kernel/drivers/net/ppp/ppp_generic.c, branch linux-6.18.y

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

2025-09-04T20:33:00Z

Cross-merge networking fixes after downstream PR (net-6.17-rc5). No conflicts. Adjacent changes: include/net/sock.h c51613fa276f ("net: add sk->sk_drop_counters") 5d6b58c932ec ("net: lockless sock_i_ino()") Signed-off-by: Jakub Kicinski

ppp: fix memory leak in pad_compress_skb

2025-09-04T14:25:48Z

If alloc_skb() fails in pad_compress_skb(), it returns NULL without releasing the old skb. The caller does: skb = pad_compress_skb(ppp, skb); if (!skb) goto drop; drop: kfree_skb(skb); When pad_compress_skb() returns NULL, the reference to the old skb is lost and kfree_skb(skb) ends up doing nothing, leading to a memory leak. Align pad_compress_skb() semantics with realloc(): only free the old skb if allocation and compression succeed. At the call site, use the new_skb variable so the original skb is not lost when pad_compress_skb() fails. Fixes: b3f9b92a6ec1 ("[PPP]: add PPP MPPE encryption module") Signed-off-by: Qingfang Deng Reviewed-by: Eric Dumazet Reviewed-by: Yue Haibing Link: https://patch.msgid.link/20250903100726.269839-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski

ppp: remove rwlock usage

2025-08-25T23:45:09Z

In struct channel, the upl lock is implemented using rwlock_t, protecting access to pch->ppp and pch->bridge. As previously discussed on the list, using rwlock in the network fast path is not recommended. This patch replaces the rwlock with a spinlock for writers, and uses RCU for readers. - pch->ppp and pch->bridge are now declared as __rcu pointers. - Readers use rcu_dereference_bh() under rcu_read_lock_bh(). - Writers use spin_lock() to update. Signed-off-by: Qingfang Deng Link: https://patch.msgid.link/20250822012548.6232-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski

ppp: fix race conditions in ppp_fill_forward_path

2025-08-19T09:25:32Z

ppp_fill_forward_path() has two race conditions: 1. The ppp->channels list can change between list_empty() and list_first_entry(), as ppp_lock() is not held. If the only channel is deleted in ppp_disconnect_channel(), list_first_entry() may access an empty head or a freed entry, and trigger a panic. 2. pch->chan can be NULL. When ppp_unregister_channel() is called, pch->chan is set to NULL before pch is removed from ppp->channels. Fix these by using a lockless RCU approach: - Use list_first_or_null_rcu() to safely test and access the first list entry. - Convert list modifications on ppp->channels to their RCU variants and add synchronize_net() after removal. - Check for a NULL pch->chan before dereferencing it. Fixes: f6efc675c9dd ("net: ppp: resolve forwarding path for bridge pppoe devices") Signed-off-by: Qingfang Deng Link: https://patch.msgid.link/20250814012559.3705-2-dqfext@gmail.com Signed-off-by: Paolo Abeni

ppp: Replace per-CPU recursion counter with lock-owner field

2025-07-17T13:36:18Z

The per-CPU variable ppp::xmit_recursion is protecting against recursion due to wrong configuration of the ppp unit. The per-CPU variable relies on disabled BH for its locking. Without per-CPU locking in local_bh_disable() on PREEMPT_RT this data structure requires explicit locking. The ppp::xmit_recursion is used as a per-CPU boolean. The counter is checked early in the send routing and the transmit path is only entered if the counter is zero. Then the counter is incremented to avoid recursion. It used to detect recursion on channel::downl and ppp::wlock. Create a struct ppp_xmit_recursion and move the counter into it. Add local_lock_t to the struct and use local_lock_nested_bh() for locking. Due to possible nesting, the lock cannot be acquired unconditionally but it requires an owner field to identify recursion before attempting to acquire the lock. The counter is incremented and checked only after the lock is acquired. Since it functions as a boolean rather than a count, and its role is now superseded by the owner field, it can be safely removed. Signed-off-by: Sebastian Andrzej Siewior Link: https://patch.msgid.link/20250715150806.700536-2-bigeasy@linutronix.de Reviewed-by: Guillaume Nault Signed-off-by: Paolo Abeni

ppp: convert to percpu netstats

2025-06-11T21:11:48Z

Convert to percpu netstats to avoid lock contention when reading them. Signed-off-by: Qingfang Deng Link: https://patch.msgid.link/20250610083211.909015-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski

ppp: Split ppp_exit_net() to ->exit_rtnl().

2025-04-23T02:07:41Z

ppp_exit_net() unregisters devices related to the netns under RTNL and destroys lists and IDR. Let's use ->exit_rtnl() for the device unregistration part to save RTNL dances for each netns. Note that we delegate the for_each_netdev_safe() part to default_device_exit_batch() and replace unregister_netdevice_queue() with ppp_nl_dellink() to align with bond, geneve, gtp, and pfcp. Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250418003259.48017-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski

net: move misc netdev_lock flavors to a separate header

2025-03-08T17:06:50Z

Move the more esoteric helpers for netdev instance lock to a dedicated header. This avoids growing netdevice.h to infinity and makes rebuilding the kernel much faster (after touching the header with the helpers). The main netdev_lock() / netdev_unlock() functions are used in static inlines in netdevice.h and will probably be used most commonly, so keep them in netdevice.h. Acked-by: Stanislav Fomichev Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org Signed-off-by: Jakub Kicinski

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

2025-03-06T21:03:35Z

Cross-merge networking fixes after downstream PR (net-6.14-rc6). Conflicts: net/ethtool/cabletest.c 2bcf4772e45a ("net: ethtool: try to protect all callback with netdev instance lock") 637399bf7e77 ("net: ethtool: netlink: Allow NULL nlattrs when getting a phy_device") No Adjacent changes. Signed-off-by: Jakub Kicinski

ppp: use IFF_NO_QUEUE in virtual interfaces

2025-03-05T01:11:17Z

For PPPoE, PPTP, and PPPoL2TP, the start_xmit() function directly forwards packets to the underlying network stack and never returns anything other than 1. So these interfaces do not require a qdisc, and the IFF_NO_QUEUE flag should be set. Introduces a direct_xmit flag in struct ppp_channel to indicate when IFF_NO_QUEUE should be applied. The flag is set in ppp_connect_channel() for relevant protocols. While at it, remove the usused latency member from struct ppp_channel. Signed-off-by: Qingfang Deng Reviewed-by: Toke Høiland-Jørgensen Link: https://patch.msgid.link/20250301135517.695809-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski