linux.git/net/ipv4, branch v6.4-rc2

tcp: add annotations around sk->sk_shutdown accesses

2023-05-10T09:27:31+00:00

Now sk->sk_shutdown is no longer a bitfield, we can add
standard READ_ONCE()/WRITE_ONCE() annotations to silence
KCSAN reports like the following:

BUG: KCSAN: data-race in tcp_disconnect / tcp_poll

write to 0xffff88814588582c of 1 bytes by task 3404 on cpu 1:
tcp_disconnect+0x4d6/0xdb0 net/ipv4/tcp.c:3121
__inet_stream_connect+0x5dd/0x6e0 net/ipv4/af_inet.c:715
inet_stream_connect+0x48/0x70 net/ipv4/af_inet.c:727
__sys_connect_file net/socket.c:2001 [inline]
__sys_connect+0x19b/0x1b0 net/socket.c:2018
__do_sys_connect net/socket.c:2028 [inline]
__se_sys_connect net/socket.c:2025 [inline]
__x64_sys_connect+0x41/0x50 net/socket.c:2025
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88814588582c of 1 bytes by task 3374 on cpu 0:
tcp_poll+0x2e6/0x7d0 net/ipv4/tcp.c:562
sock_poll+0x253/0x270 net/socket.c:1383
vfs_poll include/linux/poll.h:88 [inline]
io_poll_check_events io_uring/poll.c:281 [inline]
io_poll_task_func+0x15a/0x820 io_uring/poll.c:333
handle_tw_list io_uring/io_uring.c:1184 [inline]
tctx_task_work+0x1fe/0x4d0 io_uring/io_uring.c:1246
task_work_run+0x123/0x160 kernel/task_work.c:179
get_signal+0xe64/0xff0 kernel/signal.c:2635
arch_do_signal_or_restart+0x89/0x2a0 arch/x86/kernel/signal.c:306
exit_to_user_mode_loop+0x6f/0xe0 kernel/entry/common.c:168
exit_to_user_mode_prepare+0x6c/0xb0 kernel/entry/common.c:204
__syscall_exit_to_user_mode_work kernel/entry/common.c:286 [inline]
syscall_exit_to_user_mode+0x26/0x140 kernel/entry/common.c:297
do_syscall_64+0x4d/0xc0 arch/x86/entry/common.c:86
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x03 -> 0x00

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: deal with most data-races in sk_wait_event()

2023-05-10T09:03:32+00:00

__condition is evaluated twice in sk_wait_event() macro.

First invocation is lockless, and reads can race with writes,
as spotted by syzbot.

BUG: KCSAN: data-race in sk_stream_wait_connect / tcp_disconnect

write to 0xffff88812d83d6a0 of 4 bytes by task 9065 on cpu 1:
tcp_disconnect+0x2cd/0xdb0
inet_shutdown+0x19e/0x1f0 net/ipv4/af_inet.c:911
__sys_shutdown_sock net/socket.c:2343 [inline]
__sys_shutdown net/socket.c:2355 [inline]
__do_sys_shutdown net/socket.c:2363 [inline]
__se_sys_shutdown+0xf8/0x140 net/socket.c:2361
__x64_sys_shutdown+0x31/0x40 net/socket.c:2361
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88812d83d6a0 of 4 bytes by task 9040 on cpu 0:
sk_stream_wait_connect+0x1de/0x3a0 net/core/stream.c:75
tcp_sendmsg_locked+0x2e4/0x2120 net/ipv4/tcp.c:1266
tcp_sendmsg+0x30/0x50 net/ipv4/tcp.c:1484
inet6_sendmsg+0x63/0x80 net/ipv6/af_inet6.c:651
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
__sys_sendto+0x246/0x300 net/socket.c:2142
__do_sys_sendto net/socket.c:2154 [inline]
__se_sys_sendto net/socket.c:2150 [inline]
__x64_sys_sendto+0x78/0x90 net/socket.c:2150
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x41/0xc0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0x00000000 -> 0x00000068

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-04-26T08:17:46+00:00

No conflicts.

Signed-off-by: Paolo Abeni

ipv4: Fix potential uninit variable access bug in __ip_make_skb()

2023-04-22T13:10:39+00:00

Like commit ea30388baebc ("ipv6: Fix an uninit variable access bug in
__ip6_make_skb()"). icmphdr does not in skb linear region under the
scenario of SOCK_RAW socket. Access icmp_hdr(skb)->type directly will
trigger the uninit variable access bug.

Use a local variable icmp_type to carry the correct value in different
scenarios.

Fixes: 96793b482540 ("[IPV4]: Add ICMPMsgStats MIB (RFC 4293)")
Reviewed-by: Willem de Bruijn 
Signed-off-by: Ziyang Xuan 
Signed-off-by: David S. Miller

net: dst: fix missing initialization of rt_uncached

2023-04-22T03:26:56+00:00

xfrm_alloc_dst() followed by xfrm4_dst_destroy(), without a
xfrm4_fill_dst() call in between, causes the following BUG:

 BUG: spinlock bad magic on CPU#0, fbxhostapd/732
  lock: 0x890b7668, .magic: 890b7668, .owner: /-1, .owner_cpu: 0
 CPU: 0 PID: 732 Comm: fbxhostapd Not tainted 6.3.0-rc6-next-20230414-00613-ge8de66369925-dirty #9
 Hardware name: Marvell Kirkwood (Flattened Device Tree)
  unwind_backtrace from show_stack+0x10/0x14
  show_stack from dump_stack_lvl+0x28/0x30
  dump_stack_lvl from do_raw_spin_lock+0x20/0x80
  do_raw_spin_lock from rt_del_uncached_list+0x30/0x64
  rt_del_uncached_list from xfrm4_dst_destroy+0x3c/0xbc
  xfrm4_dst_destroy from dst_destroy+0x5c/0xb0
  dst_destroy from rcu_process_callbacks+0xc4/0xec
  rcu_process_callbacks from __do_softirq+0xb4/0x22c
  __do_softirq from call_with_stack+0x1c/0x24
  call_with_stack from do_softirq+0x60/0x6c
  do_softirq from __local_bh_enable_ip+0xa0/0xcc

Patch "net: dst: Prevent false sharing vs. dst_entry:: __refcnt" moved
rt_uncached and rt_uncached_list fields from rtable struct to dst
struct, so they are more zeroed by memset_after(xdst, 0, u.dst) in
xfrm_alloc_dst().

Note that rt_uncached (list_head) was never properly initialized at
alloc time, but xfrm[46]_dst_destroy() is written in such a way that
it was not an issue thanks to the memset:

	if (xdst->u.rt.dst.rt_uncached_list)
		rt_del_uncached_list(&xdst->u.rt);

The route code does it the other way around: rt_uncached_list is
assumed to be valid IIF rt_uncached list_head is not empty:

void rt_del_uncached_list(struct rtable *rt)
{
        if (!list_empty(&rt->dst.rt_uncached)) {
                struct uncached_list *ul = rt->dst.rt_uncached_list;

                spin_lock_bh(&ul->lock);
                list_del_init(&rt->dst.rt_uncached);
                spin_unlock_bh(&ul->lock);
        }
}

This patch adds mandatory rt_uncached list_head initialization in
generic dst_init(), and adapt xfrm[46]_dst_destroy logic to match the
rest of the code.

Fixes: d288a162dd1c ("net: dst: Prevent false sharing vs. dst_entry:: __refcnt")
Reported-by: kernel test robot 
Link: https://lore.kernel.org/oe-lkp/202304162125.18b7bcdd-oliver.sang@intel.com
Reviewed-by: David Ahern 
Reviewed-by: Eric Dumazet 
CC: Leon Romanovsky 
Signed-off-by: Maxime Bizon 
Link: https://lore.kernel.org/r/20230420182508.2417582-1-mbizon@freebox.fr
Signed-off-by: Jakub Kicinski

net: Ensure ->msg_control_user is used for user buffers

2023-04-14T10:09:27+00:00

Since commit 1f466e1f15cf ("net: cleanly handle kernel vs user
buffers for ->msg_control"), pointers to user buffers should be
stored in struct msghdr::msg_control_user, instead of the
msg_control field.  Most users of msg_control have already been
converted (where user buffers are involved), but not all of them.

This patch attempts to address the remaining cases. An exception is
made for null checks, as it should be safe to use msg_control
unconditionally for that purpose.

Cc: Christoph Hellwig 
Cc: Eric Dumazet 
Cc: "David S. Miller" 
Cc: Jakub Kicinski 
Signed-off-by: Kevin Brodsky 
Reviewed-by: Christoph Hellwig 
Signed-off-by: David S. Miller

Daniel Borkmann says:

2023-04-13T23:43:38+00:00

====================
pull-request: bpf-next 2023-04-13

We've added 260 non-merge commits during the last 36 day(s) which contain
a total of 356 files changed, 21786 insertions(+), 11275 deletions(-).

The main changes are:

1) Rework BPF verifier log behavior and implement it as a rotating log
   by default with the option to retain old-style fixed log behavior,
   from Andrii Nakryiko.

2) Adds support for using {FOU,GUE} encap with an ipip device operating
   in collect_md mode and add a set of BPF kfuncs for controlling encap
   params, from Christian Ehrig.

3) Allow BPF programs to detect at load time whether a particular kfunc
   exists or not, and also add support for this in light skeleton,
   from Alexei Starovoitov.

4) Optimize hashmap lookups when key size is multiple of 4,
   from Anton Protopopov.

5) Enable RCU semantics for task BPF kptrs and allow referenced kptr
   tasks to be stored in BPF maps, from David Vernet.

6) Add support for stashing local BPF kptr into a map value via
   bpf_kptr_xchg(). This is useful e.g. for rbtree node creation
   for new cgroups, from Dave Marchevsky.

7) Fix BTF handling of is_int_ptr to skip modifiers to work around
   tracing issues where a program cannot be attached, from Feng Zhou.

8) Migrate a big portion of test_verifier unit tests over to
   test_progs -a verifier_* via inline asm to ease {read,debug}ability,
   from Eduard Zingerman.

9) Several updates to the instruction-set.rst documentation
   which is subject to future IETF standardization
   (https://lwn.net/Articles/926882/), from Dave Thaler.

10) Fix BPF verifier in the __reg_bound_offset's 64->32 tnum sub-register
    known bits information propagation, from Daniel Borkmann.

11) Add skb bitfield compaction work related to BPF with the overall goal
    to make more of the sk_buff bits optional, from Jakub Kicinski.

12) BPF selftest cleanups for build id extraction which stand on its own
    from the upcoming integration work of build id into struct file object,
    from Jiri Olsa.

13) Add fixes and optimizations for xsk descriptor validation and several
    selftest improvements for xsk sockets, from Kal Conley.

14) Add BPF links for struct_ops and enable switching implementations
    of BPF TCP cong-ctls under a given name by replacing backing
    struct_ops map, from Kui-Feng Lee.

15) Remove a misleading BPF verifier env->bypass_spec_v1 check on variable
    offset stack read as earlier Spectre checks cover this,
    from Luis Gerhorst.

16) Fix issues in copy_from_user_nofault() for BPF and other tracers
    to resemble copy_from_user_nmi() from safety PoV, from Florian Lehner
    and Alexei Starovoitov.

17) Add --json-summary option to test_progs in order for CI tooling to
    ease parsing of test results, from Manu Bretelle.

18) Batch of improvements and refactoring to prep for upcoming
    bpf_local_storage conversion to bpf_mem_cache_{alloc,free} allocator,
    from Martin KaFai Lau.

19) Improve bpftool's visual program dump which produces the control
    flow graph in a DOT format by adding C source inline annotations,
    from Quentin Monnet.

20) Fix attaching fentry/fexit/fmod_ret/lsm to modules by extracting
    the module name from BTF of the target and searching kallsyms of
    the correct module, from Viktor Malik.

21) Improve BPF verifier handling of '  '
    to better detect whether in particular jmp32 branches are taken,
    from Yonghong Song.

22) Allow BPF TCP cong-ctls to write app_limited of struct tcp_sock.
    A built-in cc or one from a kernel module is already able to write
    to app_limited, from Yixin Shen.

Conflicts:

Documentation/bpf/bpf_devel_QA.rst
  b7abcd9c656b ("bpf, doc: Link to submitting-patches.rst for general patch submission info")
  0f10f647f455 ("bpf, docs: Use internal linking for link to netdev subsystem doc")
https://lore.kernel.org/all/20230307095812.236eb1be@canb.auug.org.au/

include/net/ip_tunnels.h
  bc9d003dc48c3 ("ip_tunnel: Preserve pointer const in ip_tunnel_info_opts")
  ac931d4cdec3d ("ipip,ip_tunnel,sit: Add FOU support for externally controlled ipip devices")
https://lore.kernel.org/all/20230413161235.4093777-1-broonie@kernel.org/

net/bpf/test_run.c
  e5995bc7e2ba ("bpf, test_run: fix crashes due to XDP frame overwriting/corruption")
  294635a8165a ("bpf, test_run: fix &xdp_frame misplacement for LIVE_FRAMES")
https://lore.kernel.org/all/20230320102619.05b80a98@canb.auug.org.au/
====================

Link: https://lore.kernel.org/r/20230413191525.7295-1-daniel@iogearbox.net
Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2023-04-13T23:04:28+00:00

Conflicts:

tools/testing/selftests/net/config
  62199e3f1658 ("selftests: net: Add VXLAN MDB test")
  3a0385be133e ("selftests: add the missing CONFIG_IP_SCTP in net config")

Signed-off-by: Jakub Kicinski

bpf,fou: Add bpf_skb_{set,get}_fou_encap kfuncs

2023-04-12T23:40:39+00:00

Add two new kfuncs that allow a BPF tc-hook, installed on an ipip
device in collect-metadata mode, to control FOU encap parameters on a
per-packet level. The set of kfuncs is registered with the fou module.

The bpf_skb_set_fou_encap kfunc is supposed to be used in tandem and after
a successful call to the bpf_skb_set_tunnel_key bpf-helper. UDP source and
destination ports can be controlled by passing a struct bpf_fou_encap. A
source port of zero will auto-assign a source port. enum bpf_fou_encap_type
is used to specify if the egress path should FOU or GUE encap the packet.

On the ingress path bpf_skb_get_fou_encap can be used to read UDP source
and destination ports from the receiver's point of view and allows for
packet multiplexing across different destination ports within a single
BPF program and ipip device.

Signed-off-by: Christian Ehrig 
Link: https://lore.kernel.org/r/e17c94a646b63e78ce0dbf3f04b2c33dc948a32d.1680874078.git.cehrig@cloudflare.com
Signed-off-by: Alexei Starovoitov

ipip,ip_tunnel,sit: Add FOU support for externally controlled ipip devices

2023-04-12T23:40:39+00:00

Today ipip devices in collect-metadata mode don't allow for sending FOU
or GUE encapsulated packets. This patch lifts the restriction by adding
a struct ip_tunnel_encap to the tunnel metadata.

On the egress path, the members of this struct can be set by the
bpf_skb_set_fou_encap kfunc via a BPF tc-hook. Instead of dropping packets
wishing to use additional UDP encapsulation, ip_md_tunnel_xmit now
evaluates the contents of this struct and adds the corresponding FOU or
GUE header. Furthermore, it is making sure that additional header bytes
are taken into account for PMTU discovery.

On the ingress path, an ipip device in collect-metadata mode will fill this
struct and a BPF tc-hook can obtain the information via a call to the
bpf_skb_get_fou_encap kfunc.

The minor change to ip_tunnel_encap, which now takes a pointer to
struct ip_tunnel_encap instead of struct ip_tunnel, allows us to control
FOU encap type and parameters on a per packet-level.

Signed-off-by: Christian Ehrig 
Link: https://lore.kernel.org/r/cfea47de655d0f870248abf725932f851b53960a.1680874078.git.cehrig@cloudflare.com
Signed-off-by: Alexei Starovoitov