kernel/linux.git/drivers/net/tun.c, branch linux-4.20.y

tun: remove unnecessary memory barrier

2019-03-10T06:10:13+00:00

[ Upstream commit ecef67cb10db7b83b3b71c61dbb29aa070ab0112 ] Replace set_current_state with __set_current_state since no memory barrier is needed at this point. Signed-off-by: Timur Celik Reviewed-by: Eric Dumazet Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: fix blocking read

2019-03-10T06:10:13+00:00

[ Upstream commit 71828b2240692cec0e68b8d867bc00e1745e7fae ] This patch moves setting of the current state into the loop. Otherwise the task may end up in a busy wait loop if none of the break conditions are met. Signed-off-by: Timur Celik Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: move the call to tun_set_real_num_queues

2019-02-06T16:27:36+00:00

[ Upstream commit 3a03cb8456cc1d61c467a5375e0a10e5207b948c ] Call tun_set_real_num_queues() after the increment of tun->numqueues since the former depends on it. Otherwise, the number of queues is not correctly accounted for, which results to warnings similar to: "vnet0 selects TX queue 11, but real number of TX queues is 11". Fixes: 0b7959b62573 ("tun: publish tfile after it's fully initialized") Reported-and-tested-by: George Amanakis Signed-off-by: George Amanakis Signed-off-by: Stanislav Fomichev Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: publish tfile after it's fully initialized

2019-01-22T20:09:48+00:00

[ Upstream commit 0b7959b6257322f7693b08a459c505d4938646f2 ] BUG: unable to handle kernel NULL pointer dereference at 00000000000000d1 Call Trace: ? napi_gro_frags+0xa7/0x2c0 tun_get_user+0xb50/0xf20 tun_chr_write_iter+0x53/0x70 new_sync_write+0xff/0x160 vfs_write+0x191/0x1e0 __x64_sys_write+0x5e/0xd0 do_syscall_64+0x47/0xf0 entry_SYSCALL_64_after_hwframe+0x44/0xa9 I think there is a subtle race between sending a packet via tap and attaching it: CPU0: CPU1: tun_chr_ioctl(TUNSETIFF) tun_set_iff tun_attach rcu_assign_pointer(tfile->tun, tun); tun_fops->write_iter() tun_chr_write_iter tun_napi_alloc_frags napi_get_frags napi->skb = napi_alloc_skb tun_napi_init netif_napi_add napi->skb = NULL napi->skb is NULL here napi_gro_frags napi_frags_skb skb = napi->skb skb_reset_mac_header(skb) panic() Move rcu_assign_pointer(tfile->tun) and rcu_assign_pointer(tun->tfiles) to be the last thing we do in tun_attach(); this should guarantee that when we call tun_get() we always get an initialized object. v2 changes: * remove extra napi_mutex locks/unlocks for napi operations Reported-by: syzbot Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver") Signed-off-by: Stanislav Fomichev Signed-off-by: David S. Miller Signed-off-by: Greg Kroah-Hartman

tun: remove skb access after netif_receive_skb

2018-12-03T22:10:27+00:00

In tun.c skb->len was accessed while doing stats accounting after a call to netif_receive_skb. We can not access skb after this call because buffers may be dropped. The fix for this bug would be to store skb->len in local variable and then use it after netif_receive_skb(). IMO using xdp data size for accounting bytes will be better because input for tun_xdp_one() is xdp_buff. Hence this patch: - fixes a bug by removing skb access after netif_receive_skb() - uses xdp data size for accounting bytes [613.019057] BUG: KASAN: use-after-free in tun_sendmsg+0x77c/0xc50 [tun] [613.021062] Read of size 4 at addr ffff8881da9ab7c0 by task vhost-1115/1155 [613.023073] [613.024003] CPU: 0 PID: 1155 Comm: vhost-1115 Not tainted 4.20.0-rc3-vm+ #232 [613.026029] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014 [613.029116] Call Trace: [613.031145] dump_stack+0x5b/0x90 [613.032219] print_address_description+0x6c/0x23c [613.034156] ? tun_sendmsg+0x77c/0xc50 [tun] [613.036141] kasan_report.cold.5+0x241/0x308 [613.038125] tun_sendmsg+0x77c/0xc50 [tun] [613.040109] ? tun_get_user+0x1960/0x1960 [tun] [613.042094] ? __isolate_free_page+0x270/0x270 [613.045173] vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net] [613.047127] ? peek_head_len.part.13+0x90/0x90 [vhost_net] [613.049096] ? get_tx_bufs+0x5a/0x2c0 [vhost_net] [613.051106] ? vhost_enable_notify+0x2d8/0x420 [vhost] [613.053139] handle_tx_copy+0x2d0/0x8f0 [vhost_net] [613.053139] ? vhost_net_buf_peek+0x340/0x340 [vhost_net] [613.053139] ? __mutex_lock+0x8d9/0xb30 [613.053139] ? finish_task_switch+0x8f/0x3f0 [613.053139] ? handle_tx+0x32/0x120 [vhost_net] [613.053139] ? mutex_trylock+0x110/0x110 [613.053139] ? finish_task_switch+0xcf/0x3f0 [613.053139] ? finish_task_switch+0x240/0x3f0 [613.053139] ? __switch_to_asm+0x34/0x70 [613.053139] ? __switch_to_asm+0x40/0x70 [613.053139] ? __schedule+0x506/0xf10 [613.053139] handle_tx+0xc7/0x120 [vhost_net] [613.053139] vhost_worker+0x166/0x200 [vhost] [613.053139] ? vhost_dev_init+0x580/0x580 [vhost] [613.053139] ? __kthread_parkme+0x77/0x90 [613.053139] ? vhost_dev_init+0x580/0x580 [vhost] [613.053139] kthread+0x1b1/0x1d0 [613.053139] ? kthread_park+0xb0/0xb0 [613.053139] ret_from_fork+0x35/0x40 [613.088705] [613.088705] Allocated by task 1155: [613.088705] kasan_kmalloc+0xbf/0xe0 [613.088705] kmem_cache_alloc+0xdc/0x220 [613.088705] __build_skb+0x2a/0x160 [613.088705] build_skb+0x14/0xc0 [613.088705] tun_sendmsg+0x4f0/0xc50 [tun] [613.088705] vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net] [613.088705] handle_tx_copy+0x2d0/0x8f0 [vhost_net] [613.088705] handle_tx+0xc7/0x120 [vhost_net] [613.088705] vhost_worker+0x166/0x200 [vhost] [613.088705] kthread+0x1b1/0x1d0 [613.088705] ret_from_fork+0x35/0x40 [613.088705] [613.088705] Freed by task 1155: [613.088705] __kasan_slab_free+0x12e/0x180 [613.088705] kmem_cache_free+0xa0/0x230 [613.088705] ip6_mc_input+0x40f/0x5a0 [613.088705] ipv6_rcv+0xc9/0x1e0 [613.088705] __netif_receive_skb_one_core+0xc1/0x100 [613.088705] netif_receive_skb_internal+0xc4/0x270 [613.088705] br_pass_frame_up+0x2b9/0x2e0 [613.088705] br_handle_frame_finish+0x2fb/0x7a0 [613.088705] br_handle_frame+0x30f/0x6c0 [613.088705] __netif_receive_skb_core+0x61a/0x15b0 [613.088705] __netif_receive_skb_one_core+0x8e/0x100 [613.088705] netif_receive_skb_internal+0xc4/0x270 [613.088705] tun_sendmsg+0x738/0xc50 [tun] [613.088705] vhost_tx_batch.isra.14+0xeb/0x1f0 [vhost_net] [613.088705] handle_tx_copy+0x2d0/0x8f0 [vhost_net] [613.088705] handle_tx+0xc7/0x120 [vhost_net] [613.088705] vhost_worker+0x166/0x200 [vhost] [613.088705] kthread+0x1b1/0x1d0 [613.088705] ret_from_fork+0x35/0x40 [613.088705] [613.088705] The buggy address belongs to the object at ffff8881da9ab740 [613.088705] which belongs to the cache skbuff_head_cache of size 232 Fixes: 043d222f93ab ("tuntap: accept an array of XDP buffs through sendmsg()") Reviewed-by: Toshiaki Makita Signed-off-by: Prashant Bhole Acked-by: Jason Wang Acked-by: Michael S. Tsirkin Signed-off-by: David S. Miller

tun: forbid iface creation with rtnl ops

2018-12-01T01:31:03+00:00

It's not supported right now (the goal of the initial patch was to support 'ip link del' only). Before the patch: $ ip link add foo type tun [ 239.632660] BUG: unable to handle kernel NULL pointer dereference at 0000000000000000 [snip] [ 239.636410] RIP: 0010:register_netdevice+0x8e/0x3a0 This panic occurs because dev->netdev_ops is not set by tun_setup(). But to have something usable, it will require more than just setting netdev_ops. Fixes: f019a7a594d9 ("tun: Implement ip link del tunXXX") CC: Eric W. Biederman Signed-off-by: Nicolas Dichtel Signed-off-by: David S. Miller

tuntap: fix multiqueue rx

2018-11-19T03:05:43+00:00

When writing packets to a descriptor associated with a combined queue, the packets should end up on that queue. Before this change all packets written to any descriptor associated with a tap interface end up on rx-0, even when the descriptor is associated with a different queue. The rx traffic can be generated by either of the following. 1. a simple tap program which spins up multiple queues and writes packets to each of the file descriptors 2. tx from a qemu vm with a tap multiqueue netdev The queue for rx traffic can be observed by either of the following (done on the hypervisor in the qemu case). 1. a simple netmap program which opens and reads from per-queue descriptors 2. configuring RPS and doing per-cpu captures with rxtxcpu Alternatively, if you printk() the return value of skb_get_rx_queue() just before each instance of netif_receive_skb() in tun.c, you will get 65535 for every skb. Calling skb_record_rx_queue() to set the rx queue to the queue_index fixes the association between descriptor and rx queue. Signed-off-by: Matthew Cover Signed-off-by: David S. Miller

tun: Consistently configure generic netdev params via rtnetlink

2018-10-16T04:40:31+00:00

Configuring generic network device parameters on tun will fail in presence of IFLA_INFO_KIND attribute in IFLA_LINKINFO nested attribute since tun_validate() always return failure. This can be visualized with following ip-link(8) command sequences: # ip link set dev tun0 group 100 # ip link set dev tun0 group 100 type tun RTNETLINK answers: Invalid argument with contrast to dummy and veth drivers: # ip link set dev dummy0 group 100 # ip link set dev dummy0 type dummy # ip link set dev veth0 group 100 # ip link set dev veth0 group 100 type veth Fix by returning zero in tun_validate() when @data is NULL that is always in case since rtnl_link_ops->maxtype is zero in tun driver. Fixes: f019a7a594d9 ("tun: Implement ip link del tunXXX") Signed-off-by: Serhey Popovych Signed-off-by: David S. Miller

net: tun: remove useless codes of tun_automq_select_queue

2018-10-11T05:35:22+00:00

Because the function __skb_get_hash_symmetric always returns non-zero. Signed-off-by: Zhang Yu Signed-off-by: Wang Li Signed-off-by: David S. Miller

Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net

2018-10-04T04:00:17+00:00

Minor conflict in net/core/rtnetlink.c, David Ahern's bug fix in 'net' overlapped the renaming of a netlink attribute in net-next. Signed-off-by: David S. Miller