linux.git/Documentation/networking, branch v5.15.197 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git doc: fix seg6_flowlabel path 2025-10-29T13:03:08+00:00 Nicolas Dichtel nicolas.dichtel@6wind.com 2025-10-10T14:18:59+00:00 5b9c949c668461efe7173ddf07cd46b26045ab5f [ Upstream commit 0b4b77eff5f8cd9be062783a1c1e198d46d0a753 ] This sysctl is not per interface; it's global per netns. Fixes: 292ecd9f5a94 ("doc: move seg6_flowlabel to seg6-sysctl.rst") Reported-by: Philippe Guibert <philippe.guibert@6wind.com> Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com> Reviewed-by: Simon Horman <horms@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 0b4b77eff5f8cd9be062783a1c1e198d46d0a753 ]

This sysctl is not per interface; it's global per netns.

Fixes: 292ecd9f5a94 ("doc: move seg6_flowlabel to seg6-sysctl.rst")
Reported-by: Philippe Guibert <philippe.guibert@6wind.com>
Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
mptcp: disable add_addr retransmission when timeout is 0 2025-08-28T14:24:35+00:00 Geliang Tang tanggeliang@kylinos.cn 2025-08-23T15:22:28+00:00 a7037057fd163b1daad324e2e123cc257c4e1866 [ Upstream commit f5ce0714623cffd00bf2a83e890d09c609b7f50a ] When add_addr_timeout was set to 0, this caused the ADD_ADDR to be retransmitted immediately, which looks like a buggy behaviour. Instead, interpret 0 as "no retransmissions needed". The documentation is updated to explicitly state that setting the timeout to 0 disables retransmission. Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout") Cc: stable@vger.kernel.org Suggested-by: Matthieu Baerts <matttbe@kernel.org> Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn> Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org> Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-5-521fe9957892@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org> [ pm.c => pm_netlink.c , drop mptcp_pm_alloc_anno_list hunk ] Signed-off-by: Sasha Levin <sashal@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit f5ce0714623cffd00bf2a83e890d09c609b7f50a ]

When add_addr_timeout was set to 0, this caused the ADD_ADDR to be
retransmitted immediately, which looks like a buggy behaviour. Instead,
interpret 0 as "no retransmissions needed".

The documentation is updated to explicitly state that setting the timeout
to 0 disables retransmission.

Fixes: 93f323b9cccc ("mptcp: add a new sysctl add_addr_timeout")
Cc: stable@vger.kernel.org
Suggested-by: Matthieu Baerts <matttbe@kernel.org>
Signed-off-by: Geliang Tang <tanggeliang@kylinos.cn>
Reviewed-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Signed-off-by: Matthieu Baerts (NGI0) <matttbe@kernel.org>
Link: https://patch.msgid.link/20250815-net-mptcp-misc-fixes-6-17-rc2-v1-5-521fe9957892@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[ pm.c => pm_netlink.c , drop mptcp_pm_alloc_anno_list hunk ]
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
can: j1939: fix error in J1939 documentation. 2024-12-14T18:50:40+00:00 Alexander Hölzl alexander.hoelzl@gmx.net 2024-10-23T14:52:57+00:00 3849d29eef43c5c994c8b519b677a6f2e4178b02 [ Upstream commit b6ec62e01aa4229bc9d3861d1073806767ea7838 ] The description of PDU1 format usage mistakenly referred to PDU2 format. Signed-off-by: Alexander Hölzl <alexander.hoelzl@gmx.net> Acked-by: Oleksij Rempel <o.rempel@pengutronix.de> Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr> Link: https://patch.msgid.link/20241023145257.82709-1-alexander.hoelzl@gmx.net Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b6ec62e01aa4229bc9d3861d1073806767ea7838 ]

The description of PDU1 format usage mistakenly referred to PDU2 format.

Signed-off-by: Alexander Hölzl <alexander.hoelzl@gmx.net>
Acked-by: Oleksij Rempel <o.rempel@pengutronix.de>
Acked-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Link: https://patch.msgid.link/20241023145257.82709-1-alexander.hoelzl@gmx.net
Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: ena: Add dynamic recycling mechanism for rx buffers 2024-06-16T11:39:52+00:00 David Arinzon darinzon@amazon.com 2023-06-12T12:14:48+00:00 a087d4b502ff27bfccdce9d37f6d1902f183b96c [ Upstream commit f7d625adeb7bc6a9ec83d32d9615889969d64484 ] The current implementation allocates page-sized rx buffers. As traffic may consist of different types and sizes of packets, in various cases, buffers are not fully used. This change (Dynamic RX Buffers - DRB) uses part of the allocated rx page needed for the incoming packet, and returns the rest of the unused page to be used again as an rx buffer for future packets. A threshold of 2K for unused space has been set in order to declare whether the remainder of the page can be reused again as an rx buffer. As a page may be reused, dma_sync_single_for_cpu() is added in order to sync the memory to the CPU side after it was owned by the HW. In addition, when the rx page can no longer be reused, it is being unmapped using dma_page_unmap(), which implicitly syncs and then unmaps the entire page. In case the kernel still handles the skbs pointing to the previous buffers from that rx page, it may access garbage pointers, caused by the implicit sync overwriting them. The implicit dma sync is removed by replacing dma_page_unmap() with dma_unmap_page_attrs() with DMA_ATTR_SKIP_CPU_SYNC flag. The functionality is disabled for XDP traffic to avoid handling several descriptors per packet. Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com> Signed-off-by: Shay Agroskin <shayagr@amazon.com> Signed-off-by: David Arinzon <darinzon@amazon.com> Link: https://lore.kernel.org/r/20230612121448.28829-1-darinzon@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Stable-dep-of: 2dc8b1e7177d ("net: ena: Fix redundant device NUMA node override") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f7d625adeb7bc6a9ec83d32d9615889969d64484 ]

The current implementation allocates page-sized rx buffers.
As traffic may consist of different types and sizes of packets,
in various cases, buffers are not fully used.

This change (Dynamic RX Buffers - DRB) uses part of the allocated rx
page needed for the incoming packet, and returns the rest of the
unused page to be used again as an rx buffer for future packets.
A threshold of 2K for unused space has been set in order to declare
whether the remainder of the page can be reused again as an rx buffer.

As a page may be reused, dma_sync_single_for_cpu() is added in order
to sync the memory to the CPU side after it was owned by the HW.
In addition, when the rx page can no longer be reused, it is being
unmapped using dma_page_unmap(), which implicitly syncs and then
unmaps the entire page. In case the kernel still handles the skbs
pointing to the previous buffers from that rx page, it may access
garbage pointers, caused by the implicit sync overwriting them.
The implicit dma sync is removed by replacing dma_page_unmap() with
dma_unmap_page_attrs() with DMA_ATTR_SKIP_CPU_SYNC flag.

The functionality is disabled for XDP traffic to avoid handling
several descriptors per packet.

Signed-off-by: Arthur Kiyanovski <akiyano@amazon.com>
Signed-off-by: Shay Agroskin <shayagr@amazon.com>
Signed-off-by: David Arinzon <darinzon@amazon.com>
Link: https://lore.kernel.org/r/20230612121448.28829-1-darinzon@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 2dc8b1e7177d ("net: ena: Fix redundant device NUMA node override")
Signed-off-by: Sasha Levin <sashal@kernel.org>
net: change accept_ra_min_rtr_lft to affect all RA lifetimes 2023-10-19T21:05:35+00:00 Patrick Rohr prohr@google.com 2023-10-13T21:21:13+00:00 aade10d51ddc109a9ae2a88c5b6f80d956b5dc01 commit 5027d54a9c30bc7ec808360378e2b4753f053f25 upstream. accept_ra_min_rtr_lft only considered the lifetime of the default route and discarded entire RAs accordingly. This change renames accept_ra_min_rtr_lft to accept_ra_min_lft, and applies the value to individual RA sections; in particular, router lifetime, PIO preferred lifetime, and RIO lifetime. If any of those lifetimes are lower than the configured value, the specific RA section is ignored. In order for the sysctl to be useful to Android, it should really apply to all lifetimes in the RA, since that is what determines the minimum frequency at which RAs must be processed by the kernel. Android uses hardware offloads to drop RAs for a fraction of the minimum of all lifetimes present in the RA (some networks have very frequent RAs (5s) with high lifetimes (2h)). Despite this, we have encountered networks that set the router lifetime to 30s which results in very frequent CPU wakeups. Instead of disabling IPv6 (and dropping IPv6 ethertype in the WiFi firmware) entirely on such networks, it seems better to ignore the misconfigured routers while still processing RAs from other IPv6 routers on the same network (i.e. to support IoT applications). The previous implementation dropped the entire RA based on router lifetime. This turned out to be hard to expand to the other lifetimes present in the RA in a consistent manner; dropping the entire RA based on RIO/PIO lifetimes would essentially require parsing the whole thing twice. Fixes: 1671bcfd76fd ("net: add sysctl accept_ra_min_rtr_lft") Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: Patrick Rohr <prohr@google.com> Reviewed-by: Maciej Żenczykowski <maze@google.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/20230726230701.919212-1-prohr@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 5027d54a9c30bc7ec808360378e2b4753f053f25 upstream.

accept_ra_min_rtr_lft only considered the lifetime of the default route
and discarded entire RAs accordingly.

This change renames accept_ra_min_rtr_lft to accept_ra_min_lft, and
applies the value to individual RA sections; in particular, router
lifetime, PIO preferred lifetime, and RIO lifetime. If any of those
lifetimes are lower than the configured value, the specific RA section
is ignored.

In order for the sysctl to be useful to Android, it should really apply
to all lifetimes in the RA, since that is what determines the minimum
frequency at which RAs must be processed by the kernel. Android uses
hardware offloads to drop RAs for a fraction of the minimum of all
lifetimes present in the RA (some networks have very frequent RAs (5s)
with high lifetimes (2h)). Despite this, we have encountered networks
that set the router lifetime to 30s which results in very frequent CPU
wakeups. Instead of disabling IPv6 (and dropping IPv6 ethertype in the
WiFi firmware) entirely on such networks, it seems better to ignore the
misconfigured routers while still processing RAs from other IPv6 routers
on the same network (i.e. to support IoT applications).

The previous implementation dropped the entire RA based on router
lifetime. This turned out to be hard to expand to the other lifetimes
present in the RA in a consistent manner; dropping the entire RA based
on RIO/PIO lifetimes would essentially require parsing the whole thing
twice.

Fixes: 1671bcfd76fd ("net: add sysctl accept_ra_min_rtr_lft")
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: Patrick Rohr <prohr@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://lore.kernel.org/r/20230726230701.919212-1-prohr@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net: add sysctl accept_ra_min_rtr_lft 2023-10-19T21:05:35+00:00 Patrick Rohr prohr@google.com 2023-10-13T21:21:12+00:00 8f12d2d66cba6535362e2f8dc57808dfb45c7cc4 commit 1671bcfd76fdc0b9e65153cf759153083755fe4c upstream. This change adds a new sysctl accept_ra_min_rtr_lft to specify the minimum acceptable router lifetime in an RA. If the received RA router lifetime is less than the configured value (and not 0), the RA is ignored. This is useful for mobile devices, whose battery life can be impacted by networks that configure RAs with a short lifetime. On such networks, the device should never gain IPv6 provisioning and should attempt to drop RAs via hardware offload, if available. Signed-off-by: Patrick Rohr <prohr@google.com> Cc: Maciej Żenczykowski <maze@google.com> Cc: Lorenzo Colitti <lorenzo@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1671bcfd76fdc0b9e65153cf759153083755fe4c upstream.

This change adds a new sysctl accept_ra_min_rtr_lft to specify the
minimum acceptable router lifetime in an RA. If the received RA router
lifetime is less than the configured value (and not 0), the RA is
ignored.
This is useful for mobile devices, whose battery life can be impacted
by networks that configure RAs with a short lifetime. On such networks,
the device should never gain IPv6 provisioning and should attempt to
drop RAs via hardware offload, if available.

Signed-off-by: Patrick Rohr <prohr@google.com>
Cc: Maciej Żenczykowski <maze@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
xsk: Honor SO_BINDTODEVICE on bind 2023-07-23T11:47:29+00:00 Ilya Maximets i.maximets@ovn.org 2023-07-03T17:53:29+00:00 edd944b70ad208f5ff7ad50949b0ec892b276a03 [ Upstream commit f7306acec9aae9893d15e745c8791124d42ab10a ] Initial creation of an AF_XDP socket requires CAP_NET_RAW capability. A privileged process might create the socket and pass it to a non-privileged process for later use. However, that process will be able to bind the socket to any network interface. Even though it will not be able to receive any traffic without modification of the BPF map, the situation is not ideal. Sockets already have a mechanism that can be used to restrict what interface they can be attached to. That is SO_BINDTODEVICE. To change the SO_BINDTODEVICE binding the process will need CAP_NET_RAW. Make xsk_bind() honor the SO_BINDTODEVICE in order to allow safer workflow when non-privileged process is using AF_XDP. The intended workflow is following: 1. First process creates a bare socket with socket(AF_XDP, ...). 2. First process loads the XSK program to the interface. 3. First process adds the socket fd to a BPF map. 4. First process ties socket fd to a particular interface using SO_BINDTODEVICE. 5. First process sends socket fd to a second process. 6. Second process allocates UMEM. 7. Second process binds socket to the interface with bind(...). 8. Second process sends/receives the traffic. All the steps above are possible today if the first process is privileged and the second one has sufficient RLIMIT_MEMLOCK and no capabilities. However, the second process will be able to bind the socket to any interface it wants on step 7 and send traffic from it. With the proposed change, the second process will be able to bind the socket only to a specific interface chosen by the first process at step 4. Fixes: 965a99098443 ("xsk: add support for bind for Rx") Signed-off-by: Ilya Maximets <i.maximets@ovn.org> Signed-off-by: Daniel Borkmann <daniel@iogearbox.net> Acked-by: Magnus Karlsson <magnus.karlsson@intel.com> Acked-by: John Fastabend <john.fastabend@gmail.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/bpf/20230703175329.3259672-1-i.maximets@ovn.org Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit f7306acec9aae9893d15e745c8791124d42ab10a ]

Initial creation of an AF_XDP socket requires CAP_NET_RAW capability. A
privileged process might create the socket and pass it to a non-privileged
process for later use. However, that process will be able to bind the socket
to any network interface. Even though it will not be able to receive any
traffic without modification of the BPF map, the situation is not ideal.

Sockets already have a mechanism that can be used to restrict what interface
they can be attached to. That is SO_BINDTODEVICE.

To change the SO_BINDTODEVICE binding the process will need CAP_NET_RAW.

Make xsk_bind() honor the SO_BINDTODEVICE in order to allow safer workflow
when non-privileged process is using AF_XDP.

The intended workflow is following:

  1. First process creates a bare socket with socket(AF_XDP, ...).
  2. First process loads the XSK program to the interface.
  3. First process adds the socket fd to a BPF map.
  4. First process ties socket fd to a particular interface using
     SO_BINDTODEVICE.
  5. First process sends socket fd to a second process.
  6. Second process allocates UMEM.
  7. Second process binds socket to the interface with bind(...).
  8. Second process sends/receives the traffic.

All the steps above are possible today if the first process is privileged
and the second one has sufficient RLIMIT_MEMLOCK and no capabilities.
However, the second process will be able to bind the socket to any interface
it wants on step 7 and send traffic from it. With the proposed change, the
second process will be able to bind the socket only to a specific interface
chosen by the first process at step 4.

Fixes: 965a99098443 ("xsk: add support for bind for Rx")
Signed-off-by: Ilya Maximets <i.maximets@ovn.org>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Magnus Karlsson <magnus.karlsson@intel.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Link: https://lore.kernel.org/bpf/20230703175329.3259672-1-i.maximets@ovn.org
Signed-off-by: Sasha Levin <sashal@kernel.org>
Remove DECnet support from kernel 2023-06-21T13:59:15+00:00 Stephen Hemminger stephen@networkplumber.org 2022-08-18T00:43:21+00:00 2a974abc09761c05fef697fe229d1b85a7ce3918 commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream. DECnet is an obsolete network protocol that receives more attention from kernel janitors than users. It belongs in computer protocol history museum not in Linux kernel. It has been "Orphaned" in kernel since 2010. The iproute2 support for DECnet was dropped in 5.0 release. The documentation link on Sourceforge says it is abandoned there as well. Leave the UAPI alone to keep userspace programs compiling. This means that there is still an empty neighbour table for AF_DECNET. The table of /proc/sys/net entries was updated to match current directories and reformatted to be alphabetical. Signed-off-by: Stephen Hemminger <stephen@networkplumber.org> Acked-by: David Ahern <dsahern@kernel.org> Acked-by: Nikolay Aleksandrov <razor@blackwall.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 1202cdd665315c525b5237e96e0bedc76d7e754f upstream.

DECnet is an obsolete network protocol that receives more attention
from kernel janitors than users. It belongs in computer protocol
history museum not in Linux kernel.

It has been "Orphaned" in kernel since 2010. The iproute2 support
for DECnet was dropped in 5.0 release. The documentation link on
Sourceforge says it is abandoned there as well.

Leave the UAPI alone to keep userspace programs compiling.
This means that there is still an empty neighbour table
for AF_DECNET.

The table of /proc/sys/net entries was updated to match
current directories and reformatted to be alphabetical.

Signed-off-by: Stephen Hemminger <stephen@networkplumber.org>
Acked-by: David Ahern <dsahern@kernel.org>
Acked-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Bonding: add arp_missed_max option 2023-06-05T07:21:19+00:00 Hangbin Liu liuhangbin@gmail.com 2021-11-30T04:29:47+00:00 7ee611fc85adbb82e63501e7cb517163bacb0086 [ Upstream commit 5944b5abd8646e8c6ac6af2b55f87dede1dae898 ] Currently, we use hard code number to verify if we are in the arp_interval timeslice. But some user may want to reduce/extend the verify timeslice. With the similar team option 'missed_max' the uers could change that number based on their own environment. Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com> Signed-off-by: Hangbin Liu <liuhangbin@gmail.com> Signed-off-by: David S. Miller <davem@davemloft.net> Stable-dep-of: 9949e2efb54e ("bonding: fix send_peer_notif overflow") Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit 5944b5abd8646e8c6ac6af2b55f87dede1dae898 ]

Currently, we use hard code number to verify if we are in the
arp_interval timeslice. But some user may want to reduce/extend
the verify timeslice. With the similar team option 'missed_max'
the uers could change that number based on their own environment.

Acked-by: Jay Vosburgh <jay.vosburgh@canonical.com>
Signed-off-by: Hangbin Liu <liuhangbin@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 9949e2efb54e ("bonding: fix send_peer_notif overflow")
Signed-off-by: Sasha Levin <sashal@kernel.org>
tcp: restrict net.ipv4.tcp_app_win 2023-04-20T10:13:53+00:00 YueHaibing yuehaibing@huawei.com 2023-04-06T06:34:50+00:00 a94f5d35fdbbaf4210cea921a702c9af30f915e9 [ Upstream commit dc5110c2d959c1707e12df5f792f41d90614adaa ] UBSAN: shift-out-of-bounds in net/ipv4/tcp_input.c:555:23 shift exponent 255 is too large for 32-bit type 'int' CPU: 1 PID: 7907 Comm: ssh Not tainted 6.3.0-rc4-00161-g62bad54b26db-dirty #206 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014 Call Trace: <TASK> dump_stack_lvl+0x136/0x150 __ubsan_handle_shift_out_of_bounds+0x21f/0x5a0 tcp_init_transfer.cold+0x3a/0xb9 tcp_finish_connect+0x1d0/0x620 tcp_rcv_state_process+0xd78/0x4d60 tcp_v4_do_rcv+0x33d/0x9d0 __release_sock+0x133/0x3b0 release_sock+0x58/0x1b0 'maxwin' is int, shifting int for 32 or more bits is undefined behaviour. Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: YueHaibing <yuehaibing@huawei.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-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 dc5110c2d959c1707e12df5f792f41d90614adaa ]

UBSAN: shift-out-of-bounds in net/ipv4/tcp_input.c:555:23
shift exponent 255 is too large for 32-bit type 'int'
CPU: 1 PID: 7907 Comm: ssh Not tainted 6.3.0-rc4-00161-g62bad54b26db-dirty #206
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.15.0-1 04/01/2014
Call Trace:
 <TASK>
 dump_stack_lvl+0x136/0x150
 __ubsan_handle_shift_out_of_bounds+0x21f/0x5a0
 tcp_init_transfer.cold+0x3a/0xb9
 tcp_finish_connect+0x1d0/0x620
 tcp_rcv_state_process+0xd78/0x4d60
 tcp_v4_do_rcv+0x33d/0x9d0
 __release_sock+0x133/0x3b0
 release_sock+0x58/0x1b0

'maxwin' is int, shifting int for 32 or more bits is undefined behaviour.

Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2")
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>