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Merge tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next
Martin KaFai Lau says:
====================
pull-request: bpf-next 2025-07-17
We've added 13 non-merge commits during the last 20 day(s) which contain
a total of 4 files changed, 712 insertions(+), 84 deletions(-).
The main changes are:
1) Avoid skipping or repeating a sk when using a TCP bpf_iter,
from Jordan Rife.
2) Clarify the driver requirement on using the XDP metadata,
from Song Yoong Siang
* tag 'for-netdev' of https://git.kernel.org/pub/scm/linux/kernel/git/bpf/bpf-next:
doc: xdp: Clarify driver implementation for XDP Rx metadata
selftests/bpf: Add tests for bucket resume logic in established sockets
selftests/bpf: Create iter_tcp_destroy test program
selftests/bpf: Create established sockets in socket iterator tests
selftests/bpf: Make ehash buckets configurable in socket iterator tests
selftests/bpf: Allow for iteration over multiple states
selftests/bpf: Allow for iteration over multiple ports
selftests/bpf: Add tests for bucket resume logic in listening sockets
bpf: tcp: Avoid socket skips and repeats during iteration
bpf: tcp: Use bpf_tcp_iter_batch_item for bpf_tcp_iter_state batch items
bpf: tcp: Get rid of st_bucket_done
bpf: tcp: Make sure iter->batch always contains a full bucket snapshot
bpf: tcp: Make mem flags configurable through bpf_iter_tcp_realloc_batch
====================
Link: https://patch.msgid.link/20250717191731.4142326-1-martin.lau@linux.dev
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
neigh_add() updates pneigh_entry() found or created by pneigh_create().
This update is serialised by RTNL, but we will remove it.
Let's move the update part to pneigh_create() and make it return errno
instead of a pointer of pneigh_entry.
Now, the pneigh code is RTNL free.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-16-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
pneigh_lookup() has ASSERT_RTNL() in the middle of the function, which
is confusing.
When called with the last argument, creat, 0, pneigh_lookup() literally
looks up a proxy neighbour entry. This is the case of the reader path
as the fast path and RTM_GETNEIGH.
pneigh_lookup(), however, creates a pneigh_entry when called with creat 1
from RTM_NEWNEIGH and SIOCSARP, which require RTNL.
Let's split pneigh_lookup() into two functions.
We will convert all the reader paths to RCU, and read_lock_bh(&tbl->lock)
in the new pneigh_lookup() will be dropped.
Signed-off-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250716221221.442239-6-kuniyu@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since "net: gro: use cb instead of skb->network_header", the skb network
header is no longer set in the GRO path.
This breaks fraglist segmentation, which relies on ip_hdr()/tcp_hdr()
to check for address/port changes.
Fix this regression by selectively setting the network header for merged
segment skbs.
Fixes: 186b1ea73a ("net: gro: use cb instead of skb->network_header")
Signed-off-by: Felix Fietkau <nbd@nbd.name>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250705150622.10699-1-nbd@nbd.name
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
The CI reported a UaF in tcp_prune_ofo_queue():
BUG: KASAN: slab-use-after-free in tcp_prune_ofo_queue+0x55d/0x660
Read of size 4 at addr ffff8880134729d8 by task socat/20348
CPU: 0 UID: 0 PID: 20348 Comm: socat Not tainted 6.16.0-rc5-virtme #1 PREEMPT(full)
Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
Call Trace:
<TASK>
dump_stack_lvl+0x82/0xd0
print_address_description.constprop.0+0x2c/0x400
print_report+0xb4/0x270
kasan_report+0xca/0x100
tcp_prune_ofo_queue+0x55d/0x660
tcp_try_rmem_schedule+0x855/0x12e0
tcp_data_queue+0x4dd/0x2260
tcp_rcv_established+0x5e8/0x2370
tcp_v4_do_rcv+0x4ba/0x8c0
__release_sock+0x27a/0x390
release_sock+0x53/0x1d0
tcp_sendmsg+0x37/0x50
sock_write_iter+0x3c1/0x520
vfs_write+0xc09/0x1210
ksys_write+0x183/0x1d0
do_syscall_64+0xc1/0x380
entry_SYSCALL_64_after_hwframe+0x77/0x7f
RIP: 0033:0x7fcf73ef2337
Code: 0f 00 f7 d8 64 89 02 48 c7 c0 ff ff ff ff eb b7 0f 1f 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
RSP: 002b:00007ffd4f924708 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fcf73ef2337
RDX: 0000000000002000 RSI: 0000555f11d1a000 RDI: 0000000000000008
RBP: 0000555f11d1a000 R08: 0000000000002000 R09: 0000000000000000
R10: 0000000000000040 R11: 0000000000000246 R12: 0000000000000008
R13: 0000000000002000 R14: 0000555ee1a44570 R15: 0000000000002000
</TASK>
Allocated by task 20348:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
__kasan_slab_alloc+0x59/0x70
kmem_cache_alloc_node_noprof+0x110/0x340
__alloc_skb+0x213/0x2e0
tcp_collapse+0x43f/0xff0
tcp_try_rmem_schedule+0x6b9/0x12e0
tcp_data_queue+0x4dd/0x2260
tcp_rcv_established+0x5e8/0x2370
tcp_v4_do_rcv+0x4ba/0x8c0
__release_sock+0x27a/0x390
release_sock+0x53/0x1d0
tcp_sendmsg+0x37/0x50
sock_write_iter+0x3c1/0x520
vfs_write+0xc09/0x1210
ksys_write+0x183/0x1d0
do_syscall_64+0xc1/0x380
entry_SYSCALL_64_after_hwframe+0x77/0x7f
Freed by task 20348:
kasan_save_stack+0x24/0x50
kasan_save_track+0x14/0x30
kasan_save_free_info+0x3b/0x60
__kasan_slab_free+0x38/0x50
kmem_cache_free+0x149/0x330
tcp_prune_ofo_queue+0x211/0x660
tcp_try_rmem_schedule+0x855/0x12e0
tcp_data_queue+0x4dd/0x2260
tcp_rcv_established+0x5e8/0x2370
tcp_v4_do_rcv+0x4ba/0x8c0
__release_sock+0x27a/0x390
release_sock+0x53/0x1d0
tcp_sendmsg+0x37/0x50
sock_write_iter+0x3c1/0x520
vfs_write+0xc09/0x1210
ksys_write+0x183/0x1d0
do_syscall_64+0xc1/0x380
entry_SYSCALL_64_after_hwframe+0x77/0x7f
The buggy address belongs to the object at ffff888013472900
which belongs to the cache skbuff_head_cache of size 232
The buggy address is located 216 bytes inside of
freed 232-byte region [ffff888013472900, ffff8880134729e8)
The buggy address belongs to the physical page:
page: refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x13472
head: order:1 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0
flags: 0x80000000000040(head|node=0|zone=1)
page_type: f5(slab)
raw: 0080000000000040 ffff88800198fb40 ffffea0000347b10 ffffea00004f5290
raw: 0000000000000000 0000000000120012 00000000f5000000 0000000000000000
head: 0080000000000040 ffff88800198fb40 ffffea0000347b10 ffffea00004f5290
head: 0000000000000000 0000000000120012 00000000f5000000 0000000000000000
head: 0080000000000001 ffffea00004d1c81 00000000ffffffff 00000000ffffffff
head: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000
page dumped because: kasan: bad access detected
Memory state around the buggy address:
ffff888013472880: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888013472900: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
>ffff888013472980: fb fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc
^
ffff888013472a00: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
ffff888013472a80: fc fc fc fc fc fc fc fc fa fb fb fb fb fb fb fb
Indeed tcp_prune_ofo_queue() is reusing the skb dropped a few lines
above. The caller wants to enqueue 'in_skb', lets check space vs the
latter.
Fixes: 1d2fbaad7c ("tcp: stronger sk_rcvbuf checks")
Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Tested-by: syzbot+865aca08c0533171bf6a@syzkaller.appspotmail.com
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/b78d2d9bdccca29021eed9a0e7097dd8dc00f485.1752567053.git.pabeni@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, TCP stack accepts incoming packet if sizes of receive queues
are below sk->sk_rcvbuf limit.
This can cause memory overshoot if the packet is big, like an 1/2 MB
BIG TCP one.
Refine the check to take into account the incoming skb truesize.
Note that we still accept the packet if the receive queue is empty,
to not completely freeze TCP flows in pathological conditions.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250711114006.480026-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
These functions to not modify the skb, add a const qualifier.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250711114006.480026-7-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp_measure_rcv_mss() is used to update icsk->icsk_ack.rcv_mss
(tcpi_rcv_mss in tcp_info) and tp->scaling_ratio.
Calling it from tcp_data_queue_ofo() makes sure these
fields are updated, and permits a better tuning
of sk->sk_rcvbuf, in the case a new flow receives many ooo
packets.
Fixes: dfa2f04833 ("tcp: get rid of sysctl_tcp_adv_win_scale")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250711114006.480026-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Add a new SNMP MIB : LINUX_MIB_BEYOND_WINDOW
Incremented when an incoming packet is received beyond the
receiver window.
nstat -az | grep TcpExtBeyondWindow
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250711114006.480026-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, TCP accepts incoming packets which might go beyond the
offered RWIN.
Add to tcp_sequence() the validation of packet end sequence.
Add the corresponding check in the fast path.
We relax this new constraint if the receive queue is empty,
to not freeze flows from buggy peers.
Add a new drop reason : SKB_DROP_REASON_TCP_INVALID_END_SEQUENCE.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250711114006.480026-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Currently, __mkroute_output overrules the MTU value configured for
broadcast routes.
This buggy behaviour can be reproduced with:
ip link set dev eth1 mtu 9000
ip route del broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2
ip route add broadcast 192.168.0.255 dev eth1 proto kernel scope link src 192.168.0.2 mtu 1500
The maximum packet size should be 1500, but it is actually 8000:
ping -b 192.168.0.255 -s 8000
Fix __mkroute_output to allow MTU values to be configured for
for broadcast routes (to support a mixed-MTU local-area-network).
Signed-off-by: Oscar Maes <oscmaes92@gmail.com>
Link: https://patch.msgid.link/20250710142714.12986-1-oscmaes92@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Replace the offset-based approach for tracking progress through a bucket
in the TCP table with one based on socket cookies. Remember the cookies
of unprocessed sockets from the last batch and use this list to
pick up where we left off or, in the case that the next socket
disappears between reads, find the first socket after that point that
still exists in the bucket and resume from there.
This approach guarantees that all sockets that existed when iteration
began and continue to exist throughout will be visited exactly once.
Sockets that are added to the table during iteration may or may not be
seen, but if they are they will be seen exactly once.
Signed-off-by: Jordan Rife <jordan@jrife.io>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Prepare for the next patch that tracks cookies between iterations by
converting struct sock **batch to union bpf_tcp_iter_batch_item *batch
inside struct bpf_tcp_iter_state.
Signed-off-by: Jordan Rife <jordan@jrife.io>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Get rid of the st_bucket_done field to simplify TCP iterator state and
logic. Before, st_bucket_done could be false if bpf_iter_tcp_batch
returned a partial batch; however, with the last patch ("bpf: tcp: Make
sure iter->batch always contains a full bucket snapshot"),
st_bucket_done == true is equivalent to iter->cur_sk == iter->end_sk.
Signed-off-by: Jordan Rife <jordan@jrife.io>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Require that iter->batch always contains a full bucket snapshot. This
invariant is important to avoid skipping or repeating sockets during
iteration when combined with the next few patches. Before, there were
two cases where a call to bpf_iter_tcp_batch may only capture part of a
bucket:
1. When bpf_iter_tcp_realloc_batch() returns -ENOMEM.
2. When more sockets are added to the bucket while calling
bpf_iter_tcp_realloc_batch(), making the updated batch size
insufficient.
In cases where the batch size only covers part of a bucket, it is
possible to forget which sockets were already visited, especially if we
have to process a bucket in more than two batches. This forces us to
choose between repeating or skipping sockets, so don't allow this:
1. Stop iteration and propagate -ENOMEM up to userspace if reallocation
fails instead of continuing with a partial batch.
2. Try bpf_iter_tcp_realloc_batch() with GFP_USER just as before, but if
we still aren't able to capture the full bucket, call
bpf_iter_tcp_realloc_batch() again while holding the bucket lock to
guarantee the bucket does not change. On the second attempt use
GFP_NOWAIT since we hold onto the spin lock.
I did some manual testing to exercise the code paths where GFP_NOWAIT is
used and where ERR_PTR(err) is returned. I used the realloc test cases
included later in this series to trigger a scenario where a realloc
happens inside bpf_iter_tcp_batch and made a small code tweak to force
the first realloc attempt to allocate a too-small batch, thus requiring
another attempt with GFP_NOWAIT. Some printks showed both reallocs with
the tests passing:
Jun 27 00:00:53 crow kernel: again GFP_USER
Jun 27 00:00:53 crow kernel: again GFP_NOWAIT
Jun 27 00:00:53 crow kernel: again GFP_USER
Jun 27 00:00:53 crow kernel: again GFP_NOWAIT
With this setup, I also forced each of the bpf_iter_tcp_realloc_batch
calls to return -ENOMEM to ensure that iteration ends and that the
read() in userspace fails.
Signed-off-by: Jordan Rife <jordan@jrife.io>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Prepare for the next patch which needs to be able to choose either
GFP_USER or GFP_NOWAIT for calls to bpf_iter_tcp_realloc_batch.
Signed-off-by: Jordan Rife <jordan@jrife.io>
Signed-off-by: Martin KaFai Lau <martin.lau@kernel.org>
Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com>
Acked-by: Stanislav Fomichev <sdf@fomichev.me>
Commit b35108a51c ("jiffies: Define secs_to_jiffies()") introduced
secs_to_jiffies(). As the value here is a multiple of 1000, use
secs_to_jiffies() instead of msecs_to_jiffies to avoid the multiplication.
This is converted using scripts/coccinelle/misc/secs_to_jiffies.cocci with
the following Coccinelle rules:
@depends on patch@
expression E;
@@
-msecs_to_jiffies(E * 1000)
+secs_to_jiffies(E)
-msecs_to_jiffies(E * MSEC_PER_SEC)
+secs_to_jiffies(E)
While here, manually convert a couple timeouts denominated in seconds
Signed-off-by: Easwar Hariharan <eahariha@linux.microsoft.com>
Link: https://patch.msgid.link/20250707-netdev-secs-to-jiffies-part-2-v2-2-b7817036342f@linux.microsoft.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
When a passive flow has not been accepted yet, it is
not wise to increase sk_rcvbuf when receiving ooo packets.
A very busy server might tune down tcp_rmem[1] to better
control how much memory can be used by sockets waiting
in its listeners accept queues.
Fixes: 63ad7dfedf ("tcp: adjust rcvbuf in presence of reorders")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250707213900.1543248-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use DEFINE_MUTEX() to initialize udp_tunnel_gro_type_lock.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250707091634.311974-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
As RACK-TLP was published as a standards-track RFC8985,
so the outdated ref draft-ietf-tcpm-rack need to be updated.
Signed-off-by: Xin Guo <guoxin0309@gmail.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Link: https://patch.msgid.link/20250705163647.301231-1-guoxin0309@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Since its introduction in commit 2e910b9532 ("net: Add a function to
splice pages into an skbuff for MSG_SPLICE_PAGES"), skb_splice_from_iter()
never used the @gfp argument. Remove it and adapt callers.
No functional change intended.
Reviewed-by: Simon Horman <horms@kernel.org>
Signed-off-by: Michal Luczaj <mhal@rbox.co>
Link: https://patch.msgid.link/20250702-splice-drop-unused-v3-2-55f68b60d2b7@rbox.co
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
MSG_ZEROCOPY data must be copied before data is queued to local
sockets, to avoid indefinite timeout until memory release.
This test is performed by skb_orphan_frags_rx, which is called when
looping an egress skb to packet sockets, error queue or ingress path.
To preserve zerocopy for skbs that are looped to ingress but are then
forwarded to an egress device rather than delivered locally, defer
this last check until an skb enters the local IP receive path.
This is analogous to existing behavior of skb_clear_delivery_time.
Signed-off-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630194312.1571410-2-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
udp_v4_early_demux now returns drop reasons as it either returns 0 or
ip_mc_validate_source, which returns itself a drop reason. However its
use was not converted in ip_rcv_finish_core and the drop reason is
ignored, leading to potentially skipping increasing LINUX_MIB_IPRPFILTER
if the drop reason is SKB_DROP_REASON_IP_RPFILTER.
This is a fix and we're not converting udp_v4_early_demux to explicitly
return a drop reason to ease backports; this can be done as a follow-up.
Fixes: d46f827016 ("net: ip: make ip_mc_validate_source() return drop reason")
Cc: Menglong Dong <menglong8.dong@gmail.com>
Reported-by: Sabrina Dubroca <sd@queasysnail.net>
Signed-off-by: Antoine Tenart <atenart@kernel.org>
Reviewed-by: Sabrina Dubroca <sd@queasysnail.net>
Link: https://patch.msgid.link/20250701074935.144134-1-atenart@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Use the new helpers as a first step to deal with
potential dst->dev races.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-8-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dst_dev_put() can overwrite dst->output while other
cpus might read this field (for instance from dst_output())
Add READ_ONCE()/WRITE_ONCE() annotations to suppress
potential issues.
We will likely need RCU protection in the future.
Fixes: 4a6ce2b6f2 ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-6-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
dst_dev_put() can overwrite dst->input while other
cpus might read this field (for instance from dst_input())
Add READ_ONCE()/WRITE_ONCE() annotations to suppress
potential issues.
We will likely need full RCU protection later.
Fixes: 4a6ce2b6f2 ("net: introduce a new function dst_dev_put()")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
(dst_entry)->expires is read and written locklessly,
add corresponding annotations.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250630121934.3399505-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
____cacheline_aligned_in_smp attribute only makes sure to align
a field to a cache line. It does not prevent the linker to use
the remaining of the cache line for other variables, causing
potential false sharing.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630093540.3052835-5-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
____cacheline_aligned_in_smp attribute only makes sure to align
a field to a cache line. It does not prevent the linker to use
the remaining of the cache line for other variables, causing
potential false sharing.
Move tcp_memory_allocated into a dedicated cache line.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Willem de Bruijn <willemb@google.com>
Link: https://patch.msgid.link/20250630093540.3052835-4-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
If the new coming segment covers more than one skbs in the ofo queue,
and which seq is equal to rcv_nxt, then the sequence range
that is duplicated will be sent as DUP SACK, the detail as below,
in step6, the {501,2001} range is clearly including too much
DUP SACK range, in violation of RFC 2883 rules.
1. client > server: Flags [.], seq 501:1001, ack 1325288529, win 20000, length 500
2. server > client: Flags [.], ack 1, [nop,nop,sack 1 {501:1001}], length 0
3. client > server: Flags [.], seq 1501:2001, ack 1325288529, win 20000, length 500
4. server > client: Flags [.], ack 1, [nop,nop,sack 2 {1501:2001} {501:1001}], length 0
5. client > server: Flags [.], seq 1:2001, ack 1325288529, win 20000, length 2000
6. server > client: Flags [.], ack 2001, [nop,nop,sack 1 {501:2001}], length 0
After this fix, the final ACK is as below:
6. server > client: Flags [.], ack 2001, options [nop,nop,sack 1 {501:1001}], length 0
[edumazet] added a new packetdrill test in the following patch.
Fixes: 1da177e4c3 ("Linux-2.6.12-rc2")
Signed-off-by: xin.guo <guoxin0309@gmail.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Link: https://patch.msgid.link/20250626123420.1933835-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
inet_rtx_syn_ack() is a simple wrapper around tcp_rtx_synack(),
if we move req->num_retrans update.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250626153017.2156274-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Now inet_rtx_syn_ack() is only used by TCP, it can directly
call tcp_rtx_synack() instead of using an indirect call
to req->rsk_ops->rtx_syn_ack().
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Neal Cardwell <ncardwell@google.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250626153017.2156274-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
lwtunnel_build_state() has check validity of encap_type,
so no need to do this before call it.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250625022059.3958215-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
lwtunnel_fill_encap() has NULL check and return 0, so no need
to check before call it.
Signed-off-by: Yue Haibing <yuehaibing@huawei.com>
Reviewed-by: Kuniyuki Iwashima <kuniyu@google.com>
Link: https://patch.msgid.link/20250624140015.3929241-1-yuehaibing@huawei.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Difference between sock_i_uid() and sk_uid() is that
after sock_orphan(), sock_i_uid() returns GLOBAL_ROOT_UID
while sk_uid() returns the last cached sk->sk_uid value.
None of sock_i_uid() callers care about this.
Use sk_uid() which is much faster and inlined.
Note that diag/dump users are calling sock_i_ino() and
can not see the full benefit yet.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-3-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
sk->sk_uid can be read while another thread changes its
value in sockfs_setattr().
Add sk_uid(const struct sock *sk) helper to factorize the needed
READ_ONCE() annotations, and add corresponding WRITE_ONCE()
where needed.
Fixes: 86741ec254 ("net: core: Add a UID field to struct sock.")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Reviewed-by: Maciej Żenczykowski <maze@google.com>
Link: https://patch.msgid.link/20250620133001.4090592-2-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
tcp_time_to_recover() does not need the @flag argument.
Its first parameter can be marked const, and of tcp_sock type.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20250618091246.1260322-1-edumazet@google.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Drivers that are using ops lock and don't depend on RTNL lock
still need to manage it because udp_tunnel's RTNL dependency.
Introduce new udp_tunnel_nic_lock and use it instead of
rtnl_lock. Drop non-UDP_TUNNEL_NIC_INFO_MAY_SLEEP mode from
udp_tunnel infra (udp_tunnel_nic_device_sync_work needs to
grab udp_tunnel_nic_lock mutex and might sleep).
Cover more places in v4:
- netlink
- udp_tunnel_notify_add_rx_port (ndo_open)
- triggers udp_tunnel_nic_device_sync_work
- udp_tunnel_notify_del_rx_port (ndo_stop)
- triggers udp_tunnel_nic_device_sync_work
- udp_tunnel_get_rx_info (__netdev_update_features)
- triggers NETDEV_UDP_TUNNEL_PUSH_INFO
- udp_tunnel_drop_rx_info (__netdev_update_features)
- triggers NETDEV_UDP_TUNNEL_DROP_INFO
- udp_tunnel_nic_reset_ntf (ndo_open)
- notifiers
- udp_tunnel_nic_netdevice_event, depending on the event:
- triggers NETDEV_UDP_TUNNEL_PUSH_INFO
- triggers NETDEV_UDP_TUNNEL_DROP_INFO
- ethnl_tunnel_info_reply_size
- udp_tunnel_nic_set_port_priv (two intel drivers)
Cc: Michael Chan <michael.chan@broadcom.com>
Suggested-by: Jakub Kicinski <kuba@kernel.org>
Signed-off-by: Stanislav Fomichev <stfomichev@gmail.com>
Link: https://patch.msgid.link/20250616162117.287806-4-stfomichev@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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>
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>
The only generic interface to execute asynchronously in the BH context is
tasklet; however, it's marked deprecated and has some design flaws. To
replace tasklets, BH workqueue support was recently added. A BH workqueue
behaves similarly to regular workqueues except that the queued work items
are executed in the BH context.
This patch converts TCP Small Queues implementation from tasklet to BH
workqueue.
Semantically, this is an equivalent conversion and there shouldn't be any
user-visible behavior changes. While workqueue's queueing and execution
paths are a bit heavier than tasklet's, unless the work item is being queued
every packet, the difference hopefully shouldn't matter.
My experience with the networking stack is very limited and this patch
definitely needs attention from someone who actually understands networking.
Signed-off-by: Tejun Heo <tj@kernel.org>
Reviewed-by: Jason Xing <kerneljasonxing@gmail.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Cc: David Ahern <dsahern@kernel.org>
Link: https://patch.msgid.link/aFBeJ38AS1ZF3Dq5@slm.duckdns.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Multicast routing is today handled in the input path. Locally generated MC
packets don't hit the IPMR code today. Thus if a VXLAN remote address is
multicast, the driver needs to set an OIF during route lookup. Thus MC
routing configuration needs to be kept in sync with the VXLAN FDB and MDB.
Ideally, the VXLAN packets would be routed by the MC routing code instead.
To that end, this patch adds support to route locally generated multicast
packets. The newly-added routines do largely what ip_mr_input() and
ip_mr_forward() do: make an MR cache lookup to find where to send the
packets, and use ip_mc_output() to send each of them. When no cache entry
is found, the packet is punted to the daemon for resolution.
However, an installation that uses a VXLAN underlay netdevice for which it
also has matching MC routes, would get a different routing with this patch.
Previously, the MC packets would be delivered directly to the underlay
port, whereas now they would be MC-routed. In order to avoid this change in
behavior, introduce an IPCB flag. Only if the flag is set will
ip_mr_output() actually engage, otherwise it reverts to ip_mc_output().
This code is based on work by Roopa Prabhu and Nikolay Aleksandrov.
Signed-off-by: Roopa Prabhu <roopa@nvidia.com>
Signed-off-by: Nikolay Aleksandrov <razor@blackwall.org>
Signed-off-by: Benjamin Poirier <bpoirier@nvidia.com>
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Link: https://patch.msgid.link/0aadbd49330471c0f758d54afb05eb3b6e3a6b65.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
Some of the work of ipmr_queue_xmit() is specific to IPMR forwarding, and
should not take place on the output path. In order to allow reuse of the
common parts, split the function into two: the ipmr_prepare_xmit() helper
that takes care of the common bits, and the ipmr_queue_fwd_xmit(), which
invokes the former and encapsulates the whole forwarding algorithm.
Signed-off-by: Petr Machata <petrm@nvidia.com>
Reviewed-by: Ido Schimmel <idosch@nvidia.com>
Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org>
Link: https://patch.msgid.link/4e8db165572a4f8bd29a723a801e854e9d20df4d.1750113335.git.petrm@nvidia.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
