user/sven/linux.git/net/core/dev.c, branch v4.14.263

gro: ensure frag0 meets IP header alignment

2021-08-04T10:22:15Z

commit 38ec4944b593fd90c5ef42aaaa53e66ae5769d04 upstream. After commit 0f6925b3e8da ("virtio_net: Do not pull payload in skb->head") Guenter Roeck reported one failure in his tests using sh architecture. After much debugging, we have been able to spot silent unaligned accesses in inet_gro_receive() The issue at hand is that upper networking stacks assume their header is word-aligned. Low level drivers are supposed to reserve NET_IP_ALIGN bytes before the Ethernet header to make that happen. This patch hardens skb_gro_reset_offset() to not allow frag0 fast-path if the fragment is not properly aligned. Some arches like x86, arm64 and powerpc do not care and define NET_IP_ALIGN as 0, this extra check will be a NOP for them. Note that if frag0 is not used, GRO will call pskb_may_pull() as many times as needed to pull network and transport headers. Fixes: 0f6925b3e8da ("virtio_net: Do not pull payload in skb->head") Fixes: 78a478d0efd9 ("gro: Inline skb_gro_header and cache frag0 virtual address") Signed-off-by: Eric Dumazet Reported-by: Guenter Roeck Cc: Xuan Zhuo Cc: "Michael S. Tsirkin" Cc: Jason Wang Acked-by: Michael S. Tsirkin Tested-by: Guenter Roeck Signed-off-by: David S. Miller Signed-off-by: Matthieu Baerts Signed-off-by: Greg Kroah-Hartman

net: Treat __napi_schedule_irqoff() as __napi_schedule() on PREEMPT_RT

2021-07-20T14:17:42Z

[ Upstream commit 8380c81d5c4fced6f4397795a5ae65758272bbfd ] __napi_schedule_irqoff() is an optimized version of __napi_schedule() which can be used where it is known that interrupts are disabled, e.g. in interrupt-handlers, spin_lock_irq() sections or hrtimer callbacks. On PREEMPT_RT enabled kernels this assumptions is not true. Force- threaded interrupt handlers and spinlocks are not disabling interrupts and the NAPI hrtimer callback is forced into softirq context which runs with interrupts enabled as well. Chasing all usage sites of __napi_schedule_irqoff() is a whack-a-mole game so make __napi_schedule_irqoff() invoke __napi_schedule() for PREEMPT_RT kernels. The callers of ____napi_schedule() in the networking core have been audited and are correct on PREEMPT_RT kernels as well. Reported-by: Juri Lelli Signed-off-by: Sebastian Andrzej Siewior Reviewed-by: Thomas Gleixner Reviewed-by: Juri Lelli Signed-off-by: David S. Miller Signed-off-by: Sasha Levin

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