kernel.git/drivers/connector/connector.c, branch linux-rolling-stable

netlink: introduce typedef for filter function

2023-12-19T14:31:40Z

Make the code using filter function a bit nicer by consolidating the filter function arguments using typedef. Suggested-by: Andy Shevchenko Signed-off-by: Jiri Pirko Signed-off-by: Paolo Abeni

connector/cn_proc: Allow non-root users access

2023-07-23T10:34:22Z

There were a couple of reasons for not allowing non-root users access initially - one is there was some point no proper receive buffer management in place for netlink multicast. But that should be long fixed. See link below for more context. Second is that some of the messages may contain data that is root only. But this should be handled with a finer granularity, which is being done at the protocol layer. The only problematic protocols are nf_queue and the firewall netlink. Hence, this restriction for non-root access was relaxed for NETLINK_ROUTE initially: https://lore.kernel.org/all/20020612013101.A22399@wotan.suse.de/ This restriction has also been removed for following protocols: NETLINK_KOBJECT_UEVENT, NETLINK_AUDIT, NETLINK_SOCK_DIAG, NETLINK_GENERIC, NETLINK_SELINUX. Since process connector messages are not sensitive (process fork, exit notifications etc.), and anyone can read /proc data, we can allow non-root access here. However, since process event notification is not the only consumer of NETLINK_CONNECTOR, we can make this change even more fine grained than the protocol level, by checking for multicast group within the protocol. Allow non-root access for NETLINK_CONNECTOR via NL_CFG_F_NONROOT_RECV but add new bind function cn_bind(), which allows non-root access only for CN_IDX_PROC multicast group. Signed-off-by: Anjali Kulkarni Reviewed-by: Liam R. Howlett Signed-off-by: David S. Miller

connector/cn_proc: Add filtering to fix some bugs

2023-07-23T10:34:22Z

The current proc connector code has the foll. bugs - if there are more than one listeners for the proc connector messages, and one of them deregisters for listening using PROC_CN_MCAST_IGNORE, they will still get all proc connector messages, as long as there is another listener. Another issue is if one client calls PROC_CN_MCAST_LISTEN, and another one calls PROC_CN_MCAST_IGNORE, then both will end up not getting any messages. This patch adds filtering and drops packet if client has sent PROC_CN_MCAST_IGNORE. This data is stored in the client socket's sk_user_data. In addition, we only increment or decrement proc_event_num_listeners once per client. This fixes the above issues. cn_release is the release function added for NETLINK_CONNECTOR. It uses the newly added netlink_release function added to netlink_sock. It will free sk_user_data. Signed-off-by: Anjali Kulkarni Reviewed-by: Liam R. Howlett Signed-off-by: David S. Miller

net/connector: Add const qualifier to cb_id

2020-12-16T19:06:49Z

The connector driver never modifies any cb_id passed to it, so add a const qualifier to those arguments so callers can declare their struct cb_id as a constant object. Fixes build warnings like these when passing a constant struct cb_id: warning: passing argument 1 of ‘cn_add_callback’ discards ‘const’ qualifier from pointer target Signed-off-by: Geoff Levand Link: https://lore.kernel.org/r/a9e49c9e-67fa-16e7-0a6b-72f6bd30c58a@infradead.org Signed-off-by: Jakub Kicinski

connector: simplify the return expression of cn_add_callback()

2020-09-21T20:48:29Z

Simplify the return expression. Signed-off-by: Qinglang Miao Signed-off-by: David S. Miller

connector: remove redundant input callback from cn_dev

2019-07-21T20:31:14Z

A small cleanup: this callback is never used. Originally fixed by Stanislav Kinsburskiy for OpenVZ7 bug OVZ-6877 cc: stanislav.kinsburskiy@gmail.com Signed-off-by: Vasily Averin Signed-off-by: David S. Miller

treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156

2019-05-30T18:26:35Z

Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner Reviewed-by: Allison Randal Reviewed-by: Richard Fontana Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman

connector: fix defined but not used warning

2018-07-08T02:00:50Z

Fix a build warning in connector.c when CONFIG_PROC_FS is not enabled by marking the unused function as __maybe_unused. ../drivers/connector/connector.c:242:12: warning: 'cn_proc_show' defined but not used [-Wunused-function] Signed-off-by: Randy Dunlap Cc: Evgeniy Polyakov Cc: netdev@vger.kernel.org Signed-off-by: David S. Miller

proc: introduce proc_create_single{,_data}

2018-05-16T05:23:35Z

Variants of proc_create{,_data} that directly take a seq_file show callback and drastically reduces the boilerplate code in the callers. All trivial callers converted over. Signed-off-by: Christoph Hellwig

drivers, connector: convert cn_callback_entry.refcnt from atomic_t to refcount_t

2017-10-22T01:22:39Z

atomic_t variables are currently used to implement reference counters with the following properties: - counter is initialized to 1 using atomic_set() - a resource is freed upon counter reaching zero - once counter reaches zero, its further increments aren't allowed - counter schema uses basic atomic operations (set, inc, inc_not_zero, dec_and_test, etc.) Such atomic variables should be converted to a newly provided refcount_t type and API that prevents accidental counter overflows and underflows. This is important since overflows and underflows can lead to use-after-free situation and be exploitable. The variable cn_callback_entry.refcnt is used as pure reference counter. Convert it to refcount_t and fix up the operations. Suggested-by: Kees Cook Reviewed-by: David Windsor Reviewed-by: Hans Liljestrand Signed-off-by: Elena Reshetova Signed-off-by: David S. Miller