linux-stable.git/net/core/sock.c, branch linux-6.3.y

netlink: Add __sock_i_ino() for __netlink_diag_dump().

2023-07-11T17:39:32+00:00

[ Upstream commit 25a9c8a4431c364f97f75558cb346d2ad3f53fbb ]

syzbot reported a warning in __local_bh_enable_ip(). [0]

Commit 8d61f926d420 ("netlink: fix potential deadlock in
netlink_set_err()") converted read_lock(&nl_table_lock) to
read_lock_irqsave() in __netlink_diag_dump() to prevent a deadlock.

However, __netlink_diag_dump() calls sock_i_ino() that uses
read_lock_bh() and read_unlock_bh().  If CONFIG_TRACE_IRQFLAGS=y,
read_unlock_bh() finally enables IRQ even though it should stay
disabled until the following read_unlock_irqrestore().

Using read_lock() in sock_i_ino() would trigger a lockdep splat
in another place that was fixed in commit f064af1e500a ("net: fix
a lockdep splat"), so let's add __sock_i_ino() that would be safe
to use under BH disabled.

[0]:
WARNING: CPU: 0 PID: 5012 at kernel/softirq.c:376 __local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376
Modules linked in:
CPU: 0 PID: 5012 Comm: syz-executor487 Not tainted 6.4.0-rc7-syzkaller-00202-g6f68fc395f49 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/27/2023
RIP: 0010:__local_bh_enable_ip+0xbe/0x130 kernel/softirq.c:376
Code: 45 bf 01 00 00 00 e8 91 5b 0a 00 e8 3c 15 3d 00 fb 65 8b 05 ec e9 b5 7e 85 c0 74 58 5b 5d c3 65 8b 05 b2 b6 b4 7e 85 c0 75 a2 <0f> 0b eb 9e e8 89 15 3d 00 eb 9f 48 89 ef e8 6f 49 18 00 eb a8 0f
RSP: 0018:ffffc90003a1f3d0 EFLAGS: 00010046
RAX: 0000000000000000 RBX: 0000000000000201 RCX: 1ffffffff1cf5996
RDX: 0000000000000000 RSI: 0000000000000201 RDI: ffffffff8805c6f3
RBP: ffffffff8805c6f3 R08: 0000000000000001 R09: ffff8880152b03a3
R10: ffffed1002a56074 R11: 0000000000000005 R12: 00000000000073e4
R13: dffffc0000000000 R14: 0000000000000002 R15: 0000000000000000
FS:  0000555556726300(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000045ad50 CR3: 000000007c646000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 
 sock_i_ino+0x83/0xa0 net/core/sock.c:2559
 __netlink_diag_dump+0x45c/0x790 net/netlink/diag.c:171
 netlink_diag_dump+0xd6/0x230 net/netlink/diag.c:207
 netlink_dump+0x570/0xc50 net/netlink/af_netlink.c:2269
 __netlink_dump_start+0x64b/0x910 net/netlink/af_netlink.c:2374
 netlink_dump_start include/linux/netlink.h:329 [inline]
 netlink_diag_handler_dump+0x1ae/0x250 net/netlink/diag.c:238
 __sock_diag_cmd net/core/sock_diag.c:238 [inline]
 sock_diag_rcv_msg+0x31e/0x440 net/core/sock_diag.c:269
 netlink_rcv_skb+0x165/0x440 net/netlink/af_netlink.c:2547
 sock_diag_rcv+0x2a/0x40 net/core/sock_diag.c:280
 netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
 netlink_unicast+0x547/0x7f0 net/netlink/af_netlink.c:1365
 netlink_sendmsg+0x925/0xe30 net/netlink/af_netlink.c:1914
 sock_sendmsg_nosec net/socket.c:724 [inline]
 sock_sendmsg+0xde/0x190 net/socket.c:747
 ____sys_sendmsg+0x71c/0x900 net/socket.c:2503
 ___sys_sendmsg+0x110/0x1b0 net/socket.c:2557
 __sys_sendmsg+0xf7/0x1c0 net/socket.c:2586
 do_syscall_x64 arch/x86/entry/common.c:50 [inline]
 do_syscall_64+0x39/0xb0 arch/x86/entry/common.c:80
 entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f5303aaabb9
Code: 28 c3 e8 2a 14 00 00 66 2e 0f 1f 84 00 00 00 00 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 c0 ff ff ff f7 d8 64 89 01 48
RSP: 002b:00007ffc7506e548 EFLAGS: 00000246 ORIG_RAX: 000000000000002e
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f5303aaabb9
RDX: 0000000000000000 RSI: 0000000020000180 RDI: 0000000000000003
RBP: 00007f5303a6ed60 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f5303a6edf0
R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000
 

Fixes: 8d61f926d420 ("netlink: fix potential deadlock in netlink_set_err()")
Reported-by: syzbot+5da61cf6a9bc1902d422@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?extid=5da61cf6a9bc1902d422
Suggested-by: Eric Dumazet 
Signed-off-by: Kuniyuki Iwashima 
Reviewed-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20230626164313.52528-1-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

revert "net: align SO_RCVMARK required privileges with SO_MARK"

2023-06-28T09:14:17+00:00

[ Upstream commit a9628e88776eb7d045cf46467f1afdd0f7fe72ea ]

This reverts commit 1f86123b9749 ("net: align SO_RCVMARK required
privileges with SO_MARK") because the reasoning in the commit message
is not really correct:
  SO_RCVMARK is used for 'reading' incoming skb mark (via cmsg), as such
  it is more equivalent to 'getsockopt(SO_MARK)' which has no priv check
  and retrieves the socket mark, rather than 'setsockopt(SO_MARK) which
  sets the socket mark and does require privs.

  Additionally incoming skb->mark may already be visible if
  sysctl_fwmark_reflect and/or sysctl_tcp_fwmark_accept are enabled.

  Furthermore, it is easier to block the getsockopt via bpf
  (either cgroup setsockopt hook, or via syscall filters)
  then to unblock it if it requires CAP_NET_RAW/ADMIN.

On Android the socket mark is (among other things) used to store
the network identifier a socket is bound to.  Setting it is privileged,
but retrieving it is not.  We'd like unprivileged userspace to be able
to read the network id of incoming packets (where mark is set via
iptables [to be moved to bpf])...

An alternative would be to add another sysctl to control whether
setting SO_RCVMARK is privilged or not.
(or even a MASK of which bits in the mark can be exposed)
But this seems like over-engineering...

Note: This is a non-trivial revert, due to later merged commit e42c7beee71d
("bpf: net: Consider has_current_bpf_ctx() when testing capable() in sk_setsockopt()")
which changed both 'ns_capable' into 'sockopt_ns_capable' calls.

Fixes: 1f86123b9749 ("net: align SO_RCVMARK required privileges with SO_MARK")
Cc: Larysa Zaremba 
Cc: Simon Horman 
Cc: Paolo Abeni 
Cc: Eyal Birger 
Cc: Jakub Kicinski 
Cc: Eric Dumazet 
Cc: Patrick Rohr 
Signed-off-by: Maciej Żenczykowski 
Reviewed-by: Simon Horman 
Reviewed-by: Kuniyuki Iwashima 
Link: https://lore.kernel.org/r/20230618103130.51628-1-maze@google.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

udp6: Fix race condition in udp6_sendmsg & connect

2023-06-09T08:47:54+00:00

[ Upstream commit 448a5ce1120c5bdbce1f1ccdabcd31c7d029f328 ]

Syzkaller got the following report:
BUG: KASAN: use-after-free in sk_setup_caps+0x621/0x690 net/core/sock.c:2018
Read of size 8 at addr ffff888027f82780 by task syz-executor276/3255

The function sk_setup_caps (called by ip6_sk_dst_store_flow->
ip6_dst_store) referenced already freed memory as this memory was
freed by parallel task in udpv6_sendmsg->ip6_sk_dst_lookup_flow->
sk_dst_check.

          task1 (connect)              task2 (udp6_sendmsg)
        sk_setup_caps->sk_dst_set |
                                  |  sk_dst_check->
                                  |      sk_dst_set
                                  |      dst_release
        sk_setup_caps references  |
        to already freed dst_entry|

The reason for this race condition is: sk_setup_caps() keeps using
the dst after transferring the ownership to the dst cache.

Found by Linux Verification Center (linuxtesting.org) with syzkaller.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Vladislav Efanov 
Signed-off-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: use indirect calls helpers for sk_exit_memory_pressure()

2023-03-02T10:35:06+00:00

Florian reported a regression and sent a patch with the following
changelog:


 There is a noticeable tcp performance regression (loopback or cross-netns),
 seen with iperf3 -Z (sendfile mode) when generic retpolines are needed.

 With SK_RECLAIM_THRESHOLD checks gone number of calls to enter/leave
 memory pressure happen much more often. For TCP indirect calls are
 used.

 We can't remove the if-set-return short-circuit check in
 tcp_enter_memory_pressure because there are callers other than
 sk_enter_memory_pressure.  Doing a check in the sk wrapper too
 reduces the indirect calls enough to recover some performance.

 Before,
 0.00-60.00  sec   322 GBytes  46.1 Gbits/sec                  receiver

 After:
 0.00-60.04  sec   359 GBytes  51.4 Gbits/sec                  receiver

 "iperf3 -c $peer -t 60 -Z -f g", connected via veth in another netns.


It seems we forgot to upstream this indirect call mitigation we
had for years, lets do this instead.

[edumazet] - It seems we forgot to upstream this indirect call
             mitigation we had for years, let's do this instead.
           - Changed to INDIRECT_CALL_INET_1() to avoid bots reports.

Fixes: 4890b686f408 ("net: keep sk->sk_forward_alloc as small as possible")
Reported-by: Florian Westphal 
Link: https://lore.kernel.org/netdev/20230227152741.4a53634b@kernel.org/T/
Signed-off-by: Brian Vazquez 
Signed-off-by: Eric Dumazet 
Link: https://lore.kernel.org/r/20230301133247.2346111-1-edumazet@google.com
Signed-off-by: Paolo Abeni

net: no longer support SOCK_REFCNT_DEBUG feature

2023-02-15T10:25:21+00:00

Commit e48c414ee61f ("[INET]: Generalise the TCP sock ID lookup routines")
commented out the definition of SOCK_REFCNT_DEBUG in 2005 and later another
commit 463c84b97f24 ("[NET]: Introduce inet_connection_sock") removed it.
Since we could track all of them through bpf and kprobe related tools
and the feature could print loads of information which might not be
that helpful even under a little bit pressure, the whole feature which
has been inactive for many years is no longer supported.

Link: https://lore.kernel.org/lkml/20230211065153.54116-1-kerneljasonxing@gmail.com/
Suggested-by: Kuniyuki Iwashima 
Signed-off-by: Jason Xing 
Reviewed-by: Kuniyuki Iwashima 
Acked-by: Wenjia Zhang 
Reviewed-by: Eric Dumazet 
Acked-by: Matthieu Baerts 
Signed-off-by: David S. Miller

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

2023-02-09T20:25:40+00:00

net/devlink/leftover.c / net/core/devlink.c:
  565b4824c39f ("devlink: change port event netdev notifier from per-net to global")
  f05bd8ebeb69 ("devlink: move code to a dedicated directory")
  687125b5799c ("devlink: split out core code")
https://lore.kernel.org/all/20230208094657.379f2b1a@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

txhash: fix sk->sk_txrehash default

2023-02-08T09:07:11+00:00

This code fix a bug that sk->sk_txrehash gets its default enable
value from sysctl_txrehash only when the socket is a TCP listener.

We should have sysctl_txrehash to set the default sk->sk_txrehash,
no matter TCP, nor listerner/connector.

Tested by following packetdrill:
  0 socket(..., SOCK_STREAM, IPPROTO_TCP) = 3
  +0 socket(..., SOCK_DGRAM, IPPROTO_UDP) = 4
  // SO_TXREHASH == 74, default to sysctl_txrehash == 1
  +0 getsockopt(3, SOL_SOCKET, 74, [1], [4]) = 0
  +0 getsockopt(4, SOL_SOCKET, 74, [1], [4]) = 0

Fixes: 26859240e4ee ("txhash: Add socket option to control TX hash rethink behavior")
Signed-off-by: Kevin Yang 
Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: add sock_init_data_uid()

2023-02-06T10:16:55+00:00

Add sock_init_data_uid() to explicitly initialize the socket uid.
To initialise the socket uid, sock_init_data() assumes a the struct
socket* sock is always embedded in a struct socket_alloc, used to
access the corresponding inode uid. This may not be true.
Examples are sockets created in tun_chr_open() and tap_open().

Fixes: 86741ec25462 ("net: core: Add a UID field to struct sock.")
Signed-off-by: Pietro Borrello 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

net: add support for ipv4 big tcp

2023-02-02T04:54:27+00:00

Similar to Eric's IPv6 BIG TCP, this patch is to enable IPv4 BIG TCP.

Firstly, allow sk->sk_gso_max_size to be set to a value greater than
GSO_LEGACY_MAX_SIZE by not trimming gso_max_size in sk_trim_gso_size()
for IPv4 TCP sockets.

Then on TX path, set IP header tot_len to 0 when skb->len > IP_MAX_MTU
in __ip_local_out() to allow to send BIG TCP packets, and this implies
that skb->len is the length of a IPv4 packet; On RX path, use skb->len
as the length of the IPv4 packet when the IP header tot_len is 0 and
skb->len > IP_MAX_MTU in ip_rcv_core(). As the API iph_set_totlen() and
skb_ip_totlen() are used in __ip_local_out() and ip_rcv_core(), we only
need to update these APIs.

Also in GRO receive, add the check for ETH_P_IP/IPPROTO_TCP, and allows
the merged packet size >= GRO_LEGACY_MAX_SIZE in skb_gro_receive(). In
GRO complete, set IP header tot_len to 0 when the merged packet size
greater than IP_MAX_MTU in iph_set_totlen() so that it can be processed
on RX path.

Note that by checking skb_is_gso_tcp() in API iph_totlen(), it makes
this implementation safe to use iph->len == 0 indicates IPv4 BIG TCP
packets.

Signed-off-by: Xin Long 
Reviewed-by: David Ahern 
Reviewed-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

net/sock: Introduce trace_sk_data_ready()

2023-01-23T11:26:50+00:00

As suggested by Cong, introduce a tracepoint for all ->sk_data_ready()
callback implementations.  For example:

<...>
  iperf-609  [002] .....  70.660425: sk_data_ready: family=2 protocol=6 func=sock_def_readable
  iperf-609  [002] .....  70.660436: sk_data_ready: family=2 protocol=6 func=sock_def_readable
<...>

Suggested-by: Cong Wang 
Signed-off-by: Peilin Ye 
Signed-off-by: David S. Miller