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2022-03-18af_netlink: Fix shift out of bounds in group mask calculationPetr Machata
When a netlink message is received, netlink_recvmsg() fills in the address of the sender. One of the fields is the 32-bit bitfield nl_groups, which carries the multicast group on which the message was received. The least significant bit corresponds to group 1, and therefore the highest group that the field can represent is 32. Above that, the UB sanitizer flags the out-of-bounds shift attempts. Which bits end up being set in such case is implementation defined, but it's either going to be a wrong non-zero value, or zero, which is at least not misleading. Make the latter choice deterministic by always setting to 0 for higher-numbered multicast groups. To get information about membership in groups >= 32, userspace is expected to use nl_pktinfo control messages[0], which are enabled by NETLINK_PKTINFO socket option. [0] https://lwn.net/Articles/147608/ The way to trigger this issue is e.g. through monitoring the BRVLAN group: # bridge monitor vlan & # ip link add name br type bridge Which produces the following citation: UBSAN: shift-out-of-bounds in net/netlink/af_netlink.c:162:19 shift exponent 32 is too large for 32-bit type 'int' Fixes: f7fa9b10edbb ("[NETLINK]: Support dynamic number of multicast groups per netlink family") Signed-off-by: Petr Machata <petrm@nvidia.com> Reviewed-by: Ido Schimmel <idosch@nvidia.com> Link: https://lore.kernel.org/r/2bef6aabf201d1fc16cca139a744700cff9dcb04.1647527635.git.petrm@nvidia.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-12-29net: Don't include filter.h from net/sock.hJakub Kicinski
sock.h is pretty heavily used (5k objects rebuilt on x86 after it's touched). We can drop the include of filter.h from it and add a forward declaration of struct sk_filter instead. This decreases the number of rebuilt objects when bpf.h is touched from ~5k to ~1k. There's a lot of missing includes this was masking. Primarily in networking tho, this time. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Marc Kleine-Budde <mkl@pengutronix.de> Acked-by: Florian Fainelli <f.fainelli@gmail.com> Acked-by: Nikolay Aleksandrov <nikolay@nvidia.com> Acked-by: Stefano Garzarella <sgarzare@redhat.com> Link: https://lore.kernel.org/bpf/20211229004913.513372-1-kuba@kernel.org
2021-12-02Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-30net: netlink: af_netlink: Prevent empty skb by adding a check on len.Harshit Mogalapalli
Adding a check on len parameter to avoid empty skb. This prevents a division error in netem_enqueue function which is caused when skb->len=0 and skb->data_len=0 in the randomized corruption step as shown below. skb->data[prandom_u32() % skb_headlen(skb)] ^= 1<<(prandom_u32() % 8); Crash Report: [ 343.170349] netdevsim netdevsim0 netdevsim3: set [1, 0] type 2 family 0 port 6081 - 0 [ 343.216110] netem: version 1.3 [ 343.235841] divide error: 0000 [#1] PREEMPT SMP KASAN NOPTI [ 343.236680] CPU: 3 PID: 4288 Comm: reproducer Not tainted 5.16.0-rc1+ [ 343.237569] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.0-2.el7 04/01/2014 [ 343.238707] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] [ 343.239499] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f 74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 [ 343.241883] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 [ 343.242589] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: 0000000000000000 [ 343.243542] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: ffff88800f8eda40 [ 343.244474] RBP: ffff88800bcd7458 R08: 0000000000000000 R09: ffffffff94fb8445 [ 343.245403] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: 0000000000000000 [ 343.246355] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15: 0000000000000020 [ 343.247291] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) knlGS:0000000000000000 [ 343.248350] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 343.249120] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: 00000000000006e0 [ 343.250076] Call Trace: [ 343.250423] <TASK> [ 343.250713] ? memcpy+0x4d/0x60 [ 343.251162] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.251795] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.252443] netem_enqueue+0xe28/0x33c0 [sch_netem] [ 343.253102] ? stack_trace_save+0x87/0xb0 [ 343.253655] ? filter_irq_stacks+0xb0/0xb0 [ 343.254220] ? netem_init+0xa0/0xa0 [sch_netem] [ 343.254837] ? __kasan_check_write+0x14/0x20 [ 343.255418] ? _raw_spin_lock+0x88/0xd6 [ 343.255953] dev_qdisc_enqueue+0x50/0x180 [ 343.256508] __dev_queue_xmit+0x1a7e/0x3090 [ 343.257083] ? netdev_core_pick_tx+0x300/0x300 [ 343.257690] ? check_kcov_mode+0x10/0x40 [ 343.258219] ? _raw_spin_unlock_irqrestore+0x29/0x40 [ 343.258899] ? __kasan_init_slab_obj+0x24/0x30 [ 343.259529] ? setup_object.isra.71+0x23/0x90 [ 343.260121] ? new_slab+0x26e/0x4b0 [ 343.260609] ? kasan_poison+0x3a/0x50 [ 343.261118] ? kasan_unpoison+0x28/0x50 [ 343.261637] ? __kasan_slab_alloc+0x71/0x90 [ 343.262214] ? memcpy+0x4d/0x60 [ 343.262674] ? write_comp_data+0x2f/0x90 [ 343.263209] ? __kasan_check_write+0x14/0x20 [ 343.263802] ? __skb_clone+0x5d6/0x840 [ 343.264329] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.264958] dev_queue_xmit+0x1c/0x20 [ 343.265470] netlink_deliver_tap+0x652/0x9c0 [ 343.266067] netlink_unicast+0x5a0/0x7f0 [ 343.266608] ? netlink_attachskb+0x860/0x860 [ 343.267183] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.267820] ? write_comp_data+0x2f/0x90 [ 343.268367] netlink_sendmsg+0x922/0xe80 [ 343.268899] ? netlink_unicast+0x7f0/0x7f0 [ 343.269472] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.270099] ? write_comp_data+0x2f/0x90 [ 343.270644] ? netlink_unicast+0x7f0/0x7f0 [ 343.271210] sock_sendmsg+0x155/0x190 [ 343.271721] ____sys_sendmsg+0x75f/0x8f0 [ 343.272262] ? kernel_sendmsg+0x60/0x60 [ 343.272788] ? write_comp_data+0x2f/0x90 [ 343.273332] ? write_comp_data+0x2f/0x90 [ 343.273869] ___sys_sendmsg+0x10f/0x190 [ 343.274405] ? sendmsg_copy_msghdr+0x80/0x80 [ 343.274984] ? slab_post_alloc_hook+0x70/0x230 [ 343.275597] ? futex_wait_setup+0x240/0x240 [ 343.276175] ? security_file_alloc+0x3e/0x170 [ 343.276779] ? write_comp_data+0x2f/0x90 [ 343.277313] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.277969] ? write_comp_data+0x2f/0x90 [ 343.278515] ? __fget_files+0x1ad/0x260 [ 343.279048] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.279685] ? write_comp_data+0x2f/0x90 [ 343.280234] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.280874] ? sockfd_lookup_light+0xd1/0x190 [ 343.281481] __sys_sendmsg+0x118/0x200 [ 343.281998] ? __sys_sendmsg_sock+0x40/0x40 [ 343.282578] ? alloc_fd+0x229/0x5e0 [ 343.283070] ? write_comp_data+0x2f/0x90 [ 343.283610] ? write_comp_data+0x2f/0x90 [ 343.284135] ? __sanitizer_cov_trace_pc+0x21/0x60 [ 343.284776] ? ktime_get_coarse_real_ts64+0xb8/0xf0 [ 343.285450] __x64_sys_sendmsg+0x7d/0xc0 [ 343.285981] ? syscall_enter_from_user_mode+0x4d/0x70 [ 343.286664] do_syscall_64+0x3a/0x80 [ 343.287158] entry_SYSCALL_64_after_hwframe+0x44/0xae [ 343.287850] RIP: 0033:0x7fdde24cf289 [ 343.288344] Code: 01 00 48 81 c4 80 00 00 00 e9 f1 fe ff ff 0f 1f 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 8b 0d b7 db 2c 00 f7 d8 64 89 01 48 [ 343.290729] RSP: 002b:00007fdde2bd6d98 EFLAGS: 00000246 ORIG_RAX: 000000000000002e [ 343.291730] RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007fdde24cf289 [ 343.292673] RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000004 [ 343.293618] RBP: 00007fdde2bd6e20 R08: 0000000100000001 R09: 0000000000000000 [ 343.294557] R10: 0000000100000001 R11: 0000000000000246 R12: 0000000000000000 [ 343.295493] R13: 0000000000021000 R14: 0000000000000000 R15: 00007fdde2bd7700 [ 343.296432] </TASK> [ 343.296735] Modules linked in: sch_netem ip6_vti ip_vti ip_gre ipip sit ip_tunnel geneve macsec macvtap tap ipvlan macvlan 8021q garp mrp hsr wireguard libchacha20poly1305 chacha_x86_64 poly1305_x86_64 ip6_udp_tunnel udp_tunnel libblake2s blake2s_x86_64 libblake2s_generic curve25519_x86_64 libcurve25519_generic libchacha xfrm_interface xfrm6_tunnel tunnel4 veth netdevsim psample batman_adv nlmon dummy team bonding tls vcan ip6_gre ip6_tunnel tunnel6 gre tun ip6t_rpfilter ipt_REJECT nf_reject_ipv4 ip6t_REJECT nf_reject_ipv6 xt_conntrack ip_set ebtable_nat ebtable_broute ip6table_nat ip6table_mangle ip6table_security ip6table_raw iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 iptable_mangle iptable_security iptable_raw ebtable_filter ebtables rfkill ip6table_filter ip6_tables iptable_filter ppdev bochs drm_vram_helper drm_ttm_helper ttm drm_kms_helper cec parport_pc drm joydev floppy parport sg syscopyarea sysfillrect sysimgblt i2c_piix4 qemu_fw_cfg fb_sys_fops pcspkr [ 343.297459] ip_tables xfs virtio_net net_failover failover sd_mod sr_mod cdrom t10_pi ata_generic pata_acpi ata_piix libata virtio_pci virtio_pci_legacy_dev serio_raw virtio_pci_modern_dev dm_mirror dm_region_hash dm_log dm_mod [ 343.311074] Dumping ftrace buffer: [ 343.311532] (ftrace buffer empty) [ 343.312040] ---[ end trace a2e3db5a6ae05099 ]--- [ 343.312691] RIP: 0010:netem_enqueue+0x1590/0x33c0 [sch_netem] [ 343.313481] Code: 89 85 58 ff ff ff e8 5f 5d e9 d3 48 8b b5 48 ff ff ff 8b 8d 50 ff ff ff 8b 85 58 ff ff ff 48 8b bd 70 ff ff ff 31 d2 2b 4f 74 <f7> f1 48 b8 00 00 00 00 00 fc ff df 49 01 d5 4c 89 e9 48 c1 e9 03 [ 343.315893] RSP: 0018:ffff88800bcd7368 EFLAGS: 00010246 [ 343.316622] RAX: 00000000ba7c0a9c RBX: 0000000000000001 RCX: 0000000000000000 [ 343.317585] RDX: 0000000000000000 RSI: ffff88800f8edb10 RDI: ffff88800f8eda40 [ 343.318549] RBP: ffff88800bcd7458 R08: 0000000000000000 R09: ffffffff94fb8445 [ 343.319503] R10: ffffffff94fb8336 R11: ffffffff94fb8445 R12: 0000000000000000 [ 343.320455] R13: ffff88800a5a7000 R14: ffff88800a5b5800 R15: 0000000000000020 [ 343.321414] FS: 00007fdde2bd7700(0000) GS:ffff888109780000(0000) knlGS:0000000000000000 [ 343.322489] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 343.323283] CR2: 00000000200000c0 CR3: 000000000ef4c000 CR4: 00000000000006e0 [ 343.324264] Kernel panic - not syncing: Fatal exception in interrupt [ 343.333717] Dumping ftrace buffer: [ 343.334175] (ftrace buffer empty) [ 343.334653] Kernel Offset: 0x13600000 from 0xffffffff81000000 (relocation range: 0xffffffff80000000-0xffffffffbfffffff) [ 343.336027] Rebooting in 86400 seconds.. Reported-by: syzkaller <syzkaller@googlegroups.com> Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com> Link: https://lore.kernel.org/r/20211129175328.55339-1-harshit.m.mogalapalli@oracle.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-11-16net: drop nopreempt requirement on sock_prot_inuse_add()Eric Dumazet
This is distracting really, let's make this simpler, because many callers had to take care of this by themselves, even if on x86 this adds more code than really needed. Signed-off-by: Eric Dumazet <edumazet@google.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-07Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
No conflicts. Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-10-05netlink: annotate data races around nlk->boundEric Dumazet
While existing code is correct, KCSAN is reporting a data-race in netlink_insert / netlink_sendmsg [1] It is correct to read nlk->bound without a lock, as netlink_autobind() will acquire all needed locks. [1] BUG: KCSAN: data-race in netlink_insert / netlink_sendmsg write to 0xffff8881031c8b30 of 1 bytes by task 18752 on cpu 0: netlink_insert+0x5cc/0x7f0 net/netlink/af_netlink.c:597 netlink_autobind+0xa9/0x150 net/netlink/af_netlink.c:842 netlink_sendmsg+0x479/0x7c0 net/netlink/af_netlink.c:1892 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] ____sys_sendmsg+0x360/0x4d0 net/socket.c:2392 ___sys_sendmsg net/socket.c:2446 [inline] __sys_sendmsg+0x1ed/0x270 net/socket.c:2475 __do_sys_sendmsg net/socket.c:2484 [inline] __se_sys_sendmsg net/socket.c:2482 [inline] __x64_sys_sendmsg+0x42/0x50 net/socket.c:2482 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae read to 0xffff8881031c8b30 of 1 bytes by task 18751 on cpu 1: netlink_sendmsg+0x270/0x7c0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:703 [inline] sock_sendmsg net/socket.c:723 [inline] __sys_sendto+0x2a8/0x370 net/socket.c:2019 __do_sys_sendto net/socket.c:2031 [inline] __se_sys_sendto net/socket.c:2027 [inline] __x64_sys_sendto+0x74/0x90 net/socket.c:2027 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3d/0x90 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x44/0xae value changed: 0x00 -> 0x01 Reported by Kernel Concurrency Sanitizer on: CPU: 1 PID: 18751 Comm: syz-executor.0 Not tainted 5.14.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: da314c9923fe ("netlink: Replace rhash_portid with bound") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-10-05netlink: remove netlink_broadcast_filteredFlorian Westphal
No users in tree since commit a3498436b3a0 ("netns: restrict uevents"), so remove this functionality. Cc: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-30net: netlink: Remove unused functionYajun Deng
lockdep_genl_is_held() and its caller arm not used now, just remove them. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Link: https://lore.kernel.org/r/20210729074854.8968-1-yajun.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-27net: netlink: add the case when nlh is NULLYajun Deng
Add the case when nlh is NULL in nlmsg_report(), so that the caller doesn't need to deal with this case. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-07-20netlink: Deal with ESRCH error in nlmsg_notify()Yajun Deng
Yonghong Song report: The bpf selftest tc_bpf failed with latest bpf-next. The following is the command to run and the result: $ ./test_progs -n 132 [ 40.947571] bpf_testmod: loading out-of-tree module taints kernel. test_tc_bpf:PASS:test_tc_bpf__open_and_load 0 nsec test_tc_bpf:PASS:bpf_tc_hook_create(BPF_TC_INGRESS) 0 nsec test_tc_bpf:PASS:bpf_tc_hook_create invalid hook.attach_point 0 nsec test_tc_bpf_basic:PASS:bpf_obj_get_info_by_fd 0 nsec test_tc_bpf_basic:PASS:bpf_tc_attach 0 nsec test_tc_bpf_basic:PASS:handle set 0 nsec test_tc_bpf_basic:PASS:priority set 0 nsec test_tc_bpf_basic:PASS:prog_id set 0 nsec test_tc_bpf_basic:PASS:bpf_tc_attach replace mode 0 nsec test_tc_bpf_basic:PASS:bpf_tc_query 0 nsec test_tc_bpf_basic:PASS:handle set 0 nsec test_tc_bpf_basic:PASS:priority set 0 nsec test_tc_bpf_basic:PASS:prog_id set 0 nsec libbpf: Kernel error message: Failed to send filter delete notification test_tc_bpf_basic:FAIL:bpf_tc_detach unexpected error: -3 (errno 3) test_tc_bpf:FAIL:test_tc_internal ingress unexpected error: -3 (errno 3) The failure seems due to the commit cfdf0d9ae75b ("rtnetlink: use nlmsg_notify() in rtnetlink_send()") Deal with ESRCH error in nlmsg_notify() even the report variable is zero. Reported-by: Yonghong Song <yhs@fb.com> Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Link: https://lore.kernel.org/r/20210719051816.11762-1-yajun.deng@linux.dev Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2021-07-13net: Use nlmsg_unicast() instead of netlink_unicast()Yajun Deng
It has 'if (err >0 )' statement in nlmsg_unicast(), so use nlmsg_unicast() instead of netlink_unicast(), this looks more concise. v2: remove the change in netfilter. Signed-off-by: Yajun Deng <yajun.deng@linux.dev> Reviewed-by: David Ahern <dsahern@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-06-29net: sock: introduce sk_error_reportAlexander Aring
This patch introduces a function wrapper to call the sk_error_report callback. That will prepare to add additional handling whenever sk_error_report is called, for example to trace socket errors. Signed-off-by: Alexander Aring <aahringo@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-05-17netlink: disable IRQs for netlink_lock_table()Johannes Berg
Syzbot reports that in mac80211 we have a potential deadlock between our "local->stop_queue_reasons_lock" (spinlock) and netlink's nl_table_lock (rwlock). This is because there's at least one situation in which we might try to send a netlink message with this spinlock held while it is also possible to take the spinlock from a hardirq context, resulting in the following deadlock scenario reported by lockdep: CPU0 CPU1 ---- ---- lock(nl_table_lock); local_irq_disable(); lock(&local->queue_stop_reason_lock); lock(nl_table_lock); <Interrupt> lock(&local->queue_stop_reason_lock); This seems valid, we can take the queue_stop_reason_lock in any kind of context ("CPU0"), and call ieee80211_report_ack_skb() with the spinlock held and IRQs disabled ("CPU1") in some code path (ieee80211_do_stop() via ieee80211_free_txskb()). Short of disallowing netlink use in scenarios like these (which would be rather complex in mac80211's case due to the deep callchain), it seems the only fix for this is to disable IRQs while nl_table_lock is held to avoid hitting this scenario, this disallows the "CPU0" portion of the reported deadlock. Note that the writer side (netlink_table_grab()) already disables IRQs for this lock. Unfortunately though, this seems like a huge hammer, and maybe the whole netlink table locking should be reworked. Reported-by: syzbot+69ff9dff50dcfe14ddd4@syzkaller.appspotmail.com Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-04-16netlink: don't call ->netlink_bind with table lock heldFlorian Westphal
When I added support to allow generic netlink multicast groups to be restricted to subscribers with CAP_NET_ADMIN I was unaware that a genl_bind implementation already existed in the past. It was reverted due to ABBA deadlock: 1. ->netlink_bind gets called with the table lock held. 2. genetlink bind callback is invoked, it grabs the genl lock. But when a new genl subsystem is (un)registered, these two locks are taken in reverse order. One solution would be to revert again and add a comment in genl referring 1e82a62fec613, "genetlink: remove genl_bind"). This would need a second change in mptcp to not expose the raw token value anymore, e.g. by hashing the token with a secret key so userspace can still associate subflow events with the correct mptcp connection. However, Paolo Abeni reminded me to double-check why the netlink table is locked in the first place. I can't find one. netlink_bind() is already called without this lock when userspace joins a group via NETLINK_ADD_MEMBERSHIP setsockopt. Same holds for the netlink_unbind operation. Digging through the history, commit f773608026ee1 ("netlink: access nlk groups safely in netlink bind and getname") expanded the lock scope. commit 3a20773beeeeade ("net: netlink: cap max groups which will be considered in netlink_bind()") ... removed the nlk->ngroups access that the lock scope extension was all about. Reduce the lock scope again and always call ->netlink_bind without the table lock. The Fixes tag should be vs. the patch mentioned in the link below, but that one got squash-merged into the patch that came earlier in the series. Fixes: 4d54cc32112d8d ("mptcp: avoid lock_fast usage in accept path") Link: https://lore.kernel.org/mptcp/20210213000001.379332-8-mathew.j.martineau@linux.intel.com/T/#u Cc: Cong Wang <xiyou.wangcong@gmail.com> Cc: Xin Long <lucien.xin@gmail.com> Cc: Johannes Berg <johannes.berg@intel.com> Cc: Sean Tranchetti <stranche@codeaurora.org> Cc: Paolo Abeni <pabeni@redhat.com> Cc: Pablo Neira Ayuso <pablo@netfilter.org> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-12mptcp: avoid lock_fast usage in accept pathFlorian Westphal
Once event support is added this may need to allocate memory while msk lock is held with softirqs disabled. Not using lock_fast also allows to do the allocation with GFP_KERNEL. Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Mat Martineau <mathew.j.martineau@linux.intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2021-02-04netlink: add tracepoint at NL_SET_ERR_MSGMarcelo Ricardo Leitner
Often userspace won't request the extack information, or they don't log it because of log level or so, and even when they do, sometimes it's not enough to know exactly what caused the error. Netlink extack is the standard way of reporting erros with descriptive error messages. With a trace point on it, we then can know exactly where the error happened, regardless of userspace app. Also, we can even see if the err msg was overwritten. The wrapper do_trace_netlink_extack() is because trace points shouldn't be called from .h files, as trace points are not that small, and the function call to do_trace_netlink_extack() on the macros is not protected by tracepoint_enabled() because the macros are called from modules, and this would require exporting some trace structs. As this is error path, it's better to export just the wrapper instead. v2: removed leftover tracepoint declaration Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Reviewed-by: David Ahern <dsahern@kernel.org> Link: https://lore.kernel.org/r/4546b63e67b2989789d146498b13cc09e1fdc543.1612403190.git.marcelo.leitner@gmail.com Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-09netlink: export policy in extended ACKJohannes Berg
Add a new attribute NLMSGERR_ATTR_POLICY to the extended ACK to advertise the policy, e.g. if an attribute was out of range, you'll know the range that's permissible. Add new NL_SET_ERR_MSG_ATTR_POL() and NL_SET_ERR_MSG_ATTR_POL() macros to set this, since realistically it's only useful to do this when the bad attribute (offset) is also returned. Use it in lib/nlattr.c which practically does all the policy validation. v2: - add and use netlink_policy_dump_attr_size_estimate() v3: - remove redundant break v4: - really remove redundant break ... sorry Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-09netlink: policy: refactor per-attr policy writingJohannes Berg
Refactor the per-attribute policy writing into a new helper function, to be used later for dumping out the policy of a rejected attribute. v2: - fix some indentation v3: - change variable order in netlink_policy_dump_write() Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-10-06netlink: add mask validationJakub Kicinski
We don't have good validation policy for existing unsigned int attrs which serve as flags (for new ones we could use NLA_BITFIELD32). With increased use of policy dumping having the validation be expressed as part of the policy is important. Add validation policy in form of a mask of supported/valid bits. Support u64 in the uAPI to be future-proof, but really for now the embedded mask member can only hold 32 bits, so anything with bit 32+ set will always fail validation. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03genetlink: allow dumping command-specific policyJakub Kicinski
Right now CTRL_CMD_GETPOLICY can only dump the family-wide policy. Support dumping policy of a specific op. v3: - rebase after per-op policy export and handle that v2: - make cmd U32, just in case. v1: - don't echo op in the output in a naive way, this should make it cleaner to extend the output format for dumping policies for all the commands at once in the future. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20201001225933.1373426-11-kuba@kernel.org Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03genetlink: properly support per-op policy dumpingJohannes Berg
Add support for per-op policy dumping. The data is pretty much as before, except that now the assumption that the policy with index 0 is "the" policy no longer holds - you now need to look at the new CTRL_ATTR_OP_POLICY attribute which is a nested attr (indexed by op) containing attributes for do and dump policies. When a single op is requested, the CTRL_ATTR_OP_POLICY will be added in the same way, since do and dump policies may differ. v2: - conditionally advertise per-command policies only if there actually is a policy being used for the do/dump and it's present at all Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03genetlink: factor skb preparation out of ctrl_dumppolicy()Johannes Berg
We'll need this later for the per-op policy index dump. Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03netlink: rework policy dump to support multiple policiesJohannes Berg
Rework the policy dump code a bit to support adding multiple policies to a single dump, in order to e.g. support per-op policies in generic netlink. v2: - move kernel-doc to implementation [Jakub] - squash the first patch to not flip-flop on the prototype [Jakub] - merge netlink_policy_dump_get_policy_idx() with the old get_policy_idx() we already had - rebase without Jakub's patch to have per-op dump Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-03netlink: compare policy more accuratelyJohannes Berg
The maxtype is really an integral part of the policy, and while we haven't gotten into a situation yet where this happens, it seems that some developer might eventually have two places pointing to identical policies, with different maxattr to exclude some attrs in one of the places. Even if not, it's really the right thing to compare both since the two data items fundamentally belong together. v2: - also do the proper comparison in get_policy_idx() Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: switch control commands to per-op policiesJakub Kicinski
In preparation for adding a new attribute to CTRL_CMD_GETPOLICY split the policies for getpolicy and getfamily apart. This will cause a slight user-visible change in that dumping the policies will switch from per family to per op, but supposedly sniffer-type applications (which are the main use case for policy dumping thus far) should support both, anyway. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: use parsed attrs in dumppolicyJakub Kicinski
Attributes are already parsed based on the policy specified in the family and ready-to-use in info->attrs. No need to call genlmsg_parse() again. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: bring back per op policyJakub Kicinski
Add policy to the struct genl_ops structure, this time with maxattr, so it can be used properly. Propagate .policy and .maxattr from the family in genl_get_cmd() if needed, this way the rest of the code does not have to worry if the policy is per op or global. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: use .start callback for dumppolicyJakub Kicinski
The structure of ctrl_dumppolicy() is clearly split into init and dumping. Move the init to a .start callback for clarity, it's a more idiomatic netlink dump code structure. Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: add a structure for dump stateJakub Kicinski
Whenever netlink dump uses more than 2 cb->args[] entries code gets hard to read. We're about to add more state to ctrl_dumppolicy() so create a structure. Since the structure is typed and clearly named we can remove the local fam_id variable and use ctx->fam_id directly. v3: - rebase onto explicit free fix v1: - s/nl_policy_dump/netlink_policy_dump_state/ - forward declare struct netlink_policy_dump_state, and move from passing unsigned long to actual pointer type - add build bug on - u16 fam_id - s/args/ctx/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02genetlink: add small version of opsJakub Kicinski
We want to add maxattr and policy back to genl_ops, to enable dumping per command policy to user space. This, however, would cause bloat for all the families with global policies. Introduce smaller version of ops (half the size of genl_ops). Translate these smaller ops into a full blown struct before use in the core. v1: - use struct assignment - put a full copy of the op in struct genl_dumpit_info - s/light/small/ Signed-off-by: Jakub Kicinski <kuba@kernel.org> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02Merge branch 'master' of ↵David S. Miller
git://git.kernel.org/pub/scm/linux/kernel/git/klassert/ipsec-next Steffen Klassert says: ==================== pull request (net-next): ipsec-next 2020-10-02 1) Add a full xfrm compatible layer for 32-bit applications on 64-bit kernels. From Dmitry Safonov. Please pull or let me know if there are problems. ==================== Signed-off-by: David S. Miller <davem@davemloft.net>
2020-10-02netlink: fix policy dump leakJohannes Berg
[ Upstream commit a95bc734e60449e7b073ff7ff70c35083b290ae9 ] If userspace doesn't complete the policy dump, we leak the allocated state. Fix this. Fixes: d07dcf9aadd6 ("netlink: add infrastructure to expose policies to userspace") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-24netlink/compat: Append NLMSG_DONE/extack to frag_listDmitry Safonov
Modules those use netlink may supply a 2nd skb, (via frag_list) that contains an alternative data set meant for applications using 32bit compatibility mode. In such a case, netlink_recvmsg will use this 2nd skb instead of the original one. Without this patch, such compat applications will retrieve all netlink dump data, but will then get an unexpected EOF. Cc: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Florian Westphal <fw@strlen.de> Signed-off-by: Dmitry Safonov <dima@arista.com> Reviewed-by: Johannes Berg <johannes@sipsolutions.net> Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
2020-09-17netlink: add spaces around '&' in netlink_recv/sendmsg()Yang Yingliang
It's hard to read the code without spaces around '&', for better reading, add spaces around '&'. Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-09-04Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netJakub Kicinski
We got slightly different patches removing a double word in a comment in net/ipv4/raw.c - picked the version from net. Simple conflict in drivers/net/ethernet/ibm/ibmvnic.c. Use cached values instead of VNIC login response buffer (following what commit 507ebe6444a4 ("ibmvnic: Fix use-after-free of VNIC login response buffer") did). Signed-off-by: Jakub Kicinski <kuba@kernel.org>
2020-09-03Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netLinus Torvalds
Pull networking fixes from David Miller: 1) Use netif_rx_ni() when necessary in batman-adv stack, from Jussi Kivilinna. 2) Fix loss of RTT samples in rxrpc, from David Howells. 3) Memory leak in hns_nic_dev_probe(), from Dignhao Liu. 4) ravb module cannot be unloaded, fix from Yuusuke Ashizuka. 5) We disable BH for too lokng in sctp_get_port_local(), add a cond_resched() here as well, from Xin Long. 6) Fix memory leak in st95hf_in_send_cmd, from Dinghao Liu. 7) Out of bound access in bpf_raw_tp_link_fill_link_info(), from Yonghong Song. 8) Missing of_node_put() in mt7530 DSA driver, from Sumera Priyadarsini. 9) Fix crash in bnxt_fw_reset_task(), from Michael Chan. 10) Fix geneve tunnel checksumming bug in hns3, from Yi Li. 11) Memory leak in rxkad_verify_response, from Dinghao Liu. 12) In tipc, don't use smp_processor_id() in preemptible context. From Tuong Lien. 13) Fix signedness issue in mlx4 memory allocation, from Shung-Hsi Yu. 14) Missing clk_disable_prepare() in gemini driver, from Dan Carpenter. 15) Fix ABI mismatch between driver and firmware in nfp, from Louis Peens. * git://git.kernel.org/pub/scm/linux/kernel/git/netdev/net: (110 commits) net/smc: fix sock refcounting in case of termination net/smc: reset sndbuf_desc if freed net/smc: set rx_off for SMCR explicitly net/smc: fix toleration of fake add_link messages tg3: Fix soft lockup when tg3_reset_task() fails. doc: net: dsa: Fix typo in config code sample net: dp83867: Fix WoL SecureOn password nfp: flower: fix ABI mismatch between driver and firmware tipc: fix shutdown() of connectionless socket ipv6: Fix sysctl max for fib_multipath_hash_policy drivers/net/wan/hdlc: Change the default of hard_header_len to 0 net: gemini: Fix another missing clk_disable_unprepare() in probe net: bcmgenet: fix mask check in bcmgenet_validate_flow() amd-xgbe: Add support for new port mode net: usb: dm9601: Add USB ID of Keenetic Plus DSL vhost: fix typo in error message net: ethernet: mlx4: Fix memory allocation in mlx4_buddy_init() pktgen: fix error message with wrong function name net: ethernet: ti: am65-cpsw: fix rmii 100Mbit link mode cxgb4: fix thermal zone device registration ...
2020-08-31netlink: policy: correct validation type checkJohannes Berg
In the policy export for binary attributes I erroneously used a != NLA_VALIDATE_NONE comparison instead of checking for the two possible values, which meant that if a validation function pointer ended up aliasing the min/max as negatives, we'd hit a warning in nla_get_range_unsigned(). Fix this to correctly check for only the two types that should be handled here, i.e. range with or without warn-too-long. Reported-by: syzbot+353df1490da781637624@syzkaller.appspotmail.com Fixes: 8aa26c575fb3 ("netlink: make NLA_BINARY validation more flexible") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-28netlink: fix a data race in netlink_rcv_wake()zhudi
The data races were reported by KCSAN: BUG: KCSAN: data-race in netlink_recvmsg / skb_queue_tail write (marked) to 0xffff8c0986e5a8c8 of 8 bytes by interrupt on cpu 3: skb_queue_tail+0xcc/0x120 __netlink_sendskb+0x55/0x80 netlink_broadcast_filtered+0x465/0x7e0 nlmsg_notify+0x8f/0x120 rtnl_notify+0x8e/0xb0 __neigh_notify+0xf2/0x120 neigh_update+0x927/0xde0 arp_process+0x8a3/0xf50 arp_rcv+0x27c/0x3b0 __netif_receive_skb_core+0x181c/0x1840 __netif_receive_skb+0x38/0xf0 netif_receive_skb_internal+0x77/0x1c0 napi_gro_receive+0x1bd/0x1f0 e1000_clean_rx_irq+0x538/0xb20 [e1000] e1000_clean+0x5e4/0x1340 [e1000] net_rx_action+0x310/0x9d0 __do_softirq+0xe8/0x308 irq_exit+0x109/0x110 do_IRQ+0x7f/0xe0 ret_from_intr+0x0/0x1d 0xffffffffffffffff read to 0xffff8c0986e5a8c8 of 8 bytes by task 1463 on cpu 0: netlink_recvmsg+0x40b/0x820 sock_recvmsg+0xc9/0xd0 ___sys_recvmsg+0x1a4/0x3b0 __sys_recvmsg+0x86/0x120 __x64_sys_recvmsg+0x52/0x70 do_syscall_64+0xb5/0x360 entry_SYSCALL_64_after_hwframe+0x65/0xca 0xffffffffffffffff Since the write is under sk_receive_queue->lock but the read is done as lockless. so fix it by using skb_queue_empty_lockless() instead of skb_queue_empty() for the read in netlink_rcv_wake() Signed-off-by: zhudi <zhudi21@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-24net: netlink: delete repeated wordsRandy Dunlap
Drop duplicated words in net/netlink/. Signed-off-by: Randy Dunlap <rdunlap@infradead.org> Cc: "David S. Miller" <davem@davemloft.net> Cc: Jakub Kicinski <kuba@kernel.org> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-23treewide: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/v5.7/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org>
2020-08-23Merge git://git.kernel.org/pub/scm/linux/kernel/git/netdev/netDavid S. Miller
2020-08-19netlink: fix state reallocation in policy exportJohannes Berg
Evidently, when I did this previously, we didn't have more than 10 policies and didn't run into the reallocation path, because it's missing a memset() for the unused policies. Fix that. Fixes: d07dcf9aadd6 ("netlink: add infrastructure to expose policies to userspace") Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-18netlink: make NLA_BINARY validation more flexibleJohannes Berg
Add range validation for NLA_BINARY, allowing validation of any combination of combination minimum or maximum lengths, using the existing NLA_POLICY_RANGE()/NLA_POLICY_FULL_RANGE() macros, just like for integers where the value is checked. Also make NLA_POLICY_EXACT_LEN(), NLA_POLICY_EXACT_LEN_WARN() and NLA_POLICY_MIN_LEN() special cases of this, removing the old types NLA_EXACT_LEN and NLA_MIN_LEN. This allows us to save some code where both minimum and maximum lengths are requires, currently the policy only allows maximum (NLA_BINARY), minimum (NLA_MIN_LEN) or exact (NLA_EXACT_LEN), so a range of lengths cannot be accepted and must be checked by the code that consumes the attributes later. Also, this allows advertising the correct ranges in the policy export to userspace. Here, NLA_MIN_LEN and NLA_EXACT_LEN already were special cases of NLA_BINARY with min and min/max length respectively. Signed-off-by: Johannes Berg <johannes.berg@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-08-06Merge tag 'thermal-v5.9-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux Pull thermal updates from Daniel Lezcano: - Add support to enable/disable the thermal zones resulting on core code and drivers cleanup (Andrzej Pietrasiewicz) - Add generic netlink support for userspace notifications: events, temperature and discovery commands (Daniel Lezcano) - Fix redundant initialization for a ret variable (Colin Ian King) - Remove the clock cooling code as it is used nowhere (Amit Kucheria) - Add the rcar_gen3_thermal's r8a774e1 support (Marian-Cristian Rotariu) - Replace all references to thermal.txt in the documentation to the corresponding yaml files (Amit Kucheria) - Add maintainer entry for the IPA (Lukasz Luba) - Add support for MSM8939 for the tsens (Shawn Guo) - Update power allocator and devfreq cooling to SPDX licensing (Lukasz Luba) - Add Cannon Lake Low Power PCH support (Sumeet Pawnikar) - Add tsensor support for V2 mediatek thermal system (Henry Yen) - Fix thermal zone lookup by ID for the core code (Thierry Reding) * tag 'thermal-v5.9-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/thermal/linux: (40 commits) thermal: intel: intel_pch_thermal: Add Cannon Lake Low Power PCH support thermal: mediatek: Add tsensor support for V2 thermal system thermal: mediatek: Prepare to add support for other platforms thermal: Update power allocator and devfreq cooling to SPDX licensing MAINTAINERS: update entry to thermal governors file name prefixing thermal: core: Add thermal zone enable/disable notification thermal: qcom: tsens-v0_1: Add support for MSM8939 dt-bindings: tsens: qcom: Document MSM8939 compatible thermal: core: Fix thermal zone lookup by ID thermal: int340x: processor_thermal: fix: update Jasper Lake PCI id thermal: imx8mm: Support module autoloading thermal: ti-soc-thermal: Fix reversed condition in ti_thermal_expose_sensor() MAINTAINERS: Add maintenance information for IPA thermal: rcar_gen3_thermal: Do not shadow thcode variable dt-bindings: thermal: Get rid of thermal.txt and replace references thermal: core: Move initialization after core initcall thermal: netlink: Improve the initcall ordering net: genetlink: Move initialization to core_initcall thermal: rcar_gen3_thermal: Add r8a774e1 support thermal/drivers/clock_cooling: Remove clock_cooling code ...
2020-07-25bpf: Refactor bpf_iter_reg to have separate seq_info memberYonghong Song
There is no functionality change for this patch. Struct bpf_iter_reg is used to register a bpf_iter target, which includes information for both prog_load, link_create and seq_file creation. This patch puts fields related seq_file creation into a different structure. This will be useful for map elements iterator where one iterator covers different map types and different map types may have different seq_ops, init/fini private_data function and private_data size. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200723184109.590030-1-yhs@fb.com
2020-07-24net: pass a sockptr_t into ->setsockoptChristoph Hellwig
Rework the remaining setsockopt code to pass a sockptr_t instead of a plain user pointer. This removes the last remaining set_fs(KERNEL_DS) outside of architecture specific code. Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Stefan Schmidt <stefan@datenfreihafen.org> [ieee802154] Acked-by: Matthieu Baerts <matthieu.baerts@tessares.net> Signed-off-by: David S. Miller <davem@davemloft.net>
2020-07-21bpf: net: Use precomputed btf_id for bpf iteratorsYonghong Song
One additional field btf_id is added to struct bpf_ctx_arg_aux to store the precomputed btf_ids. The btf_id is computed at build time with BTF_ID_LIST or BTF_ID_LIST_GLOBAL macro definitions. All existing bpf iterators are changed to used pre-compute btf_ids. Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Link: https://lore.kernel.org/bpf/20200720163403.1393551-1-yhs@fb.com
2020-07-21net: genetlink: Move initialization to core_initcallDaniel Lezcano
The generic netlink is initialized far after the netlink protocol itself at subsys_initcall. The devlink is initialized at the same level, but after, as shown by a disassembly of the vmlinux: [ ... ] 374 ffff8000115f22c0 <__initcall_devlink_init4>: 375 ffff8000115f22c4 <__initcall_genl_init4>: [ ... ] The function devlink_init() calls genl_register_family() before the generic netlink subsystem is initialized. As the generic netlink initcall level is set since 2005, it seems that was not a problem, but now we have the thermal framework initialized at the core_initcall level which creates the generic netlink family and sends a notification which leads to a subtle memory corruption only detectable when the CONFIG_INIT_ON_ALLOC_DEFAULT_ON option is set with the earlycon at init time. The thermal framework needs to be initialized early in order to begin the mitigation as soon as possible. Moving it to postcore_initcall is acceptable. This patch changes the initialization level for the generic netlink family to the core_initcall and comes after the netlink protocol initialization. Signed-off-by: Daniel Lezcano <daniel.lezcano@linaro.org> Acked-by: David S. Miller <davem@davemloft.net> Tested-by: Marek Szyprowski <m.szyprowski@samsung.com> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org> Link: https://lore.kernel.org/r/20200715074120.8768-1-daniel.lezcano@linaro.org
2020-07-01genetlink: remove genl_bindSean Tranchetti
A potential deadlock can occur during registering or unregistering a new generic netlink family between the main nl_table_lock and the cb_lock where each thread wants the lock held by the other, as demonstrated below. 1) Thread 1 is performing a netlink_bind() operation on a socket. As part of this call, it will call netlink_lock_table(), incrementing the nl_table_users count to 1. 2) Thread 2 is registering (or unregistering) a genl_family via the genl_(un)register_family() API. The cb_lock semaphore will be taken for writing. 3) Thread 1 will call genl_bind() as part of the bind operation to handle subscribing to GENL multicast groups at the request of the user. It will attempt to take the cb_lock semaphore for reading, but it will fail and be scheduled away, waiting for Thread 2 to finish the write. 4) Thread 2 will call netlink_table_grab() during the (un)registration call. However, as Thread 1 has incremented nl_table_users, it will not be able to proceed, and both threads will be stuck waiting for the other. genl_bind() is a noop, unless a genl_family implements the mcast_bind() function to handle setting up family-specific multicast operations. Since no one in-tree uses this functionality as Cong pointed out, simply removing the genl_bind() function will remove the possibility for deadlock, as there is no attempt by Thread 1 above to take the cb_lock semaphore. Fixes: c380d9a7afff ("genetlink: pass multicast bind/unbind to families") Suggested-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Johannes Berg <johannes.berg@intel.com> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: Sean Tranchetti <stranche@codeaurora.org> Signed-off-by: David S. Miller <davem@davemloft.net>
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