user/sven/linux.git/net/core/dev.c, branch v4.14.238

can: dev: Move device back to init netns on owning netns delete

2021-03-30T12:40:12Z

commit 3a5ca857079ea022e0b1b17fc154f7ad7dbc150f upstream. When a non-initial netns is destroyed, the usual policy is to delete all virtual network interfaces contained, but move physical interfaces back to the initial netns. This keeps the physical interface visible on the system. CAN devices are somewhat special, as they define rtnl_link_ops even if they are physical devices. If a CAN interface is moved into a non-initial netns, destroying that netns lets the interface vanish instead of moving it back to the initial netns. default_device_exit() skips CAN interfaces due to having rtnl_link_ops set. Reproducer: ip netns add foo ip link set can0 netns foo ip netns delete foo WARNING: CPU: 1 PID: 84 at net/core/dev.c:11030 ops_exit_list+0x38/0x60 CPU: 1 PID: 84 Comm: kworker/u4:2 Not tainted 5.10.19 #1 Workqueue: netns cleanup_net [] (unwind_backtrace) from [] (show_stack+0x10/0x14) [] (show_stack) from [] (dump_stack+0x94/0xa8) [] (dump_stack) from [] (__warn+0xb8/0x114) [] (__warn) from [] (warn_slowpath_fmt+0x7c/0xac) [] (warn_slowpath_fmt) from [] (ops_exit_list+0x38/0x60) [] (ops_exit_list) from [] (cleanup_net+0x230/0x380) [] (cleanup_net) from [] (process_one_work+0x1d8/0x438) [] (process_one_work) from [] (worker_thread+0x64/0x5a8) [] (worker_thread) from [] (kthread+0x148/0x14c) [] (kthread) from [] (ret_from_fork+0x14/0x2c) To properly restore physical CAN devices to the initial netns on owning netns exit, introduce a flag on rtnl_link_ops that can be set by drivers. For CAN devices setting this flag, default_device_exit() considers them non-virtual, applying the usual namespace move. The issue was introduced in the commit mentioned below, as at that time CAN devices did not have a dellink() operation. Fixes: e008b5fc8dc7 ("net: Simplfy default_device_exit and improve batching.") Link: https://lore.kernel.org/r/20210302122423.872326-1-martin@strongswan.org Signed-off-by: Martin Willi Signed-off-by: Marc Kleine-Budde Signed-off-by: Greg Kroah-Hartman

net: disable netpoll on fresh napis

2020-09-12T11:39:12Z

[ Upstream commit 96e97bc07e90f175a8980a22827faf702ca4cb30 ] napi_disable() makes sure to set the NAPI_STATE_NPSVC bit to prevent netpoll from accessing rings before init is complete. However, the same is not done for fresh napi instances in netif_napi_add(), even though we expect NAPI instances to be added as disabled. This causes crashes during driver reconfiguration (enabling XDP, changing the channel count) - if there is any printk() after netif_napi_add() but before napi_enable(). To ensure memory ordering is correct we need to use RCU accessors. Reported-by: Rob Sherwood Fixes: 2d8bff12699a ("netpoll: Close race condition between poll_one_napi and napi_disable") Signed-off-by: Jakub Kicinski Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

dev: Defer free of skbs in flush_backlog

2020-07-31T14:44:44Z

[ Upstream commit 7df5cb75cfb8acf96c7f2342530eb41e0c11f4c3 ] IRQs are disabled when freeing skbs in input queue. Use the IRQ safe variant to free skbs here. Fixes: 145dd5f9c88f ("net: flush the softnet backlog in process context") Signed-off-by: Subash Abhinov Kasiviswanathan Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: fix memleak in register_netdevice()

2020-06-30T19:37:58Z

[ Upstream commit 814152a89ed52c722ab92e9fbabcac3cb8a39245 ] I got a memleak report when doing some fuzz test: unreferenced object 0xffff888112584000 (size 13599): comm "ip", pid 3048, jiffies 4294911734 (age 343.491s) hex dump (first 32 bytes): 74 61 70 30 00 00 00 00 00 00 00 00 00 00 00 00 tap0............ 00 ee d9 19 81 88 ff ff 00 00 00 00 00 00 00 00 ................ backtrace: [<000000002f60ba65>] __kmalloc_node+0x309/0x3a0 [<0000000075b211ec>] kvmalloc_node+0x7f/0xc0 [<00000000d3a97396>] alloc_netdev_mqs+0x76/0xfc0 [<00000000609c3655>] __tun_chr_ioctl+0x1456/0x3d70 [<000000001127ca24>] ksys_ioctl+0xe5/0x130 [<00000000b7d5e66a>] __x64_sys_ioctl+0x6f/0xb0 [<00000000e1023498>] do_syscall_64+0x56/0xa0 [<000000009ec0eb12>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 unreferenced object 0xffff888111845cc0 (size 8): comm "ip", pid 3048, jiffies 4294911734 (age 343.491s) hex dump (first 8 bytes): 74 61 70 30 00 88 ff ff tap0.... backtrace: [<000000004c159777>] kstrdup+0x35/0x70 [<00000000d8b496ad>] kstrdup_const+0x3d/0x50 [<00000000494e884a>] kvasprintf_const+0xf1/0x180 [<0000000097880a2b>] kobject_set_name_vargs+0x56/0x140 [<000000008fbdfc7b>] dev_set_name+0xab/0xe0 [<000000005b99e3b4>] netdev_register_kobject+0xc0/0x390 [<00000000602704fe>] register_netdevice+0xb61/0x1250 [<000000002b7ca244>] __tun_chr_ioctl+0x1cd1/0x3d70 [<000000001127ca24>] ksys_ioctl+0xe5/0x130 [<00000000b7d5e66a>] __x64_sys_ioctl+0x6f/0xb0 [<00000000e1023498>] do_syscall_64+0x56/0xa0 [<000000009ec0eb12>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 unreferenced object 0xffff88811886d800 (size 512): comm "ip", pid 3048, jiffies 4294911734 (age 343.491s) hex dump (first 32 bytes): 00 00 00 00 ad 4e ad de ff ff ff ff 00 00 00 00 .....N.......... ff ff ff ff ff ff ff ff c0 66 3d a3 ff ff ff ff .........f=..... backtrace: [<0000000050315800>] device_add+0x61e/0x1950 [<0000000021008dfb>] netdev_register_kobject+0x17e/0x390 [<00000000602704fe>] register_netdevice+0xb61/0x1250 [<000000002b7ca244>] __tun_chr_ioctl+0x1cd1/0x3d70 [<000000001127ca24>] ksys_ioctl+0xe5/0x130 [<00000000b7d5e66a>] __x64_sys_ioctl+0x6f/0xb0 [<00000000e1023498>] do_syscall_64+0x56/0xa0 [<000000009ec0eb12>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 If call_netdevice_notifiers() failed, then rollback_registered() calls netdev_unregister_kobject() which holds the kobject. The reference cannot be put because the netdev won't be add to todo list, so it will leads a memleak, we need put the reference to avoid memleak. Reported-by: Hulk Robot Signed-off-by: Yang Yingliang Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: core: device_rename: Use rwsem instead of a seqcount

2020-06-25T13:42:02Z

[ Upstream commit 11d6011c2cf29f7c8181ebde6c8bc0c4d83adcd7 ] Sequence counters write paths are critical sections that must never be preempted, and blocking, even for CONFIG_PREEMPTION=n, is not allowed. Commit 5dbe7c178d3f ("net: fix kernel deadlock with interface rename and netdev name retrieval.") handled a deadlock, observed with CONFIG_PREEMPTION=n, where the devnet_rename seqcount read side was infinitely spinning: it got scheduled after the seqcount write side blocked inside its own critical section. To fix that deadlock, among other issues, the commit added a cond_resched() inside the read side section. While this will get the non-preemptible kernel eventually unstuck, the seqcount reader is fully exhausting its slice just spinning -- until TIF_NEED_RESCHED is set. The fix is also still broken: if the seqcount reader belongs to a real-time scheduling policy, it can spin forever and the kernel will livelock. Disabling preemption over the seqcount write side critical section will not work: inside it are a number of GFP_KERNEL allocations and mutex locking through the drivers/base/ :: device_rename() call chain. >From all the above, replace the seqcount with a rwsem. Fixes: 5dbe7c178d3f (net: fix kernel deadlock with interface rename and netdev name retrieval.) Fixes: 30e6c9fa93cf (net: devnet_rename_seq should be a seqcount) Fixes: c91f6df2db49 (sockopt: Change getsockopt() of SO_BINDTODEVICE to return an interface name) Cc: Reported-by: kbuild test robot [ v1 missing up_read() on error exit ] Reported-by: Dan Carpenter [ v1 missing up_read() on error exit ] Signed-off-by: Ahmed S. Darwish Reviewed-by: Sebastian Andrzej Siewior Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

sched/rt, net: Use CONFIG_PREEMPTION.patch

2020-06-25T13:42:02Z

[ Upstream commit 2da2b32fd9346009e9acdb68c570ca8d3966aba7 ] CONFIG_PREEMPTION is selected by CONFIG_PREEMPT and by CONFIG_PREEMPT_RT. Both PREEMPT and PREEMPT_RT require the same functionality which today depends on CONFIG_PREEMPT. Update the comment to use CONFIG_PREEMPTION. Signed-off-by: Thomas Gleixner Signed-off-by: Sebastian Andrzej Siewior Signed-off-by: Thomas Gleixner Acked-by: David S. Miller Cc: Linus Torvalds Cc: Peter Zijlstra Cc: netdev@vger.kernel.org Link: https://lore.kernel.org/r/20191015191821.11479-22-bigeasy@linutronix.de Signed-off-by: Ingo Molnar Signed-off-by: Sasha Levin

net: fix a potential recursive NETDEV_FEAT_CHANGE

2020-05-20T06:17:12Z

[ Upstream commit dd912306ff008891c82cd9f63e8181e47a9cb2fb ] syzbot managed to trigger a recursive NETDEV_FEAT_CHANGE event between bonding master and slave. I managed to find a reproducer for this: ip li set bond0 up ifenslave bond0 eth0 brctl addbr br0 ethtool -K eth0 lro off brctl addif br0 bond0 ip li set br0 up When a NETDEV_FEAT_CHANGE event is triggered on a bonding slave, it captures this and calls bond_compute_features() to fixup its master's and other slaves' features. However, when syncing with its lower devices by netdev_sync_lower_features() this event is triggered again on slaves when the LRO feature fails to change, so it goes back and forth recursively until the kernel stack is exhausted. Commit 17b85d29e82c intentionally lets __netdev_update_features() return -1 for such a failure case, so we have to just rely on the existing check inside netdev_sync_lower_features() and skip NETDEV_FEAT_CHANGE event only for this specific failure case. Fixes: fd867d51f889 ("net/core: generic support for disabling netdev features down stack") Reported-by: syzbot+e73ceacfd8560cc8a3ca@syzkaller.appspotmail.com Reported-by: syzbot+c2fb6f9ddcea95ba49b5@syzkaller.appspotmail.com Cc: Jarod Wilson Cc: Nikolay Aleksandrov Cc: Josh Poimboeuf Cc: Jann Horn Reviewed-by: Jay Vosburgh Signed-off-by: Cong Wang Acked-by: Nikolay Aleksandrov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: revert default NAPI poll timeout to 2 jiffies

2020-04-24T06:00:53Z

[ Upstream commit a4837980fd9fa4c70a821d11831698901baef56b ] For HZ < 1000 timeout 2000us rounds up to 1 jiffy but expires randomly because next timer interrupt could come shortly after starting softirq. For commonly used CONFIG_HZ=1000 nothing changes. Fixes: 7acf8a1e8a28 ("Replace 2 jiffies with sysctl netdev_budget_usecs to enable softirq tuning") Reported-by: Dmitry Yakunin Signed-off-by: Konstantin Khlebnikov Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net: rtnetlink: validate IFLA_MTU attribute in rtnl_create_link()

2020-01-29T14:02:36Z

[ Upstream commit d836f5c69d87473ff65c06a6123e5b2cf5e56f5b ] rtnl_create_link() needs to apply dev->min_mtu and dev->max_mtu checks that we apply in do_setlink() Otherwise malicious users can crash the kernel, for example after an integer overflow : BUG: KASAN: use-after-free in memset include/linux/string.h:365 [inline] BUG: KASAN: use-after-free in __alloc_skb+0x37b/0x5e0 net/core/skbuff.c:238 Write of size 32 at addr ffff88819f20b9c0 by task swapper/0/0 CPU: 0 PID: 0 Comm: swapper/0 Not tainted 5.5.0-rc1-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x197/0x210 lib/dump_stack.c:118 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506 kasan_report+0x12/0x20 mm/kasan/common.c:639 check_memory_region_inline mm/kasan/generic.c:185 [inline] check_memory_region+0x134/0x1a0 mm/kasan/generic.c:192 memset+0x24/0x40 mm/kasan/common.c:108 memset include/linux/string.h:365 [inline] __alloc_skb+0x37b/0x5e0 net/core/skbuff.c:238 alloc_skb include/linux/skbuff.h:1049 [inline] alloc_skb_with_frags+0x93/0x590 net/core/skbuff.c:5664 sock_alloc_send_pskb+0x7ad/0x920 net/core/sock.c:2242 sock_alloc_send_skb+0x32/0x40 net/core/sock.c:2259 mld_newpack+0x1d7/0x7f0 net/ipv6/mcast.c:1609 add_grhead.isra.0+0x299/0x370 net/ipv6/mcast.c:1713 add_grec+0x7db/0x10b0 net/ipv6/mcast.c:1844 mld_send_cr net/ipv6/mcast.c:1970 [inline] mld_ifc_timer_expire+0x3d3/0x950 net/ipv6/mcast.c:2477 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404 expire_timers kernel/time/timer.c:1449 [inline] __run_timers kernel/time/timer.c:1773 [inline] __run_timers kernel/time/timer.c:1740 [inline] run_timer_softirq+0x6c3/0x1790 kernel/time/timer.c:1786 __do_softirq+0x262/0x98c kernel/softirq.c:292 invoke_softirq kernel/softirq.c:373 [inline] irq_exit+0x19b/0x1e0 kernel/softirq.c:413 exiting_irq arch/x86/include/asm/apic.h:536 [inline] smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1137 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: 98 6b ea f9 eb 8a cc cc cc cc cc cc e9 07 00 00 00 0f 00 2d 44 1c 60 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d 34 1c 60 00 fb f4 cc 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 4e 5d 9a f9 e8 79 RSP: 0018:ffffffff89807ce8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff13266ae RBX: ffffffff8987a1c0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff8987aa54 RBP: ffffffff89807d18 R08: ffffffff8987a1c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff8a799980 R14: 0000000000000000 R15: 0000000000000000 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:690 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3c8/0x6e0 kernel/sched/idle.c:269 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:361 rest_init+0x23b/0x371 init/main.c:451 arch_call_rest_init+0xe/0x1b start_kernel+0x904/0x943 init/main.c:784 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242 The buggy address belongs to the page: page:ffffea00067c82c0 refcount:0 mapcount:0 mapping:0000000000000000 index:0x0 raw: 057ffe0000000000 ffffea00067c82c8 ffffea00067c82c8 0000000000000000 raw: 0000000000000000 0000000000000000 00000000ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff88819f20b880: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88819f20b900: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff >ffff88819f20b980: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ^ ffff88819f20ba00: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ffff88819f20ba80: ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff ff Fixes: 61e84623ace3 ("net: centralize net_device min/max MTU checking") Signed-off-by: Eric Dumazet Reported-by: syzbot Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

net-sysfs: Fix reference count leak

2020-01-29T14:02:36Z

[ Upstream commit cb626bf566eb4433318d35681286c494f04fedcc ] Netdev_register_kobject is calling device_initialize. In case of error reference taken by device_initialize is not given up. Drivers are supposed to call free_netdev in case of error. In non-error case the last reference is given up there and device release sequence is triggered. In error case this reference is kept and the release sequence is never started. Fix this by setting reg_state as NETREG_UNREGISTERED if registering fails. This is the rootcause for couple of memory leaks reported by Syzkaller: BUG: memory leak unreferenced object 0xffff8880675ca008 (size 256): comm "netdev_register", pid 281, jiffies 4294696663 (age 6.808s) hex dump (first 32 bytes): 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................ backtrace: [<0000000058ca4711>] kmem_cache_alloc_trace+0x167/0x280 [<000000002340019b>] device_add+0x882/0x1750 [<000000001d588c3a>] netdev_register_kobject+0x128/0x380 [<0000000011ef5535>] register_netdevice+0xa1b/0xf00 [<000000007fcf1c99>] __tun_chr_ioctl+0x20d5/0x3dd0 [<000000006a5b7b2b>] tun_chr_ioctl+0x2f/0x40 [<00000000f30f834a>] do_vfs_ioctl+0x1c7/0x1510 [<00000000fba062ea>] ksys_ioctl+0x99/0xb0 [<00000000b1c1b8d2>] __x64_sys_ioctl+0x78/0xb0 [<00000000984cabb9>] do_syscall_64+0x16f/0x580 [<000000000bde033d>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [<00000000e6ca2d9f>] 0xffffffffffffffff BUG: memory leak unreferenced object 0xffff8880668ba588 (size 8): comm "kobject_set_nam", pid 286, jiffies 4294725297 (age 9.871s) hex dump (first 8 bytes): 6e 72 30 00 cc be df 2b nr0....+ backtrace: [<00000000a322332a>] __kmalloc_track_caller+0x16e/0x290 [<00000000236fd26b>] kstrdup+0x3e/0x70 [<00000000dd4a2815>] kstrdup_const+0x3e/0x50 [<0000000049a377fc>] kvasprintf_const+0x10e/0x160 [<00000000627fc711>] kobject_set_name_vargs+0x5b/0x140 [<0000000019eeab06>] dev_set_name+0xc0/0xf0 [<0000000069cb12bc>] netdev_register_kobject+0xc8/0x320 [<00000000f2e83732>] register_netdevice+0xa1b/0xf00 [<000000009e1f57cc>] __tun_chr_ioctl+0x20d5/0x3dd0 [<000000009c560784>] tun_chr_ioctl+0x2f/0x40 [<000000000d759e02>] do_vfs_ioctl+0x1c7/0x1510 [<00000000351d7c31>] ksys_ioctl+0x99/0xb0 [<000000008390040a>] __x64_sys_ioctl+0x78/0xb0 [<0000000052d196b7>] do_syscall_64+0x16f/0x580 [<0000000019af9236>] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [<00000000bc384531>] 0xffffffffffffffff v3 -> v4: Set reg_state to NETREG_UNREGISTERED if registering fails v2 -> v3: * Replaced BUG_ON with WARN_ON in free_netdev and netdev_release v1 -> v2: * Relying on driver calling free_netdev rather than calling put_device directly in error path Reported-by: syzbot+ad8ca40ecd77896d51e2@syzkaller.appspotmail.com Cc: David Miller Cc: Greg Kroah-Hartman Cc: Lukas Bulwahn Signed-off-by: Jouni Hogander Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman