linux-stable.git/net/core, branch v6.4.7

xdp: use trusted arguments in XDP hints kfuncs

2023-07-23T11:53:48+00:00

[ Upstream commit 2e06c57d66d3f6c26faa5f5b479fb3add34ce85a ]

Currently, verifier does not reject XDP programs that pass NULL pointer to
hints functions. At the same time, this case is not handled in any driver
implementation (including veth). For example, changing

bpf_xdp_metadata_rx_timestamp(ctx, ×tamp);

to

bpf_xdp_metadata_rx_timestamp(ctx, NULL);

in xdp_metadata test successfully crashes the system.

Add KF_TRUSTED_ARGS flag to hints kfunc definitions, so driver code
does not have to worry about getting invalid pointers.

Fixes: 3d76a4d3d4e5 ("bpf: XDP metadata RX kfuncs")
Reported-by: Stanislav Fomichev 
Closes: https://lore.kernel.org/bpf/ZKWo0BbpLfkZHbyE@google.com/
Signed-off-by: Larysa Zaremba 
Acked-by: Jesper Dangaard Brouer 
Acked-by: Stanislav Fomichev 
Link: https://lore.kernel.org/r/20230711105930.29170-1-larysa.zaremba@intel.com
Signed-off-by: Alexei Starovoitov 
Signed-off-by: Sasha Levin

net: prevent skb corruption on frag list segmentation

2023-07-23T11:53:42+00:00

[ Upstream commit c329b261afe71197d9da83c1f18eb45a7e97e089 ]

Ian reported several skb corruptions triggered by rx-gro-list,
collecting different oops alike:

[   62.624003] BUG: kernel NULL pointer dereference, address: 00000000000000c0
[   62.631083] #PF: supervisor read access in kernel mode
[   62.636312] #PF: error_code(0x0000) - not-present page
[   62.641541] PGD 0 P4D 0
[   62.644174] Oops: 0000 [#1] PREEMPT SMP NOPTI
[   62.648629] CPU: 1 PID: 913 Comm: napi/eno2-79 Not tainted 6.4.0 #364
[   62.655162] Hardware name: Supermicro Super Server/A2SDi-12C-HLN4F, BIOS 1.7a 10/13/2022
[   62.663344] RIP: 0010:__udp_gso_segment (./include/linux/skbuff.h:2858
./include/linux/udp.h:23 net/ipv4/udp_offload.c:228 net/ipv4/udp_offload.c:261
net/ipv4/udp_offload.c:277)
[   62.687193] RSP: 0018:ffffbd3a83b4f868 EFLAGS: 00010246
[   62.692515] RAX: 00000000000000ce RBX: 0000000000000000 RCX: 0000000000000000
[   62.699743] RDX: ffffa124def8a000 RSI: 0000000000000079 RDI: ffffa125952a14d4
[   62.706970] RBP: ffffa124def8a000 R08: 0000000000000022 R09: 00002000001558c9
[   62.714199] R10: 0000000000000000 R11: 00000000be554639 R12: 00000000000000e2
[   62.721426] R13: ffffa125952a1400 R14: ffffa125952a1400 R15: 00002000001558c9
[   62.728654] FS:  0000000000000000(0000) GS:ffffa127efa40000(0000)
knlGS:0000000000000000
[   62.736852] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   62.742702] CR2: 00000000000000c0 CR3: 00000001034b0000 CR4: 00000000003526e0
[   62.749948] Call Trace:
[   62.752498]  
[   62.779267] inet_gso_segment (net/ipv4/af_inet.c:1398)
[   62.787605] skb_mac_gso_segment (net/core/gro.c:141)
[   62.791906] __skb_gso_segment (net/core/dev.c:3403 (discriminator 2))
[   62.800492] validate_xmit_skb (./include/linux/netdevice.h:4862
net/core/dev.c:3659)
[   62.804695] validate_xmit_skb_list (net/core/dev.c:3710)
[   62.809158] sch_direct_xmit (net/sched/sch_generic.c:330)
[   62.813198] __dev_queue_xmit (net/core/dev.c:3805 net/core/dev.c:4210)
net/netfilter/core.c:626)
[   62.821093] br_dev_queue_push_xmit (net/bridge/br_forward.c:55)
[   62.825652] maybe_deliver (net/bridge/br_forward.c:193)
[   62.829420] br_flood (net/bridge/br_forward.c:233)
[   62.832758] br_handle_frame_finish (net/bridge/br_input.c:215)
[   62.837403] br_handle_frame (net/bridge/br_input.c:298
net/bridge/br_input.c:416)
[   62.851417] __netif_receive_skb_core.constprop.0 (net/core/dev.c:5387)
[   62.866114] __netif_receive_skb_list_core (net/core/dev.c:5570)
[   62.871367] netif_receive_skb_list_internal (net/core/dev.c:5638
net/core/dev.c:5727)
[   62.876795] napi_complete_done (./include/linux/list.h:37
./include/net/gro.h:434 ./include/net/gro.h:429 net/core/dev.c:6067)
[   62.881004] ixgbe_poll (drivers/net/ethernet/intel/ixgbe/ixgbe_main.c:3191)
[   62.893534] __napi_poll (net/core/dev.c:6498)
[   62.897133] napi_threaded_poll (./include/linux/netpoll.h:89
net/core/dev.c:6640)
[   62.905276] kthread (kernel/kthread.c:379)
[   62.913435] ret_from_fork (arch/x86/entry/entry_64.S:314)
[   62.917119]  

In the critical scenario, rx-gro-list GRO-ed packets are fed, via a
bridge, both to the local input path and to an egress device (tun).

The segmentation of such packets unsafely writes to the cloned skbs
with shared heads.

This change addresses the issue by uncloning as needed the
to-be-segmented skbs.

Reported-by: Ian Kumlien 
Tested-by: Ian Kumlien 
Fixes: 3a1296a38d0c ("net: Support GRO/GSO fraglist chaining.")
Signed-off-by: Paolo Abeni 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

udp6: add a missing call into udp_fail_queue_rcv_skb tracepoint

2023-07-23T11:53:41+00:00

[ Upstream commit 8139dccd464aaee4a2c351506ff883733c6ca5a3 ]

The tracepoint has existed for 12 years, but it only covered udp
over the legacy IPv4 protocol. Having it enabled for udp6 removes
the unnecessary difference in error visibility.

Signed-off-by: Ivan Babrou 
Fixes: 296f7ea75b45 ("udp: add tracepoints for queueing skb to rcvbuf")
Acked-by: Paolo Abeni 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

netlink: Add __sock_i_ino() for __netlink_diag_dump().

2023-07-19T14:35:38+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

netlink: do not hard code device address lenth in fdb dumps

2023-07-19T14:35:35+00:00

[ Upstream commit aa5406950726e336c5c9585b09799a734b6e77bf ]

syzbot reports that some netdev devices do not have a six bytes
address [1]

Replace ETH_ALEN by dev->addr_len.

[1] (Case of a device where dev->addr_len = 4)

BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in copyout+0xb8/0x100 lib/iov_iter.c:169
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
copyout+0xb8/0x100 lib/iov_iter.c:169
_copy_to_iter+0x6d8/0x1d00 lib/iov_iter.c:536
copy_to_iter include/linux/uio.h:206 [inline]
simple_copy_to_iter+0x68/0xa0 net/core/datagram.c:513
__skb_datagram_iter+0x123/0xdc0 net/core/datagram.c:419
skb_copy_datagram_iter+0x5c/0x200 net/core/datagram.c:527
skb_copy_datagram_msg include/linux/skbuff.h:3960 [inline]
netlink_recvmsg+0x4ae/0x15a0 net/netlink/af_netlink.c:1970
sock_recvmsg_nosec net/socket.c:1019 [inline]
sock_recvmsg net/socket.c:1040 [inline]
____sys_recvmsg+0x283/0x7f0 net/socket.c:2722
___sys_recvmsg+0x223/0x840 net/socket.c:2764
do_recvmmsg+0x4f9/0xfd0 net/socket.c:2858
__sys_recvmmsg net/socket.c:2937 [inline]
__do_sys_recvmmsg net/socket.c:2960 [inline]
__se_sys_recvmmsg net/socket.c:2953 [inline]
__x64_sys_recvmmsg+0x397/0x490 net/socket.c:2953
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

Uninit was stored to memory at:
__nla_put lib/nlattr.c:1009 [inline]
nla_put+0x1c6/0x230 lib/nlattr.c:1067
nlmsg_populate_fdb_fill+0x2b8/0x600 net/core/rtnetlink.c:4071
nlmsg_populate_fdb net/core/rtnetlink.c:4418 [inline]
ndo_dflt_fdb_dump+0x616/0x840 net/core/rtnetlink.c:4456
rtnl_fdb_dump+0x14ff/0x1fc0 net/core/rtnetlink.c:4629
netlink_dump+0x9d1/0x1310 net/netlink/af_netlink.c:2268
netlink_recvmsg+0xc5c/0x15a0 net/netlink/af_netlink.c:1995
sock_recvmsg_nosec+0x7a/0x120 net/socket.c:1019
____sys_recvmsg+0x664/0x7f0 net/socket.c:2720
___sys_recvmsg+0x223/0x840 net/socket.c:2764
do_recvmmsg+0x4f9/0xfd0 net/socket.c:2858
__sys_recvmmsg net/socket.c:2937 [inline]
__do_sys_recvmmsg net/socket.c:2960 [inline]
__se_sys_recvmmsg net/socket.c:2953 [inline]
__x64_sys_recvmmsg+0x397/0x490 net/socket.c:2953
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

Uninit was created at:
slab_post_alloc_hook+0x12d/0xb60 mm/slab.h:716
slab_alloc_node mm/slub.c:3451 [inline]
__kmem_cache_alloc_node+0x4ff/0x8b0 mm/slub.c:3490
kmalloc_trace+0x51/0x200 mm/slab_common.c:1057
kmalloc include/linux/slab.h:559 [inline]
__hw_addr_create net/core/dev_addr_lists.c:60 [inline]
__hw_addr_add_ex+0x2e5/0x9e0 net/core/dev_addr_lists.c:118
__dev_mc_add net/core/dev_addr_lists.c:867 [inline]
dev_mc_add+0x9a/0x130 net/core/dev_addr_lists.c:885
igmp6_group_added+0x267/0xbc0 net/ipv6/mcast.c:680
ipv6_mc_up+0x296/0x3b0 net/ipv6/mcast.c:2754
ipv6_mc_remap+0x1e/0x30 net/ipv6/mcast.c:2708
addrconf_type_change net/ipv6/addrconf.c:3731 [inline]
addrconf_notify+0x4d3/0x1d90 net/ipv6/addrconf.c:3699
notifier_call_chain kernel/notifier.c:93 [inline]
raw_notifier_call_chain+0xe4/0x430 kernel/notifier.c:461
call_netdevice_notifiers_info net/core/dev.c:1935 [inline]
call_netdevice_notifiers_extack net/core/dev.c:1973 [inline]
call_netdevice_notifiers+0x1ee/0x2d0 net/core/dev.c:1987
bond_enslave+0xccd/0x53f0 drivers/net/bonding/bond_main.c:1906
do_set_master net/core/rtnetlink.c:2626 [inline]
rtnl_newlink_create net/core/rtnetlink.c:3460 [inline]
__rtnl_newlink net/core/rtnetlink.c:3660 [inline]
rtnl_newlink+0x378c/0x40e0 net/core/rtnetlink.c:3673
rtnetlink_rcv_msg+0x16a6/0x1840 net/core/rtnetlink.c:6395
netlink_rcv_skb+0x371/0x650 net/netlink/af_netlink.c:2546
rtnetlink_rcv+0x34/0x40 net/core/rtnetlink.c:6413
netlink_unicast_kernel net/netlink/af_netlink.c:1339 [inline]
netlink_unicast+0xf28/0x1230 net/netlink/af_netlink.c:1365
netlink_sendmsg+0x122f/0x13d0 net/netlink/af_netlink.c:1913
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x999/0xd50 net/socket.c:2503
___sys_sendmsg+0x28d/0x3c0 net/socket.c:2557
__sys_sendmsg net/socket.c:2586 [inline]
__do_sys_sendmsg net/socket.c:2595 [inline]
__se_sys_sendmsg net/socket.c:2593 [inline]
__x64_sys_sendmsg+0x304/0x490 net/socket.c:2593
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

Bytes 2856-2857 of 3500 are uninitialized
Memory access of size 3500 starts at ffff888018d99104
Data copied to user address 0000000020000480

Fixes: d83b06036048 ("net: add fdb generic dump routine")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Reviewed-by: Jiri Pirko 
Link: https://lore.kernel.org/r/20230621174720.1845040-1-edumazet@google.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Sasha Levin

bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings

2023-07-19T14:35:34+00:00

[ Upstream commit 9a5cb79762e0eda17ca15c2a6eaca4622383c21c ]

When calling bpf_sk_lookup_tcp(), bpf_sk_lookup_udp() or
bpf_skc_lookup_tcp() from tc/xdp ingress, VRF socket bindings aren't
respoected, i.e. unbound sockets are returned, and bound sockets aren't
found.

VRF binding is determined by the sdif argument to sk_lookup(), however
when called from tc the IP SKB control block isn't initialized and thus
inet{,6}_sdif() always returns 0.

Fix by calculating sdif for the tc/xdp flows by observing the device's
l3 enslaved state.

The cg/sk_skb hooking points which are expected to support
inet{,6}_sdif() pass sdif=-1 which makes __bpf_skc_lookup() use the
existing logic.

Fixes: 6acc9b432e67 ("bpf: Add helper to retrieve socket in BPF")
Signed-off-by: Gilad Sever 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Shmulik Ladkani 
Reviewed-by: Eyal Birger 
Acked-by: Stanislav Fomichev 
Cc: David Ahern 
Link: https://lore.kernel.org/bpf/20230621104211.301902-4-gilad9366@gmail.com
Signed-off-by: Sasha Levin

bpf: Call __bpf_sk_lookup()/__bpf_skc_lookup() directly via TC hookpoint

2023-07-19T14:35:34+00:00

[ Upstream commit 97fbfeb86917bdbe9c41d5143e335a929147f405 ]

skb->dev always exists in the tc flow. There is no need to use
bpf_skc_lookup(), bpf_sk_lookup() from this code path.

This change facilitates fixing the tc flow to be VRF aware.

Signed-off-by: Gilad Sever 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Shmulik Ladkani 
Reviewed-by: Eyal Birger 
Acked-by: Stanislav Fomichev 
Link: https://lore.kernel.org/bpf/20230621104211.301902-3-gilad9366@gmail.com
Stable-dep-of: 9a5cb79762e0 ("bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings")
Signed-off-by: Sasha Levin

bpf: Factor out socket lookup functions for the TC hookpoint.

2023-07-19T14:35:33+00:00

[ Upstream commit 6e98730bc0b44acaf86eccc75f823128aa9c9e79 ]

Change BPF helper socket lookup functions to use TC specific variants:
bpf_tc_sk_lookup_tcp() / bpf_tc_sk_lookup_udp() / bpf_tc_skc_lookup_tcp()
instead of sharing implementation with the cg / sk_skb hooking points.
This allows introducing a separate logic for the TC flow.

The tc functions are identical to the original code.

Signed-off-by: Gilad Sever 
Signed-off-by: Daniel Borkmann 
Reviewed-by: Shmulik Ladkani 
Reviewed-by: Eyal Birger 
Acked-by: Stanislav Fomichev 
Link: https://lore.kernel.org/bpf/20230621104211.301902-2-gilad9366@gmail.com
Stable-dep-of: 9a5cb79762e0 ("bpf: Fix bpf socket lookup from tc/xdp to respect socket VRF bindings")
Signed-off-by: Sasha Levin

rtnetlink: extend RTEXT_FILTER_SKIP_STATS to IFLA_VF_INFO

2023-07-19T14:35:30+00:00

[ Upstream commit fa0e21fa44438a0e856d42224bfa24641d37b979 ]

This filter already exists for excluding IPv6 SNMP stats. Extend its
definition to also exclude IFLA_VF_INFO stats in RTM_GETLINK.

This patch constitutes a partial fix for a netlink attribute nesting
overflow bug in IFLA_VFINFO_LIST. By excluding the stats when the
requester doesn't need them, the truncation of the VF list is avoided.

While it was technically only the stats added in commit c5a9f6f0ab40
("net/core: Add drop counters to VF statistics") breaking the camel's
back, the appreciable size of the stats data should never have been
included without due consideration for the maximum number of VFs
supported by PCI.

Fixes: 3b766cd83232 ("net/core: Add reading VF statistics through the PF netdevice")
Fixes: c5a9f6f0ab40 ("net/core: Add drop counters to VF statistics")
Signed-off-by: Edwin Peer 
Cc: Edwin Peer 
Signed-off-by: Gal Pressman 
Link: https://lore.kernel.org/r/20230611105108.122586-1-gal@nvidia.com
Signed-off-by: Paolo Abeni 
Signed-off-by: Sasha Levin

revert "net: align SO_RCVMARK required privileges with SO_MARK"

2023-06-22T09:45:23+00:00

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