net: selectively purge error queue in IP_RECVERR / IPV6_RECVERR

Setting IP_RECVERR and IPV6_RECVERR options to zero currently
purges the socket error queue, which was probably not expected
for zeroc

net: selectively purge error queue in IP_RECVERR / IPV6_RECVERR

Setting IP_RECVERR and IPV6_RECVERR options to zero currently
purges the socket error queue, which was probably not expected
for zerocopy and tx_timestamp users.

I discovered this issue while preparing commit 6b5f43ea0815
("inet: move inet->recverr to inet->inet_flags"), I presume this
change does not need to be backported to stable kernels.

Add skb_errqueue_purge() helper to purge error messages only.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Cc: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: move inet->is_icsk to inet->inet_flags

We move single bit fields to inet->inet_flags to avoid races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@

inet: move inet->is_icsk to inet->inet_flags

We move single bit fields to inet->inet_flags to avoid races.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: move inet->transparent to inet->inet_flags

IP_TRANSPARENT socket option can now be set/read
without locking the socket.

v2: removed unused issk variable in mptcp_setsockopt_sol_ip_set_transpa

inet: move inet->transparent to inet->inet_flags

IP_TRANSPARENT socket option can now be set/read
without locking the socket.

v2: removed unused issk variable in mptcp_setsockopt_sol_ip_set_transparent()
v4: rebased after commit 3f326a821b99 ("mptcp: change the mpc check helper to return a sk")

Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet: move inet->freebind to inet->inet_flags

IP_FREEBIND socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeg

inet: move inet->freebind to inet->inet_flags

IP_FREEBIND socket option can now be set/read
without locking the socket.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Reviewed-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: annotate data-races around sock->ops

IPV6_ADDRFORM socket option is evil, because it can change sock->ops
while other threads might read it. Same issue for sk->sk_family
being set to AF_INET.

net: annotate data-races around sock->ops

IPV6_ADDRFORM socket option is evil, because it can change sock->ops
while other threads might read it. Same issue for sk->sk_family
being set to AF_INET.

Adding READ_ONCE() over sock->ops reads is needed for sockets
that might be impacted by IPV6_ADDRFORM.

Note that mptcp_is_tcpsk() can also overwrite sock->ops.

Adding annotations for all sk->sk_family reads will require
more patches :/

BUG: KCSAN: data-race in ____sys_sendmsg / do_ipv6_setsockopt

write to 0xffff888109f24ca0 of 8 bytes by task 4470 on cpu 0:
do_ipv6_setsockopt+0x2c5e/0x2ce0 net/ipv6/ipv6_sockglue.c:491
ipv6_setsockopt+0x57/0x130 net/ipv6/ipv6_sockglue.c:1012
udpv6_setsockopt+0x95/0xa0 net/ipv6/udp.c:1690
sock_common_setsockopt+0x61/0x70 net/core/sock.c:3663
__sys_setsockopt+0x1c3/0x230 net/socket.c:2273
__do_sys_setsockopt net/socket.c:2284 [inline]
__se_sys_setsockopt net/socket.c:2281 [inline]
__x64_sys_setsockopt+0x66/0x80 net/socket.c:2281
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 0xffff888109f24ca0 of 8 bytes by task 4469 on cpu 1:
sock_sendmsg_nosec net/socket.c:724 [inline]
sock_sendmsg net/socket.c:747 [inline]
____sys_sendmsg+0x349/0x4c0 net/socket.c:2503
___sys_sendmsg net/socket.c:2557 [inline]
__sys_sendmmsg+0x263/0x500 net/socket.c:2643
__do_sys_sendmmsg net/socket.c:2672 [inline]
__se_sys_sendmmsg net/socket.c:2669 [inline]
__x64_sys_sendmmsg+0x57/0x60 net/socket.c:2669
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: 0xffffffff850e32b8 -> 0xffffffff850da890

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4469 Comm: syz-executor.1 Not tainted 6.4.0-rc5-syzkaller-00313-g4c605260bc60 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/25/2023

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20230808135809.2300241-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

net/ipv6: Initialise msg_control_is_user

do_ipv6_setsockopt() makes use of struct msghdr::msg_control in the
IPV6_2292PKTOPTIONS case. Make sure to initialise
msg_control_is_user accordingly.

Cc: C

net/ipv6: Initialise msg_control_is_user

do_ipv6_setsockopt() makes use of struct msghdr::msg_control in the
IPV6_2292PKTOPTIONS case. Make sure to initialise
msg_control_is_user accordingly.

Cc: Christoph Hellwig <hch@lst.de>
Cc: Eric Dumazet <edumazet@google.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

net: no longer support SOCK_REFCNT_DEBUG feature

Commit e48c414ee61f ("[INET]: Generalise the TCP sock ID lookup routines")
commented out the definition of SOCK_REFCNT_DEBUG in 2005 and later anothe

net: no longer support SOCK_REFCNT_DEBUG feature

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 <kuniyu@amazon.com>
Signed-off-by: Jason Xing <kernelxing@tencent.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Wenjia Zhang <wenjia@linux.ibm.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

inet6: Clean up failure path in do_ipv6_setsockopt().

We can reuse the unlock label above and need not repeat the same code.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Davi

inet6: Clean up failure path in do_ipv6_setsockopt().

We can reuse the unlock label above and need not repeat the same code.

Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

tcp: Fix data races around icsk->icsk_af_ops.

setsockopt(IPV6_ADDRFORM) and tcp_v6_connect() change icsk->icsk_af_ops
under lock_sock(), but tcp_(get|set)sockopt() read it locklessly. To
avoid load

tcp: Fix data races around icsk->icsk_af_ops.

setsockopt(IPV6_ADDRFORM) and tcp_v6_connect() change icsk->icsk_af_ops
under lock_sock(), but tcp_(get|set)sockopt() read it locklessly. To
avoid load/store tearing, we need to add READ_ONCE() and WRITE_ONCE()
for the reads and writes.

Thanks to Eric Dumazet for providing the syzbot report:

BUG: KCSAN: data-race in tcp_setsockopt / tcp_v6_connect

write to 0xffff88813c624518 of 8 bytes by task 23936 on cpu 0:
tcp_v6_connect+0x5b3/0xce0 net/ipv6/tcp_ipv6.c:240
__inet_stream_connect+0x159/0x6d0 net/ipv4/af_inet.c:660
inet_stream_connect+0x44/0x70 net/ipv4/af_inet.c:724
__sys_connect_file net/socket.c:1976 [inline]
__sys_connect+0x197/0x1b0 net/socket.c:1993
__do_sys_connect net/socket.c:2003 [inline]
__se_sys_connect net/socket.c:2000 [inline]
__x64_sys_connect+0x3d/0x50 net/socket.c:2000
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

read to 0xffff88813c624518 of 8 bytes by task 23937 on cpu 1:
tcp_setsockopt+0x147/0x1c80 net/ipv4/tcp.c:3789
sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3585
__sys_setsockopt+0x212/0x2b0 net/socket.c:2252
__do_sys_setsockopt net/socket.c:2263 [inline]
__se_sys_setsockopt net/socket.c:2260 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2260
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x2b/0x70 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd

value changed: 0xffffffff8539af68 -> 0xffffffff8539aff8

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23937 Comm: syz-executor.5 Not tainted
6.0.0-rc4-syzkaller-00331-g4ed9c1e971b1-dirty #0

Hardware name: Google Google Compute Engine/Google Compute Engine,
BIOS Google 08/26/2022

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Reported-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

ipv6: Fix data races around sk->sk_prot.

Commit 086d49058cd8 ("ipv6: annotate some data-races around sk->sk_prot")
fixed some data-races around sk->sk_prot but it was not enough.

Some functions in

ipv6: Fix data races around sk->sk_prot.

Commit 086d49058cd8 ("ipv6: annotate some data-races around sk->sk_prot")
fixed some data-races around sk->sk_prot but it was not enough.

Some functions in inet6_(stream|dgram)_ops still access sk->sk_prot
without lock_sock() or rtnl_lock(), so they need READ_ONCE() to avoid
load tearing.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

udp: Call inet6_destroy_sock() in setsockopt(IPV6_ADDRFORM).

Commit 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") forgot
to add a change to free inet6_sk(sk)->rxpmtu while converting an IPv6

udp: Call inet6_destroy_sock() in setsockopt(IPV6_ADDRFORM).

Commit 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support") forgot
to add a change to free inet6_sk(sk)->rxpmtu while converting an IPv6
socket into IPv4 with IPV6_ADDRFORM. After conversion, sk_prot is
changed to udp_prot and ->destroy() never cleans it up, resulting in
a memory leak.

This is due to the discrepancy between inet6_destroy_sock() and
IPV6_ADDRFORM, so let's call inet6_destroy_sock() from IPV6_ADDRFORM
to remove the difference.

However, this is not enough for now because rxpmtu can be changed
without lock_sock() after commit 03485f2adcde ("udpv6: Add lockless
sendmsg() support"). We will fix this case in the following patch.

Note we will rename inet6_destroy_sock() to inet6_cleanup_sock() and
remove unnecessary inet6_destroy_sock() calls in sk_prot->destroy()
in the future.

Fixes: 4b340ae20d0e ("IPv6: Complete IPV6_DONTFRAG support")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

tcp/udp: Fix memory leak in ipv6_renew_options().

syzbot reported a memory leak [0] related to IPV6_ADDRFORM.

The scenario is that while one thread is converting an IPv6 socket into
IPv4 with IPV6_

tcp/udp: Fix memory leak in ipv6_renew_options().

syzbot reported a memory leak [0] related to IPV6_ADDRFORM.

The scenario is that while one thread is converting an IPv6 socket into
IPv4 with IPV6_ADDRFORM, another thread calls do_ipv6_setsockopt() and
allocates memory to inet6_sk(sk)->XXX after conversion.

Then, the converted sk with (tcp|udp)_prot never frees the IPv6 resources,
which inet6_destroy_sock() should have cleaned up.

setsockopt(IPV6_ADDRFORM) setsockopt(IPV6_DSTOPTS)
+-----------------------+ +----------------------+
- do_ipv6_setsockopt(sk, ...)
- sockopt_lock_sock(sk) - do_ipv6_setsockopt(sk, ...)
- lock_sock(sk) ^._ called via tcpv6_prot
- WRITE_ONCE(sk->sk_prot, &tcp_prot) before WRITE_ONCE()
- xchg(&np->opt, NULL)
- txopt_put(opt)
- sockopt_release_sock(sk)
- release_sock(sk) - sockopt_lock_sock(sk)
- lock_sock(sk)
- ipv6_set_opt_hdr(sk, ...)
- ipv6_update_options(sk, opt)
- xchg(&inet6_sk(sk)->opt, opt)
^._ opt is never freed.

- sockopt_release_sock(sk)
- release_sock(sk)

Since IPV6_DSTOPTS allocates options under lock_sock(), we can avoid this
memory leak by testing whether sk_family is changed by IPV6_ADDRFORM after
acquiring the lock.

This issue exists from the initial commit between IPV6_ADDRFORM and
IPV6_PKTOPTIONS.

[0]:
BUG: memory leak
unreferenced object 0xffff888009ab9f80 (size 96):
comm "syz-executor583", pid 328, jiffies 4294916198 (age 13.034s)
hex dump (first 32 bytes):
01 00 00 00 48 00 00 00 08 00 00 00 00 00 00 00 ....H...........
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
backtrace:
[<000000002ee98ae1>] kmalloc include/linux/slab.h:605 [inline]
[<000000002ee98ae1>] sock_kmalloc+0xb3/0x100 net/core/sock.c:2566
[<0000000065d7b698>] ipv6_renew_options+0x21e/0x10b0 net/ipv6/exthdrs.c:1318
[<00000000a8c756d7>] ipv6_set_opt_hdr net/ipv6/ipv6_sockglue.c:354 [inline]
[<00000000a8c756d7>] do_ipv6_setsockopt.constprop.0+0x28b7/0x4350 net/ipv6/ipv6_sockglue.c:668
[<000000002854d204>] ipv6_setsockopt+0xdf/0x190 net/ipv6/ipv6_sockglue.c:1021
[<00000000e69fdcf8>] tcp_setsockopt+0x13b/0x2620 net/ipv4/tcp.c:3789
[<0000000090da4b9b>] __sys_setsockopt+0x239/0x620 net/socket.c:2252
[<00000000b10d192f>] __do_sys_setsockopt net/socket.c:2263 [inline]
[<00000000b10d192f>] __se_sys_setsockopt net/socket.c:2260 [inline]
[<00000000b10d192f>] __x64_sys_setsockopt+0xbe/0x160 net/socket.c:2260
[<000000000a80d7aa>] do_syscall_x64 arch/x86/entry/common.c:50 [inline]
[<000000000a80d7aa>] do_syscall_64+0x38/0x90 arch/x86/entry/common.c:80
[<000000004562b5c6>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

show more ...

bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()

This patch changes bpf_getsockopt(SOL_IPV6) to reuse
do_ipv6_getsockopt(). It removes the duplicated code from
bpf_getsockopt(SOL_

bpf: Change bpf_getsockopt(SOL_IPV6) to reuse do_ipv6_getsockopt()

This patch changes bpf_getsockopt(SOL_IPV6) to reuse
do_ipv6_getsockopt(). It removes the duplicated code from
bpf_getsockopt(SOL_IPV6).

This also makes bpf_getsockopt(SOL_IPV6) supporting the same
set of optnames as in bpf_setsockopt(SOL_IPV6). In particular,
this adds IPV6_AUTOFLOWLABEL support to bpf_getsockopt(SOL_IPV6).

ipv6 could be compiled as a module. Like how other code solved it
with stubs in ipv6_stubs.h, this patch adds the do_ipv6_getsockopt
to the ipv6_bpf_stub.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002931.2896218-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

bpf: net: Avoid do_ipv6_getsockopt() taking sk lock when called from bpf

Similar to the earlier patch that changes sk_getsockopt() to
use sockopt_{lock,release}_sock() such that it can avoid taking

bpf: net: Avoid do_ipv6_getsockopt() taking sk lock when called from bpf

Similar to the earlier patch that changes sk_getsockopt() to
use sockopt_{lock,release}_sock() such that it can avoid taking the
lock when called from bpf. This patch also changes do_ipv6_getsockopt()
to use sockopt_{lock,release}_sock() such that bpf_getsockopt(SOL_IPV6)
can reuse do_ipv6_getsockopt().

Although bpf_getsockopt(SOL_IPV6) currently does not support optname
that requires lock_sock(), using sockopt_{lock,release}_sock()
consistently across *_getsockopt() will make future optname addition
harder to miss the sockopt_{lock,release}_sock() usage. eg. when
adding new optname that requires a lock and the new optname is
needed in bpf_getsockopt() also.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002859.2893064-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

bpf: net: Change do_ipv6_getsockopt() to take the sockptr_t argument

Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument . This patch also changes
do_ipv6_getso

bpf: net: Change do_ipv6_getsockopt() to take the sockptr_t argument

Similar to the earlier patch that changes sk_getsockopt() to
take the sockptr_t argument . This patch also changes
do_ipv6_getsockopt() to take the sockptr_t argument such that
a latter patch can make bpf_getsockopt(SOL_IPV6) to reuse
do_ipv6_getsockopt().

Note on the change in ip6_mc_msfget(). This function is to
return an array of sockaddr_storage in optval. This function
is shared between ipv6_get_msfilter() and compat_ipv6_get_msfilter().
However, the sockaddr_storage is stored at different offset of the
optval because of the difference between group_filter and
compat_group_filter. Thus, a new 'ss_offset' argument is
added to ip6_mc_msfget().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002853.2892532-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

net: Add a len argument to compat_ipv6_get_msfilter()

Pass the len to the compat_ipv6_get_msfilter() instead of
compat_ipv6_get_msfilter() getting it again from optlen.
Its counter part ipv6_get_msf

net: Add a len argument to compat_ipv6_get_msfilter()

Pass the len to the compat_ipv6_get_msfilter() instead of
compat_ipv6_get_msfilter() getting it again from optlen.
Its counter part ipv6_get_msfilter() is also taking the
len from do_ipv6_getsockopt().

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002846.2892091-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

net: Remove unused flags argument from do_ipv6_getsockopt

The 'unsigned int flags' argument is always 0, so it can be removed.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://

net: Remove unused flags argument from do_ipv6_getsockopt

The 'unsigned int flags' argument is always 0, so it can be removed.

Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20220902002840.2891763-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

show more ...

net: Fix data-races around sysctl_optmem_max.

While reading sysctl_optmem_max, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc

net: Fix data-races around sysctl_optmem_max.

While reading sysctl_optmem_max, it can be changed concurrently.
Thus, we need to add READ_ONCE() to its readers.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

show more ...

bpf: Change bpf_setsockopt(SOL_IPV6) to reuse do_ipv6_setsockopt()

After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IPV6)
and reuses the implement

bpf: Change bpf_setsockopt(SOL_IPV6) to reuse do_ipv6_setsockopt()

After the prep work in the previous patches,
this patch removes the dup code from bpf_setsockopt(SOL_IPV6)
and reuses the implementation in do_ipv6_setsockopt().

ipv6 could be compiled as a module. Like how other code solved it
with stubs in ipv6_stubs.h, this patch adds the do_ipv6_setsockopt
to the ipv6_bpf_stub.

The current bpf_setsockopt(IPV6_TCLASS) does not take the
INET_ECN_MASK into the account for tcp. The
do_ipv6_setsockopt(IPV6_TCLASS) will handle it correctly.

The existing optname white-list is refactored into a new
function sol_ipv6_setsockopt().

After this last SOL_IPV6 dup code removal, the __bpf_setsockopt()
is simplified enough that the extra "{ }" around the if statement
can be removed.

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061834.4181198-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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bpf: net: Change do_ipv6_setsockopt() to use the sockopt's lock_sock() and capable()

Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called b

bpf: net: Change do_ipv6_setsockopt() to use the sockopt's lock_sock() and capable()

Similar to the earlier patch that avoids sk_setsockopt() from
taking sk lock and doing capable test when called by bpf. This patch
changes do_ipv6_setsockopt() to use the sockopt_{lock,release}_sock()
and sockopt_[ns_]capable().

Reviewed-by: Stanislav Fomichev <sdf@google.com>
Signed-off-by: Martin KaFai Lau <kafai@fb.com>
Link: https://lore.kernel.org/r/20220817061744.4176893-1-kafai@fb.com
Signed-off-by: Alexei Starovoitov <ast@kernel.org>

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ipv6: annotate some data-races around sk->sk_prot

IPv6 has this hack changing sk->sk_prot when an IPv6 socket
is 'converted' to an IPv4 one with IPV6_ADDRFORM option.

This operation is only perform

ipv6: annotate some data-races around sk->sk_prot

IPv6 has this hack changing sk->sk_prot when an IPv6 socket
is 'converted' to an IPv4 one with IPV6_ADDRFORM option.

This operation is only performed for TCP and UDP, knowing
their 'struct proto' for the two network families are populated
in the same way, and can not disappear while a reader
might use and dereference sk->sk_prot.

If we think about it all reads of sk->sk_prot while
either socket lock or RTNL is not acquired should be using READ_ONCE().

Also note that other layers like MPTCP, XFRM, CHELSIO_TLS also
write over sk->sk_prot.

BUG: KCSAN: data-race in inet6_recvmsg / ipv6_setsockopt

write to 0xffff8881386f7aa8 of 8 bytes by task 26932 on cpu 0:
do_ipv6_setsockopt net/ipv6/ipv6_sockglue.c:492 [inline]
ipv6_setsockopt+0x3758/0x3910 net/ipv6/ipv6_sockglue.c:1019
udpv6_setsockopt+0x85/0x90 net/ipv6/udp.c:1649
sock_common_setsockopt+0x5d/0x70 net/core/sock.c:3489
__sys_setsockopt+0x209/0x2a0 net/socket.c:2180
__do_sys_setsockopt net/socket.c:2191 [inline]
__se_sys_setsockopt net/socket.c:2188 [inline]
__x64_sys_setsockopt+0x62/0x70 net/socket.c:2188
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

read to 0xffff8881386f7aa8 of 8 bytes by task 26911 on cpu 1:
inet6_recvmsg+0x7a/0x210 net/ipv6/af_inet6.c:659
____sys_recvmsg+0x16c/0x320
___sys_recvmsg net/socket.c:2674 [inline]
do_recvmmsg+0x3f5/0xae0 net/socket.c:2768
__sys_recvmmsg net/socket.c:2847 [inline]
__do_sys_recvmmsg net/socket.c:2870 [inline]
__se_sys_recvmmsg net/socket.c:2863 [inline]
__x64_sys_recvmmsg+0xde/0x160 net/socket.c:2863
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x44/0xd0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x44/0xae

value changed: 0xffffffff85e0e980 -> 0xffffffff85e01580

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 26911 Comm: syz-executor.3 Not tainted 5.17.0-rc2-syzkaller-00316-g0457e5153e0e-dirty #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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net-ipv6: changes to ->tclass (via IPV6_TCLASS) should sk_dst_reset()

This is to match ipv4 behaviour, see __ip_sock_set_tos()
implementation.

Technically for ipv6 this might not be required becaus

net-ipv6: changes to ->tclass (via IPV6_TCLASS) should sk_dst_reset()

This is to match ipv4 behaviour, see __ip_sock_set_tos()
implementation.

Technically for ipv6 this might not be required because normally we
do not allow tclass to influence routing, yet the cli tooling does
support it:

lpk11:~# ip -6 rule add pref 5 tos 45 lookup 5
lpk11:~# ip -6 rule
5: from all tos 0x45 lookup 5

and in general dscp/tclass based routing does make sense.

We already have cases where dscp can affect vlan priority and/or
transmit queue (especially on wifi).

So let's just make things match. Easier to reason about and no harm.

Cc: Eric Dumazet <edumazet@google.com>
Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Link: https://lore.kernel.org/r/20211123223208.1117871-1-zenczykowski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net-ipv6: do not allow IPV6_TCLASS to muck with tcp's ECN

This is to match ipv4 behaviour, see __ip_sock_set_tos()
implementation at ipv4/ip_sockglue.c:579

void __ip_sock_set_tos(struct sock *sk, i

net-ipv6: do not allow IPV6_TCLASS to muck with tcp's ECN

This is to match ipv4 behaviour, see __ip_sock_set_tos()
implementation at ipv4/ip_sockglue.c:579

void __ip_sock_set_tos(struct sock *sk, int val)
{
if (sk->sk_type == SOCK_STREAM) {
val &= ~INET_ECN_MASK;
val |= inet_sk(sk)->tos & INET_ECN_MASK;
}
if (inet_sk(sk)->tos != val) {
inet_sk(sk)->tos = val;
sk->sk_priority = rt_tos2priority(val);
sk_dst_reset(sk);
}
}

Cc: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20211123223154.1117794-1-zenczykowski@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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net: drop nopreempt requirement on sock_prot_inuse_add()

This is distracting really, let's make this simpler,
because many callers had to take care of this
by themselves, even if on x86 this adds mo

net: drop nopreempt requirement on sock_prot_inuse_add()

This is distracting really, let's make this simpler,
because many callers had to take care of this
by themselves, even if on x86 this adds more
code than really needed.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

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ipv6: guard IPV6_MINHOPCOUNT with a static key

RFC 5082 IPV6_MINHOPCOUNT is rarely used on hosts.

Add a static key to remove from TCP fast path useless code,
and potential cache line miss to fetch

ipv6: guard IPV6_MINHOPCOUNT with a static key

RFC 5082 IPV6_MINHOPCOUNT is rarely used on hosts.

Add a static key to remove from TCP fast path useless code,
and potential cache line miss to fetch tcp_inet6_sk(sk)->min_hopcount

Note that once ip6_min_hopcount static key has been enabled,
it stays enabled until next boot.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Soheil Hassas Yeganeh <soheil@google.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

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