kernel/linux.git/include/net/sock.h, branch v6.18.21

net: Drop the lock in skb_may_tx_timestamp()

2026-03-04T12:20:49+00:00

[ Upstream commit 983512f3a87fd8dc4c94dfa6b596b6e57df5aad7 ] skb_may_tx_timestamp() may acquire sock::sk_callback_lock. The lock must not be taken in IRQ context, only softirq is okay. A few drivers receive the timestamp via a dedicated interrupt and complete the TX timestamp from that handler. This will lead to a deadlock if the lock is already write-locked on the same CPU. Taking the lock can be avoided. The socket (pointed by the skb) will remain valid until the skb is released. The ->sk_socket and ->file member will be set to NULL once the user closes the socket which may happen before the timestamp arrives. If we happen to observe the pointer while the socket is closing but before the pointer is set to NULL then we may use it because both pointer (and the file's cred member) are RCU freed. Drop the lock. Use READ_ONCE() to obtain the individual pointer. Add a matching WRITE_ONCE() where the pointer are cleared. Link: https://lore.kernel.org/all/20260205145104.iWinkXHv@linutronix.de Fixes: b245be1f4db1a ("net-timestamp: no-payload only sysctl") Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Willem de Bruijn Reviewed-by: Jason Xing Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20260220183858.N4ERjFW6@linutronix.de Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

Revert "net: group sk_backlog and sk_receive_queue"

2025-09-30T01:30:32+00:00

This reverts commit 4effb335b5dab08cb6e2c38d038910f8b527cfc9. This was a benefit for UDP flood case, which was later greatly improved with commits 6471658dc66c ("udp: use skb_attempt_defer_free()") and b650bf0977d3 ("udp: remove busylock and add per NUMA queues"). Apparently blamed commit added a regression for RAW sockets, possibly because they do not use the dual RX queue strategy that UDP has. sock_queue_rcv_skb_reason() and RAW recvmsg() compete for sk_receive_buf and sk_rmem_alloc changes, and them being in the same cache line reduce performance. Fixes: 4effb335b5da ("net: group sk_backlog and sk_receive_queue") Reported-by: kernel test robot Closes: https://lore.kernel.org/oe-lkp/202509281326.f605b4eb-lkp@intel.com Signed-off-by: Eric Dumazet Cc: Willem de Bruijn Cc: David Ahern Cc: Kuniyuki Iwashima Link: https://patch.msgid.link/20250929182112.824154-1-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

net: move sk->sk_err_soft and sk->sk_sndbuf

2025-09-23T00:55:24+00:00

sk->sk_sndbuf is read-mostly in tx path, so move it from sock_write_tx group to more appropriate sock_read_tx. sk->sk_err_soft was not identified previously, but is used from tcp_ack(). Move it to sock_write_tx group for better cache locality. Also change tcp_ack() to clear sk->sk_err_soft only if needed. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250919204856.2977245-3-edumazet@google.com Signed-off-by: Jakub Kicinski

net: move sk_uid and sk_protocol to sock_read_tx

2025-09-23T00:55:24+00:00

sk_uid and sk_protocol are read from inet6_csk_route_socket() for each TCP transmit. Also read from udpv6_sendmsg(), udp_sendmsg() and others. Move them to sock_read_tx for better cache locality. Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250919204856.2977245-2-edumazet@google.com Signed-off-by: Jakub Kicinski

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

2025-09-18T18:26:06+00:00

Cross-merge networking fixes after downstream PR (net-6.17-rc7). No conflicts. Adjacent changes: drivers/net/ethernet/mellanox/mlx5/core/en/fs.h 9536fbe10c9d ("net/mlx5e: Add PSP steering in local NIC RX") 7601a0a46216 ("net/mlx5e: Add a miss level for ipsec crypto offload") Signed-off-by: Jakub Kicinski

net: clear sk->sk_ino in sk_set_socket(sk, NULL)

2025-09-18T14:47:17+00:00

Andrei Vagin reported that blamed commit broke CRIU. Indeed, while we want to keep sk_uid unchanged when a socket is cloned, we want to clear sk->sk_ino. Otherwise, sock_diag might report multiple sockets sharing the same inode number. Move the clearing part from sock_orphan() to sk_set_socket(sk, NULL), called both from sock_orphan() and sk_clone_lock(). Fixes: 5d6b58c932ec ("net: lockless sock_i_ino()") Closes: https://lore.kernel.org/netdev/aMhX-VnXkYDpKd9V@google.com/ Closes: https://github.com/checkpoint-restore/criu/issues/2744 Reported-by: Andrei Vagin Signed-off-by: Eric Dumazet Acked-by: Andrei Vagin Link: https://patch.msgid.link/20250917135337.1736101-1-edumazet@google.com Signed-off-by: Jakub Kicinski

Merge branch 'add-basic-psp-encryption-for-tcp-connections'

2025-09-18T10:38:34+00:00

Daniel Zahka says: ================== add basic PSP encryption for TCP connections This is v13 of the PSP RFC [1] posted by Jakub Kicinski one year ago. General developments since v1 include a fork of packetdrill [2] with support for PSP added, as well as some test cases, and an implementation of PSP key exchange and connection upgrade [3] integrated into the fbthrift RPC library. Both [2] and [3] have been tested on server platforms with PSP-capable CX7 NICs. Below is the cover letter from the original RFC: Add support for PSP encryption of TCP connections. PSP is a protocol out of Google: https://github.com/google/psp/blob/main/doc/PSP_Arch_Spec.pdf which shares some similarities with IPsec. I added some more info in the first patch so I'll keep it short here. The protocol can work in multiple modes including tunneling. But I'm mostly interested in using it as TLS replacement because of its superior offload characteristics. So this patch does three things: - it adds "core" PSP code PSP is offload-centric, and requires some additional care and feeding, so first chunk of the code exposes device info. This part can be reused by PSP implementations in xfrm, tunneling etc. - TCP integration TLS style Reuse some of the existing concepts from TLS offload, such as attaching crypto state to a socket, marking skbs as "decrypted", egress validation. PSP does not prescribe key exchange protocols. To use PSP as a more efficient TLS offload we intend to perform a TLS handshake ("inline" in the same TCP connection) and negotiate switching to PSP based on capabilities of both endpoints. This is also why I'm not including a software implementation. Nobody would use it in production, software TLS is faster, it has larger crypto records. - mlx5 implementation That's mostly other people's work, not 100% sure those folks consider it ready hence the RFC in the title. But it works :) Not posted, queued a branch [4] are follow up pieces: - standard stats - netdevsim implementation and tests [1] https://lore.kernel.org/netdev/20240510030435.120935-1-kuba@kernel.org/ [2] https://github.com/danieldzahka/packetdrill [3] https://github.com/danieldzahka/fbthrift/tree/dzahka/psp [4] https://github.com/kuba-moo/linux/tree/psp Comments we intend to defer to future series: - we prefer to keep the version field in the tx-assoc netlink request, because it makes parsing keys require less state early on, but we are willing to change in the next version of this series. - using a static branch to wrap psp_enqueue_set_decrypted() and other functions called from tcp. - using INDIRECT_CALL for tls/psp in sk_validate_xmit_skb(). We prefer to address this in a dedicated patch series, so that this series does not need to modify the way tls_validate_xmit_skb() is declared and stubbed out. v12: https://lore.kernel.org/netdev/20250916000559.1320151-1-kuba@kernel.org/ v11: https://lore.kernel.org/20250911014735.118695-1-daniel.zahka@gmail.com v10: https://lore.kernel.org/netdev/20250828162953.2707727-1-daniel.zahka@gmail.com/ v9: https://lore.kernel.org/netdev/20250827155340.2738246-1-daniel.zahka@gmail.com/ v8: https://lore.kernel.org/netdev/20250825200112.1750547-1-daniel.zahka@gmail.com/ v7: https://lore.kernel.org/netdev/20250820113120.992829-1-daniel.zahka@gmail.com/ v6: https://lore.kernel.org/netdev/20250812003009.2455540-1-daniel.zahka@gmail.com/ v5: https://lore.kernel.org/netdev/20250723203454.519540-1-daniel.zahka@gmail.com/ v4: https://lore.kernel.org/netdev/20250716144551.3646755-1-daniel.zahka@gmail.com/ v3: https://lore.kernel.org/netdev/20250702171326.3265825-1-daniel.zahka@gmail.com/ v2: https://lore.kernel.org/netdev/20250625135210.2975231-1-daniel.zahka@gmail.com/ v1: https://lore.kernel.org/netdev/20240510030435.120935-1-kuba@kernel.org/ ================== Links: https://patch.msgid.link/20250917000954.859376-1-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni --- * add-basic-psp-encryption-for-tcp-connections: net/mlx5e: Implement PSP key_rotate operation net/mlx5e: Add Rx data path offload psp: provide decapsulation and receive helper for drivers net/mlx5e: Configure PSP Rx flow steering rules net/mlx5e: Add PSP steering in local NIC RX net/mlx5e: Implement PSP Tx data path psp: provide encapsulation helper for drivers net/mlx5e: Implement PSP operations .assoc_add and .assoc_del net/mlx5e: Support PSP offload functionality psp: track generations of device key net: psp: update the TCP MSS to reflect PSP packet overhead net: psp: add socket security association code net: tcp: allow tcp_timewait_sock to validate skbs before handing to device net: move sk_validate_xmit_skb() to net/core/dev.c psp: add op for rotation of device key tcp: add datapath logic for PSP with inline key exchange net: modify core data structures for PSP datapath support psp: base PSP device support psp: add documentation

net: move sk_validate_xmit_skb() to net/core/dev.c

2025-09-18T10:32:06+00:00

Move definition of sk_validate_xmit_skb() from net/core/sock.c to net/core/dev.c. This change is in preparation of the next patch, where sk_validate_xmit_skb() will need to cast sk to a tcp_timewait_sock *, and access member fields. Including linux/tcp.h from linux/sock.h creates a circular dependency, and dev.c is the only current call site of this function. Reviewed-by: Willem de Bruijn Signed-off-by: Daniel Zahka Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250917000954.859376-7-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni

net: modify core data structures for PSP datapath support

2025-09-18T10:32:06+00:00

Add pointers to psp data structures to core networking structs, and an SKB extension to carry the PSP information from the drivers to the socket layer. Reviewed-by: Willem de Bruijn Signed-off-by: Jakub Kicinski Co-developed-by: Daniel Zahka Signed-off-by: Daniel Zahka Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250917000954.859376-4-daniel.zahka@gmail.com Signed-off-by: Paolo Abeni