[ Upstream commit d3a5f2871a ]
Syzkaller reported a bug [1] where sk->sk_forward_alloc can overflow.
When we send data, if an skb exists at the tail of the write queue, the
kernel will attempt to append the new data to that skb. However, the code
that checks for available space in the skb is flawed:
'''
copy = size_goal - skb->len
'''
The types of the variables involved are:
'''
copy: ssize_t (s64 on 64-bit systems)
size_goal: int
skb->len: unsigned int
'''
Due to C's type promotion rules, the signed size_goal is converted to an
unsigned int to match skb->len before the subtraction. The result is an
unsigned int.
When this unsigned int result is then assigned to the s64 copy variable,
it is zero-extended, preserving its non-negative value. Consequently, copy
is always >= 0.
Assume we are sending 2GB of data and size_goal has been adjusted to a
value smaller than skb->len. The subtraction will result in copy holding a
very large positive integer. In the subsequent logic, this large value is
used to update sk->sk_forward_alloc, which can easily cause it to overflow.
The syzkaller reproducer uses TCP_REPAIR to reliably create this
condition. However, this can also occur in real-world scenarios. The
tcp_bound_to_half_wnd() function can also reduce size_goal to a small
value. This would cause the subsequent tcp_wmem_schedule() to set
sk->sk_forward_alloc to a value close to INT_MAX. Further memory
allocation requests would then cause sk_forward_alloc to wrap around and
become negative.
[1]: https://syzkaller.appspot.com/bug?extid=de6565462ab540f50e47
Reported-by: syzbot+de6565462ab540f50e47@syzkaller.appspotmail.com
Fixes: 270a1c3de4 ("tcp: Support MSG_SPLICE_PAGES")
Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Howells <dhowells@redhat.com>
Link: https://patch.msgid.link/20250707054112.101081-1-jiayuan.chen@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dbe0ca8da1 ]
There is a bug with passive TFO sockets returning an invalid NAPI ID 0
from SO_INCOMING_NAPI_ID. Normally this is not an issue, but zero copy
receive relies on a correct NAPI ID to process sockets on the right
queue.
Fix by adding a sk_mark_napi_id_set().
Fixes: e5907459ce ("tcp: Record Rx hash and NAPI ID in tcp_child_process")
Signed-off-by: David Wei <dw@davidwei.uk>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250617212102.175711-5-dw@davidwei.uk
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit d0fa59897e ]
After the following commit from 2024:
commit e37ab73736 ("tcp: fix to allow timestamp undo if no retransmits were sent")
...there was buggy behavior where TCP connections without SACK support
could easily see erroneous undo events at the end of fast recovery or
RTO recovery episodes. The erroneous undo events could cause those
connections to suffer repeated loss recovery episodes and high
retransmit rates.
The problem was an interaction between the non-SACK behavior on these
connections and the undo logic. The problem is that, for non-SACK
connections at the end of a loss recovery episode, if snd_una ==
high_seq, then tcp_is_non_sack_preventing_reopen() holds steady in
CA_Recovery or CA_Loss, but clears tp->retrans_stamp to 0. Then upon
the next ACK the "tcp: fix to allow timestamp undo if no retransmits
were sent" logic saw the tp->retrans_stamp at 0 and erroneously
concluded that no data was retransmitted, and erroneously performed an
undo of the cwnd reduction, restoring cwnd immediately to the value it
had before loss recovery. This caused an immediate burst of traffic
and build-up of queues and likely another immediate loss recovery
episode.
This commit fixes tcp_packet_delayed() to ignore zero retrans_stamp
values for non-SACK connections when snd_una is at or above high_seq,
because tcp_is_non_sack_preventing_reopen() clears retrans_stamp in
this case, so it's not a valid signal that we can undo.
Note that the commit named in the Fixes footer restored long-present
behavior from roughly 2005-2019, so apparently this bug was present
for a while during that era, and this was simply not caught.
Fixes: e37ab73736 ("tcp: fix to allow timestamp undo if no retransmits were sent")
Reported-by: Eric Wheeler <netdev@lists.ewheeler.net>
Closes: https://lore.kernel.org/netdev/64ea9333-e7f9-0df-b0f2-8d566143acab@ewheeler.net/
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Co-developed-by: Yuchung Cheng <ycheng@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1c0829788a ]
The statistics are incremented with raw_cpu_inc() assuming it always
happens with bottom half disabled. Without per-CPU locking in
local_bh_disable() on PREEMPT_RT this is no longer true.
Use this_cpu_inc() on PREEMPT_RT for the increment to not worry about
preemption.
Cc: David Ahern <dsahern@kernel.org>
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://patch.msgid.link/20250512092736.229935-4-bigeasy@linutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit cd171461b9 ]
tcp_rcv_state_process() must tweak tp->advmss for TS enabled flows
before the call to tcp_init_transfer() / tcp_init_buffer_space().
Otherwise tp->rcvq_space.space is off by 120 bytes
(TCP_INIT_CWND * TCPOLEN_TSTAMP_ALIGNED).
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Wei Wang <weiwan@google.com>
Link: https://patch.msgid.link/20250513193919.1089692-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b879dcb1ae ]
tcp_rcv_rtt_update() goal is to maintain an estimation of the RTT
in tp->rcv_rtt_est.rtt_us, used by tcp_rcv_space_adjust()
When TCP TS are enabled, tcp_rcv_rtt_update() is using
EWMA to smooth the samples.
Change this to immediately latch the incoming value if it
is lower than tp->rcv_rtt_est.rtt_us, so that tcp_rcv_space_adjust()
does not overshoot tp->rcvq_space.space and sk->sk_rcvbuf.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250513193919.1089692-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3382a1ed7f ]
Commit a1e40ac5b5 ("net: gso: fix udp gso fraglist segmentation after
pull from frag_list") detected invalid geometry in frag_list skbs and
redirects them from skb_segment_list to more robust skb_segment. But some
packets with modified geometry can also hit bugs in that code. We don't
know how many such cases exist. Addressing each one by one also requires
touching the complex skb_segment code, which risks introducing bugs for
other types of skbs. Instead, linearize all these packets that fail the
basic invariants on gso fraglist skbs. That is more robust.
If only part of the fraglist payload is pulled into head_skb, it will
always cause exception when splitting skbs by skb_segment. For detailed
call stack information, see below.
Valid SKB_GSO_FRAGLIST skbs
- consist of two or more segments
- the head_skb holds the protocol headers plus first gso_size
- one or more frag_list skbs hold exactly one segment
- all but the last must be gso_size
Optional datapath hooks such as NAT and BPF (bpf_skb_pull_data) can
modify fraglist skbs, breaking these invariants.
In extreme cases they pull one part of data into skb linear. For UDP,
this causes three payloads with lengths of (11,11,10) bytes were
pulled tail to become (12,10,10) bytes.
The skbs no longer meets the above SKB_GSO_FRAGLIST conditions because
payload was pulled into head_skb, it needs to be linearized before pass
to regular skb_segment.
skb_segment+0xcd0/0xd14
__udp_gso_segment+0x334/0x5f4
udp4_ufo_fragment+0x118/0x15c
inet_gso_segment+0x164/0x338
skb_mac_gso_segment+0xc4/0x13c
__skb_gso_segment+0xc4/0x124
validate_xmit_skb+0x9c/0x2c0
validate_xmit_skb_list+0x4c/0x80
sch_direct_xmit+0x70/0x404
__dev_queue_xmit+0x64c/0xe5c
neigh_resolve_output+0x178/0x1c4
ip_finish_output2+0x37c/0x47c
__ip_finish_output+0x194/0x240
ip_finish_output+0x20/0xf4
ip_output+0x100/0x1a0
NF_HOOK+0xc4/0x16c
ip_forward+0x314/0x32c
ip_rcv+0x90/0x118
__netif_receive_skb+0x74/0x124
process_backlog+0xe8/0x1a4
__napi_poll+0x5c/0x1f8
net_rx_action+0x154/0x314
handle_softirqs+0x154/0x4b8
[118.376811] [C201134] rxq0_pus: [name:bug&]kernel BUG at net/core/skbuff.c:4278!
[118.376829] [C201134] rxq0_pus: [name:traps&]Internal error: Oops - BUG: 00000000f2000800 [#1] PREEMPT SMP
[118.470774] [C201134] rxq0_pus: [name:mrdump&]Kernel Offset: 0x178cc00000 from 0xffffffc008000000
[118.470810] [C201134] rxq0_pus: [name:mrdump&]PHYS_OFFSET: 0x40000000
[118.470827] [C201134] rxq0_pus: [name:mrdump&]pstate: 60400005 (nZCv daif +PAN -UAO)
[118.470848] [C201134] rxq0_pus: [name:mrdump&]pc : [0xffffffd79598aefc] skb_segment+0xcd0/0xd14
[118.470900] [C201134] rxq0_pus: [name:mrdump&]lr : [0xffffffd79598a5e8] skb_segment+0x3bc/0xd14
[118.470928] [C201134] rxq0_pus: [name:mrdump&]sp : ffffffc008013770
Fixes: a1e40ac5b5 ("gso: fix udp gso fraglist segmentation after pull from frag_list")
Signed-off-by: Shiming Cheng <shiming.cheng@mediatek.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 028363685b ]
The current scheme for caching the encap socket can lead to reference
leaks when we try to delete the netns.
The reference chain is: xfrm_state -> enacp_sk -> netns
Since the encap socket is a userspace socket, it holds a reference on
the netns. If we delete the espintcp state (through flush or
individual delete) before removing the netns, the reference on the
socket is dropped and the netns is correctly deleted. Otherwise, the
netns may not be reachable anymore (if all processes within the ns
have terminated), so we cannot delete the xfrm state to drop its
reference on the socket.
This patch results in a small (~2% in my tests) performance
regression.
A GC-type mechanism could be added for the socket cache, to clear
references if the state hasn't been used "recently", but it's a lot
more complex than just not caching the socket.
Fixes: e27cca96cd ("xfrm: add espintcp (RFC 8229)")
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50f37fc2a3 ]
if CONFIG_NET_IPGRE is enabled, but CONFIG_IPV6 is disabled:
net/ipv4/ip_gre.c: In function ‘ipgre_err’:
net/ipv4/ip_gre.c:144:22: error: variable ‘data_len’ set but not used [-Werror=unused-but-set-variable]
144 | unsigned int data_len = 0;
| ^~~~~~~~
Fix this by moving all data_len processing inside the IPV6-only section
that uses its result.
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202501121007.2GofXmh5-lkp@intel.com/
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/d09113cfe2bfaca02f3dddf832fb5f48dd20958b.1738704881.git.geert@linux-m68k.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 5a1ccffd30 ]
The following patch will not set skb->sk from VRF path.
Let's fetch net from fib_rule->fr_net instead of sock_net(skb->sk)
in fib[46]_rule_configure().
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Tested-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20250207072502.87775-5-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 254ba7e603 ]
fib_valid_key_len() is called in the beginning of fib_table_insert()
or fib_table_delete() to check if the prefix length is valid.
fib_table_insert() and fib_table_delete() are called from 3 paths
- ip_rt_ioctl()
- inet_rtm_newroute() / inet_rtm_delroute()
- fib_magic()
In the first ioctl() path, rtentry_to_fib_config() checks the prefix
length with bad_mask(). Also, fib_magic() always passes the correct
prefix: 32 or ifa->ifa_prefixlen, which is already validated.
Let's move fib_valid_key_len() to the rtnetlink path, rtm_to_fib_config().
While at it, 2 direct returns in rtm_to_fib_config() are changed to
goto to match other places in the same function
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250228042328.96624-12-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 149dfb3161 ]
- Move tcp_count_delivered() earlier and split tcp_count_delivered_ce()
out of it
- Move tcp_in_ack_event() later
- While at it, remove the inline from tcp_in_ack_event() and let
the compiler to decide
Accurate ECN's heuristics does not know if there is going
to be ACE field based CE counter increase or not until after
rtx queue has been processed. Only then the number of ACKed
bytes/pkts is available. As CE or not affects presence of
FLAG_ECE, that information for tcp_in_ack_event is not yet
available in the old location of the call to tcp_in_ack_event().
Signed-off-by: Ilpo Järvinen <ij@kernel.org>
Signed-off-by: Chia-Yu Chang <chia-yu.chang@nokia-bell-labs.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit b936a9b8d4 ]
If any address or port is changed, update it in all packets and recalculate
checksum.
Fixes: 9fd1ff5d2a ("udp: Support UDP fraglist GRO/GSO.")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250426153210.14044-1-nbd@nbd.name
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4d25ca2d68 ]
mono_delivery_time was added to check if skb->tstamp has delivery
time in mono clock base (i.e. EDT) otherwise skb->tstamp has
timestamp in ingress and delivery_time at egress.
Renaming the bitfield from mono_delivery_time to tstamp_type is for
extensibilty for other timestamps such as userspace timestamp
(i.e. SO_TXTIME) set via sock opts.
As we are renaming the mono_delivery_time to tstamp_type, it makes
sense to start assigning tstamp_type based on enum defined
in this commit.
Earlier we used bool arg flag to check if the tstamp is mono in
function skb_set_delivery_time, Now the signature of the functions
accepts tstamp_type to distinguish between mono and real time.
Also skb_set_delivery_type_by_clockid is a new function which accepts
clockid to determine the tstamp_type.
In future tstamp_type:1 can be extended to support userspace timestamp
by increasing the bitfield.
Signed-off-by: Abhishek Chauhan <quic_abchauha@quicinc.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Reviewed-by: Martin KaFai Lau <martin.lau@kernel.org>
Link: https://lore.kernel.org/r/20240509211834.3235191-2-quic_abchauha@quicinc.com
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Stable-dep-of: 3908feb1bd ("Bluetooth: L2CAP: copy RX timestamp to new fragments")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8930424777 ]
Because skb_tunnel_check_pmtu() doesn't handle PACKET_HOST packets,
commit 30a92c9e3d ("openvswitch: Set the skbuff pkt_type for proper
pmtud support.") forced skb->pkt_type to PACKET_OUTGOING for
openvswitch packets that are sent using the OVS_ACTION_ATTR_OUTPUT
action. This allowed such packets to invoke the
iptunnel_pmtud_check_icmp() or iptunnel_pmtud_check_icmpv6() helpers
and thus trigger PMTU update on the input device.
However, this also broke other parts of PMTU discovery. Since these
packets don't have the PACKET_HOST type anymore, they won't trigger the
sending of ICMP Fragmentation Needed or Packet Too Big messages to
remote hosts when oversized (see the skb_in->pkt_type condition in
__icmp_send() for example).
These two skb->pkt_type checks are therefore incompatible as one
requires skb->pkt_type to be PACKET_HOST, while the other requires it
to be anything but PACKET_HOST.
It makes sense to not trigger ICMP messages for non-PACKET_HOST packets
as these messages should be generated only for incoming l2-unicast
packets. However there doesn't seem to be any reason for
skb_tunnel_check_pmtu() to ignore PACKET_HOST packets.
Allow both cases to work by allowing skb_tunnel_check_pmtu() to work on
PACKET_HOST packets and not overriding skb->pkt_type in openvswitch
anymore.
Fixes: 30a92c9e3d ("openvswitch: Set the skbuff pkt_type for proper pmtud support.")
Fixes: 4cb47a8644 ("tunnels: PMTU discovery support for directly bridged IP packets")
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Reviewed-by: Aaron Conole <aconole@redhat.com>
Tested-by: Aaron Conole <aconole@redhat.com>
Link: https://patch.msgid.link/eac941652b86fddf8909df9b3bf0d97bc9444793.1743208264.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit df207de9d9 ]
Matt Dowling reported a weird UDP memory usage issue.
Under normal operation, the UDP memory usage reported in /proc/net/sockstat
remains close to zero. However, it occasionally spiked to 524,288 pages
and never dropped. Moreover, the value doubled when the application was
terminated. Finally, it caused intermittent packet drops.
We can reproduce the issue with the script below [0]:
1. /proc/net/sockstat reports 0 pages
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 0
2. Run the script till the report reaches 524,288
# python3 test.py & sleep 5
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 3 mem 524288 <-- (INT_MAX + 1) >> PAGE_SHIFT
3. Kill the socket and confirm the number never drops
# pkill python3 && sleep 5
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 524288
4. (necessary since v6.0) Trigger proto_memory_pcpu_drain()
# python3 test.py & sleep 1 && pkill python3
5. The number doubles
# cat /proc/net/sockstat | grep UDP:
UDP: inuse 1 mem 1048577
The application set INT_MAX to SO_RCVBUF, which triggered an integer
overflow in udp_rmem_release().
When a socket is close()d, udp_destruct_common() purges its receive
queue and sums up skb->truesize in the queue. This total is calculated
and stored in a local unsigned integer variable.
The total size is then passed to udp_rmem_release() to adjust memory
accounting. However, because the function takes a signed integer
argument, the total size can wrap around, causing an overflow.
Then, the released amount is calculated as follows:
1) Add size to sk->sk_forward_alloc.
2) Round down sk->sk_forward_alloc to the nearest lower multiple of
PAGE_SIZE and assign it to amount.
3) Subtract amount from sk->sk_forward_alloc.
4) Pass amount >> PAGE_SHIFT to __sk_mem_reduce_allocated().
When the issue occurred, the total in udp_destruct_common() was 2147484480
(INT_MAX + 833), which was cast to -2147482816 in udp_rmem_release().
At 1) sk->sk_forward_alloc is changed from 3264 to -2147479552, and
2) sets -2147479552 to amount. 3) reverts the wraparound, so we don't
see a warning in inet_sock_destruct(). However, udp_memory_allocated
ends up doubling at 4).
Since commit 3cd3399dd7 ("net: implement per-cpu reserves for
memory_allocated"), memory usage no longer doubles immediately after
a socket is close()d because __sk_mem_reduce_allocated() caches the
amount in udp_memory_per_cpu_fw_alloc. However, the next time a UDP
socket receives a packet, the subtraction takes effect, causing UDP
memory usage to double.
This issue makes further memory allocation fail once the socket's
sk->sk_rmem_alloc exceeds net.ipv4.udp_rmem_min, resulting in packet
drops.
To prevent this issue, let's use unsigned int for the calculation and
call sk_forward_alloc_add() only once for the small delta.
Note that first_packet_length() also potentially has the same problem.
[0]:
from socket import *
SO_RCVBUFFORCE = 33
INT_MAX = (2 ** 31) - 1
s = socket(AF_INET, SOCK_DGRAM)
s.bind(('', 0))
s.setsockopt(SOL_SOCKET, SO_RCVBUFFORCE, INT_MAX)
c = socket(AF_INET, SOCK_DGRAM)
c.connect(s.getsockname())
data = b'a' * 100
while True:
c.send(data)
Fixes: f970bd9e3a ("udp: implement memory accounting helpers")
Reported-by: Matt Dowling <madowlin@amazon.com>
Signed-off-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250401184501.67377-3-kuniyu@amazon.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit bac76cf898 upstream.
We have some problem closing zero-window fin-wait-1 tcp sockets in our
environment. This patch come from the investigation.
Previously tcp_abort only sends out reset and calls tcp_done when the
socket is not SOCK_DEAD, aka orphan. For orphan socket, it will only
purging the write queue, but not close the socket and left it to the
timer.
While purging the write queue, tp->packets_out and sk->sk_write_queue
is cleared along the way. However tcp_retransmit_timer have early
return based on !tp->packets_out and tcp_probe_timer have early
return based on !sk->sk_write_queue.
This caused ICSK_TIME_RETRANS and ICSK_TIME_PROBE0 not being resched
and socket not being killed by the timers, converting a zero-windowed
orphan into a forever orphan.
This patch removes the SOCK_DEAD check in tcp_abort, making it send
reset to peer and close the socket accordingly. Preventing the
timer-less orphan from happening.
According to Lorenzo's email in the v1 thread, the check was there to
prevent force-closing the same socket twice. That situation is handled
by testing for TCP_CLOSE inside lock, and returning -ENOENT if it is
already closed.
The -ENOENT code comes from the associate patch Lorenzo made for
iproute2-ss; link attached below, which also conform to RFC 9293.
At the end of the patch, tcp_write_queue_purge(sk) is removed because it
was already called in tcp_done_with_error().
p.s. This is the same patch with v2. Resent due to mis-labeled "changes
requested" on patchwork.kernel.org.
Link: https://patchwork.ozlabs.org/project/netdev/patch/1450773094-7978-3-git-send-email-lorenzo@google.com/
Fixes: c1e64e298b ("net: diag: Support destroying TCP sockets.")
Signed-off-by: Xueming Feng <kuro@kuroa.me>
Tested-by: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20240826102327.1461482-1-kuro@kuroa.me
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Link: https://lore.kernel.org/lkml/Z9OZS%2Fhc+v5og6%2FU@perf/
[youngmin: Resolved minor conflict in net/ipv4/tcp.c]
Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
commit 5ce4645c23 upstream.
tcp_abort() has the same issue than the one fixed in the prior patch
in tcp_write_err().
In order to get consistent results from tcp_poll(), we must call
sk_error_report() after tcp_done().
We can use tcp_done_with_error() to centralize this logic.
Fixes: c1e64e298b ("net: diag: Support destroying TCP sockets.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Neal Cardwell <ncardwell@google.com>
Link: https://lore.kernel.org/r/20240528125253.1966136-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
[youngmin: Resolved minor conflict in net/ipv4/tcp.c]
Signed-off-by: Youngmin Nam <youngmin.nam@samsung.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 3c9231ea64 ]
When I read through the TSO codes, I found out that we probably
miss initializing the tx_flags of last seg when TSO is turned
off, which means at the following points no more timestamp
(for this last one) will be generated. There are three flags
to be handled in this patch:
1. SKBTX_HW_TSTAMP
2. SKBTX_BPF
3. SKBTX_SCHED_TSTAMP
Note that SKBTX_BPF[1] was added in 6.14.0-rc2 by commit
6b98ec7e88 ("bpf: Add BPF_SOCK_OPS_TSTAMP_SCHED_CB callback")
and only belongs to net-next branch material for now. The common
issue of the above three flags can be fixed by this single patch.
This patch initializes the tx_flags to SKBTX_ANY_TSTAMP like what
the UDP GSO does to make the newly segmented last skb inherit the
tx_flags so that requested timestamp will be generated in each
certain layer, or else that last one has zero value of tx_flags
which leads to no timestamp at all.
Fixes: 4ed2d765df ("net-timestamp: TCP timestamping")
Signed-off-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit ee01b2f2d7 ]
In __udp_gso_segment the skb destructor is removed before segmenting the
skb but the socket reference is kept as-is. This is an issue if the
original skb is later orphaned as we can hit the following bug:
kernel BUG at ./include/linux/skbuff.h:3312! (skb_orphan)
RIP: 0010:ip_rcv_core+0x8b2/0xca0
Call Trace:
ip_rcv+0xab/0x6e0
__netif_receive_skb_one_core+0x168/0x1b0
process_backlog+0x384/0x1100
__napi_poll.constprop.0+0xa1/0x370
net_rx_action+0x925/0xe50
The above can happen following a sequence of events when using
OpenVSwitch, when an OVS_ACTION_ATTR_USERSPACE action precedes an
OVS_ACTION_ATTR_OUTPUT action:
1. OVS_ACTION_ATTR_USERSPACE is handled (in do_execute_actions): the skb
goes through queue_gso_packets and then __udp_gso_segment, where its
destructor is removed.
2. The segments' data are copied and sent to userspace.
3. OVS_ACTION_ATTR_OUTPUT is handled (in do_execute_actions) and the
same original skb is sent to its path.
4. If it later hits skb_orphan, we hit the bug.
Fix this by also removing the reference to the socket in
__udp_gso_segment.
Fixes: ad405857b1 ("udp: better wmem accounting on gso")
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Link: https://patch.msgid.link/20250226171352.258045-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8d52da23b6 ]
Recently a bug was discovered where the server had entered TCP_ESTABLISHED
state, but the upper layers were not notified.
The same 5-tuple packet may be processed by different CPUSs, so two
CPUs may receive different ack packets at the same time when the
state is TCP_NEW_SYN_RECV.
In that case, req->ts_recent in tcp_check_req may be changed concurrently,
which will probably cause the newsk's ts_recent to be incorrectly large.
So that tcp_validate_incoming will fail. At this point, newsk will not be
able to enter the TCP_ESTABLISHED.
cpu1 cpu2
tcp_check_req
tcp_check_req
req->ts_recent = rcv_tsval = t1
req->ts_recent = rcv_tsval = t2
syn_recv_sock
tcp_sk(child)->rx_opt.ts_recent = req->ts_recent = t2 // t1 < t2
tcp_child_process
tcp_rcv_state_process
tcp_validate_incoming
tcp_paws_check
if ((s32)(rx_opt->ts_recent - rx_opt->rcv_tsval) <= paws_win)
// t2 - t1 > paws_win, failed
tcp_v4_do_rcv
tcp_rcv_state_process
// TCP_ESTABLISHED
The cpu2's skb or a newly received skb will call tcp_v4_do_rcv to get
the newsk into the TCP_ESTABLISHED state, but at this point it is no
longer possible to notify the upper layer application. A notification
mechanism could be added here, but the fix is more complex, so the
current fix is used.
In tcp_check_req, req->ts_recent is used to assign a value to
tcp_sk(child)->rx_opt.ts_recent, so removing the change in req->ts_recent
and changing tcp_sk(child)->rx_opt.ts_recent directly after owning the
req fixes this bug.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Wang Hai <wanghai38@huawei.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.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 7e863e5db6 ]
Pass a dscp_t variable to ip_route_input(), instead of a plain u8, to
prevent accidental setting of ECN bits in ->flowi4_tos.
Callers of ip_route_input() to consider are:
* input_action_end_dx4_finish() and input_action_end_dt4() in
net/ipv6/seg6_local.c. These functions set the tos parameter to 0,
which is already a valid dscp_t value, so they don't need to be
adjusted for the new prototype.
* icmp_route_lookup(), which already has a dscp_t variable to pass as
parameter. We just need to remove the inet_dscp_to_dsfield()
conversion.
* br_nf_pre_routing_finish(), ip_options_rcv_srr() and ip4ip6_err(),
which get the DSCP directly from IPv4 headers. Define a helper to
read the .tos field of struct iphdr as dscp_t, so that these
function don't have to do the conversion manually.
While there, declare *iph as const in br_nf_pre_routing_finish(),
declare its local variables in reverse-christmas-tree order and move
the "err = ip_route_input()" assignment out of the conditional to avoid
checkpatch warning.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/e9d40781d64d3d69f4c79ac8a008b8d67a033e8d.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 913c83a610 ]
Pass a dscp_t variable to icmp_route_lookup(), instead of a plain u8,
to prevent accidental setting of ECN bits in ->flowi4_tos. Rename that
variable ("tos" -> "dscp") to make the intent clear.
While there, reorganise the function parameters to fill up horizontal
space.
Signed-off-by: Guillaume Nault <gnault@redhat.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/294fead85c6035bcdc5fcf9a6bb4ce8798c45ba1.1727807926.git.gnault@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4805646c42 ]
The function is called to resolve a route for an ICMP message that is
sent in response to a situation. Based on the type of the generated ICMP
message, the function is either passed the DS field of the packet that
generated the ICMP message or a DS field that is derived from it.
Unmask the upper DSCP bits before resolving and output route via
ip_route_output_key_hash() so that in the future the lookup could be
performed according to the full DSCP value.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 1c6f50b37f ]
Align the ICMP code to other callers of ip_route_input() and pass the
full DS field. In the future this will allow us to perform a route
lookup according to the full DSCP value.
No functional changes intended since the upper DSCP bits are masked when
comparing against the TOS selectors in FIB rules and routes.
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Guillaume Nault <gnault@redhat.com>
Acked-by: Florian Westphal <fw@strlen.de>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20240821125251.1571445-11-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit db3efdcf70 ]
Introduce a tracepoint for icmp_send, which can help users to get more
detail information conveniently when icmp abnormal events happen.
1. Giving an usecase example:
=============================
When an application experiences packet loss due to an unreachable UDP
destination port, the kernel will send an exception message through the
icmp_send function. By adding a trace point for icmp_send, developers or
system administrators can obtain detailed information about the UDP
packet loss, including the type, code, source address, destination address,
source port, and destination port. This facilitates the trouble-shooting
of UDP packet loss issues especially for those network-service
applications.
2. Operation Instructions:
==========================
Switch to the tracing directory.
cd /sys/kernel/tracing
Filter for destination port unreachable.
echo "type==3 && code==3" > events/icmp/icmp_send/filter
Enable trace event.
echo 1 > events/icmp/icmp_send/enable
3. Result View:
================
udp_client_erro-11370 [002] ...s.12 124.728002:
icmp_send: icmp_send: type=3, code=3.
From 127.0.0.1:41895 to 127.0.0.1:6666 ulen=23
skbaddr=00000000589b167a
Signed-off-by: Peilin He <he.peilin@zte.com.cn>
Signed-off-by: xu xin <xu.xin16@zte.com.cn>
Reviewed-by: Yunkai Zhang <zhang.yunkai@zte.com.cn>
Cc: Yang Yang <yang.yang29@zte.com.cn>
Cc: Liu Chun <liu.chun2@zte.com.cn>
Cc: Xuexin Jiang <jiang.xuexin@zte.com.cn>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Stable-dep-of: 27843ce6ba ("ipvlan: ensure network headers are in skb linear part")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 36b62df568 ]
'sk->copied_seq' was updated in the tcp_eat_skb() function when the action
of a BPF program was SK_REDIRECT. For other actions, like SK_PASS, the
update logic for 'sk->copied_seq' was moved to tcp_bpf_recvmsg_parser()
to ensure the accuracy of the 'fionread' feature.
It works for a single stream_verdict scenario, as it also modified
sk_data_ready->sk_psock_verdict_data_ready->tcp_read_skb
to remove updating 'sk->copied_seq'.
However, for programs where both stream_parser and stream_verdict are
active (strparser purpose), tcp_read_sock() was used instead of
tcp_read_skb() (sk_data_ready->strp_data_ready->tcp_read_sock).
tcp_read_sock() now still updates 'sk->copied_seq', leading to duplicate
updates.
In summary, for strparser + SK_PASS, copied_seq is redundantly calculated
in both tcp_read_sock() and tcp_bpf_recvmsg_parser().
The issue causes incorrect copied_seq calculations, which prevent
correct data reads from the recv() interface in user-land.
We do not want to add new proto_ops to implement a new version of
tcp_read_sock, as this would introduce code complexity [1].
We could have added noack and copied_seq to desc, and then called
ops->read_sock. However, unfortunately, other modules didn’t fully
initialize desc to zero. So, for now, we are directly calling
tcp_read_sock_noack() in tcp_bpf.c.
[1]: https://lore.kernel.org/bpf/20241218053408.437295-1-mrpre@163.com
Fixes: e5c6de5fa0 ("bpf, sockmap: Incorrectly handling copied_seq")
Suggested-by: Jakub Sitnicki <jakub@cloudflare.com>
Signed-off-by: Jiayuan Chen <mrpre@163.com>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Jakub Sitnicki <jakub@cloudflare.com>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Link: https://patch.msgid.link/20250122100917.49845-3-mrpre@163.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 9b6412e697 ]
Xiumei reported hitting the WARN in xfrm6_tunnel_net_exit while
running tests that boil down to:
- create a pair of netns
- run a basic TCP test over ipcomp6
- delete the pair of netns
The xfrm_state found on spi_byaddr was not deleted at the time we
delete the netns, because we still have a reference on it. This
lingering reference comes from a secpath (which holds a ref on the
xfrm_state), which is still attached to an skb. This skb is not
leaked, it ends up on sk_receive_queue and then gets defer-free'd by
skb_attempt_defer_free.
The problem happens when we defer freeing an skb (push it on one CPU's
defer_list), and don't flush that list before the netns is deleted. In
that case, we still have a reference on the xfrm_state that we don't
expect at this point.
We already drop the skb's dst in the TCP receive path when it's no
longer needed, so let's also drop the secpath. At this point,
tcp_filter has already called into the LSM hooks that may require the
secpath, so it should not be needed anymore. However, in some of those
places, the MPTCP extension has just been attached to the skb, so we
cannot simply drop all extensions.
Fixes: 68822bdf76 ("net: generalize skb freeing deferral to per-cpu lists")
Reported-by: Xiumei Mu <xmu@redhat.com>
Signed-off-by: Sabrina Dubroca <sd@queasysnail.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/5055ba8f8f72bdcb602faa299faca73c280b7735.1739743613.git.sd@queasysnail.net
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 4eae0ee0f1 ]
The arp_req_set_public() function is called with the rtnl lock held,
which provides enough synchronization protection. This makes the RCU
variant of dev_getbyhwaddr() unnecessary. Switch to using the simpler
dev_getbyhwaddr() function since we already have the required rtnl
locking.
This change helps maintain consistency in the networking code by using
the appropriate helper function for the existing locking context.
Since we're not holding the RCU read lock in arp_req_set_public()
existing code could trigger false positive locking warnings.
Fixes: 941666c2e3 ("net: RCU conversion of dev_getbyhwaddr() and arp_ioctl()")
Suggested-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Signed-off-by: Breno Leitao <leitao@debian.org>
Link: https://patch.msgid.link/20250218-arm_fix_selftest-v5-2-d3d6892db9e1@debian.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit f5da7c4518 ]
Since commit under Fixes we set the window clamp in accordance
to newly measured rcvbuf scaling_ratio. If the scaling_ratio
decreased significantly we may put ourselves in a situation
where windows become smaller than rcvq_space, preventing
tcp_rcv_space_adjust() from increasing rcvbuf.
The significant decrease of scaling_ratio is far more likely
since commit 697a6c8cec ("tcp: increase the default TCP scaling ratio"),
which increased the "default" scaling ratio from ~30% to 50%.
Hitting the bad condition depends a lot on TCP tuning, and
drivers at play. One of Meta's workloads hits it reliably
under following conditions:
- default rcvbuf of 125k
- sender MTU 1500, receiver MTU 5000
- driver settles on scaling_ratio of 78 for the config above.
Initial rcvq_space gets calculated as TCP_INIT_CWND * tp->advmss
(10 * 5k = 50k). Once we find out the true scaling ratio and
MSS we clamp the windows to 38k. Triggering the condition also
depends on the message sequence of this workload. I can't repro
the problem with simple iperf or TCP_RR-style tests.
Fixes: a2cbb16039 ("tcp: Update window clamping condition")
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20250217232905.3162187-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a42b69f692 ]
arp_xmit() can be called without RTNL or RCU protection.
Use RCU protection to avoid potential UAF.
Fixes: 29a26a5680 ("netfilter: Pass struct net into the netfilter hooks")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250207135841.1948589-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 139512191b ]
__ip_rt_update_pmtu() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: 2fbc6e89b2 ("ipv4: Update exception handling for multipath routes via same device")
Fixes: 1de6b15a43 ("Namespaceify min_pmtu sysctl")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7d3f3b4367 ]
Check number of paths by fib_info_num_path(),
and update_or_create_fnhe() for every path.
Problem is that pmtu is cached only for the oif
that has received icmp message "need to frag",
other oifs will still try to use "default" iface mtu.
An example topology showing the problem:
| host1
+---------+
| dummy0 | 10.179.20.18/32 mtu9000
+---------+
+-----------+----------------+
+---------+ +---------+
| ens17f0 | 10.179.2.141/31 | ens17f1 | 10.179.2.13/31
+---------+ +---------+
| (all here have mtu 9000) |
+------+ +------+
| ro1 | 10.179.2.140/31 | ro2 | 10.179.2.12/31
+------+ +------+
| |
---------+------------+-------------------+------
|
+-----+
| ro3 | 10.10.10.10 mtu1500
+-----+
|
========================================
some networks
========================================
|
+-----+
| eth0| 10.10.30.30 mtu9000
+-----+
| host2
host1 have enabled multipath and
sysctl net.ipv4.fib_multipath_hash_policy = 1:
default proto static src 10.179.20.18
nexthop via 10.179.2.12 dev ens17f1 weight 1
nexthop via 10.179.2.140 dev ens17f0 weight 1
When host1 tries to do pmtud from 10.179.20.18/32 to host2,
host1 receives at ens17f1 iface an icmp packet from ro3 that ro3 mtu=1500.
And host1 caches it in nexthop exceptions cache.
Problem is that it is cached only for the iface that has received icmp,
and there is no way that ro3 will send icmp msg to host1 via another path.
Host1 now have this routes to host2:
ip r g 10.10.30.30 sport 30000 dport 443
10.10.30.30 via 10.179.2.12 dev ens17f1 src 10.179.20.18 uid 0
cache expires 521sec mtu 1500
ip r g 10.10.30.30 sport 30033 dport 443
10.10.30.30 via 10.179.2.140 dev ens17f0 src 10.179.20.18 uid 0
cache
So when host1 tries again to reach host2 with mtu>1500,
if packet flow is lucky enough to be hashed with oif=ens17f1 its ok,
if oif=ens17f0 it blackholes and still gets icmp msgs from ro3 to ens17f1,
until lucky day when ro3 will send it through another flow to ens17f0.
Signed-off-by: Vladimir Vdovin <deliran@verdict.gg>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/20241108093427.317942-1-deliran@verdict.gg
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: 139512191b ("ipv4: use RCU protection in __ip_rt_update_pmtu()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 719817cd29 ]
inet_select_addr() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: c4544c7243 ("[NETNS]: Process inet_select_addr inside a namespace.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250205155120.1676781-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit dd205fcc33 ]
rt_is_expired() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: e84f84f276 ("netns: place rt_genid into struct net")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 71b8471c93 ]
ipv4_default_advmss() must use RCU protection to make
sure the net structure it reads does not disappear.
Fixes: 2e9589ff80 ("ipv4: Namespaceify min_adv_mss sysctl knob")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Link: https://patch.msgid.link/20250205155120.1676781-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 235174b2be ]
Commit 4094871db1 ("udp: only do GSO if # of segs > 1") avoided GSO
for small packets. But the kernel currently dismisses GSO requests only
after checking MTU/PMTU on gso_size. This means any packets, regardless
of their payload sizes, could be dropped when PMTU becomes smaller than
requested gso_size. We encountered this issue in production and it
caused a reliability problem that new QUIC connection cannot be
established before PMTU cache expired, while non GSO sockets still
worked fine at the same time.
Ideally, do not check any GSO related constraints when payload size is
smaller than requested gso_size, and return EMSGSIZE instead of EINVAL
on MTU/PMTU check failure to be more specific on the error cause.
Fixes: 4094871db1 ("udp: only do GSO if # of segs > 1")
Signed-off-by: Yan Zhai <yan@cloudflare.com>
Suggested-by: Willem de Bruijn <willemdebruijn.kernel@gmail.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 8c670bdfa5 ]
Testing with iperf3 using the "pasta" protocol splicer has revealed
a problem in the way tcp handles window advertising in extreme memory
squeeze situations.
Under memory pressure, a socket endpoint may temporarily advertise
a zero-sized window, but this is not stored as part of the socket data.
The reasoning behind this is that it is considered a temporary setting
which shouldn't influence any further calculations.
However, if we happen to stall at an unfortunate value of the current
window size, the algorithm selecting a new value will consistently fail
to advertise a non-zero window once we have freed up enough memory.
This means that this side's notion of the current window size is
different from the one last advertised to the peer, causing the latter
to not send any data to resolve the sitution.
The problem occurs on the iperf3 server side, and the socket in question
is a completely regular socket with the default settings for the
fedora40 kernel. We do not use SO_PEEK or SO_RCVBUF on the socket.
The following excerpt of a logging session, with own comments added,
shows more in detail what is happening:
// tcp_v4_rcv(->)
// tcp_rcv_established(->)
[5201<->39222]: ==== Activating log @ net/ipv4/tcp_input.c/tcp_data_queue()/5257 ====
[5201<->39222]: tcp_data_queue(->)
[5201<->39222]: DROPPING skb [265600160..265665640], reason: SKB_DROP_REASON_PROTO_MEM
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 259909392->260034360 (124968), unread 5565800, qlen 85, ofoq 0]
[OFO queue: gap: 65480, len: 0]
[5201<->39222]: tcp_data_queue(<-)
[5201<->39222]: __tcp_transmit_skb(->)
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: tcp_select_window(->)
[5201<->39222]: (inet_csk(sk)->icsk_ack.pending & ICSK_ACK_NOMEM) ? --> TRUE
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
returning 0
[5201<->39222]: tcp_select_window(<-)
[5201<->39222]: ADVERTISING WIN 0, ACK_SEQ: 265600160
[5201<->39222]: [__tcp_transmit_skb(<-)
[5201<->39222]: tcp_rcv_established(<-)
[5201<->39222]: tcp_v4_rcv(<-)
// Receive queue is at 85 buffers and we are out of memory.
// We drop the incoming buffer, although it is in sequence, and decide
// to send an advertisement with a window of zero.
// We don't update tp->rcv_wnd and tp->rcv_wup accordingly, which means
// we unconditionally shrink the window.
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 0, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 260040464->260040464 (0), unread 5559696, qlen 85, ofoq 0]
returning 6104 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// After each read, the algorithm for calculating the new receive
// window in __tcp_cleanup_rbuf() finds it is too small to advertise
// or to update tp->rcv_wnd.
// Meanwhile, the peer thinks the window is zero, and will not send
// any more data to trigger an update from the interrupt mode side.
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 260099840->260171536 (71696), unread 5428624, qlen 83, ofoq 0]
returning 131072 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// The above pattern repeats again and again, since nothing changes
// between the reads.
[...]
[5201<->39222]: tcp_recvmsg_locked(->)
[5201<->39222]: __tcp_cleanup_rbuf(->) tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160
[5201<->39222]: [new_win = 262144, win_now = 131184, 2 * win_now = 262368]
[5201<->39222]: [new_win >= (2 * win_now) ? --> time_to_ack = 0]
[5201<->39222]: NOT calling tcp_send_ack()
[tp->rcv_wup: 265469200, tp->rcv_wnd: 262144, tp->rcv_nxt 265600160]
[5201<->39222]: __tcp_cleanup_rbuf(<-)
[rcv_nxt 265600160, rcv_wnd 262144, snt_ack 265469200, win_now 131184]
[copied_seq 265600160->265600160 (0), unread 0, qlen 0, ofoq 0]
returning 54672 bytes
[5201<->39222]: tcp_recvmsg_locked(<-)
// The receive queue is empty, but no new advertisement has been sent.
// The peer still thinks the receive window is zero, and sends nothing.
// We have ended up in a deadlock situation.
Note that well behaved endpoints will send win0 probes, so the problem
will not occur.
Furthermore, we have observed that in these situations this side may
send out an updated 'th->ack_seq´ which is not stored in tp->rcv_wup
as it should be. Backing ack_seq seems to be harmless, but is of
course still wrong from a protocol viewpoint.
We fix this by updating the socket state correctly when a packet has
been dropped because of memory exhaustion and we have to advertize
a zero window.
Further testing shows that the connection recovers neatly from the
squeeze situation, and traffic can continue indefinitely.
Fixes: e2142825c1 ("net: tcp: send zero-window ACK when no memory")
Cc: Menglong Dong <menglong8.dong@gmail.com>
Reviewed-by: Stefano Brivio <sbrivio@redhat.com>
Signed-off-by: Jon Maloy <jmaloy@redhat.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20250127231304.1465565-1-jmaloy@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 25c1a9ca53 ]
I noticed that HyStart incorrectly marks the start of rounds,
leading to inaccurate measurements of ACK train lengths and
resetting the `ca->sample_cnt` variable. This inaccuracy can impact
HyStart's functionality in terminating exponential cwnd growth during
Slow-Start, potentially degrading TCP performance.
The issue arises because the changes introduced in commit 4e1fddc98d
("tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flows")
moved the caller of the `bictcp_hystart_reset` function inside the `hystart_update` function.
This modification added an additional condition for triggering the caller,
requiring that (tcp_snd_cwnd(tp) >= hystart_low_window) must also
be satisfied before invoking `bictcp_hystart_reset`.
This fix ensures that `bictcp_hystart_reset` is correctly called
at the start of a new round, regardless of the congestion window size.
This is achieved by moving the condition
(tcp_snd_cwnd(tp) >= hystart_low_window)
from before calling `bictcp_hystart_reset` to after it.
I tested with a client and a server connected through two Linux software routers.
In this setup, the minimum RTT was 150 ms, the bottleneck bandwidth was 50 Mbps,
and the bottleneck buffer size was 1 BDP, calculated as (50M / 1514 / 8) * 0.150 = 619 packets.
I conducted the test twice, transferring data from the server to the client for 1.5 seconds.
Before the patch was applied, HYSTART-DELAY stopped the exponential growth of cwnd when
cwnd = 516, and the bottleneck link was not yet saturated (516 < 619).
After the patch was applied, HYSTART-ACK-TRAIN stopped the exponential growth of cwnd when
cwnd = 632, and the bottleneck link was saturated (632 > 619).
In this test, applying the patch resulted in 300 KB more data delivered.
Fixes: 4e1fddc98d ("tcp_cubic: fix spurious Hystart ACK train detections for not-cwnd-limited flows")
Signed-off-by: Mahdi Arghavani <ma.arghavani@yahoo.com>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Cc: Neal Cardwell <ncardwell@google.com>
Cc: Eric Dumazet <edumazet@google.com>
Cc: Haibo Zhang <haibo.zhang@otago.ac.nz>
Cc: David Eyers <david.eyers@otago.ac.nz>
Cc: Abbas Arghavani <abbas.arghavani@mdu.se>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Tested-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 3440fa34ad ]
Following fields of 'struct mr_mfc' can be updated
concurrently (no lock protection) from ip_mr_forward()
and ip6_mr_forward()
- bytes
- pkt
- wrong_if
- lastuse
They also can be read from other functions.
Convert bytes, pkt and wrong_if to atomic_long_t,
and use READ_ONCE()/WRITE_ONCE() for lastuse.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/20250114221049.1190631-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit a853c60950 ]
All inet_getpeer() callers except ip4_frag_init() don't need
to acquire a permanent refcount on the inetpeer.
They can switch to full RCU protection.
Move the refcount_inc_not_zero() into ip4_frag_init(),
so that all the other callers no longer have to
perform a pair of expensive atomic operations on
a possibly contended cache line.
inet_putpeer() no longer needs to be exported.
After this patch, my DUT can receive 8,400,000 UDP packets
per second targeting closed ports, using 50% less cpu cycles
than before.
Also change two calls to l3mdev_master_ifindex() by
l3mdev_master_ifindex_rcu() (Ido ideas)
Fixes: 8c2bd38b95 ("icmp: change the order of rate limits")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 50b362f21d ]
inet_putpeer() will be removed in the following patch,
because we will no longer use refcounts.
Update inetpeer timestamp (p->dtime) at lookup time.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a853c60950 ("inetpeer: do not get a refcount in inet_getpeer()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 7a596a50c4 ]
All callers of inet_getpeer() want to create an inetpeer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a853c60950 ("inetpeer: do not get a refcount in inet_getpeer()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
[ Upstream commit 661cd8fc8e ]
All callers of inet_getpeer_v4() and inet_getpeer_v6()
want to create an inetpeer.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241215175629.1248773-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Stable-dep-of: a853c60950 ("inetpeer: do not get a refcount in inet_getpeer()")
Signed-off-by: Sasha Levin <sashal@kernel.org>
commit 90e0569dd3 upstream.
The per-netns IP tunnel hash table is protected by the RTNL mutex and
ip_tunnel_find() is only called from the control path where the mutex is
taken.
Add a lockdep expression to hlist_for_each_entry_rcu() in
ip_tunnel_find() in order to validate that the mutex is held and to
silence the suspicious RCU usage warning [1].
[1]
WARNING: suspicious RCU usage
6.12.0-rc3-custom-gd95d9a31aceb #139 Not tainted
-----------------------------
net/ipv4/ip_tunnel.c:221 RCU-list traversed in non-reader section!!
other info that might help us debug this:
rcu_scheduler_active = 2, debug_locks = 1
1 lock held by ip/362:
#0: ffffffff86fc7cb0 (rtnl_mutex){+.+.}-{3:3}, at: rtnetlink_rcv_msg+0x377/0xf60
stack backtrace:
CPU: 12 UID: 0 PID: 362 Comm: ip Not tainted 6.12.0-rc3-custom-gd95d9a31aceb #139
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0xba/0x110
lockdep_rcu_suspicious.cold+0x4f/0xd6
ip_tunnel_find+0x435/0x4d0
ip_tunnel_newlink+0x517/0x7a0
ipgre_newlink+0x14c/0x170
__rtnl_newlink+0x1173/0x19c0
rtnl_newlink+0x6c/0xa0
rtnetlink_rcv_msg+0x3cc/0xf60
netlink_rcv_skb+0x171/0x450
netlink_unicast+0x539/0x7f0
netlink_sendmsg+0x8c1/0xd80
____sys_sendmsg+0x8f9/0xc20
___sys_sendmsg+0x197/0x1e0
__sys_sendmsg+0x122/0x1f0
do_syscall_64+0xbb/0x1d0
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Fixes: c544193214 ("GRE: Refactor GRE tunneling code.")
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20241023123009.749764-1-idosch@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Alva Lan <alvalan9@foxmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
[ Upstream commit 80fb40baba ]
This is a follow-up to 3c5b4d69c3 ("net: annotate data-races around
sk->sk_mark"). sk->sk_mark can be read and written without holding
the socket lock. IPv6 equivalent is already covered with READ_ONCE()
annotation in tcp_v6_send_response().
Fixes: 3c5b4d69c3 ("net: annotate data-races around sk->sk_mark")
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/f459d1fc44f205e13f6d8bdca2c8bfb9902ffac9.1736244569.git.daniel@iogearbox.net
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
