb pointer passed into it (e.g. in rx_handler). The original skb may be freed as a result of this operation. The callers of __netif_receive_skb_core may further process original skb by using pt_prev pointer returned by __netif_receive_skb_core thus leading to unpleasant effects. The solution is to pass skb by reference into __netif_receive_skb_core. v2: Added Fixes tag and comment regarding ppt_prev and skb invariant. Fixes: 88eb1944e18c ("net: core: propagate SKB lists through packet_type lookup") Signed-off-by: Boris Sukholitko Acked-by: Edward Cree Signed-off-by: David S. Miller

netprio_cgroup: Fix unlimited memory leak of v2 cgroups

2020-05-10T03:59:21Z

If systemd is configured to use hybrid mode which enables the use of both cgroup v1 and v2, systemd will create new cgroup on both the default root (v2) and netprio_cgroup hierarchy (v1) for a new session and attach task to the two cgroups. If the task does some network thing then the v2 cgroup can never be freed after the session exited. One of our machines ran into OOM due to this memory leak. In the scenario described above when sk_alloc() is called cgroup_sk_alloc() thought it's in v2 mode, so it stores the cgroup pointer in sk->sk_cgrp_data and increments the cgroup refcnt, but then sock_update_netprioidx() thought it's in v1 mode, so it stores netprioidx value in sk->sk_cgrp_data, so the cgroup refcnt will never be freed. Currently we do the mode switch when someone writes to the ifpriomap cgroup control file. The easiest fix is to also do the switch when a task is attached to a new cgroup. Fixes: bd1060a1d671 ("sock, cgroup: add sock->sk_cgroup") Reported-by: Yang Yingliang Tested-by: Yang Yingliang Signed-off-by: Zefan Li Acked-by: Tejun Heo Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2020-05-09T01:58:39Z

Daniel Borkmann says: ==================== pull-request: bpf 2020-05-09 The following pull-request contains BPF updates for your *net* tree. We've added 4 non-merge commits during the last 9 day(s) which contain a total of 4 files changed, 11 insertions(+), 6 deletions(-). The main changes are: 1) Fix msg_pop_data() helper incorrectly setting an sge length in some cases as well as fixing bpf_tcp_ingress() wrongly accounting bytes in sg.size, from John Fastabend. 2) Fix to return an -EFAULT error when copy_to_user() of the value fails in map_lookup_and_delete_elem(), from Wei Yongjun. 3) Fix sk_psock refcnt leak in tcp_bpf_recvmsg(), from Xiyu Yang. ==================== Signed-off-by: Jakub Kicinski

net: fix a potential recursive NETDEV_FEAT_CHANGE

2020-05-08T01:18:36Z

syzbot managed to trigger a recursive NETDEV_FEAT_CHANGE event between bonding master and slave. I managed to find a reproducer for this: ip li set bond0 up ifenslave bond0 eth0 brctl addbr br0 ethtool -K eth0 lro off brctl addif br0 bond0 ip li set br0 up When a NETDEV_FEAT_CHANGE event is triggered on a bonding slave, it captures this and calls bond_compute_features() to fixup its master's and other slaves' features. However, when syncing with its lower devices by netdev_sync_lower_features() this event is triggered again on slaves when the LRO feature fails to change, so it goes back and forth recursively until the kernel stack is exhausted. Commit 17b85d29e82c intentionally lets __netdev_update_features() return -1 for such a failure case, so we have to just rely on the existing check inside netdev_sync_lower_features() and skip NETDEV_FEAT_CHANGE event only for this specific failure case. Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack") Reported-by: syzbot+e73ceacfd8560cc8a3ca@syzkaller.appspotmail.com Reported-by: syzbot+c2fb6f9ddcea95ba49b5@syzkaller.appspotmail.com Cc: Jarod Wilson Cc: Nikolay Aleksandrov Cc: Josh Poimboeuf Cc: Jann Horn Reviewed-by: Jay Vosburgh Signed-off-by: Cong Wang Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller

bpf, sockmap: msg_pop_data can incorrecty set an sge length

2020-05-05T22:22:15Z

When sk_msg_pop() is called where the pop operation is working on the end of a sge element and there is no additional trailing data and there _is_ data in front of pop, like the following case, |____________a_____________|__pop__| We have out of order operations where we incorrectly set the pop variable so that instead of zero'ing pop we incorrectly leave it untouched, effectively. This can cause later logic to shift the buffers around believing it should pop extra space. The result is we have 'popped' more data then we expected potentially breaking program logic. It took us a while to hit this case because typically we pop headers which seem to rarely be at the end of a scatterlist elements but we can't rely on this. Fixes: 7246d8ed4dcce ("bpf: helper to pop data from messages") Signed-off-by: John Fastabend Signed-off-by: Daniel Borkmann Reviewed-by: Jakub Sitnicki Acked-by: Martin KaFai Lau Link: https://lore.kernel.org/bpf/158861288359.14306.7654891716919968144.stgit@john-Precision-5820-Tower

neigh: send protocol value in neighbor create notification

2020-05-05T20:38:59Z

When a new neighbor entry has been added, event is generated but it does not include protocol, because its value is assigned after the event notification routine has run, so move protocol assignment code earlier. Fixes: df9b0e30d44c ("neighbor: Add protocol attribute") Cc: David Ahern Signed-off-by: Roman Mashak Reviewed-by: David Ahern Signed-off-by: David S. Miller

devlink: Fix reporter's recovery condition

2020-05-04T17:40:39Z

Devlink health core conditions the reporter's recovery with the expiration of the grace period. This is not relevant for the first recovery. Explicitly demand that the grace period will only apply to recoveries other than the first. Fixes: c8e1da0bf923 ("devlink: Add health report functionality") Signed-off-by: Aya Levin Reviewed-by: Moshe Shemesh Reviewed-by: Jiri Pirko Signed-off-by: David S. Miller

drop_monitor: work around gcc-10 stringop-overflow warning

2020-05-01T22:45:16Z

The current gcc-10 snapshot produces a false-positive warning: net/core/drop_monitor.c: In function 'trace_drop_common.constprop': cc1: error: writing 8 bytes into a region of size 0 [-Werror=stringop-overflow=] In file included from net/core/drop_monitor.c:23: include/uapi/linux/net_dropmon.h:36:8: note: at offset 0 to object 'entries' with size 4 declared here 36 | __u32 entries; | ^~~~~~~ I reported this in the gcc bugzilla, but in case it does not get fixed in the release, work around it by using a temporary variable. Fixes: 9a8afc8d3962 ("Network Drop Monitor: Adding drop monitor implementation & Netlink protocol") Link: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94881 Signed-off-by: Arnd Bergmann Acked-by: Neil Horman Signed-off-by: David S. Miller