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path: root/drivers/net/ppp
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13 hoursMerge branch 'main' of ↵Mark Brown
https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net-next.git # Conflicts: # MAINTAINERS
5 daysppp: defer channel free to an RCU grace period to fix pppol2tp RX UAFNorbert Szetei
pppol2tp_recv() runs in the L2TP UDP-encap softirq RX path: l2tp_udp_encap_recv() -> l2tp_recv_common() -> pppol2tp_recv() -> ppp_input(&po->chan) It runs under rcu_read_lock() holding only an l2tp_session reference and takes NO reference on the internal PPP channel (struct channel, chan->ppp) that ppp_input() dereferences. The pppox socket is SOCK_RCU_FREE, so 'po' and the embedded ppp_channel are RCU-safe. But the internal struct channel is a separate allocation that ppp_release_channel() frees with a plain kfree(): close(data socket) -> pppol2tp_release() -> pppox_unbind_sock() -> ppp_unregister_channel() -> ppp_release_channel() -> kfree(pch) For a channel that is bound (PPPIOCGCHAN) but not attached to a ppp unit (no PPPIOCCONNECT, pch->ppp == NULL) and not bridged, teardown skips both ppp_disconnect_channel()'s synchronize_net() and ppp_unbridge_channels()'s synchronize_rcu(), so the kfree() has no grace period. rcu_read_lock() in pppol2tp_recv() does not protect against a plain kfree(), so an in-flight ppp_input() on one CPU can dereference the channel just freed by close() on another CPU. The bug is reachable by an unprivileged user. Defer the channel free to an RCU callback via call_rcu() so the grace period fences any in-flight ppp_input(). The disconnect and unbridge teardown paths already fence with synchronize_net()/synchronize_rcu(); call_rcu() does the same here without stalling the close() path. Fixes: ee40fb2e1eb5 ("l2tp: protect sock pointer of struct pppol2tp_session with RCU") Assisted-by: Claude:claude-opus-4-8 Signed-off-by: Norbert Szetei <norbert@doyensec.com> Reviewed-by: Qingfang Deng <qingfang.deng@linux.dev> Link: https://patch.msgid.link/E793FCF2-58DE-4387-A983-C7B4BC3158BD@doyensec.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
7 daysppp/ppp_{async,synctty}: drop unused {a,}syncppp::bytes_{sent,rcvd}Jiri Slaby (SUSE)
The bytes_sent and bytes_rcvd members of structs asyncppp and syncppp are not used. Drop them. Signed-off-by: Jiri Slaby (SUSE) <jirislaby@kernel.org> Cc: Andrew Lunn <andrew+netdev@lunn.ch> Cc: "David S. Miller" <davem@davemloft.net> Cc: Eric Dumazet <edumazet@google.com> Cc: Jakub Kicinski <kuba@kernel.org> Cc: Paolo Abeni <pabeni@redhat.com> Link: https://patch.msgid.link/20260702060420.95023-1-jirislaby@kernel.org Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-06-22Merge tag 'tty-7.2-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty / serial driver updates from Greg KH: "Here is the big set of TTY and Serial driver updates for 7.2-rc1. Overall we end up removing more code than added, due to an obsolete synclink_gt driver being removed from the tree, always a nice thing to see happen. Other than that driver removal, major things included in here are: - max310x serial driver updates and fixes - 8250 driver updates and rework in places to make it more "modern" - dts file updates - serial driver core tweaks and updates - vt code cleanups - vc_screen crash fixes - other minor driver updates and cleanups All of these have been in linux-next for well over a week with no reported issues" * tag 'tty-7.2-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: (49 commits) serial: 8250_pci: Don't specify conflicting values to pci_device_id members vc_screen: fix null-ptr-deref in vcs_notifier() during concurrent vcs_write serial: qcom_geni: Fix RX DMA stall when SE_DMA_RX_LEN_IN is zero vt: merge ucs_is_zero_width()/ucs_is_double_width() into ucs_get_width() serial: 8250: fix possible ISR soft lockup dt-bindings: serial: rs485: remove deprecated .txt binding stub serial: qcom-geni: trace: Add tracepoint support for Qualcomm GENI serial tty: serial: Use named initializers for arrays of i2c_device_data serial: 8250_dw: remove clock-notifier infrastructure serial: 8250_dw: unregister 8250 port if clk_notifier_register() fails amba/serial: amba-pl011: Bring back zx29 UART support serial: 8250: Add support for console flow control serial: 8250: Check LSR timeout on console flow control serial: 8250: Set cons_flow on port registration tty: serial: 8250: protect against NULL uart->port.dev in register arm64: dts: add support for A9 based Amlogic BY401 dt-bindings: arm: amlogic: add A311Y3 support serial: max310x: fix compile errors if CONFIG_SPI_MASTER is disabled serial: qcom-geni: Avoid probing debug console UART without console support serial: max310x: add comments for PLL limits ...
2026-05-19net: pppoe: implement GRO/GSO supportFelix Fietkau
Only handles packets where the pppoe header length field matches the exact packet length. Significantly improves rx throughput. When running NAT traffic through a MediaTek MT7621 devices from a host behind PPPoE to a host directly connected via ethernet, the TCP throughput that the device is able to handle improves from ~130 Mbit/s to ~630 Mbit/s, using fraglist GRO. Signed-off-by: Felix Fietkau <nbd@nbd.name> Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Tested-by: Pablo Neira Ayuso <pablo@netfilter.org> Link: https://patch.msgid.link/20260513013400.7467-1-qingfang.deng@linux.dev Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-05-11tty: synclink_gt: remove broken driverEthan Nelson-Moore
The synclink_gt driver was marked as broken in commit 426263d5fb40 ("tty: synclink_gt: mark as BROKEN") in July 2023 because it had severe structural problems and there had been no evidence of users since 2016. Since then, no meaningful improvements have been made to the driver, and it is unlikely that will ever happen due to the lack of interest. Drop the driver and references to it in comments and documentation. include/uapi/linux/synclink.h is also removed. The only use of this header I have found is the linux-raw-sys Rust crate. It generates bindings for all UAPI headers, but has a hardcoded list of headers and ioctls, including this one, so that does not indicate that anyone is using it. I have sent a pull request to remove the include and ioctl definitions for this header (see the link below). Link: https://github.com/sunfishcode/linux-raw-sys/pull/185 Signed-off-by: Ethan Nelson-Moore <enelsonmoore@gmail.com> Acked-by: Jakub Kicinski <kuba@kernel.org> Link: https://patch.msgid.link/20260504031519.18877-1-enelsonmoore@gmail.com Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2026-05-01pppoe: optimize hash with word accessQingfang Deng
Currently, hash_item() processes the 6-byte Ethernet address and the 2-byte session ID byte-wise to compute a hash. Optimize this by using 16-bit word operations: XOR three 16-bit words from the Ethernet address and the 16-bit session ID, then fold the result. This reduces the total number of loads and XORs. The Ethernet addresses in a skb and struct pppoe_addr are both 2-byte aligned, so the u16 pointer cast is safe. Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Link: https://patch.msgid.link/20260429023848.153425-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-28ppp: add PPPOX symbolQingfang Deng
Add a dedicated CONFIG_PPPOX symbol to handle the PPPoX generic module, avoiding redundant pppox.o definitions in the Makefile. Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Link: https://patch.msgid.link/20260428012830.3069-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-20pppoe: drop PFC framesQingfang Deng
RFC 2516 Section 7 states that Protocol Field Compression (PFC) is NOT RECOMMENDED for PPPoE. In practice, pppd does not support negotiating PFC for PPPoE sessions, and the current PPPoE driver assumes an uncompressed (2-byte) protocol field. However, the generic PPP layer function ppp_input() is not aware of the negotiation result, and still accepts PFC frames. If a peer with a broken implementation or an attacker sends a frame with a compressed (1-byte) protocol field, the subsequent PPP payload is shifted by one byte. This causes the network header to be 4-byte misaligned, which may trigger unaligned access exceptions on some architectures. To reduce the attack surface, drop PPPoE PFC frames. Introduce ppp_skb_is_compressed_proto() helper function to be used in both ppp_generic.c and pppoe.c to avoid open-coding. Fixes: 7fb1b8ca8fa1 ("ppp: Move PFC decompression to PPP generic layer") Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20260415022456.141758-2-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-14Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Merge in late fixes in preparation for the net-next PR. Conflicts: include/net/sch_generic.h a6bd339dbb351 ("net_sched: fix skb memory leak in deferred qdisc drops") ff2998f29f390 ("net: sched: introduce qdisc-specific drop reason tracing") https://lore.kernel.org/adz0iX85FHMz0HdO@sirena.org.uk drivers/net/ethernet/airoha/airoha_eth.c 1acdfbdb516b ("net: airoha: Fix VIP configuration for AN7583 SoC") bf3471e6e6c0 ("net: airoha: Make flow control source port mapping dependent on nbq parameter") Adjacent changes: drivers/net/ethernet/airoha/airoha_ppe.c f44218cd5e6a ("net: airoha: Reset PPE cpu port configuration in airoha_ppe_hw_init()") 7da62262ec96 ("inet: add ip_local_port_step_width sysctl to improve port usage distribution") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-12pppox: remove sk_pppox() helperQingfang Deng
The sk member can be directly accessed from struct pppox_sock without relying on type casting. Remove the sk_pppox() helper and update all call sites to use po->sk directly. Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Link: https://patch.msgid.link/20260410054954.114031-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-12ppp: require CAP_NET_ADMIN in target netns for unattached ioctlsTaegu Ha
/dev/ppp open is currently authorized against file->f_cred->user_ns, while unattached administrative ioctls operate on current->nsproxy->net_ns. As a result, a local unprivileged user can create a new user namespace with CLONE_NEWUSER, gain CAP_NET_ADMIN only in that new user namespace, and still issue PPPIOCNEWUNIT, PPPIOCATTACH, or PPPIOCATTCHAN against an inherited network namespace. Require CAP_NET_ADMIN in the user namespace that owns the target network namespace before handling unattached PPP administrative ioctls. This preserves normal pppd operation in the network namespace it is actually privileged in, while rejecting the userns-only inherited-netns case. Fixes: 273ec51dd7ce ("net: ppp_generic - introduce net-namespace functionality v2") Signed-off-by: Taegu Ha <hataegu0826@gmail.com> Link: https://patch.msgid.link/20260409071117.4354-1-hataegu0826@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-09ppp: consolidate refcount decrementsQingfang Deng
ppp_destroy_{channel,interface} are always called after refcount_dec_and_test(). To reduce boilerplate code, consolidate the decrements by moving them into the two functions. To reflect this change in semantics, rename the functions to ppp_release_*. Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Link: https://patch.msgid.link/20260407094058.257246-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-03ppp: update Kconfig help messageQingfang Deng
Both links of the PPPoE section are no longer valid, and the CVS version is no longer relevant. - Replace the TLDP URL with the pppd project homepage. - Update pppd version requirement for PPPoE. - Update RP-PPPoE project homepage, and clarify that it's only needed for server mode. Signed-off-by: Qingfang Deng <qingfang.deng@linux.dev> Reviewed-by: Julian Braha <julianbraha@gmail.com> Link: https://patch.msgid.link/20260402050053.144250-1-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-04-01ppp: dead code cleanup in KconfigJulian Braha
There is already an 'if PPP' condition wrapping several config options e.g. PPP_MPPE and PPPOE, making the 'depends on PPP' statement for each of these a duplicate dependency (dead code). I propose leaving the outer 'if PPP...endif' and removing the individual 'depends on PPP' statement from each option. This dead code was found by kconfirm, a static analysis tool for Kconfig. Signed-off-by: Julian Braha <julianbraha@gmail.com> Reviewed-by: Qingfang Deng <dqfext@gmail.com> Link: https://patch.msgid.link/20260330213258.13982-1-julianbraha@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-17ppp: require callers of ppp_dev_name() to hold RCUQingfang Deng
ppp_dev_name() holds the RCU read lock internally to protect pch->ppp. However, as it returns netdev->name to the caller, the caller should also hold either RCU or RTNL lock to prevent the netdev from being freed. The only two references of the function is in the L2TP driver, both of which already hold RCU. So remove the internal RCU lock and document that callers must hold RCU. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Reviewed-by: Breno Leitao <leitao@debian.org> Link: https://patch.msgid.link/20260316092824.479149-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-17ppp: remove pch->chan NULL checks from tx pathQingfang Deng
Now that ppp_disconnect_channel() is called before pch->chan is set to NULL, a channel from ppp->channels list on the transmit path is guaranteed to have non-NULL pch->chan. Remove the pch->chan NULL checks from ppp_push(), ppp_mp_explode(), and ppp_fill_forward_path(), where a channel is obtained from the list. Remove the corresponding WRITE/READ_ONCE annotations as they no longer race. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Link: https://patch.msgid.link/20260312093732.277254-2-dqfext@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-17ppp: disconnect channel before nullifying pch->chanQingfang Deng
In ppp_unregister_channel(), pch->chan is set to NULL before calling ppp_disconnect_channel(), which removes the channel from ppp->channels list using list_del_rcu() + synchronize_net(). This creates an intermediate state where the channel is still connected (on the list) but already unregistered (pch->chan == NULL). Call ppp_disconnect_channel() before setting pch->chan to NULL. After the synchronize_net(), no new reader on the transmit path will hold a reference to the channel from the list. This eliminates the problematic state, and prepares for removing the pch->chan NULL checks from the transmit path in a subsequent patch. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Link: https://patch.msgid.link/20260312093732.277254-1-dqfext@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-03-09ppp: simplify input error handlingQingfang Deng
Currently, ppp_input_error() indicates an error by allocating a 0-length skb and calling ppp_do_recv(). It takes an error code argument, which is stored in skb->cb, but not used by ppp_receive_frame(). Simplify the error handling by removing the unused parameter and the unnecessary skb allocation. Instead, call ppp_receive_error() directly from ppp_input_error() under the recv lock, and the length check in ppp_receive_frame() can be removed. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-03-05ppp: don't store tx skb in the fastpathQingfang Deng
Currently, ppp->xmit_pending is used in ppp_send_frame() to pass a skb to ppp_push(), and holds the skb when a PPP channel cannot immediately transmit it. This state is redundant because the transmit queue (ppp->file.xq) can already handle the backlog. Furthermore, during normal operation, an skb is queued in file.xq only to be immediately dequeued, causing unnecessary overhead. Refactor the transmit path to avoid stashing the skb when possible: - Remove ppp->xmit_pending. - Rename ppp_send_frame() to ppp_prepare_tx_skb(), and don't call ppp_push() in it. It returns 1 if the skb is consumed (dropped/handled) or 0 if it can be passed to ppp_push(). - Update ppp_push() to accept the skb. It returns 1 if the skb is consumed, or 0 if the channel is busy. - Optimize __ppp_xmit_process(): - Fastpath: If the queue is empty, attempt to send the skb directly via ppp_push(). If busy, queue it. - Slowpath: If the queue is not empty, process the backlog in file.xq. Split dequeuing loop into a separate function ppp_xmit_flush() so ppp_channel_push() uses that directly instead of passing a NULL skb to __ppp_xmit_process(). This simplifies the states and reduces locking in the fastpath. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Link: https://patch.msgid.link/20260303093219.234403-1-dqfext@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-26Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-7.0-rc2). Conflicts: tools/testing/selftests/drivers/net/hw/rss_ctx.py 19c3a2a81d2b ("selftests: drv-net: rss: Generate unique ports for RSS context tests") ce5a0f4612db ("selftests: drv-net: rss_ctx: test RSS contexts persist after ifdown/up") include/net/inet_connection_sock.h 858d2a4f67ff6 ("tcp: fix potential race in tcp_v6_syn_recv_sock()") fcd3d039fab69 ("tcp: make tcp_v{4,6}_send_check() static") https://lore.kernel.org/aZ8PSFLzBrEU3I89@sirena.org.uk drivers/net/ethernet/mellanox/mlx5/core/en/xsk/setup.c drivers/net/ethernet/mellanox/mlx5/core/en/xsk/pool.c 69050f8d6d075 ("treewide: Replace kmalloc with kmalloc_obj for non-scalar types") bf4afc53b77ae ("Convert 'alloc_obj' family to use the new default GFP_KERNEL argument") 8a96b9144f18a ("net/mlx5e: Alloc xsk channel param out of mlx5e_open_xsk()") Adjacent changes: net/netfilter/ipvs/ip_vs_ctl.c c59bd9e62e06 ("ipvs: use more counters to avoid service lookups") bf4afc53b77a ("Convert 'alloc_obj' family to use the new default GFP_KERNEL argument") Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-26pppoe: remove kernel-mode relay supportQingfang Deng
The kernel-mode PPPoE relay feature and its two associated ioctls (PPPOEIOCSFWD and PPPOEIOCDFWD) are not used by any existing userspace PPPoE implementations. The most commonly-used package, RP-PPPoE [1], handles the relaying entirely in userspace. This legacy code has remained in the driver since its introduction in kernel 2.3.99-pre7 for over two decades, but has served no practical purpose. Remove the unused relay code. [1] https://dianne.skoll.ca/projects/rp-pppoe/ Signed-off-by: Qingfang Deng <dqfext@gmail.com> Acked-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/20260224015053.42472-1-dqfext@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2026-02-25net: pppoe: avoid zero-length arrays in struct pppoe_hdrEric Woudstra
Jakub Kicinski reported following issue in upcoming patches: W=1 C=1 GCC build gives us: net/bridge/netfilter/nf_conntrack_bridge.c: note: in included file (through ../include/linux/if_pppox.h, ../include/uapi/linux/netfilter_bridge.h, ../include/linux/netfilter_bridge.h): include/uapi/linux/if_pppox.h: 153:29: warning: array of flexible structures sparse doesn't like that hdr has a zero-length array which overlaps proto. The kernel code doesn't currently need those arrays. PPPoE connection is functional after applying this patch. Reviewed-by: Nikolay Aleksandrov <razor@blackwall.org> Reviewed-by: Kees Cook <kees@kernel.org> Signed-off-by: Eric Woudstra <ericwouds@gmail.com> Link: https://patch.msgid.link/20260224155030.106918-1-ericwouds@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2026-02-21Convert 'alloc_obj' family to use the new default GFP_KERNEL argumentLinus Torvalds
This was done entirely with mindless brute force, using git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' | xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/' to convert the new alloc_obj() users that had a simple GFP_KERNEL argument to just drop that argument. Note that due to the extreme simplicity of the scripting, any slightly more complex cases spread over multiple lines would not be triggered: they definitely exist, but this covers the vast bulk of the cases, and the resulting diff is also then easier to check automatically. For the same reason the 'flex' versions will be done as a separate conversion. Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21treewide: Replace kmalloc with kmalloc_obj for non-scalar typesKees Cook
This is the result of running the Coccinelle script from scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to avoid scalar types (which need careful case-by-case checking), and instead replace kmalloc-family calls that allocate struct or union object instances: Single allocations: kmalloc(sizeof(TYPE), ...) are replaced with: kmalloc_obj(TYPE, ...) Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...) are replaced with: kmalloc_objs(TYPE, COUNT, ...) Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...) are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...) (where TYPE may also be *VAR) The resulting allocations no longer return "void *", instead returning "TYPE *". Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-05ppp: enable TX scatter-gatherQingfang Deng
PPP channels using chan->direct_xmit prepend the PPP header to a skb and call dev_queue_xmit() directly. In this mode the skb does not need to be linear, but the PPP netdevice currently does not advertise scatter-gather features, causing unnecessary linearization and preventing GSO. Enable NETIF_F_SG and NETIF_F_FRAGLIST on PPP devices. In case a linear buffer is required (PPP compression, multilink, and channels without direct_xmit), call skb_linearize() explicitly. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Link: https://patch.msgid.link/20260129012902.941-1-dqfext@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-11-04net: Convert proto_ops connect() callbacks to use sockaddr_unsizedKees Cook
Update all struct proto_ops connect() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-11-04net: Convert proto_ops bind() callbacks to use sockaddr_unsizedKees Cook
Update all struct proto_ops bind() callback function prototypes from "struct sockaddr *" to "struct sockaddr_unsized *" to avoid lying to the compiler about object sizes. Calls into struct proto handlers gain casts that will be removed in the struct proto conversion patch. No binary changes expected. Signed-off-by: Kees Cook <kees@kernel.org> Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
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 <kuba@kernel.org>
2025-09-04ppp: fix memory leak in pad_compress_skbQingfang Deng
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 <dqfext@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Yue Haibing <yuehaibing@huawei.com> Link: https://patch.msgid.link/20250903100726.269839-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29pppoe: drop sock reference counting on fast pathQingfang Deng
Now that PPPoE sockets are freed via RCU (SOCK_RCU_FREE), it is no longer necessary to take a reference count when looking up sockets on the receive path. Readers are protected by RCU, so the socket memory remains valid until after a grace period. Convert fast-path lookups to avoid refcounting: - Replace get_item() and sk_receive_skb() in pppoe_rcv() with __get_item() and __sk_receive_skb(). - Rework get_item_by_addr() into __get_item_by_addr() (no refcount and move RCU lock into pppoe_ioctl) - Remove unnecessary sock_put() calls. This avoids cacheline bouncing from atomic reference counting and improves performance on the receive fast path. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250828012018.15922-2-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-29pppoe: remove rwlock usageQingfang Deng
Like ppp_generic.c, convert the PPPoE socket hash table to use RCU for lookups and a spinlock for updates. This removes rwlock usage and allows lockless readers on the fast path. - Mark hash table and list pointers as __rcu. - Use spin_lock() to protect writers. - Readers use rcu_dereference() under rcu_read_lock(). All known callers of get_item() already hold the RCU read lock, so no additional locking is needed. - get_item() now uses refcount_inc_not_zero() instead of sock_hold() to safely take a reference. This prevents crashes if a socket is already in the process of being freed (sk_refcnt == 0). - Set SOCK_RCU_FREE to defer socket freeing until after an RCU grace period. - Move skb_queue_purge() into sk_destruct callback to ensure purge happens after an RCU grace period. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Reviewed-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250828012018.15922-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-25ppp: remove rwlock usageQingfang Deng
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 <dqfext@gmail.com> Link: https://patch.msgid.link/20250822012548.6232-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-21Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Cross-merge networking fixes after downstream PR (net-6.17-rc3). No conflicts or adjacent changes. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-19ppp: fix race conditions in ppp_fill_forward_pathQingfang Deng
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 <dqfext@gmail.com> Link: https://patch.msgid.link/20250814012559.3705-2-dqfext@gmail.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-08-18ppp: use vmalloc_array() to simplify codeQianfeng Rong
Remove array_size() calls and replace vmalloc() with vmalloc_array() in bsd_alloc(). vmalloc_array() is also optimized better, resulting in less instructions being used. Signed-off-by: Qianfeng Rong <rongqianfeng@vivo.com> Link: https://patch.msgid.link/20250816090659.117699-4-rongqianfeng@vivo.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-18ppp: mppe: Use SHA-1 library instead of crypto_shashEric Biggers
Now that a SHA-1 library API is available, use it instead of crypto_shash. This is simpler and faster. Signed-off-by: Eric Biggers <ebiggers@kernel.org> Link: https://patch.msgid.link/20250815020705.23055-1-ebiggers@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-08-07pptp: fix pptp_xmit() error pathEric Dumazet
I accidentally added a bug in pptp_xmit() that syzbot caught for us. Only call ip_rt_put() if a route has been allocated. BUG: unable to handle page fault for address: ffffffffffffffdb PGD df3b067 P4D df3b067 PUD df3d067 PMD 0 Oops: Oops: 0002 [#1] SMP KASAN PTI CPU: 1 UID: 0 PID: 6346 Comm: syz.0.336 Not tainted 6.16.0-next-20250804-syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/12/2025 RIP: 0010:arch_atomic_add_return arch/x86/include/asm/atomic.h:85 [inline] RIP: 0010:raw_atomic_sub_return_release include/linux/atomic/atomic-arch-fallback.h:846 [inline] RIP: 0010:atomic_sub_return_release include/linux/atomic/atomic-instrumented.h:327 [inline] RIP: 0010:__rcuref_put include/linux/rcuref.h:109 [inline] RIP: 0010:rcuref_put+0x172/0x210 include/linux/rcuref.h:173 Call Trace: <TASK> dst_release+0x24/0x1b0 net/core/dst.c:167 ip_rt_put include/net/route.h:285 [inline] pptp_xmit+0x14b/0x1a90 drivers/net/ppp/pptp.c:267 __ppp_channel_push+0xf2/0x1c0 drivers/net/ppp/ppp_generic.c:2166 ppp_channel_push+0x123/0x660 drivers/net/ppp/ppp_generic.c:2198 ppp_write+0x2b0/0x400 drivers/net/ppp/ppp_generic.c:544 vfs_write+0x27b/0xb30 fs/read_write.c:684 ksys_write+0x145/0x250 fs/read_write.c:738 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f Fixes: de9c4861fb42 ("pptp: ensure minimal skb length in pptp_xmit()") Reported-by: syzbot+27d7cfbc93457e472e00@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/689095a5.050a0220.1fc43d.0009.GAE@google.com/ Signed-off-by: Eric Dumazet <edumazet@google.com> Link: https://patch.msgid.link/20250807142146.2877060-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-30pptp: ensure minimal skb length in pptp_xmit()Eric Dumazet
Commit aabc6596ffb3 ("net: ppp: Add bound checking for skb data on ppp_sync_txmung") fixed ppp_sync_txmunge() We need a similar fix in pptp_xmit(), otherwise we might read uninit data as reported by syzbot. BUG: KMSAN: uninit-value in pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193 pptp_xmit+0xc34/0x2720 drivers/net/ppp/pptp.c:193 ppp_channel_bridge_input drivers/net/ppp/ppp_generic.c:2290 [inline] ppp_input+0x1d6/0xe60 drivers/net/ppp/ppp_generic.c:2314 pppoe_rcv_core+0x1e8/0x760 drivers/net/ppp/pppoe.c:379 sk_backlog_rcv+0x142/0x420 include/net/sock.h:1148 __release_sock+0x1d3/0x330 net/core/sock.c:3213 release_sock+0x6b/0x270 net/core/sock.c:3767 pppoe_sendmsg+0x15d/0xcb0 drivers/net/ppp/pppoe.c:904 sock_sendmsg_nosec net/socket.c:712 [inline] __sock_sendmsg+0x330/0x3d0 net/socket.c:727 ____sys_sendmsg+0x893/0xd80 net/socket.c:2566 ___sys_sendmsg+0x271/0x3b0 net/socket.c:2620 __sys_sendmmsg+0x2d9/0x7c0 net/socket.c:2709 Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+afad90ffc8645324afe5@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/68887d86.a00a0220.b12ec.00cd.GAE@google.com/T/#u Signed-off-by: Eric Dumazet <edumazet@google.com> Reviewed-by: Dawid Osuchowski <dawid.osuchowski@linux.intel.com> Link: https://patch.msgid.link/20250729080207.1863408-1-edumazet@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-07-17ppp: Replace per-CPU recursion counter with lock-owner fieldSebastian Andrzej Siewior
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 <bigeasy@linutronix.de> Link: https://patch.msgid.link/20250715150806.700536-2-bigeasy@linutronix.de Reviewed-by: Guillaume Nault <gnault@redhat.com> Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-06-24pppoe: drop PACKET_OTHERHOST before skb_share_check()Qingfang Deng
Align with ip_rcv() by dropping PACKET_OTHERHOST packets before calling skb_share_check(). This avoids unnecessary skb processing for packets that will be discarded anyway. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Acked-by: Guillaume Nault <gnault@redhat.com> Link: https://patch.msgid.link/20250623033431.408810-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-06-11ppp: convert to percpu netstatsQingfang Deng
Convert to percpu netstats to avoid lock contention when reading them. Signed-off-by: Qingfang Deng <dqfext@gmail.com> Link: https://patch.msgid.link/20250610083211.909015-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-22ppp: Split ppp_exit_net() to ->exit_rtnl().Kuniyuki Iwashima
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 <kuniyu@amazon.com> Link: https://patch.msgid.link/20250418003259.48017-4-kuniyu@amazon.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-04-10net: ppp: Add bound checking for skb data on ppp_sync_txmungArnaud Lecomte
Ensure we have enough data in linear buffer from skb before accessing initial bytes. This prevents potential out-of-bounds accesses when processing short packets. When ppp_sync_txmung receives an incoming package with an empty payload: (remote) gef➤ p *(struct pppoe_hdr *) (skb->head + skb->network_header) $18 = { type = 0x1, ver = 0x1, code = 0x0, sid = 0x2, length = 0x0, tag = 0xffff8880371cdb96 } from the skb struct (trimmed) tail = 0x16, end = 0x140, head = 0xffff88803346f400 "4", data = 0xffff88803346f416 ":\377", truesize = 0x380, len = 0x0, data_len = 0x0, mac_len = 0xe, hdr_len = 0x0, it is not safe to access data[2]. Reported-by: syzbot+29fc8991b0ecb186cf40@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=29fc8991b0ecb186cf40 Tested-by: syzbot+29fc8991b0ecb186cf40@syzkaller.appspotmail.com Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Arnaud Lecomte <contact@arnaud-lcm.com> Link: https://patch.msgid.link/20250408-bound-checking-ppp_txmung-v2-1-94bb6e1b92d0@arnaud-lcm.com [pabeni@redhat.com: fixed subj typo] Signed-off-by: Paolo Abeni <pabeni@redhat.com>
2025-03-08net: move misc netdev_lock flavors to a separate headerJakub Kicinski
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 <sdf@fomichev.me> Link: https://patch.msgid.link/20250307183006.2312761-1-kuba@kernel.org Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-06Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
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 <kuba@kernel.org>
2025-03-04ppp: use IFF_NO_QUEUE in virtual interfacesQingfang Deng
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 <dqfext@gmail.com> Reviewed-by: Toke Høiland-Jørgensen <toke@redhat.com> Link: https://patch.msgid.link/20250301135517.695809-1-dqfext@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-03-04ppp: Fix KMSAN uninit-value warning with bpfJiayuan Chen
Syzbot caught an "KMSAN: uninit-value" warning [1], which is caused by the ppp driver not initializing a 2-byte header when using socket filter. The following code can generate a PPP filter BPF program: ''' struct bpf_program fp; pcap_t *handle; handle = pcap_open_dead(DLT_PPP_PPPD, 65535); pcap_compile(handle, &fp, "ip and outbound", 0, 0); bpf_dump(&fp, 1); ''' Its output is: ''' (000) ldh [2] (001) jeq #0x21 jt 2 jf 5 (002) ldb [0] (003) jeq #0x1 jt 4 jf 5 (004) ret #65535 (005) ret #0 ''' Wen can find similar code at the following link: https://github.com/ppp-project/ppp/blob/master/pppd/options.c#L1680 The maintainer of this code repository is also the original maintainer of the ppp driver. As you can see the BPF program skips 2 bytes of data and then reads the 'Protocol' field to determine if it's an IP packet. Then it read the first byte of the first 2 bytes to determine the direction. The issue is that only the first byte indicating direction is initialized in current ppp driver code while the second byte is not initialized. For normal BPF programs generated by libpcap, uninitialized data won't be used, so it's not a problem. However, for carefully crafted BPF programs, such as those generated by syzkaller [2], which start reading from offset 0, the uninitialized data will be used and caught by KMSAN. [1] https://syzkaller.appspot.com/bug?extid=853242d9c9917165d791 [2] https://syzkaller.appspot.com/text?tag=ReproC&x=11994913980000 Cc: Paul Mackerras <paulus@samba.org> Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Reported-by: syzbot+853242d9c9917165d791@syzkaller.appspotmail.com Closes: https://lore.kernel.org/bpf/000000000000dea025060d6bc3bc@google.com/ Signed-off-by: Jiayuan Chen <jiayuan.chen@linux.dev> Reviewed-by: Simon Horman <horms@kernel.org> Link: https://patch.msgid.link/20250228141408.393864-1-jiayuan.chen@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-21net: Use link/peer netns in newlink() of rtnl_link_opsXiao Liang
Add two helper functions - rtnl_newlink_link_net() and rtnl_newlink_peer_net() for netns fallback logic. Peer netns falls back to link netns, and link netns falls back to source netns. Convert the use of params->net in netdevice drivers to one of the helper functions for clarity. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-4-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2025-02-21rtnetlink: Pack newlink() params into structXiao Liang
There are 4 net namespaces involved when creating links: - source netns - where the netlink socket resides, - target netns - where to put the device being created, - link netns - netns associated with the device (backend), - peer netns - netns of peer device. Currently, two nets are passed to newlink() callback - "src_net" parameter and "dev_net" (implicitly in net_device). They are set as follows, depending on netlink attributes in the request. +------------+-------------------+---------+---------+ | peer netns | IFLA_LINK_NETNSID | src_net | dev_net | +------------+-------------------+---------+---------+ | | absent | source | target | | absent +-------------------+---------+---------+ | | present | link | link | +------------+-------------------+---------+---------+ | | absent | peer | target | | present +-------------------+---------+---------+ | | present | peer | link | +------------+-------------------+---------+---------+ When IFLA_LINK_NETNSID is present, the device is created in link netns first and then moved to target netns. This has some side effects, including extra ifindex allocation, ifname validation and link events. These could be avoided if we create it in target netns from the beginning. On the other hand, the meaning of src_net parameter is ambiguous. It varies depending on how parameters are passed. It is the effective link (or peer netns) by design, but some drivers ignore it and use dev_net instead. To provide more netns context for drivers, this patch packs existing newlink() parameters, along with the source netns, link netns and peer netns, into a struct. The old "src_net" is renamed to "net" to avoid confusion with real source netns, and will be deprecated later. The use of src_net are converted to params->net trivially. Signed-off-by: Xiao Liang <shaw.leon@gmail.com> Reviewed-by: Kuniyuki Iwashima <kuniyu@amazon.com> Link: https://patch.msgid.link/20250219125039.18024-3-shaw.leon@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
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