kernel/linux.git/include/net/inet_hashtables.h, branch v7.1-rc5

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-03-26T19:09:57+00:00

Cross-merge networking fixes after downstream PR (net-7.0-rc6). No conflicts, or adjacent changes. Signed-off-by: Jakub Kicinski

udp: Fix wildcard bind conflict check when using hash2

2026-03-24T01:46:45+00:00

When binding a udp_sock to a local address and port, UDP uses two hashes (udptable->hash and udptable->hash2) for collision detection. The current code switches to "hash2" when hslot->count > 10. "hash2" is keyed by local address and local port. "hash" is keyed by local port only. The issue can be shown in the following bind sequence (pseudo code): bind(fd1, "[fd00::1]:8888") bind(fd2, "[fd00::2]:8888") bind(fd3, "[fd00::3]:8888") bind(fd4, "[fd00::4]:8888") bind(fd5, "[fd00::5]:8888") bind(fd6, "[fd00::6]:8888") bind(fd7, "[fd00::7]:8888") bind(fd8, "[fd00::8]:8888") bind(fd9, "[fd00::9]:8888") bind(fd10, "[fd00::10]:8888") /* Correctly return -EADDRINUSE because "hash" is used * instead of "hash2". udp_lib_lport_inuse() detects the * conflict. */ bind(fail_fd, "[::]:8888") /* After one more socket is bound to "[fd00::11]:8888", * hslot->count exceeds 10 and "hash2" is used instead. */ bind(fd11, "[fd00::11]:8888") bind(fail_fd, "[::]:8888") /* succeeds unexpectedly */ The same issue applies to the IPv4 wildcard address "0.0.0.0" and the IPv4-mapped wildcard address "::ffff:0.0.0.0". For example, if there are existing sockets bound to "192.168.1.[1-11]:8888", then binding "0.0.0.0:8888" or "[::ffff:0.0.0.0]:8888" can also miss the conflict when hslot->count > 10. TCP inet_csk_get_port() already has the correct check in inet_use_bhash2_on_bind(). Rename it to inet_use_hash2_on_bind() and move it to inet_hashtables.h so udp.c can reuse it in this fix. Fixes: 30fff9231fad ("udp: bind() optimisation") Reported-by: Andrew Onyshchuk Signed-off-by: Martin KaFai Lau Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260319181817.1901357-1-martin.lau@linux.dev Signed-off-by: Jakub Kicinski

Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net

2026-03-05T20:11:05+00:00

Cross-merge networking fixes after downstream PR (net-7.0-rc3). No conflicts. Adjacent changes: net/netfilter/nft_set_rbtree.c fb7fb4016300 ("netfilter: nf_tables: clone set on flush only") 3aea466a4399 ("netfilter: nft_set_rbtree: don't disable bh when acquiring tree lock") Signed-off-by: Jakub Kicinski

dccp Remove inet_hashinfo2_init_mod().

2026-03-03T02:50:28+00:00

Commit c92c81df93df ("net: dccp: fix kernel crash on module load") added inet_hashinfo2_init_mod() for DCCP. Commit 22d6c9eebf2e ("net: Unexport shared functions for DCCP.") removed EXPORT_SYMBOL_GPL() it but forgot to remove the function itself. Let's remove inet_hashinfo2_init_mod(). Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260301063756.1581685-1-kuniyu@google.com Signed-off-by: Jakub Kicinski

inet: annotate data-races around isk->inet_num

2026-02-28T01:16:59+00:00

UDP/TCP lookups are using RCU, thus isk->inet_num accesses should use READ_ONCE() and WRITE_ONCE() where needed. Fixes: 3ab5aee7fe84 ("net: Convert TCP & DCCP hash tables to use RCU / hlist_nulls") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20260225203545.1512417-1-edumazet@google.com Signed-off-by: Jakub Kicinski

tcp: Update bind bucket state on port release

2025-09-23T08:12:15+00:00

Today, once an inet_bind_bucket enters a state where fastreuse >= 0 or fastreuseport >= 0 after a socket is explicitly bound to a port, it remains in that state until all sockets are removed and the bucket is destroyed. In this state, the bucket is skipped during ephemeral port selection in connect(). For applications using a reduced ephemeral port range (IP_LOCAL_PORT_RANGE socket option), this can cause faster port exhaustion since blocked buckets are excluded from reuse. The reason the bucket state isn't updated on port release is unclear. Possibly a performance trade-off to avoid scanning bucket owners, or just an oversight. Fix it by recalculating the bucket state when a socket releases a port. To limit overhead, each inet_bind2_bucket stores its own (fastreuse, fastreuseport) state. On port release, only the relevant port-addr bucket is scanned, and the overall state is derived from these. Signed-off-by: Jakub Sitnicki Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250917-update-bind-bucket-state-on-unhash-v5-1-57168b661b47@cloudflare.com Signed-off-by: Paolo Abeni

tcp: Remove inet6_hash().

2025-09-22T18:38:43+00:00

inet_hash() and inet6_hash() are exactly the same. Also, we do not need to export inet6_hash(). Let's consolidate the two into __inet_hash() and rename it to inet_hash(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250919083706.1863217-3-kuniyu@google.com Signed-off-by: Jakub Kicinski

tcp: Remove osk from __inet_hash() arg.

2025-09-22T18:38:42+00:00

__inet_hash() is called from inet_hash() and inet6_hash with osk NULL. Let's remove the 2nd arg from __inet_hash(). Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250919083706.1863217-2-kuniyu@google.com Signed-off-by: Jakub Kicinski

tcp: Don't pass hashinfo to socket lookup helpers.

2025-08-26T00:53:35+00:00

These socket lookup functions required struct inet_hashinfo because they are shared by TCP and DCCP. * __inet_lookup_established() * __inet_lookup_listener() * __inet6_lookup_established() * inet6_lookup_listener() DCCP has gone, and we don't need to pass hashinfo down to them. Let's fetch net->ipv4.tcp_death_row.hashinfo directly in the above 4 functions. Signed-off-by: Kuniyuki Iwashima Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250822190803.540788-5-kuniyu@google.com Signed-off-by: Jakub Kicinski

ipv4: adopt dst_dev, skb_dst_dev and skb_dst_dev_net[_rcu]

2025-07-02T21:32:30+00:00

Use the new helpers as a first step to deal with potential dst->dev races. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250630121934.3399505-8-edumazet@google.com Signed-off-by: Jakub Kicinski