linux-stable.git/net/core, branch v6.5

rtnetlink: Reject negative ifindexes in RTM_NEWLINK

2023-08-24T07:45:52+00:00

Negative ifindexes are illegal, but the kernel does not validate the
ifindex in the ancillary header of RTM_NEWLINK messages, resulting in
the kernel generating a warning [1] when such an ifindex is specified.

Fix by rejecting negative ifindexes.

[1]
WARNING: CPU: 0 PID: 5031 at net/core/dev.c:9593 dev_index_reserve+0x1a2/0x1c0 net/core/dev.c:9593
[...]
Call Trace:
 
 register_netdevice+0x69a/0x1490 net/core/dev.c:10081
 br_dev_newlink+0x27/0x110 net/bridge/br_netlink.c:1552
 rtnl_newlink_create net/core/rtnetlink.c:3471 [inline]
 __rtnl_newlink+0x115e/0x18c0 net/core/rtnetlink.c:3688
 rtnl_newlink+0x67/0xa0 net/core/rtnetlink.c:3701
 rtnetlink_rcv_msg+0x439/0xd30 net/core/rtnetlink.c:6427
 netlink_rcv_skb+0x16b/0x440 net/netlink/af_netlink.c:2545
 netlink_unicast_kernel net/netlink/af_netlink.c:1342 [inline]
 netlink_unicast+0x536/0x810 net/netlink/af_netlink.c:1368
 netlink_sendmsg+0x93c/0xe40 net/netlink/af_netlink.c:1910
 sock_sendmsg_nosec net/socket.c:728 [inline]
 sock_sendmsg+0xd9/0x180 net/socket.c:751
 ____sys_sendmsg+0x6ac/0x940 net/socket.c:2538
 ___sys_sendmsg+0x135/0x1d0 net/socket.c:2592
 __sys_sendmsg+0x117/0x1e0 net/socket.c:2621
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 38f7b870d4a6 ("[RTNETLINK]: Link creation API")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Ido Schimmel 
Reviewed-by: Jiri Pirko 
Reviewed-by: Jakub Kicinski 
Link: https://lore.kernel.org/r/20230823064348.2252280-1-idosch@nvidia.com
Signed-off-by: Paolo Abeni

net: validate veth and vxcan peer ifindexes

2023-08-20T10:40:03+00:00

veth and vxcan need to make sure the ifindexes of the peer
are not negative, core does not validate this.

Using iproute2 with user-space-level checking removed:

Before:

  # ./ip link add index 10 type veth peer index -1
  # ip link show
  1: lo:  mtu 65536 qdisc noqueue state UNKNOWN mode DEFAULT group default qlen 1000
    link/loopback 00:00:00:00:00:00 brd 00:00:00:00:00:00
  2: enp1s0:  mtu 1500 qdisc fq_codel state UP mode DEFAULT group default qlen 1000
    link/ether 52:54:00:74:b2:03 brd ff:ff:ff:ff:ff:ff
  10: veth1@veth0:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether 8a:90:ff:57:6d:5d brd ff:ff:ff:ff:ff:ff
  -1: veth0@veth1:  mtu 1500 qdisc noop state DOWN mode DEFAULT group default qlen 1000
    link/ether ae:ed:18:e6:fa:7f brd ff:ff:ff:ff:ff:ff

Now:

  $ ./ip link add index 10 type veth peer index -1
  Error: ifindex can't be negative.

This problem surfaced in net-next because an explicit WARN()
was added, the root cause is older.

Fixes: e6f8f1a739b6 ("veth: Allow to create peer link with given ifindex")
Fixes: a8f820a380a2 ("can: add Virtual CAN Tunnel driver (vxcan)")
Reported-by: syzbot+5ba06978f34abb058571@syzkaller.appspotmail.com
Signed-off-by: Jakub Kicinski 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

sock: Fix misuse of sk_under_memory_pressure()

2023-08-17T18:34:36+00:00

The status of global socket memory pressure is updated when:

  a) __sk_mem_raise_allocated():

	enter: sk_memory_allocated(sk) >  sysctl_mem[1]
	leave: sk_memory_allocated(sk) <= sysctl_mem[0]

  b) __sk_mem_reduce_allocated():

	leave: sk_under_memory_pressure(sk) &&
		sk_memory_allocated(sk) < sysctl_mem[0]

So the conditions of leaving global pressure are inconstant, which
may lead to the situation that one pressured net-memcg prevents the
global pressure from being cleared when there is indeed no global
pressure, thus the global constrains are still in effect unexpectedly
on the other sockets.

This patch fixes this by ignoring the net-memcg's pressure when
deciding whether should leave global memory pressure.

Fixes: e1aab161e013 ("socket: initial cgroup code.")
Signed-off-by: Abel Wu 
Acked-by: Shakeel Butt 
Link: https://lore.kernel.org/r/20230816091226.1542-1-wuyun.abel@bytedance.com
Signed-off-by: Jakub Kicinski

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2023-08-10T17:41:36+00:00

Martin KaFai Lau says:

====================
pull-request: bpf 2023-08-09

We've added 5 non-merge commits during the last 7 day(s) which contain
a total of 6 files changed, 102 insertions(+), 8 deletions(-).

The main changes are:

1) A bpf sockmap memleak fix and a fix in accessing the programs of
   a sockmap under the incorrect map type from Xu Kuohai.

2) A refcount underflow fix in xsk from Magnus Karlsson.

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  selftests/bpf: Add sockmap test for redirecting partial skb data
  selftests/bpf: fix a CI failure caused by vsock sockmap test
  bpf, sockmap: Fix bug that strp_done cannot be called
  bpf, sockmap: Fix map type error in sock_map_del_link
  xsk: fix refcount underflow in error path
====================

Link: https://lore.kernel.org/r/20230810055303.120917-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski

bpf, sockmap: Fix bug that strp_done cannot be called

2023-08-10T03:29:02+00:00

strp_done is only called when psock->progs.stream_parser is not NULL,
but stream_parser was set to NULL by sk_psock_stop_strp(), called
by sk_psock_drop() earlier. So, strp_done can never be called.

Introduce SK_PSOCK_RX_ENABLED to mark whether there is strp on psock.
Change the condition for calling strp_done from judging whether
stream_parser is set to judging whether this flag is set. This flag is
only set once when strp_init() succeeds, and will never be cleared later.

Fixes: c0d95d3380ee ("bpf, sockmap: Re-evaluate proto ops when psock is removed from sockmap")
Signed-off-by: Xu Kuohai 
Reviewed-by: John Fastabend 
Link: https://lore.kernel.org/r/20230804073740.194770-3-xukuohai@huaweicloud.com
Signed-off-by: Martin KaFai Lau

bpf, sockmap: Fix map type error in sock_map_del_link

2023-08-10T03:29:02+00:00

sock_map_del_link() operates on both SOCKMAP and SOCKHASH, although
both types have member named "progs", the offset of "progs" member in
these two types is different, so "progs" should be accessed with the
real map type.

Fixes: 604326b41a6f ("bpf, sockmap: convert to generic sk_msg interface")
Signed-off-by: Xu Kuohai 
Reviewed-by: John Fastabend 
Link: https://lore.kernel.org/r/20230804073740.194770-2-xukuohai@huaweicloud.com
Signed-off-by: Martin KaFai Lau

net/unix: use consistent error code in SO_PEERPIDFD

2023-08-08T22:56:48+00:00

Change the new (unreleased) SO_PEERPIDFD sockopt to return ENODATA
rather than ESRCH if a socket type does not support remote peer-PID
queries.

Currently, SO_PEERPIDFD returns ESRCH when the socket in question is
not an AF_UNIX socket. This is quite unexpected, given that one would
assume ESRCH means the peer process already exited and thus cannot be
found. However, in that case the sockopt actually returns EINVAL (via
pidfd_prepare()). This is rather inconsistent with other syscalls, which
usually return ESRCH if a given PID refers to a non-existant process.

This changes SO_PEERPIDFD to return ENODATA instead. This is also what
SO_PEERGROUPS returns, and thus keeps a consistent behavior across
sockopts.

Note that this code is returned in 2 cases: First, if the socket type is
not AF_UNIX, and secondly if the socket was not yet connected. In both
cases ENODATA seems suitable.

Signed-off-by: David Rheinsberg 
Reviewed-by: Christian Brauner 
Acked-by: Luca Boccassi 
Fixes: 7b26952a91cf ("net: core: add getsockopt SO_PEERPIDFD")
Link: https://lore.kernel.org/r/20230807081225.816199-1-david@readahead.eu
Signed-off-by: Jakub Kicinski

net: core: remove unnecessary frame_sz check in bpf_xdp_adjust_tail()

2023-08-08T02:14:41+00:00

Syzkaller reported the following issue:
=======================================
Too BIG xdp->frame_sz = 131072
WARNING: CPU: 0 PID: 5020 at net/core/filter.c:4121
  ____bpf_xdp_adjust_tail net/core/filter.c:4121 [inline]
WARNING: CPU: 0 PID: 5020 at net/core/filter.c:4121
  bpf_xdp_adjust_tail+0x466/0xa10 net/core/filter.c:4103
...
Call Trace:
 
 bpf_prog_4add87e5301a4105+0x1a/0x1c
 __bpf_prog_run include/linux/filter.h:600 [inline]
 bpf_prog_run_xdp include/linux/filter.h:775 [inline]
 bpf_prog_run_generic_xdp+0x57e/0x11e0 net/core/dev.c:4721
 netif_receive_generic_xdp net/core/dev.c:4807 [inline]
 do_xdp_generic+0x35c/0x770 net/core/dev.c:4866
 tun_get_user+0x2340/0x3ca0 drivers/net/tun.c:1919
 tun_chr_write_iter+0xe8/0x210 drivers/net/tun.c:2043
 call_write_iter include/linux/fs.h:1871 [inline]
 new_sync_write fs/read_write.c:491 [inline]
 vfs_write+0x650/0xe40 fs/read_write.c:584
 ksys_write+0x12f/0x250 fs/read_write.c:637
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x38/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

xdp->frame_sz > PAGE_SIZE check was introduced in commit c8741e2bfe87
("xdp: Allow bpf_xdp_adjust_tail() to grow packet size"). But Jesper
Dangaard Brouer  noted that after introducing the
xdp_init_buff() which all XDP driver use - it's safe to remove this
check. The original intend was to catch cases where XDP drivers have
not been updated to use xdp.frame_sz, but that is not longer a concern
(since xdp_init_buff).

Running the initial syzkaller repro it was discovered that the
contiguous physical memory allocation is used for both xdp paths in
tun_get_user(), e.g. tun_build_skb() and tun_alloc_skb(). It was also
stated by Jesper Dangaard Brouer  that XDP can
work on higher order pages, as long as this is contiguous physical
memory (e.g. a page).

Reported-and-tested-by: syzbot+f817490f5bd20541b90a@syzkaller.appspotmail.com
Closes: https://lore.kernel.org/all/000000000000774b9205f1d8a80d@google.com/T/
Link: https://syzkaller.appspot.com/bug?extid=f817490f5bd20541b90a
Link: https://lore.kernel.org/all/20230725155403.796-1-andrew.kanner@gmail.com/T/
Fixes: 43b5169d8355 ("net, xdp: Introduce xdp_init_buff utility routine")
Signed-off-by: Andrew Kanner 
Acked-by: Jesper Dangaard Brouer 
Acked-by: Jason Wang 
Link: https://lore.kernel.org/r/20230803190316.2380231-1-andrew.kanner@gmail.com
Signed-off-by: Jakub Kicinski

Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf

2023-08-03T18:22:53+00:00

Martin KaFai Lau says:

====================
pull-request: bpf 2023-08-03

We've added 5 non-merge commits during the last 7 day(s) which contain
a total of 3 files changed, 37 insertions(+), 20 deletions(-).

The main changes are:

1) Disable preemption in perf_event_output helpers code,
   from Jiri Olsa

2) Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing,
   from Lin Ma

3) Multiple warning splat fixes in cpumap from Hou Tao

* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf:
  bpf, cpumap: Handle skb as well when clean up ptr_ring
  bpf, cpumap: Make sure kthread is running before map update returns
  bpf: Add length check for SK_DIAG_BPF_STORAGE_REQ_MAP_FD parsing
  bpf: Disable preemption in bpf_event_output
  bpf: Disable preemption in bpf_perf_event_output
====================

Link: https://lore.kernel.org/r/20230803181429.994607-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski

bpf: sockmap: Remove preempt_disable in sock_map_sk_acquire

2023-08-01T07:24:34+00:00

Disabling preemption in sock_map_sk_acquire conflicts with GFP_ATOMIC
allocation later in sk_psock_init_link on PREEMPT_RT kernels, since
GFP_ATOMIC might sleep on RT (see bpf: Make BPF and PREEMPT_RT co-exist
patchset notes for details).

This causes calling bpf_map_update_elem on BPF_MAP_TYPE_SOCKMAP maps to
BUG (sleeping function called from invalid context) on RT kernels.

preempt_disable was introduced together with lock_sk and rcu_read_lock
in commit 99ba2b5aba24e ("bpf: sockhash, disallow bpf_tcp_close and update
in parallel"), probably to match disabled migration of BPF programs, and
is no longer necessary.

Remove preempt_disable to fix BUG in sock_map_update_common on RT.

Signed-off-by: Tomas Glozar 
Reviewed-by: Jakub Sitnicki 
Link: https://lore.kernel.org/all/20200224140131.461979697@linutronix.de/
Fixes: 99ba2b5aba24 ("bpf: sockhash, disallow bpf_tcp_close and update in parallel")
Reviewed-by: John Fastabend 
Link: https://lore.kernel.org/r/20230728064411.305576-1-tglozar@redhat.com
Signed-off-by: Paolo Abeni