[ Upstream commit c39e342a050a4425348e6fe7f75827c0a1a7ebc5 ]
There is a race in the TUN driver between napi_busy_loop and
napi_gro_frags. This commit resolves the race by adding the NAPI struct
via netif_tx_napi_add, instead of netif_napi_add, which disables polling
for the NAPI struct.
KCSAN reported:
BUG: KCSAN: data-race in gro_normal_list.part.0 / napi_busy_loop
write to 0xffff8880b5d474b0 of 4 bytes by task 11205 on cpu 0:
gro_normal_list.part.0+0x77/0xb0 net/core/dev.c:5682
gro_normal_list net/core/dev.c:5678 [inline]
gro_normal_one net/core/dev.c:5692 [inline]
napi_frags_finish net/core/dev.c:5705 [inline]
napi_gro_frags+0x625/0x770 net/core/dev.c:5778
tun_get_user+0x2150/0x26a0 drivers/net/tun.c:1976
tun_chr_write_iter+0x79/0xd0 drivers/net/tun.c:2022
call_write_iter include/linux/fs.h:1895 [inline]
do_iter_readv_writev+0x487/0x5b0 fs/read_write.c:693
do_iter_write fs/read_write.c:970 [inline]
do_iter_write+0x13b/0x3c0 fs/read_write.c:951
vfs_writev+0x118/0x1c0 fs/read_write.c:1015
do_writev+0xe3/0x250 fs/read_write.c:1058
__do_sys_writev fs/read_write.c:1131 [inline]
__se_sys_writev fs/read_write.c:1128 [inline]
__x64_sys_writev+0x4e/0x60 fs/read_write.c:1128
do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
read to 0xffff8880b5d474b0 of 4 bytes by task 11168 on cpu 1:
gro_normal_list net/core/dev.c:5678 [inline]
napi_busy_loop+0xda/0x4f0 net/core/dev.c:6126
sk_busy_loop include/net/busy_poll.h:108 [inline]
__skb_recv_udp+0x4ad/0x560 net/ipv4/udp.c:1689
udpv6_recvmsg+0x29e/0xe90 net/ipv6/udp.c:288
inet6_recvmsg+0xbb/0x240 net/ipv6/af_inet6.c:592
sock_recvmsg_nosec net/socket.c:871 [inline]
sock_recvmsg net/socket.c:889 [inline]
sock_recvmsg+0x92/0xb0 net/socket.c:885
sock_read_iter+0x15f/0x1e0 net/socket.c:967
call_read_iter include/linux/fs.h:1889 [inline]
new_sync_read+0x389/0x4f0 fs/read_write.c:414
__vfs_read+0xb1/0xc0 fs/read_write.c:427
vfs_read fs/read_write.c:461 [inline]
vfs_read+0x143/0x2c0 fs/read_write.c:446
ksys_read+0xd5/0x1b0 fs/read_write.c:587
__do_sys_read fs/read_write.c:597 [inline]
__se_sys_read fs/read_write.c:595 [inline]
__x64_sys_read+0x4c/0x60 fs/read_write.c:595
do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
entry_SYSCALL_64_after_hwframe+0x44/0xa9
Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 11168 Comm: syz-executor.0 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Fixes: 943170998b20 ("tun: enable NAPI for TUN/TAP driver")
Signed-off-by: Petar Penkov <ppenkov@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
As mentioned in https://github.com/google/ktsan/wiki/READ_ONCE-and-WRITE_ONCE#it-may-improve-performance
a C compiler can legally transform
if (e->queue_index != queue_index)
e->queue_index = queue_index;
to :
e->queue_index = queue_index;
Note that the code using jiffies has no issue, since jiffies
has volatile attribute.
if (e->updated != jiffies)
e->updated = jiffies;
Fixes: 83b1bc122cab ("tun: align write-heavy flow entry members to a cache line")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Zhang Yu <zhangyu31@baidu.com>
Cc: Wang Li <wangli39@baidu.com>
Cc: Li RongQing <lirongqing@baidu.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Jakub Kicinski <jakub.kicinski@netronome.com>
commit 174e23810cd31
("sk_buff: drop all skb extensions on free and skb scrubbing") made napi
recycle always drop skb extensions. The additional skb_ext_del() that is
performed via nf_reset on napi skb recycle is not needed anymore.
Most nf_reset() calls in the stack are there so queued skb won't block
'rmmod nf_conntrack' indefinitely.
This removes the skb_ext_del from nf_reset, and renames it to a more
fitting nf_reset_ct().
In a few selected places, add a call to skb_ext_reset to make sure that
no active extensions remain.
I am submitting this for "net", because we're still early in the release
cycle. The patch applies to net-next too, but I think the rename causes
needless divergence between those trees.
Suggested-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Florian Westphal <fw@strlen.de>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>
I got a UAF repport in tun driver when doing fuzzy test:
[ 466.269490] ==================================================================
[ 466.271792] BUG: KASAN: use-after-free in tun_chr_read_iter+0x2ca/0x2d0
[ 466.271806] Read of size 8 at addr ffff888372139250 by task tun-test/2699
[ 466.271810]
[ 466.271824] CPU: 1 PID: 2699 Comm: tun-test Not tainted 5.3.0-rc1-00001-g5a9433db2614-dirty #427
[ 466.271833] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.12.1-0-ga5cab58e9a3f-prebuilt.qemu.org 04/01/2014
[ 466.271838] Call Trace:
[ 466.271858] dump_stack+0xca/0x13e
[ 466.271871] ? tun_chr_read_iter+0x2ca/0x2d0
[ 466.271890] print_address_description+0x79/0x440
[ 466.271906] ? vprintk_func+0x5e/0xf0
[ 466.271920] ? tun_chr_read_iter+0x2ca/0x2d0
[ 466.271935] __kasan_report+0x15c/0x1df
[ 466.271958] ? tun_chr_read_iter+0x2ca/0x2d0
[ 466.271976] kasan_report+0xe/0x20
[ 466.271987] tun_chr_read_iter+0x2ca/0x2d0
[ 466.272013] do_iter_readv_writev+0x4b7/0x740
[ 466.272032] ? default_llseek+0x2d0/0x2d0
[ 466.272072] do_iter_read+0x1c5/0x5e0
[ 466.272110] vfs_readv+0x108/0x180
[ 466.299007] ? compat_rw_copy_check_uvector+0x440/0x440
[ 466.299020] ? fsnotify+0x888/0xd50
[ 466.299040] ? __fsnotify_parent+0xd0/0x350
[ 466.299064] ? fsnotify_first_mark+0x1e0/0x1e0
[ 466.304548] ? vfs_write+0x264/0x510
[ 466.304569] ? ksys_write+0x101/0x210
[ 466.304591] ? do_preadv+0x116/0x1a0
[ 466.304609] do_preadv+0x116/0x1a0
[ 466.309829] do_syscall_64+0xc8/0x600
[ 466.309849] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 466.309861] RIP: 0033:0x4560f9
[ 466.309875] Code: 00 00 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 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 b8 ff ff ff f7 d8 64 89 01 48
[ 466.309889] RSP: 002b:00007ffffa5166e8 EFLAGS: 00000206 ORIG_RAX: 0000000000000127
[ 466.322992] RAX: ffffffffffffffda RBX: 0000000000400460 RCX: 00000000004560f9
[ 466.322999] RDX: 0000000000000003 RSI: 00000000200008c0 RDI: 0000000000000003
[ 466.323007] RBP: 00007ffffa516700 R08: 0000000000000004 R09: 0000000000000000
[ 466.323014] R10: 0000000000000000 R11: 0000000000000206 R12: 000000000040cb10
[ 466.323021] R13: 0000000000000000 R14: 00000000006d7018 R15: 0000000000000000
[ 466.323057]
[ 466.323064] Allocated by task 2605:
[ 466.335165] save_stack+0x19/0x80
[ 466.336240] __kasan_kmalloc.constprop.8+0xa0/0xd0
[ 466.337755] kmem_cache_alloc+0xe8/0x320
[ 466.339050] getname_flags+0xca/0x560
[ 466.340229] user_path_at_empty+0x2c/0x50
[ 466.341508] vfs_statx+0xe6/0x190
[ 466.342619] __do_sys_newstat+0x81/0x100
[ 466.343908] do_syscall_64+0xc8/0x600
[ 466.345303] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 466.347034]
[ 466.347517] Freed by task 2605:
[ 466.348471] save_stack+0x19/0x80
[ 466.349476] __kasan_slab_free+0x12e/0x180
[ 466.350726] kmem_cache_free+0xc8/0x430
[ 466.351874] putname+0xe2/0x120
[ 466.352921] filename_lookup+0x257/0x3e0
[ 466.354319] vfs_statx+0xe6/0x190
[ 466.355498] __do_sys_newstat+0x81/0x100
[ 466.356889] do_syscall_64+0xc8/0x600
[ 466.358037] entry_SYSCALL_64_after_hwframe+0x49/0xbe
[ 466.359567]
[ 466.360050] The buggy address belongs to the object at ffff888372139100
[ 466.360050] which belongs to the cache names_cache of size 4096
[ 466.363735] The buggy address is located 336 bytes inside of
[ 466.363735] 4096-byte region [ffff888372139100, ffff88837213a100)
[ 466.367179] The buggy address belongs to the page:
[ 466.368604] page:ffffea000dc84e00 refcount:1 mapcount:0 mapping:ffff8883df1b4f00 index:0x0 compound_mapcount: 0
[ 466.371582] flags: 0x2fffff80010200(slab|head)
[ 466.372910] raw: 002fffff80010200 dead000000000100 dead000000000122 ffff8883df1b4f00
[ 466.375209] raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
[ 466.377778] page dumped because: kasan: bad access detected
[ 466.379730]
[ 466.380288] Memory state around the buggy address:
[ 466.381844] ffff888372139100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.384009] ffff888372139180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.386131] >ffff888372139200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.388257] ^
[ 466.390234] ffff888372139280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.392512] ffff888372139300: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 466.394667] ==================================================================
tun_chr_read_iter() accessed the memory which freed by free_netdev()
called by tun_set_iff():
CPUA CPUB
tun_set_iff()
alloc_netdev_mqs()
tun_attach()
tun_chr_read_iter()
tun_get()
tun_do_read()
tun_ring_recv()
register_netdevice() <-- inject error
goto err_detach
tun_detach_all() <-- set RCV_SHUTDOWN
free_netdev() <-- called from
err_free_dev path
netdev_freemem() <-- free the memory
without check refcount
(In this path, the refcount cannot prevent
freeing the memory of dev, and the memory
will be used by dev_put() called by
tun_chr_read_iter() on CPUB.)
(Break from tun_ring_recv(),
because RCV_SHUTDOWN is set)
tun_put()
dev_put() <-- use the memory
freed by netdev_freemem()
Put the publishing of tfile->tun after register_netdevice(),
so tun_get() won't get the tun pointer that freed by
err_detach path if register_netdevice() failed.
Fixes: eb0fb363f920 ("tuntap: attach queue 0 before registering netdevice")
Reported-by: Hulk Robot <hulkci@huawei.com>
Suggested-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: Yang Yingliang <yangyingliang@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
- v1 -> v2: Move skb_set_owner_w to __tun_build_skb to reduce patch size
Small packets going out of a tap device go through an optimized code
path that uses build_skb() rather than sock_alloc_send_pskb(). The
latter calls skb_set_owner_w(), but the small packet code path does not.
The net effect is that small packets are not owned by the userland
application's socket (e.g. QEMU), while large packets are.
This can be seen with a TCP session, where packets are not owned when
the window size is small enough (around PAGE_SIZE), while they are once
the window grows (note that this requires the host to support virtio
tso for the guest to offload segmentation).
All this leads to inconsistent behaviour in the kernel, especially on
netfilter modules that uses sk->socket (e.g. xt_owner).
Fixes: 66ccbc9c87c2 ("tap: use build_skb() for small packet")
Signed-off-by: Alexis Bauvin <abauvin@scaleway.com>
Acked-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
socket->wq is assign-once, set when we are initializing both struct socket it's in and struct socket_wq it points to. As the matter of fact, the only reason for separate allocation was the ability to RCU-delay freeing of socket_wq. RCU-delaying the freeing of socket itself gets rid of that need, so we can just fold struct socket_wq into the end of struct socket and simplify the life both for sock_alloc_inode() (one allocation instead of two) and for tun/tap oddballs, where we used to embed struct socket and struct socket_wq into the same structure (now - embedding just the struct socket). Note that reference to struct socket_wq in struct sock does remain a reference - that's unchanged. Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: David S. Miller <davem@davemloft.net>
Currently after setting tap0 link up, the tun code wakes tx/rx waited queues up in tun_net_open() when .ndo_open() is called, however the IFF_UP flag has not been set yet. If there's already a wait queue, it would fail to transmit when checking the IFF_UP flag in tun_sendmsg(). Then the saving vhost_poll_start() will add the wq into wqh until it is waken up again. Although this works when IFF_UP flag has been set when tun_chr_poll detects; this is not true if IFF_UP flag has not been set at that time. Sadly the latter case is a fatal error, as the wq will never be waken up in future unless later manually setting link up on purpose. Fix this by moving the wakeup process into the NETDEV_UP event notifying process, this makes sure IFF_UP has been set before all waited queues been waken up. Signed-off-by: Fei Li <lifei.shirley@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Based on 3 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version [author] [graeme] [gregory] [gg]@[slimlogic] [co] [uk] [author] [kishon] [vijay] [abraham] [i] [kishon]@[ti] [com] [based] [on] [twl6030]_[usb] [c] [author] [hema] [hk] [hemahk]@[ti] [com] this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1105 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Reviewed-by: Kate Stewart <kstewart@linuxfoundation.org> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.202006027@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When a queue(tfile) is detached through __tun_detach(), we move the
last enabled tfile to the position where detached one sit but don't
NULL out last position. We expect to synchronize the datapath through
tun->numqueues. Unfortunately, this won't work since we're lacking
sufficient mechanism to order or synchronize the access to
tun->numqueues.
To fix this, NULL out the last position during detaching and check
RCU protected tfile against NULL instead of checking tun->numqueues in
datapath.
Cc: YueHaibing <yuehaibing@huawei.com>
Cc: Cong Wang <xiyou.wangcong@gmail.com>
Cc: weiyongjun (A) <weiyongjun1@huawei.com>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: c8d68e6be1c3b ("tuntap: multiqueue support")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Wei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
We need check if tun->numqueues is zero (e.g for the persist device)
before trying to use it for modular arithmetic.
Reported-by: Eric Dumazet <eric.dumazet@gmail.com>
Fixes: 96f84061620c6("tun: add eBPF based queue selection method")
Signed-off-by: Jason Wang <jasowang@redhat.com>
Reviewed-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>