Daniel Borkmann says: ==================== pull-request: bpf 2021-10-26 We've added 12 non-merge commits during the last 7 day(s) which contain a total of 23 files changed, 118 insertions(+), 98 deletions(-). The main changes are: 1) Fix potential race window in BPF tail call compatibility check, from Toke Høiland-Jørgensen. 2) Fix memory leak in cgroup fs due to missing cgroup_bpf_offline(), from Quanyang Wang. 3) Fix file descriptor reference counting in generic_map_update_batch(), from Xu Kuohai. 4) Fix bpf_jit_limit knob to the max supported limit by the arch's JIT, from Lorenz Bauer. 5) Fix BPF sockmap ->poll callbacks for UDP and AF_UNIX sockets, from Cong Wang and Yucong Sun. 6) Fix BPF sockmap concurrency issue in TCP on non-blocking sendmsg calls, from Liu Jian. 7) Fix build failure of INODE_STORAGE and TASK_STORAGE maps on !CONFIG_NET, from Tejun Heo. * https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf: bpf: Fix potential race in tail call compatibility check bpf: Move BPF_MAP_TYPE for INODE_STORAGE and TASK_STORAGE outside of CONFIG_NET selftests/bpf: Use recv_timeout() instead of retries net: Implement ->sock_is_readable() for UDP and AF_UNIX skmsg: Extract and reuse sk_msg_is_readable() net: Rename ->stream_memory_read to ->sock_is_readable tcp_bpf: Fix one concurrency problem in the tcp_bpf_send_verdict function cgroup: Fix memory leak caused by missing cgroup_bpf_offline bpf: Fix error usage of map_fd and fdget() in generic_map_update_batch() bpf: Prevent increasing bpf_jit_limit above max bpf: Define bpf_jit_alloc_exec_limit for arm64 JIT bpf: Define bpf_jit_alloc_exec_limit for riscv JIT ==================== Link: https://lore.kernel.org/r/20211026201920.11296-1-daniel@iogearbox.net Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp_bpf_sock_is_readable() is pretty much generic, we can extract it and reuse it for non-TCP sockets. Signed-off-by: Cong Wang <cong.wang@bytedance.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211008203306.37525-3-xiyou.wangcong@gmail.com
During a testing of an user-space application which transmits UDP
multicast datagrams and utilizes multicast routing to send the UDP
datagrams out of defined network interfaces, I've found a multicast
router does not fill-in UDP checksum into locally produced, looped-back
and forwarded UDP datagrams, if an original output NIC the datagrams
are sent to has UDP TX checksum offload enabled.
The datagrams are sent malformed out of the NIC the datagrams have been
forwarded to.
It is because:
1. If TX checksum offload is enabled on the output NIC, UDP checksum
is not calculated by kernel and is not filled into skb data.
2. dev_loopback_xmit(), which is called solely by
ip_mc_finish_output(), sets skb->ip_summed = CHECKSUM_UNNECESSARY
unconditionally.
3. Since 35fc92a9 ("[NET]: Allow forwarding of ip_summed except
CHECKSUM_COMPLETE"), the ip_summed value is preserved during
forwarding.
4. If ip_summed != CHECKSUM_PARTIAL, checksum is not calculated during
a packet egress.
The minimum fix in dev_loopback_xmit():
1. Preserves skb->ip_summed CHECKSUM_PARTIAL. This is the
case when the original output NIC has TX checksum offload enabled.
The effects are:
a) If the forwarding destination interface supports TX checksum
offloading, the NIC driver is responsible to fill-in the
checksum.
b) If the forwarding destination interface does NOT support TX
checksum offloading, checksums are filled-in by kernel before
skb is submitted to the NIC driver.
c) For local delivery, checksum validation is skipped as in the
case of CHECKSUM_UNNECESSARY, thanks to skb_csum_unnecessary().
2. Translates ip_summed CHECKSUM_NONE to CHECKSUM_UNNECESSARY. It
means, for CHECKSUM_NONE, the behavior is unmodified and is there
to skip a looped-back packet local delivery checksum validation.
Signed-off-by: Cyril Strejc <cyril.strejc@skoda.cz>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Currently in net_ns_get_ownership() it may not be able to set uid or gid
if make_kuid or make_kgid returns an invalid value, and an uninit-value
issue can be triggered by this.
This patch is to fix it by initializing the uid and gid before calling
net_ns_get_ownership(), as it does in kobject_get_ownership()
Fixes: e6dee9f3893c ("net-sysfs: add netdev_change_owner()")
Reported-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
Acked-by: Christian Brauner <christian.brauner@ubuntu.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Drivers call netdev_set_num_tc() and then netdev_set_tc_queue()
to set the queue count and offset for each TC. So the queue count
and offset for the TCs may be zero for a short period after dev->num_tc
has been set. If a TX packet is being transmitted at this time in the
code path netdev_pick_tx() -> skb_tx_hash(), skb_tx_hash() may see
nonzero dev->num_tc but zero qcount for the TC. The while loop that
keeps looping while hash >= qcount will not end.
Fix it by checking the TC's qcount to be nonzero before using it.
Fixes: eadec877ce9c ("net: Add support for subordinate traffic classes to netdev_pick_tx")
Reviewed-by: Andy Gospodarek <gospo@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Restrict bpf_jit_limit to the maximum supported by the arch's JIT. Signed-off-by: Lorenz Bauer <lmb@cloudflare.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20211014142554.53120-4-lmb@cloudflare.com
Christoph Paasch reports [1] about incorrect skb->truesize
after skb_expand_head() call in ip6_xmit.
This may happen because of two reasons:
- skb_set_owner_w() for newly cloned skb is called too early,
before pskb_expand_head() where truesize is adjusted for (!skb-sk) case.
- pskb_expand_head() does not adjust truesize in (skb->sk) case.
In this case sk->sk_wmem_alloc should be adjusted too.
[1] https://lkml.org/lkml/2021/8/20/1082
Fixes: f1260ff15a71 ("skbuff: introduce skb_expand_head()")
Fixes: 2d85a1b31dde ("ipv6: ip6_finish_output2: set sk into newly allocated nskb")
Reported-by: Christoph Paasch <christoph.paasch@gmail.com>
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/644330dd-477e-0462-83bf-9f514c41edd1@virtuozzo.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
This reverts commit ec18e8455484370d633a718c6456ddbf6eceef21.
It turns out that there are user space programs which got broken by that
change. One example is the "ifstat" program shipped by Debian:
https://packages.debian.org/source/bullseye/ifstat
which, confusingly enough, seems to not have anything in common with the
much more familiar (at least to me) ifstat program from iproute2:
https://git.kernel.org/pub/scm/network/iproute2/iproute2.git/tree/misc/ifstat.c
root@debian:~# ifstat
ifstat: /proc/net/dev: unsupported format.
This change modified the header (first two lines of text) in
/proc/net/dev so that it looks like this:
root@debian:~# cat /proc/net/dev
Interface| Receive | Transmit
| bytes packets errs drop fifo frame compressed multicast| bytes packets errs drop fifo colls carrier compressed
lo: 97400 1204 0 0 0 0 0 0 97400 1204 0 0 0 0 0 0
bond0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sit0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
eno2: 5002206 6651 0 0 0 0 0 0 105518642 1465023 0 0 0 0 0 0
swp0: 134531 2448 0 0 0 0 0 0 99599598 1464381 0 0 0 0 0 0
swp1: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
swp2: 4867675 4203 0 0 0 0 0 0 58134 631 0 0 0 0 0 0
sw0p0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw0p1: 124739 2448 0 1422 0 0 0 0 93741184 1464369 0 0 0 0 0 0
sw0p2: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw2p0: 4850863 4203 0 0 0 0 0 0 54722 619 0 0 0 0 0 0
sw2p1: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw2p2: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw2p3: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
br0: 10508 212 0 212 0 0 0 212 61369558 958857 0 0 0 0 0 0
whereas before it looked like this:
root@debian:~# cat /proc/net/dev
Inter-| Receive | Transmit
face |bytes packets errs drop fifo frame compressed multicast|bytes packets errs drop fifo colls carrier compressed
lo: 13160 164 0 0 0 0 0 0 13160 164 0 0 0 0 0 0
bond0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sit0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
eno2: 30824 268 0 0 0 0 0 0 3332 37 0 0 0 0 0 0
swp0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
swp1: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
swp2: 30824 268 0 0 0 0 0 0 2428 27 0 0 0 0 0 0
sw0p0: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw0p1: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw0p2: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw2p0: 29752 268 0 0 0 0 0 0 1564 17 0 0 0 0 0 0
sw2p1: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw2p2: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
sw2p3: 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0
The reason why the ifstat shipped by Debian (v1.1, with a Debian patch
upgrading it to 1.1-8.1 at the time of writing) is broken is because its
"proc" driver/backend parses the header very literally:
main/drivers.c#L825
if (!data->checked && strncmp(buf, "Inter-|", 7))
goto badproc;
and there's no way in which the header can be changed such that programs
parsing like that would not get broken.
Even if we fix this ancient and very "lightly" maintained program to
parse the text output of /proc/net/dev in a more sensible way, this
story seems bound to repeat again with other programs, and modifying
them all could cause more trouble than it's worth. On the other hand,
the reverted patch had no other reason than an aesthetic one, so
reverting it is the simplest way out.
I don't know what other distributions would be affected; the fact that
Debian doesn't ship the iproute2 version of the program (a different
code base altogether, which uses netlink and not /proc/net/dev) is
surprising in itself.
Fixes: ec18e8455484 ("net: procfs: add seq_puts() statement for dev_mcast")
Link: https://lore.kernel.org/netdev/20211009163511.vayjvtn3rrteglsu@skbuf/
Cc: Yajun Deng <yajun.deng@linux.dev>
Cc: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Link: https://lore.kernel.org/r/20211013001909.3164185-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
rtnl_fill_statsinfo() is filling skb with one mandatory if_stats_msg structure.
nlmsg_put(skb, pid, seq, type, sizeof(struct if_stats_msg), flags);
But if_nlmsg_stats_size() never considered the needed storage.
This bug did not show up because alloc_skb(X) allocates skb with
extra tailroom, because of added alignments. This could very well
be changed in the future to have deterministic behavior.
Fixes: 10c9ead9f3c6 ("rtnetlink: add new RTM_GETSTATS message to dump link stats")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Roopa Prabhu <roopa@nvidia.com>
Acked-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Jann Horn reported that SO_PEERCRED and SO_PEERGROUPS implementations
are racy, as af_unix can concurrently change sk_peer_pid and sk_peer_cred.
In order to fix this issue, this patch adds a new spinlock that needs
to be used whenever these fields are read or written.
Jann also pointed out that l2cap_sock_get_peer_pid_cb() is currently
reading sk->sk_peer_pid which makes no sense, as this field
is only possibly set by AF_UNIX sockets.
We will have to clean this in a separate patch.
This could be done by reverting b48596d1dc25 "Bluetooth: L2CAP: Add get_peer_pid callback"
or implementing what was truly expected.
Fixes: 109f6e39fa07 ("af_unix: Allow SO_PEERCRED to work across namespaces.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: Jann Horn <jannh@google.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
Cc: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: David S. Miller <davem@davemloft.net>