linux-stable.git/net/ipv4, branch v6.0.8 Linux kernel stable tree net: also flag accepted sockets supporting msghdr originated zerocopy 2022-11-10T17:17:35+00:00 Stefan Metzmacher metze@samba.org 2022-10-26T23:25:59+00:00 cb525522fccc24baf0ca8181d54f2dd7b631bdc7 commit 71b7786ea478f3c4611deff4d2b9676b0c17c56b upstream. Without this only the client initiated tcp sockets have SOCK_SUPPORT_ZC. The listening socket on the server also has it, but the accepted connections didn't, which meant IORING_OP_SEND[MSG]_ZC will always fails with -EOPNOTSUPP. Fixes: e993ffe3da4b ("net: flag sockets supporting msghdr originated zerocopy") Cc: <stable@vger.kernel.org> # 6.0 CC: Jens Axboe <axboe@kernel.dk> Link: https://lore.kernel.org/io-uring/20221024141503.22b4e251@kernel.org/T/#m38aa19b0b825758fb97860a38ad13122051f9dda Signed-off-by: Stefan Metzmacher <metze@samba.org> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 71b7786ea478f3c4611deff4d2b9676b0c17c56b upstream.

Without this only the client initiated tcp sockets have SOCK_SUPPORT_ZC.
The listening socket on the server also has it, but the accepted
connections didn't, which meant IORING_OP_SEND[MSG]_ZC will always
fails with -EOPNOTSUPP.

Fixes: e993ffe3da4b ("net: flag sockets supporting msghdr originated zerocopy")
Cc: <stable@vger.kernel.org> # 6.0
CC: Jens Axboe <axboe@kernel.dk>
Link: https://lore.kernel.org/io-uring/20221024141503.22b4e251@kernel.org/T/#m38aa19b0b825758fb97860a38ad13122051f9dda
Signed-off-by: Stefan Metzmacher <metze@samba.org>
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: remove SOCK_SUPPORT_ZC from sockmap 2022-11-10T17:17:35+00:00 Pavel Begunkov asml.silence@gmail.com 2022-10-26T23:25:57+00:00 5aa83e4d56c5398e2c8d92f2fb7bed90d66e5caf commit fee9ac06647e59a69fb7aec58f25267c134264b4 upstream. sockmap replaces ->sk_prot with its own callbacks, we should remove SOCK_SUPPORT_ZC as the new proto doesn't support msghdr::ubuf_info. Cc: <stable@vger.kernel.org> # 6.0 Reported-by: Jakub Kicinski <kuba@kernel.org> Fixes: e993ffe3da4bc ("net: flag sockets supporting msghdr originated zerocopy") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fee9ac06647e59a69fb7aec58f25267c134264b4 upstream.

sockmap replaces ->sk_prot with its own callbacks, we should remove
SOCK_SUPPORT_ZC as the new proto doesn't support msghdr::ubuf_info.

Cc: <stable@vger.kernel.org> # 6.0
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: e993ffe3da4bc ("net: flag sockets supporting msghdr originated zerocopy")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/ulp: remove SOCK_SUPPORT_ZC from tls sockets 2022-11-10T17:17:34+00:00 Pavel Begunkov asml.silence@gmail.com 2022-10-26T23:25:58+00:00 fa8701aa70b14f6f47d635f44b7e627870069eac commit e276d62dcfdee6582486e8b8344dd869518e14be upstream. Remove SOCK_SUPPORT_ZC when we're setting ulp as it might not support msghdr::ubuf_info, e.g. like TLS replacing ->sk_prot with a new set of handlers. Cc: <stable@vger.kernel.org> # 6.0 Reported-by: Jakub Kicinski <kuba@kernel.org> Fixes: e993ffe3da4bc ("net: flag sockets supporting msghdr originated zerocopy") Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e276d62dcfdee6582486e8b8344dd869518e14be upstream.

Remove SOCK_SUPPORT_ZC when we're setting ulp as it might not support
msghdr::ubuf_info, e.g. like TLS replacing ->sk_prot with a new set of
handlers.

Cc: <stable@vger.kernel.org> # 6.0
Reported-by: Jakub Kicinski <kuba@kernel.org>
Fixes: e993ffe3da4bc ("net: flag sockets supporting msghdr originated zerocopy")
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
nh: fix scope used to find saddr when adding non gw nh 2022-11-03T15:00:33+00:00 Nicolas Dichtel nicolas.dichtel@6wind.com 2022-10-20T10:09:52+00:00 c26249b15a254e9ada5a495b902f1ef1ddad4204 [ Upstream commit bac0f937c343d651874f83b265ca8f5070ed4f06 ] As explained by Julian, fib_nh_scope is related to fib_nh_gw4, but fib_info_update_nhc_saddr() needs the scope of the route, which is the scope "before" fib_nh_scope, ie fib_nh_scope - 1. This patch fixes the problem described in commit 747c14307214 ("ip: fix dflt addr selection for connected nexthop"). Fixes: 597cfe4fc339 ("nexthop: Add support for IPv4 nexthops") Link: https://lore.kernel.org/netdev/6c8a44ba-c2d5-cdf-c5c7-5baf97cba38@ssi.bg/ Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Julian Anastasov <ja@ssi.bg> Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit bac0f937c343d651874f83b265ca8f5070ed4f06 ]

As explained by Julian, fib_nh_scope is related to fib_nh_gw4, but
fib_info_update_nhc_saddr() needs the scope of the route, which is
the scope "before" fib_nh_scope, ie fib_nh_scope - 1.

This patch fixes the problem described in commit 747c14307214 ("ip: fix
dflt addr selection for connected nexthop").

Fixes: 597cfe4fc339 ("nexthop: Add support for IPv4 nexthops")
Link: https://lore.kernel.org/netdev/6c8a44ba-c2d5-cdf-c5c7-5baf97cba38@ssi.bg/
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: fix indefinite deferral of RTO with SACK reneging 2022-11-03T15:00:31+00:00 Neal Cardwell ncardwell@google.com 2022-10-21T17:08:21+00:00 0262c9f7cfdf1e43d2a2fdc5d4617c14e4ba0879 [ Upstream commit 3d2af9cce3133b3bc596a9d065c6f9d93419ccfb ] This commit fixes a bug that can cause a TCP data sender to repeatedly defer RTOs when encountering SACK reneging. The bug is that when we're in fast recovery in a scenario with SACK reneging, every time we get an ACK we call tcp_check_sack_reneging() and it can note the apparent SACK reneging and rearm the RTO timer for srtt/2 into the future. In some SACK reneging scenarios that can happen repeatedly until the receive window fills up, at which point the sender can't send any more, the ACKs stop arriving, and the RTO fires at srtt/2 after the last ACK. But that can take far too long (O(10 secs)), since the connection is stuck in fast recovery with a low cwnd that cannot grow beyond ssthresh, even if more bandwidth is available. This fix changes the logic in tcp_check_sack_reneging() to only rearm the RTO timer if data is cumulatively ACKed, indicating forward progress. This avoids this kind of nearly infinite loop of RTO timer re-arming. In addition, this meets the goals of tcp_check_sack_reneging() in handling Windows TCP behavior that looks temporarily like SACK reneging but is not really. Many thanks to Jakub Kicinski and Neil Spring, who reported this issue and provided critical packet traces that enabled root-causing this issue. Also, many thanks to Jakub Kicinski for testing this fix. Fixes: 5ae344c949e7 ("tcp: reduce spurious retransmits due to transient SACK reneging") Reported-by: Jakub Kicinski <kuba@kernel.org> Reported-by: Neil Spring <ntspring@fb.com> Signed-off-by: Neal Cardwell <ncardwell@google.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Cc: Yuchung Cheng <ycheng@google.com> Tested-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20221021170821.1093930-1-ncardwell.kernel@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 3d2af9cce3133b3bc596a9d065c6f9d93419ccfb ]

This commit fixes a bug that can cause a TCP data sender to repeatedly
defer RTOs when encountering SACK reneging.

The bug is that when we're in fast recovery in a scenario with SACK
reneging, every time we get an ACK we call tcp_check_sack_reneging()
and it can note the apparent SACK reneging and rearm the RTO timer for
srtt/2 into the future. In some SACK reneging scenarios that can
happen repeatedly until the receive window fills up, at which point
the sender can't send any more, the ACKs stop arriving, and the RTO
fires at srtt/2 after the last ACK. But that can take far too long
(O(10 secs)), since the connection is stuck in fast recovery with a
low cwnd that cannot grow beyond ssthresh, even if more bandwidth is
available.

This fix changes the logic in tcp_check_sack_reneging() to only rearm
the RTO timer if data is cumulatively ACKed, indicating forward
progress. This avoids this kind of nearly infinite loop of RTO timer
re-arming. In addition, this meets the goals of
tcp_check_sack_reneging() in handling Windows TCP behavior that looks
temporarily like SACK reneging but is not really.

Many thanks to Jakub Kicinski and Neil Spring, who reported this issue
and provided critical packet traces that enabled root-causing this
issue. Also, many thanks to Jakub Kicinski for testing this fix.

Fixes: 5ae344c949e7 ("tcp: reduce spurious retransmits due to transient SACK reneging")
Reported-by: Jakub Kicinski <kuba@kernel.org>
Reported-by: Neil Spring <ntspring@fb.com>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: Yuchung Cheng <ycheng@google.com>
Tested-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/20221021170821.1093930-1-ncardwell.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: fix a signed-integer-overflow bug in tcp_add_backlog() 2022-11-03T15:00:31+00:00 Lu Wei luwei32@huawei.com 2022-10-21T04:06:22+00:00 28addf029417d53b1df062b4c87feb7bc033cb5f [ Upstream commit ec791d8149ff60c40ad2074af3b92a39c916a03f ] The type of sk_rcvbuf and sk_sndbuf in struct sock is int, and in tcp_add_backlog(), the variable limit is caculated by adding sk_rcvbuf, sk_sndbuf and 64 * 1024, it may exceed the max value of int and overflow. This patch reduces the limit budget by halving the sndbuf to solve this issue since ACK packets are much smaller than the payload. Fixes: c9c3321257e1 ("tcp: add tcp_add_backlog()") Signed-off-by: Lu Wei <luwei32@huawei.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit ec791d8149ff60c40ad2074af3b92a39c916a03f ]

The type of sk_rcvbuf and sk_sndbuf in struct sock is int, and
in tcp_add_backlog(), the variable limit is caculated by adding
sk_rcvbuf, sk_sndbuf and 64 * 1024, it may exceed the max value
of int and overflow. This patch reduces the limit budget by
halving the sndbuf to solve this issue since ACK packets are much
smaller than the payload.

Fixes: c9c3321257e1 ("tcp: add tcp_add_backlog()")
Signed-off-by: Lu Wei <luwei32@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Acked-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces. 2022-10-29T08:08:34+00:00 Guillaume Nault gnault@redhat.com 2022-10-13T14:37:47+00:00 de16491c13a74f194229fd835a7fa3db1bf7240f [ Upstream commit 1fcc064b305a1aadeff0d4bff961094d27660acd ] Currently netfilter's rpfilter and fib modules implicitely initialise ->flowic_uid with 0. This is normally the root UID. However, this isn't the case in user namespaces, where user ID 0 is mapped to a different kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get the root UID of the user namespace, thus keeping the same behaviour whether or not we're running in a user namepspace. Note, this is similar to commit 8bcfd0925ef1 ("ipv4: add missing initialization for flowi4_uid"), which fixed the rp_filter sysctl. Fixes: 622ec2c9d524 ("net: core: add UID to flows, rules, and routes") Signed-off-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 1fcc064b305a1aadeff0d4bff961094d27660acd ]

Currently netfilter's rpfilter and fib modules implicitely initialise
->flowic_uid with 0. This is normally the root UID. However, this isn't
the case in user namespaces, where user ID 0 is mapped to a different
kernel UID. By initialising ->flowic_uid with sock_net_uid(), we get
the root UID of the user namespace, thus keeping the same behaviour
whether or not we're running in a user namepspace.

Note, this is similar to commit 8bcfd0925ef1 ("ipv4: add missing
initialization for flowi4_uid"), which fixed the rp_filter sysctl.

Fixes: 622ec2c9d524 ("net: core: add UID to flows, rules, and routes")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
netfilter: rpfilter/fib: Populate flowic_l3mdev field 2022-10-29T08:08:34+00:00 Phil Sutter phil@nwl.cc 2022-10-05T16:07:05+00:00 14051ae7d470cd93069d1cfa8ca21d24d527c97b [ Upstream commit acc641ab95b66b813c1ce856c377a2bbe71e7f52 ] Use the introduced field for correct operation with VRF devices instead of conditionally overwriting flowic_oif. This is a partial revert of commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by mistake"), implementing a simpler solution. Signed-off-by: Phil Sutter <phil@nwl.cc> Reviewed-by: David Ahern <dsahern@kernel.org> Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Florian Westphal <fw@strlen.de> Stable-dep-of: 1fcc064b305a ("netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces.") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit acc641ab95b66b813c1ce856c377a2bbe71e7f52 ]

Use the introduced field for correct operation with VRF devices instead
of conditionally overwriting flowic_oif. This is a partial revert of
commit b575b24b8eee3 ("netfilter: Fix rpfilter dropping vrf packets by
mistake"), implementing a simpler solution.

Signed-off-by: Phil Sutter <phil@nwl.cc>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Stable-dep-of: 1fcc064b305a ("netfilter: rpfilter/fib: Set ->flowic_uid correctly for user namespaces.")
Signed-off-by: Sasha Levin <sashal@kernel.org>
udp: Update reuse->has_conns under reuseport_lock. 2022-10-29T08:08:33+00:00 Kuniyuki Iwashima kuniyu@amazon.com 2022-10-14T18:26:25+00:00 1fb3a672317fba2a54f1bc8a6401235c6f11f883 [ Upstream commit 69421bf98482d089e50799f45e48b25ce4a8d154 ] When we call connect() for a UDP socket in a reuseport group, we have to update sk->sk_reuseport_cb->has_conns to 1. Otherwise, the kernel could select a unconnected socket wrongly for packets sent to the connected socket. However, the current way to set has_conns is illegal and possible to trigger that problem. reuseport_has_conns() changes has_conns under rcu_read_lock(), which upgrades the RCU reader to the updater. Then, it must do the update under the updater's lock, reuseport_lock, but it doesn't for now. For this reason, there is a race below where we fail to set has_conns resulting in the wrong socket selection. To avoid the race, let's split the reader and updater with proper locking. cpu1 cpu2 +----+ +----+ __ip[46]_datagram_connect() reuseport_grow() . . |- reuseport_has_conns(sk, true) |- more_reuse = __reuseport_alloc(more_socks_size) | . | | |- rcu_read_lock() | |- reuse = rcu_dereference(sk->sk_reuseport_cb) | | | | | /* reuse->has_conns == 0 here */ | | |- more_reuse->has_conns = reuse->has_conns | |- reuse->has_conns = 1 | /* more_reuse->has_conns SHOULD BE 1 HERE */ | | | | | |- rcu_assign_pointer(reuse->socks[i]->sk_reuseport_cb, | | | more_reuse) | `- rcu_read_unlock() `- kfree_rcu(reuse, rcu) | |- sk->sk_state = TCP_ESTABLISHED Note the likely(reuse) in reuseport_has_conns_set() is always true, but we put the test there for ease of review. [0] For the record, usually, sk_reuseport_cb is changed under lock_sock(). The only exception is reuseport_grow() & TCP reqsk migration case. 1) shutdown() TCP listener, which is moved into the latter part of reuse->socks[] to migrate reqsk. 2) New listen() overflows reuse->socks[] and call reuseport_grow(). 3) reuse->max_socks overflows u16 with the new listener. 4) reuseport_grow() pops the old shutdown()ed listener from the array and update its sk->sk_reuseport_cb as NULL without lock_sock(). shutdown()ed TCP sk->sk_reuseport_cb can be changed without lock_sock(), but, reuseport_has_conns_set() is called only for UDP under lock_sock(), so likely(reuse) never be false in reuseport_has_conns_set(). [0]: https://lore.kernel.org/netdev/CANn89iLja=eQHbsM_Ta2sQF0tOGU8vAGrh_izRuuHjuO1ouUag@mail.gmail.com/ Fixes: acdcecc61285 ("udp: correct reuseport selection with connected sockets") Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://lore.kernel.org/r/20221014182625.89913-1-kuniyu@amazon.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 69421bf98482d089e50799f45e48b25ce4a8d154 ]

When we call connect() for a UDP socket in a reuseport group, we have
to update sk->sk_reuseport_cb->has_conns to 1.  Otherwise, the kernel
could select a unconnected socket wrongly for packets sent to the
connected socket.

However, the current way to set has_conns is illegal and possible to
trigger that problem.  reuseport_has_conns() changes has_conns under
rcu_read_lock(), which upgrades the RCU reader to the updater.  Then,
it must do the update under the updater's lock, reuseport_lock, but
it doesn't for now.

For this reason, there is a race below where we fail to set has_conns
resulting in the wrong socket selection.  To avoid the race, let's split
the reader and updater with proper locking.

 cpu1                               cpu2
+----+                             +----+

__ip[46]_datagram_connect()        reuseport_grow()
.                                  .
|- reuseport_has_conns(sk, true)   |- more_reuse = __reuseport_alloc(more_socks_size)
|  .                               |
|  |- rcu_read_lock()
|  |- reuse = rcu_dereference(sk->sk_reuseport_cb)
|  |
|  |                               |  /* reuse->has_conns == 0 here */
|  |                               |- more_reuse->has_conns = reuse->has_conns
|  |- reuse->has_conns = 1         |  /* more_reuse->has_conns SHOULD BE 1 HERE */
|  |                               |
|  |                               |- rcu_assign_pointer(reuse->socks[i]->sk_reuseport_cb,
|  |                               |                     more_reuse)
|  `- rcu_read_unlock()            `- kfree_rcu(reuse, rcu)
|
|- sk->sk_state = TCP_ESTABLISHED

Note the likely(reuse) in reuseport_has_conns_set() is always true,
but we put the test there for ease of review.  [0]

For the record, usually, sk_reuseport_cb is changed under lock_sock().
The only exception is reuseport_grow() & TCP reqsk migration case.

  1) shutdown() TCP listener, which is moved into the latter part of
     reuse->socks[] to migrate reqsk.

  2) New listen() overflows reuse->socks[] and call reuseport_grow().

  3) reuse->max_socks overflows u16 with the new listener.

  4) reuseport_grow() pops the old shutdown()ed listener from the array
     and update its sk->sk_reuseport_cb as NULL without lock_sock().

shutdown()ed TCP sk->sk_reuseport_cb can be changed without lock_sock(),
but, reuseport_has_conns_set() is called only for UDP under lock_sock(),
so likely(reuse) never be false in reuseport_has_conns_set().

[0]: https://lore.kernel.org/netdev/CANn89iLja=eQHbsM_Ta2sQF0tOGU8vAGrh_izRuuHjuO1ouUag@mail.gmail.com/

Fixes: acdcecc61285 ("udp: correct reuseport selection with connected sockets")
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://lore.kernel.org/r/20221014182625.89913-1-kuniyu@amazon.com
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: flag sockets supporting msghdr originated zerocopy 2022-10-26T10:22:56+00:00 Pavel Begunkov asml.silence@gmail.com 2022-10-21T10:16:39+00:00 f9467c175d6b45bc2ae6fdf7f2a4896b70a4fd46 commit e993ffe3da4bcddea0536b03be1031bf35cd8d85 upstream. We need an efficient way in io_uring to check whether a socket supports zerocopy with msghdr provided ubuf_info. Add a new flag into the struct socket flags fields. Cc: <stable@vger.kernel.org> # 6.0 Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/3dafafab822b1c66308bb58a0ac738b1e3f53f74.1666346426.git.asml.silence@gmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit e993ffe3da4bcddea0536b03be1031bf35cd8d85 upstream.

We need an efficient way in io_uring to check whether a socket supports
zerocopy with msghdr provided ubuf_info. Add a new flag into the struct
socket flags fields.

Cc: <stable@vger.kernel.org> # 6.0
Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Acked-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/r/3dafafab822b1c66308bb58a0ac738b1e3f53f74.1666346426.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>