kernel/linux.git/net/core/link_watch.c, branch v6.12.80

ipvlan: Fix use-after-free in ipvlan_get_iflink().

2025-01-17T12:40:39+00:00

[ Upstream commit cb358ff94154774d031159b018adf45e17673941 ] syzbot presented an use-after-free report [0] regarding ipvlan and linkwatch. ipvlan does not hold a refcnt of the lower device unlike vlan and macvlan. If the linkwatch work is triggered for the ipvlan dev, the lower dev might have already been freed, resulting in UAF of ipvlan->phy_dev in ipvlan_get_iflink(). We can delay the lower dev unregistration like vlan and macvlan by holding the lower dev's refcnt in dev->netdev_ops->ndo_init() and releasing it in dev->priv_destructor(). Jakub pointed out calling .ndo_XXX after unregister_netdevice() has returned is error prone and suggested [1] addressing this UAF in the core by taking commit 750e51603395 ("net: avoid potential UAF in default_operstate()") further. Let's assume unregistering devices DOWN and use RCU protection in default_operstate() not to race with the device unregistration. [0]: BUG: KASAN: slab-use-after-free in ipvlan_get_iflink+0x84/0x88 drivers/net/ipvlan/ipvlan_main.c:353 Read of size 4 at addr ffff0000d768c0e0 by task kworker/u8:35/6944 CPU: 0 UID: 0 PID: 6944 Comm: kworker/u8:35 Not tainted 6.13.0-rc2-g9bc5c9515b48 #12 4c3cb9e8b4565456f6a355f312ff91f4f29b3c47 Hardware name: linux,dummy-virt (DT) Workqueue: events_unbound linkwatch_event Call trace: show_stack+0x38/0x50 arch/arm64/kernel/stacktrace.c:484 (C) __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0xbc/0x108 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x16c/0x6f0 mm/kasan/report.c:489 kasan_report+0xc0/0x120 mm/kasan/report.c:602 __asan_report_load4_noabort+0x20/0x30 mm/kasan/report_generic.c:380 ipvlan_get_iflink+0x84/0x88 drivers/net/ipvlan/ipvlan_main.c:353 dev_get_iflink+0x7c/0xd8 net/core/dev.c:674 default_operstate net/core/link_watch.c:45 [inline] rfc2863_policy+0x144/0x360 net/core/link_watch.c:72 linkwatch_do_dev+0x60/0x228 net/core/link_watch.c:175 __linkwatch_run_queue+0x2f4/0x5b8 net/core/link_watch.c:239 linkwatch_event+0x64/0xa8 net/core/link_watch.c:282 process_one_work+0x700/0x1398 kernel/workqueue.c:3229 process_scheduled_works kernel/workqueue.c:3310 [inline] worker_thread+0x8c4/0xe10 kernel/workqueue.c:3391 kthread+0x2b0/0x360 kernel/kthread.c:389 ret_from_fork+0x10/0x20 arch/arm64/kernel/entry.S:862 Allocated by task 9303: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x68 mm/kasan/common.c:68 kasan_save_alloc_info+0x44/0x58 mm/kasan/generic.c:568 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x84/0xa0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4283 [inline] __kmalloc_node_noprof+0x2a0/0x560 mm/slub.c:4289 __kvmalloc_node_noprof+0x9c/0x230 mm/util.c:650 alloc_netdev_mqs+0xb4/0x1118 net/core/dev.c:11209 rtnl_create_link+0x2b8/0xb60 net/core/rtnetlink.c:3595 rtnl_newlink_create+0x19c/0x868 net/core/rtnetlink.c:3771 __rtnl_newlink net/core/rtnetlink.c:3896 [inline] rtnl_newlink+0x122c/0x15c0 net/core/rtnetlink.c:4011 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6901 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2542 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6928 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg net/socket.c:726 [inline] __sys_sendto+0x2ec/0x438 net/socket.c:2197 __do_sys_sendto net/socket.c:2204 [inline] __se_sys_sendto net/socket.c:2200 [inline] __arm64_sys_sendto+0xe4/0x110 net/socket.c:2200 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600 Freed by task 10200: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x30/0x68 mm/kasan/common.c:68 kasan_save_free_info+0x58/0x70 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x48/0x68 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x140/0x420 mm/slub.c:4746 kvfree+0x4c/0x68 mm/util.c:693 netdev_release+0x94/0xc8 net/core/net-sysfs.c:2034 device_release+0x98/0x1c0 kobject_cleanup lib/kobject.c:689 [inline] kobject_release lib/kobject.c:720 [inline] kref_put include/linux/kref.h:65 [inline] kobject_put+0x2b0/0x438 lib/kobject.c:737 netdev_run_todo+0xdd8/0xf48 net/core/dev.c:10924 rtnl_unlock net/core/rtnetlink.c:152 [inline] rtnl_net_unlock net/core/rtnetlink.c:209 [inline] rtnl_dellink+0x484/0x680 net/core/rtnetlink.c:3526 rtnetlink_rcv_msg+0x61c/0x918 net/core/rtnetlink.c:6901 netlink_rcv_skb+0x1dc/0x398 net/netlink/af_netlink.c:2542 rtnetlink_rcv+0x34/0x50 net/core/rtnetlink.c:6928 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x618/0x838 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x5fc/0x8b0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg net/socket.c:726 [inline] ____sys_sendmsg+0x410/0x708 net/socket.c:2583 ___sys_sendmsg+0x178/0x1d8 net/socket.c:2637 __sys_sendmsg net/socket.c:2669 [inline] __do_sys_sendmsg net/socket.c:2674 [inline] __se_sys_sendmsg net/socket.c:2672 [inline] __arm64_sys_sendmsg+0x12c/0x1c8 net/socket.c:2672 __invoke_syscall arch/arm64/kernel/syscall.c:35 [inline] invoke_syscall+0x90/0x278 arch/arm64/kernel/syscall.c:49 el0_svc_common+0x13c/0x250 arch/arm64/kernel/syscall.c:132 do_el0_svc+0x54/0x70 arch/arm64/kernel/syscall.c:151 el0_svc+0x4c/0xa8 arch/arm64/kernel/entry-common.c:744 el0t_64_sync_handler+0x78/0x108 arch/arm64/kernel/entry-common.c:762 el0t_64_sync+0x198/0x1a0 arch/arm64/kernel/entry.S:600 The buggy address belongs to the object at ffff0000d768c000 which belongs to the cache kmalloc-cg-4k of size 4096 The buggy address is located 224 bytes inside of freed 4096-byte region [ffff0000d768c000, ffff0000d768d000) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x117688 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 memcg:ffff0000c77ef981 flags: 0xbfffe0000000040(head|node=0|zone=2|lastcpupid=0x1ffff) page_type: f5(slab) raw: 0bfffe0000000040 ffff0000c000f500 dead000000000100 dead000000000122 raw: 0000000000000000 0000000000040004 00000001f5000000 ffff0000c77ef981 head: 0bfffe0000000040 ffff0000c000f500 dead000000000100 dead000000000122 head: 0000000000000000 0000000000040004 00000001f5000000 ffff0000c77ef981 head: 0bfffe0000000003 fffffdffc35da201 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff0000d768bf80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff0000d768c000: fa fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff0000d768c080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff0000d768c100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff0000d768c180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 8c55facecd7a ("net: linkwatch: only report IF_OPER_LOWERLAYERDOWN if iflink is actually down") Reported-by: syzkaller Suggested-by: Jakub Kicinski Link: https://lore.kernel.org/netdev/20250102174400.085fd8ac@kernel.org/ [1] Signed-off-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20250106071911.64355-1-kuniyu@amazon.com Signed-off-by: Jakub Kicinski Signed-off-by: Sasha Levin

net: avoid potential UAF in default_operstate()

2024-12-14T19:03:10+00:00

[ Upstream commit 750e51603395e755537da08f745864c93e3ce741 ] syzbot reported an UAF in default_operstate() [1] Issue is a race between device and netns dismantles. After calling __rtnl_unlock() from netdev_run_todo(), we can not assume the netns of each device is still alive. Make sure the device is not in NETREG_UNREGISTERED state, and add an ASSERT_RTNL() before the call to __dev_get_by_index(). We might move this ASSERT_RTNL() in __dev_get_by_index() in the future. [1] BUG: KASAN: slab-use-after-free in __dev_get_by_index+0x5d/0x110 net/core/dev.c:852 Read of size 8 at addr ffff888043eba1b0 by task syz.0.0/5339 CPU: 0 UID: 0 PID: 5339 Comm: syz.0.0 Not tainted 6.12.0-syzkaller-10296-gaaf20f870da0 #0 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.16.3-debian-1.16.3-2~bpo12+1 04/01/2014 Call Trace: __dump_stack lib/dump_stack.c:94 [inline] dump_stack_lvl+0x241/0x360 lib/dump_stack.c:120 print_address_description mm/kasan/report.c:378 [inline] print_report+0x169/0x550 mm/kasan/report.c:489 kasan_report+0x143/0x180 mm/kasan/report.c:602 __dev_get_by_index+0x5d/0x110 net/core/dev.c:852 default_operstate net/core/link_watch.c:51 [inline] rfc2863_policy+0x224/0x300 net/core/link_watch.c:67 linkwatch_do_dev+0x3e/0x170 net/core/link_watch.c:170 netdev_run_todo+0x461/0x1000 net/core/dev.c:10894 rtnl_unlock net/core/rtnetlink.c:152 [inline] rtnl_net_unlock include/linux/rtnetlink.h:133 [inline] rtnl_dellink+0x760/0x8d0 net/core/rtnetlink.c:3520 rtnetlink_rcv_msg+0x791/0xcf0 net/core/rtnetlink.c:6911 netlink_rcv_skb+0x1e3/0x430 net/netlink/af_netlink.c:2541 netlink_unicast_kernel net/netlink/af_netlink.c:1321 [inline] netlink_unicast+0x7f6/0x990 net/netlink/af_netlink.c:1347 netlink_sendmsg+0x8e4/0xcb0 net/netlink/af_netlink.c:1891 sock_sendmsg_nosec net/socket.c:711 [inline] __sock_sendmsg+0x221/0x270 net/socket.c:726 ____sys_sendmsg+0x52a/0x7e0 net/socket.c:2583 ___sys_sendmsg net/socket.c:2637 [inline] __sys_sendmsg+0x269/0x350 net/socket.c:2669 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f2a3cb80809 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 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 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f2a3d9cd058 EFLAGS: 00000246 ORIG_RAX: 000000000000002e RAX: ffffffffffffffda RBX: 00007f2a3cd45fa0 RCX: 00007f2a3cb80809 RDX: 0000000000000000 RSI: 0000000020000000 RDI: 0000000000000008 RBP: 00007f2a3cbf393e R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007f2a3cd45fa0 R15: 00007ffd03bc65c8 Allocated by task 5339: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 poison_kmalloc_redzone mm/kasan/common.c:377 [inline] __kasan_kmalloc+0x98/0xb0 mm/kasan/common.c:394 kasan_kmalloc include/linux/kasan.h:260 [inline] __kmalloc_cache_noprof+0x243/0x390 mm/slub.c:4314 kmalloc_noprof include/linux/slab.h:901 [inline] kmalloc_array_noprof include/linux/slab.h:945 [inline] netdev_create_hash net/core/dev.c:11870 [inline] netdev_init+0x10c/0x250 net/core/dev.c:11890 ops_init+0x31e/0x590 net/core/net_namespace.c:138 setup_net+0x287/0x9e0 net/core/net_namespace.c:362 copy_net_ns+0x33f/0x570 net/core/net_namespace.c:500 create_new_namespaces+0x425/0x7b0 kernel/nsproxy.c:110 unshare_nsproxy_namespaces+0x124/0x180 kernel/nsproxy.c:228 ksys_unshare+0x57d/0xa70 kernel/fork.c:3314 __do_sys_unshare kernel/fork.c:3385 [inline] __se_sys_unshare kernel/fork.c:3383 [inline] __x64_sys_unshare+0x38/0x40 kernel/fork.c:3383 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f Freed by task 12: kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 kasan_save_free_info+0x40/0x50 mm/kasan/generic.c:582 poison_slab_object mm/kasan/common.c:247 [inline] __kasan_slab_free+0x59/0x70 mm/kasan/common.c:264 kasan_slab_free include/linux/kasan.h:233 [inline] slab_free_hook mm/slub.c:2338 [inline] slab_free mm/slub.c:4598 [inline] kfree+0x196/0x420 mm/slub.c:4746 netdev_exit+0x65/0xd0 net/core/dev.c:11992 ops_exit_list net/core/net_namespace.c:172 [inline] cleanup_net+0x802/0xcc0 net/core/net_namespace.c:632 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 The buggy address belongs to the object at ffff888043eba000 which belongs to the cache kmalloc-2k of size 2048 The buggy address is located 432 bytes inside of freed 2048-byte region [ffff888043eba000, ffff888043eba800) The buggy address belongs to the physical page: page: refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x43eb8 head: order:3 mapcount:0 entire_mapcount:0 nr_pages_mapped:0 pincount:0 flags: 0x4fff00000000040(head|node=1|zone=1|lastcpupid=0x7ff) page_type: f5(slab) raw: 04fff00000000040 ffff88801ac42000 dead000000000122 0000000000000000 raw: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 04fff00000000040 ffff88801ac42000 dead000000000122 0000000000000000 head: 0000000000000000 0000000000080008 00000001f5000000 0000000000000000 head: 04fff00000000003 ffffea00010fae01 ffffffffffffffff 0000000000000000 head: 0000000000000008 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected page_owner tracks the page as allocated page last allocated via order 3, migratetype Unmovable, gfp_mask 0xd20c0(__GFP_IO|__GFP_FS|__GFP_NOWARN|__GFP_NORETRY|__GFP_COMP|__GFP_NOMEMALLOC), pid 5339, tgid 5338 (syz.0.0), ts 69674195892, free_ts 69663220888 set_page_owner include/linux/page_owner.h:32 [inline] post_alloc_hook+0x1f3/0x230 mm/page_alloc.c:1556 prep_new_page mm/page_alloc.c:1564 [inline] get_page_from_freelist+0x3649/0x3790 mm/page_alloc.c:3474 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4751 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 alloc_slab_page+0x6a/0x140 mm/slub.c:2408 allocate_slab+0x5a/0x2f0 mm/slub.c:2574 new_slab mm/slub.c:2627 [inline] ___slab_alloc+0xcd1/0x14b0 mm/slub.c:3815 __slab_alloc+0x58/0xa0 mm/slub.c:3905 __slab_alloc_node mm/slub.c:3980 [inline] slab_alloc_node mm/slub.c:4141 [inline] __do_kmalloc_node mm/slub.c:4282 [inline] __kmalloc_noprof+0x2e6/0x4c0 mm/slub.c:4295 kmalloc_noprof include/linux/slab.h:905 [inline] sk_prot_alloc+0xe0/0x210 net/core/sock.c:2165 sk_alloc+0x38/0x370 net/core/sock.c:2218 __netlink_create+0x65/0x260 net/netlink/af_netlink.c:629 __netlink_kernel_create+0x174/0x6f0 net/netlink/af_netlink.c:2015 netlink_kernel_create include/linux/netlink.h:62 [inline] uevent_net_init+0xed/0x2d0 lib/kobject_uevent.c:783 ops_init+0x31e/0x590 net/core/net_namespace.c:138 setup_net+0x287/0x9e0 net/core/net_namespace.c:362 page last free pid 1032 tgid 1032 stack trace: reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_unref_page+0xdf9/0x1140 mm/page_alloc.c:2657 __slab_free+0x31b/0x3d0 mm/slub.c:4509 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4104 [inline] slab_alloc_node mm/slub.c:4153 [inline] kmem_cache_alloc_node_noprof+0x1d9/0x380 mm/slub.c:4205 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1323 [inline] alloc_skb_with_frags+0xc3/0x820 net/core/skbuff.c:6612 sock_alloc_send_pskb+0x91a/0xa60 net/core/sock.c:2881 sock_alloc_send_skb include/net/sock.h:1797 [inline] mld_newpack+0x1c3/0xaf0 net/ipv6/mcast.c:1747 add_grhead net/ipv6/mcast.c:1850 [inline] add_grec+0x1492/0x19a0 net/ipv6/mcast.c:1988 mld_send_initial_cr+0x228/0x4b0 net/ipv6/mcast.c:2234 ipv6_mc_dad_complete+0x88/0x490 net/ipv6/mcast.c:2245 addrconf_dad_completed+0x712/0xcd0 net/ipv6/addrconf.c:4342 addrconf_dad_work+0xdc2/0x16f0 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 Memory state around the buggy address: ffff888043eba080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043eba100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb >ffff888043eba180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff888043eba200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ffff888043eba280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb Fixes: 8c55facecd7a ("net: linkwatch: only report IF_OPER_LOWERLAYERDOWN if iflink is actually down") Reported-by: syzbot+1939f24bdb783e9e43d9@syzkaller.appspotmail.com Closes: https://lore.kernel.org/netdev/674f3a18.050a0220.48a03.0041.GAE@google.com/T/#u Signed-off-by: Eric Dumazet Reviewed-by: Vladimir Oltean Link: https://patch.msgid.link/20241203170933.2449307-1-edumazet@google.com Signed-off-by: Paolo Abeni Signed-off-by: Sasha Levin

net: linkwatch: use system_unbound_wq

2024-08-06T19:12:53+00:00

linkwatch_event() grabs possibly very contended RTNL mutex. system_wq is not suitable for such work. Inspired by many noisy syzbot reports. 3 locks held by kworker/0:7/5266: #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3206 [inline] #0: ffff888015480948 ((wq_completion)events){+.+.}-{0:0}, at: process_scheduled_works+0x90a/0x1830 kernel/workqueue.c:3312 #1: ffffc90003f6fd00 ((linkwatch_work).work){+.+.}-{0:0}, at: process_one_work kernel/workqueue.c:3207 [inline] , at: process_scheduled_works+0x945/0x1830 kernel/workqueue.c:3312 #2: ffffffff8fa6f208 (rtnl_mutex){+.+.}-{3:3}, at: linkwatch_event+0xe/0x60 net/core/link_watch.c:276 Reported-by: syzbot Fixes: 1da177e4c3f4 ("Linux-2.6.12-rc2") Signed-off-by: Eric Dumazet Reviewed-by: Kuniyuki Iwashima Link: https://patch.msgid.link/20240805085821.1616528-1-edumazet@google.com Signed-off-by: Jakub Kicinski

net: add netdev_set_operstate() helper

2024-02-14T11:20:13+00:00

dev_base_lock is going away, add netdev_set_operstate() helper so that hsr does not have to know core internals. Remove dev_base_lock acquisition from rfc2863_policy() v3: use an "unsigned int" for dev->operstate, so that try_cmpxchg() can work on all arches. ( https://lore.kernel.org/oe-kbuild-all/202402081918.OLyGaea3-lkp@intel.com/ ) Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

net-sysfs: convert dev->operstate reads to lockless ones

2024-02-14T11:20:13+00:00

operstate_show() can omit dev_base_lock acquisition only to read dev->operstate. Annotate accesses to dev->operstate. Writers still acquire dev_base_lock for mutual exclusion. Signed-off-by: Eric Dumazet Signed-off-by: David S. Miller

Revert "net: rtnetlink: remove local list in __linkwatch_run_queue()"

2023-12-11T10:57:16+00:00

This reverts commit b8dbbbc535a9 ("net: rtnetlink: remove local list in __linkwatch_run_queue()"). It's evidently broken when there's a non-urgent work that gets added back, and then the loop can never finish. While reverting, add a note about that. Reported-by: Marek Szyprowski Fixes: b8dbbbc535a9 ("net: rtnetlink: remove local list in __linkwatch_run_queue()") Signed-off-by: Johannes Berg Signed-off-by: David S. Miller

net: rtnetlink: remove local list in __linkwatch_run_queue()

2023-12-07T03:25:43+00:00

Due to linkwatch_forget_dev() (and perhaps others?) checking for list_empty(&dev->link_watch_list), we must have all manipulations of even the local on-stack list 'wrk' here under spinlock, since even that list can be reached otherwise via dev->link_watch_list. This is already the case, but makes this a bit counter-intuitive, often local lists are used to _not_ have to use locking for their local use. Remove the local list as it doesn't seem to serve any purpose. While at it, move a variable declaration into the loop using it. Reviewed-by: Jiri Pirko Signed-off-by: Johannes Berg Link: https://lore.kernel.org/r/20231205170011.56576dcc1727.I698b72219d9f6ce789bd209b8f6dffd0ca32a8f2@changeid Signed-off-by: Jakub Kicinski

net: core: synchronize link-watch when carrier is queried

2023-12-06T04:16:45+00:00

There are multiple ways to query for the carrier state: through rtnetlink, sysfs, and (possibly) ethtool. Synchronize linkwatch work before these operations so that we don't have a situation where userspace queries the carrier state between the driver's carrier off->on transition and linkwatch running and expects it to work, when really (at least) TX cannot work until linkwatch has run. I previously posted a longer explanation of how this applies to wireless [1] but with this wireless can simply query the state before sending data, to ensure the kernel is ready for it. [1] https://lore.kernel.org/all/346b21d87c69f817ea3c37caceb34f1f56255884.camel@sipsolutions.net/ Signed-off-by: Johannes Berg Reviewed-by: Jiri Pirko Link: https://lore.kernel.org/r/20231204214706.303c62768415.I1caedccae72ee5a45c9085c5eb49c145ce1c0dd5@changeid Signed-off-by: Jakub Kicinski

net: linkwatch: only report IF_OPER_LOWERLAYERDOWN if iflink is actually down

2022-11-16T09:45:00+00:00

RFC 2863 says: The lowerLayerDown state is also a refinement on the down state. This new state indicates that this interface runs "on top of" one or more other interfaces (see ifStackTable) and that this interface is down specifically because one or more of these lower-layer interfaces are down. DSA interfaces are virtual network devices, stacked on top of the DSA master, but they have a physical MAC, with a PHY that reports a real link status. But since DSA (perhaps improperly) uses an iflink to describe the relationship to its master since commit c084080151e1 ("dsa: set ->iflink on slave interfaces to the ifindex of the parent"), default_operstate() will misinterpret this to mean that every time the carrier of a DSA interface is not ok, it is because of the master being not ok. In fact, since commit c0a8a9c27493 ("net: dsa: automatically bring user ports down when master goes down"), DSA cannot even in theory be in the lowerLayerDown state, because it just calls dev_close_many(), thereby going down, when the master goes down. We could revert the commit that creates an iflink between a DSA user port and its master, especially since now we have an alternative IFLA_DSA_MASTER which has less side effects. But there may be tooling in use which relies on the iflink, which has existed since 2009. We could also probably do something local within DSA to overwrite what rfc2863_policy() did, in a way similar to hsr_set_operstate(), but this seems like a hack. What seems appropriate is to follow the iflink, and check the carrier status of that interface as well. If that's down too, yes, keep reporting lowerLayerDown, otherwise just down. Signed-off-by: Vladimir Oltean Signed-off-by: David S. Miller

net: rename reference+tracking helpers

2022-06-10T04:52:55+00:00

Netdev reference helpers have a dev_ prefix for historic reasons. Renaming the old helpers would be too much churn but we can rename the tracking ones which are relatively recent and should be the default for new code. Rename: dev_hold_track() -> netdev_hold() dev_put_track() -> netdev_put() dev_replace_track() -> netdev_ref_replace() Link: https://lore.kernel.org/r/20220608043955.919359-1-kuba@kernel.org Signed-off-by: Jakub Kicinski