kernel/linux.git/drivers/net/ppp, branch linux-7.0.y

pppoe: drop PFC frames

2026-05-23T11:09:20+00:00

[ Upstream commit cc1ff87bce1ccd38410ab10960f576dcd17db679 ] 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 Reviewed-by: Simon Horman Link: https://patch.msgid.link/20260415022456.141758-2-qingfang.deng@linux.dev Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

ppp: require CAP_NET_ADMIN in target netns for unattached ioctls

2026-05-23T11:08:39+00:00

[ Upstream commit 2bb6379416fd19f44c3423a00bfd8626259f6067 ] /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 Link: https://patch.msgid.link/20260409071117.4354-1-hataegu0826@gmail.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

ppp: enable TX scatter-gather

2026-02-05T09:06:27+00:00

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 Link: https://patch.msgid.link/20260129012902.941-1-dqfext@gmail.com Signed-off-by: Paolo Abeni

net: Convert proto_ops connect() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

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 Link: https://patch.msgid.link/20251104002617.2752303-3-kees@kernel.org Signed-off-by: Jakub Kicinski

net: Convert proto_ops bind() callbacks to use sockaddr_unsized

2025-11-05T03:10:32+00:00

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 Link: https://patch.msgid.link/20251104002617.2752303-2-kees@kernel.org Signed-off-by: Jakub Kicinski

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

2025-09-04T20:33:00+00:00

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

2025-09-04T14:25:48+00:00

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

pppoe: drop sock reference counting on fast path

2025-08-29T20:39:54+00:00

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 Reviewed-by: Eric Dumazet Link: https://patch.msgid.link/20250828012018.15922-2-dqfext@gmail.com Signed-off-by: Jakub Kicinski