mainline inclusion
from mainline-v6.5-rc3
commit 9bc3047374d5bec163e83e743709e23753376f0c
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I7QXHX
CVE: CVE-2023-4194

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=9bc3047374d5bec163e83e743709e23753376f0c

---------------------------

Commit a096ccca initializes the "sk_uid" field in the protocol socket
(struct sock) from the "/dev/net/tun" device node's owner UID. Per
original commit 86741ec2 ("net: core: Add a UID field to struct
sock.", 2016-11-04), that's wrong: the idea is to cache the UID of the
userspace process that creates the socket. Commit 86741ec2 mentions
socket() and accept(); with "tun", the action that creates the socket is
open("/dev/net/tun").

Therefore the device node's owner UID is irrelevant. In most cases,
"/dev/net/tun" will be owned by root, so in practice, commit a096ccca
has no observable effect:

- before, "sk_uid" would be zero, due to undefined behavior
  (CVE-2023-1076),

- after, "sk_uid" would be zero, due to "/dev/net/tun" being owned by root.

What matters is the (fs)UID of the process performing the open(), so cache
that in "sk_uid".

Cc: Eric Dumazet <edumazet@google.com>
Cc: Lorenzo Colitti <lorenzo@google.com>
Cc: Paolo Abeni <pabeni@redhat.com>
Cc: Pietro Borrello <borrello@diag.uniroma1.it>
Cc: netdev@vger.kernel.org
Cc: stable@vger.kernel.org
Fixes: a096ccca ("tun: tun_chr_open(): correctly initialize socket uid")
Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2173435Signed-off-by: NLaszlo Ersek <lersek@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NDong Chenchen <dongchenchen2@huawei.com>

mainline inclusion
from mainline-v6.3-rc1
commit a096ccca
category: bugfix
bugzilla: https://gitee.com/src-openeuler/kernel/issues/I6I7UC
CVE: CVE-2023-1076

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?id=a096ccca6e503a5c575717ff8a36ace27510ab0a

--------------------------------

sock_init_data() assumes that the `struct socket` passed in input is
contained in a `struct socket_alloc` allocated with sock_alloc().
However, tun_chr_open() passes a `struct socket` embedded in a `struct
tun_file` allocated with sk_alloc().
This causes a type confusion when issuing a container_of() with
SOCK_INODE() in sock_init_data() which results in assigning a wrong
sk_uid to the `struct sock` in input.
On default configuration, the type confused field overlaps with the
high 4 bytes of `struct tun_struct __rcu *tun` of `struct tun_file`,
NULL at the time of call, which makes the uid of all tun sockets 0,
i.e., the root one.
Fix the assignment by using sock_init_data_uid().

Fixes: 86741ec2 ("net: core: Add a UID field to struct sock.")
Signed-off-by: NPietro Borrello <borrello@diag.uniroma1.it>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NBaisong Zhong <zhongbaisong@huawei.com>
Reviewed-by: NLiu Jian <liujian56@huawei.com>
Reviewed-by: NXiu Jianfeng <xiujianfeng@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

stable inclusion
from stable-v4.19.268
commit 1f23f1890d91812c35d32eab1b49621b6d32dc7b
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I69KBO
CVE: NA

--------------------------------

[ Upstream commit 5daadc86 ]

syzbot reported use-after-free in tun_detach() [1].  This causes call
trace like below:

==================================================================
BUG: KASAN: use-after-free in notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75
Read of size 8 at addr ffff88807324e2a8 by task syz-executor.0/3673

CPU: 0 PID: 3673 Comm: syz-executor.0 Not tainted 6.1.0-rc5-syzkaller-00044-gcc675d22 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 <TASK>
 __dump_stack lib/dump_stack.c:88 [inline]
 dump_stack_lvl+0xd1/0x138 lib/dump_stack.c:106
 print_address_description mm/kasan/report.c:284 [inline]
 print_report+0x15e/0x461 mm/kasan/report.c:395
 kasan_report+0xbf/0x1f0 mm/kasan/report.c:495
 notifier_call_chain+0x1ee/0x200 kernel/notifier.c:75
 call_netdevice_notifiers_info+0x86/0x130 net/core/dev.c:1942
 call_netdevice_notifiers_extack net/core/dev.c:1983 [inline]
 call_netdevice_notifiers net/core/dev.c:1997 [inline]
 netdev_wait_allrefs_any net/core/dev.c:10237 [inline]
 netdev_run_todo+0xbc6/0x1100 net/core/dev.c:10351
 tun_detach drivers/net/tun.c:704 [inline]
 tun_chr_close+0xe4/0x190 drivers/net/tun.c:3467
 __fput+0x27c/0xa90 fs/file_table.c:320
 task_work_run+0x16f/0x270 kernel/task_work.c:179
 exit_task_work include/linux/task_work.h:38 [inline]
 do_exit+0xb3d/0x2a30 kernel/exit.c:820
 do_group_exit+0xd4/0x2a0 kernel/exit.c:950
 get_signal+0x21b1/0x2440 kernel/signal.c:2858
 arch_do_signal_or_restart+0x86/0x2300 arch/x86/kernel/signal.c:869
 exit_to_user_mode_loop kernel/entry/common.c:168 [inline]
 exit_to_user_mode_prepare+0x15f/0x250 kernel/entry/common.c:203
 __syscall_exit_to_user_mode_work kernel/entry/common.c:285 [inline]
 syscall_exit_to_user_mode+0x1d/0x50 kernel/entry/common.c:296
 do_syscall_64+0x46/0xb0 arch/x86/entry/common.c:86
 entry_SYSCALL_64_after_hwframe+0x63/0xcd

The cause of the issue is that sock_put() from __tun_detach() drops
last reference count for struct net, and then notifier_call_chain()
from netdev_state_change() accesses that struct net.

This patch fixes the issue by calling sock_put() from tun_detach()
after all necessary accesses for the struct net has done.

Fixes: 83c1f36f ("tun: send netlink notification when the device is modified")
Reported-by: syzbot+106f9b687cd64ee70cd1@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=96eb7f1ce75ef933697f24eeab928c4a716edefe [1]
Signed-off-by: NShigeru Yoshida <syoshida@redhat.com>
Link: https://lore.kernel.org/r/20221124175134.1589053-1-syoshida@redhat.comSigned-off-by: NPaolo Abeni <pabeni@redhat.com>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

maillist inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5Z86E

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/netdev/net.git/commit/?id=363a5328f4b0

--------------------------------

Recently, we got two syzkaller problems because of oversize packet
when napi frags enabled.

One of the problems is because the first seg size of the iov_iter
from user space is very big, it is 2147479538 which is bigger than
the threshold value for bail out early in __alloc_pages(). And
skb->pfmemalloc is true, __kmalloc_reserve() would use pfmemalloc
reserves without __GFP_NOWARN flag. Thus we got a warning as following:

========================================================
WARNING: CPU: 1 PID: 17965 at mm/page_alloc.c:5295 __alloc_pages+0x1308/0x16c4 mm/page_alloc.c:5295
...
Call trace:
 __alloc_pages+0x1308/0x16c4 mm/page_alloc.c:5295
 __alloc_pages_node include/linux/gfp.h:550 [inline]
 alloc_pages_node include/linux/gfp.h:564 [inline]
 kmalloc_large_node+0x94/0x350 mm/slub.c:4038
 __kmalloc_node_track_caller+0x620/0x8e4 mm/slub.c:4545
 __kmalloc_reserve.constprop.0+0x1e4/0x2b0 net/core/skbuff.c:151
 pskb_expand_head+0x130/0x8b0 net/core/skbuff.c:1654
 __skb_grow include/linux/skbuff.h:2779 [inline]
 tun_napi_alloc_frags+0x144/0x610 drivers/net/tun.c:1477
 tun_get_user+0x31c/0x2010 drivers/net/tun.c:1835
 tun_chr_write_iter+0x98/0x100 drivers/net/tun.c:2036

The other problem is because odd IPv6 packets without NEXTHDR_NONE
extension header and have big packet length, it is 2127925 which is
bigger than ETH_MAX_MTU(65535). After ipv6_gso_pull_exthdrs() in
ipv6_gro_receive(), network_header offset and transport_header offset
are all bigger than U16_MAX. That would trigger skb->network_header
and skb->transport_header overflow error, because they are all '__u16'
type. Eventually, it would affect the value for __skb_push(skb, value),
and make it be a big value. After __skb_push() in ipv6_gro_receive(),
skb->data would less than skb->head, an out of bounds memory bug occurred.
That would trigger the problem as following:

==================================================================
BUG: KASAN: use-after-free in eth_type_trans+0x100/0x260
...
Call trace:
 dump_backtrace+0xd8/0x130
 show_stack+0x1c/0x50
 dump_stack_lvl+0x64/0x7c
 print_address_description.constprop.0+0xbc/0x2e8
 print_report+0x100/0x1e4
 kasan_report+0x80/0x120
 __asan_load8+0x78/0xa0
 eth_type_trans+0x100/0x260
 napi_gro_frags+0x164/0x550
 tun_get_user+0xda4/0x1270
 tun_chr_write_iter+0x74/0x130
 do_iter_readv_writev+0x130/0x1ec
 do_iter_write+0xbc/0x1e0
 vfs_writev+0x13c/0x26c

To fix the problems, restrict the packet size less than
(ETH_MAX_MTU - NET_SKB_PAD - NET_IP_ALIGN) which has considered reserved
skb space in napi_alloc_skb() because transport_header is an offset from
skb->head. Add len check in tun_napi_alloc_frags() simply.

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NZiyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20221029094101.1653855-1-william.xuanziyang@huawei.comSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Conflicts:
	drivers/net/tun.c
Signed-off-by: NZiyang Xuan <william.xuanziyang@huawei.com>
Reviewed-by: NYue Haibing <yuehaibing@huawei.com>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

stable inclusion
from stable-4.19.251
commit a12fae7621434d0360202156e13969874e002661
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5I4FP
CVE: NA

--------------------------------

commit ff1fa208 upstream.

Eric reports that syzbot made short work out of my speculative
fix. Indeed when queue gets detached its tfile->tun remains,
so we would try to stop NAPI twice with a detach(), close()
sequence.

Alternative fix would be to move tun_napi_disable() to
tun_detach_all() and let the NAPI run after the queue
has been detached.

Fixes: a8fc8cb5 ("net: tun: stop NAPI when detaching queues")
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Reported-by: NEric Dumazet <edumazet@google.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Link: https://lore.kernel.org/r/20220629181911.372047-1-kuba@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

stable inclusion
from stable-4.19.251
commit e90525753e3cf0566ac4917ae98785ff478ede0c
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5I4FP
CVE: NA

--------------------------------

commit a8fc8cb5 upstream.

While looking at a syzbot report I noticed the NAPI only gets
disabled before it's deleted. I think that user can detach
the queue before destroying the device and the NAPI will never
be stopped.

Fixes: 94317099 ("tun: enable NAPI for TUN/TAP driver")
Acked-by: NPetar Penkov <ppenkov@aviatrix.com>
Link: https://lore.kernel.org/r/20220623042105.2274812-1-kuba@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

stable inclusion
from stable-4.19.251
commit 82e729aee59acefe135fceffadcbc5b86dd4f1b9
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I5I4FP
CVE: NA

--------------------------------

commit 3b9bc84d upstream.

Syzbot found a race between tun file and device destruction.
NAPIs live in struct tun_file which can get destroyed before
the netdev so we have to del them explicitly. The current
code is missing deleting the NAPI if the queue was detached
first.

Fixes: 94317099 ("tun: enable NAPI for TUN/TAP driver")
Reported-by: syzbot+b75c138e9286ac742647@syzkaller.appspotmail.com
Link: https://lore.kernel.org/r/20220623042039.2274708-1-kuba@kernel.orgSigned-off-by: NJakub Kicinski <kuba@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYongqiang Liu <liuyongqiang13@huawei.com>

stable inclusion
from linux-4.19.218
commit a57c5cbfb5c4dff95797a189b4d093b6343bc6d2

--------------------------------

commit a31d27fb upstream.

As stated in the bonding doc, trans_start must be set manually for drivers
using NETIF_F_LLTX:
 Drivers that use NETIF_F_LLTX flag must also update
 netdev_queue->trans_start. If they do not, then the ARP monitor will
 immediately fail any slaves using that driver, and those slaves will stay
 down.

Link: https://www.kernel.org/doc/html/v5.15/networking/bonding.html#arp-monitor-operationSigned-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

stable inclusion
from linux-4.19.129
commit 75e36c19ff10836e5d03f87cf17793cf83b59430

--------------------------------

[ Upstream commit 96aa1b22 ]

Tun in IFF_NAPI_FRAGS mode calls napi_gro_frags. Unlike netif_rx and
netif_gro_receive, this expects skb->data to point to the mac layer.

But skb_probe_transport_header, __skb_get_hash_symmetric, and
xdp_do_generic in tun_get_user need skb->data to point to the network
header. Flow dissection also needs skb->protocol set, so
eth_type_trans has to be called.

Ensure the link layer header lies in linear as eth_type_trans pulls
ETH_HLEN. Then take the same code paths for frags as for not frags.
Push the link layer header back just before calling napi_gro_frags.

By pulling up to ETH_HLEN from frag0 into linear, this disables the
frag0 optimization in the special case when IFF_NAPI_FRAGS is used
with zero length iov[0] (and thus empty skb->linear).

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Acked-by: NPetar Penkov <ppenkov@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

stable inclusion
from linux-4.19.100
commit 8f50a05dd6fe2372ac0d5c67645e4e480254ce30

--------------------------------

[ Upstream commit 1efba987 ]

If both IFF_NAPI_FRAGS mode and XDP are enabled, and the XDP program
consumes the skb, we need to clear the napi.skb (or risk
a use-after-free) and release the mutex (or risk a deadlock)

WARNING: lock held when returning to user space!
5.5.0-rc6-syzkaller #0 Not tainted
------------------------------------------------
syz-executor.0/455 is leaving the kernel with locks still held!
1 lock held by syz-executor.0/455:
 #0: ffff888098f6e748 (&tfile->napi_mutex){+.+.}, at: tun_get_user+0x1604/0x3fc0 drivers/net/tun.c:1835

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Cc: Petar Penkov <ppenkov@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit c39e342a ]

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: 94317099 ("tun: enable NAPI for TUN/TAP driver")
Signed-off-by: NPetar Penkov <ppenkov@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 77f22f92 ]

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: eb0fb363 ("tuntap: attach queue 0 before registering netdevice")
Reported-by: NHulk Robot <hulkci@huawei.com>
Suggested-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 4b663366 ]

- 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: 66ccbc9c ("tap: use build_skb() for small packet")
Signed-off-by: NAlexis Bauvin <abauvin@scaleway.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 72b319dc ]

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: NFei Li <lifei.shirley@bytedance.com>
Acked-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

mainline inclusion
from mainline-5.1
commit 9871a9e47a2646fe30ae7fd2e67668a8d30912f6
category: bugfix
bugzilla: 13267
CVE: NA

-------------------------------------------------

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: c8d68e6b ("tuntap: multiqueue support")
Signed-off-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NMao Wenan <maowenan@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

mainline inclusion
from mainline-5.1
commit a35d310f03a692bf4798eb309a1950a06a150620
category: bugfix
bugzilla: 13267
CVE: NA

-------------------------------------------------

We need check if tun->numqueues is zero (e.g for the persist device)
before trying to use it for modular arithmetic.
Reported-by: NEric Dumazet <eric.dumazet@gmail.com>
Fixes: 96f84061("tun: add eBPF based queue selection method")
Signed-off-by: NJason Wang <jasowang@redhat.com>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NMao Wenan <maowenan@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

hulk inclusion
category: bugfix
bugzilla: 13267
CVE: NA

-------------------------------------------------

This reverts commit f21e16fe09f32e389c66b9a83c7e47dd1e3e6ce6.

Sync code with mainline
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NMao Wenan <maowenan@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

hulk inclusion
category: bugfix
bugzilla: 13267
CVE: NA

from: https://lkml.org/lkml/2019/4/28/294

-------------------------------------------------

KASAN report this:

BUG: KASAN: use-after-free in tun_net_xmit+0x1670/0x1750 drivers/net/tun.c:1104
Read of size 8 at addr ffff88836cc26a70 by task swapper/3/0

CPU: 3 PID: 0 Comm: swapper/3 Not tainted 4.19.32 #6
Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.10.2-1ubuntu1 04/01/2014
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0xca/0x13e lib/dump_stack.c:113
 print_address_description+0x79/0x330 mm/kasan/report.c:253
 kasan_report_error mm/kasan/report.c:351 [inline]
 kasan_report+0x18a/0x2d0 mm/kasan/report.c:409
 tun_net_xmit+0x1670/0x1750 drivers/net/tun.c:1104
 __netdev_start_xmit include/linux/netdevice.h:4300 [inline]
 netdev_start_xmit include/linux/netdevice.h:4309 [inline]
 xmit_one net/core/dev.c:3243 [inline]
 dev_hard_start_xmit+0x17c/0x780 net/core/dev.c:3259
 sch_direct_xmit+0x24f/0x8a0 net/sched/sch_generic.c:327
 qdisc_restart net/sched/sch_generic.c:390 [inline]
 __qdisc_run+0x45b/0x1590 net/sched/sch_generic.c:398
 qdisc_run include/net/pkt_sched.h:120 [inline]
 __dev_xmit_skb net/core/dev.c:3438 [inline]
 __dev_queue_xmit+0xa6b/0x2500 net/core/dev.c:3797
 neigh_output include/net/neighbour.h:501 [inline]
 ip6_finish_output2+0xa36/0x2290 net/ipv6/ip6_output.c:120
 ip6_finish_output+0x3e7/0xa20 net/ipv6/ip6_output.c:154
 NF_HOOK_COND include/linux/netfilter.h:278 [inline]
 ip6_output+0x1e2/0x720 net/ipv6/ip6_output.c:171
 dst_output include/net/dst.h:444 [inline]
 NF_HOOK include/linux/netfilter.h:289 [inline]
 mld_sendpack+0x740/0xf20 net/ipv6/mcast.c:1683
 mld_send_cr net/ipv6/mcast.c:1979 [inline]
 mld_ifc_timer_expire+0x3cc/0x7f0 net/ipv6/mcast.c:2478
 call_timer_fn+0x1ea/0x6a0 kernel/time/timer.c:1326
 expire_timers kernel/time/timer.c:1363 [inline]
 __run_timers kernel/time/timer.c:1682 [inline]
 run_timer_softirq+0x637/0x1070 kernel/time/timer.c:1695
 __do_softirq+0x26d/0xabd kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:372 [inline]
 irq_exit+0x209/0x290 kernel/softirq.c:412
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0xf6/0x480 arch/x86/kernel/apic/apic.c:1056
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:864
 </IRQ>
RIP: 0010:native_safe_halt+0x2/0x10 arch/x86/include/asm/irqflags.h:58
Code: 01 f0 0f 82 bc fd ff ff 48 c7 c7 40 25 b1 83 e8 a1 72 03 ff e9 ab fd ff ff 4c 89 e7 e8 37 f5 a7 fe e9 6a ff ff ff 90 90 fb f4 <c3> 0f 1f 00 66 2e 0f 1f 84 00 00 00 00 00 f4 c3 90 90 90 90 90 90
RSP: 0018:ffff8883e0f2fd20 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000007 RBX: dffffc0000000000 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8883e0f04f1c
RBP: 0000000000000003 R08: ffffed107c5dc77b R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000000 R12: ffffffff848b96e0
R13: 0000000000000003 R14: 1ffff1107c1e5fae R15: 0000000000000000
 arch_safe_halt arch/x86/include/asm/paravirt.h:94 [inline]
 default_idle+0x24/0x2b0 arch/x86/kernel/process.c:561
 cpuidle_idle_call kernel/sched/idle.c:153 [inline]
 do_idle+0x2ca/0x420 kernel/sched/idle.c:262
 cpu_startup_entry+0xcb/0xe0 kernel/sched/idle.c:368
 start_secondary+0x421/0x570 arch/x86/kernel/smpboot.c:271
 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:243

Allocated by task 19764:
 set_track mm/kasan/kasan.c:460 [inline]
 kasan_kmalloc+0xa0/0xd0 mm/kasan/kasan.c:553
 __kmalloc+0x11b/0x2d0 mm/slub.c:3750
 kmalloc include/linux/slab.h:518 [inline]
 sk_prot_alloc+0xf6/0x290 net/core/sock.c:1469
 sk_alloc+0x3d/0xc00 net/core/sock.c:1523
 tun_chr_open+0x80/0x560 drivers/net/tun.c:3204
 misc_open+0x367/0x4e0 drivers/char/misc.c:141
 chrdev_open+0x212/0x580 fs/char_dev.c:417
 do_dentry_open+0x704/0x1050 fs/open.c:777
 do_last fs/namei.c:3418 [inline]
 path_openat+0x7ed/0x2ae0 fs/namei.c:3533
 do_filp_open+0x1aa/0x2b0 fs/namei.c:3564
 do_sys_open+0x307/0x430 fs/open.c:1069
 do_syscall_64+0xc8/0x580 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 19764:
 set_track mm/kasan/kasan.c:460 [inline]
 __kasan_slab_free+0x12e/0x180 mm/kasan/kasan.c:521
 slab_free_hook mm/slub.c:1370 [inline]
 slab_free_freelist_hook mm/slub.c:1397 [inline]
 slab_free mm/slub.c:2952 [inline]
 kfree+0xeb/0x2f0 mm/slub.c:3905
 sk_prot_free net/core/sock.c:1506 [inline]
 __sk_destruct+0x4e6/0x6a0 net/core/sock.c:1588
 sk_destruct+0x48/0x70 net/core/sock.c:1596
 __sk_free+0xa9/0x270 net/core/sock.c:1607
 sk_free+0x2a/0x30 net/core/sock.c:1618
 sock_put include/net/sock.h:1696 [inline]
 __tun_detach+0x464/0xf70 drivers/net/tun.c:735
 tun_detach drivers/net/tun.c:747 [inline]
 tun_chr_close+0xd8/0x190 drivers/net/tun.c:3241
 __fput+0x27f/0x7f0 fs/file_table.c:278
 task_work_run+0x136/0x1b0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:193 [inline]
 exit_to_usermode_loop+0x1a7/0x1d0 arch/x86/entry/common.c:166
 prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
 do_syscall_64+0x461/0x580 arch/x86/entry/common.c:293
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88836cc26600
 which belongs to the cache kmalloc-4096 of size 4096
The buggy address is located 1136 bytes inside of
 4096-byte region [ffff88836cc26600, ffff88836cc27600)
The buggy address belongs to the page:
page:ffffea000db30800 count:1 mapcount:0 mapping:ffff8883e280e600 index:0x0 compound_mapcount: 0
flags: 0x2fffff80008100(slab|head)
raw: 002fffff80008100 dead000000000100 dead000000000200 ffff8883e280e600
raw: 0000000000000000 0000000000070007 00000001ffffffff 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88836cc26900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88836cc26980: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
> ffff88836cc26a00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                             ^
 ffff88836cc26a80: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
 ffff88836cc26b00: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb

If tun driver have multiqueues, user close the last queue by
tun_detach, then tun->tfiles[index] is not cleared. Then a new
queue may add to the tun, which using rcu_assign_pointer
tun->tfiles[index] to the new tfile and increase the numqueues.
However if there send a packet during this time, which picking the last
queue, it may uses the old tun->tfiles[index], beacause there no
RCU grace period.

synchronize everything explicitly and make sure tfile is valid
before use it.
Reported-by: NHulk Robot <hulkci@huawei.com>
Fixes: c8d68e6b ("tuntap: multiqueue support")
Signed-off-by: NJason Wang <jasowang@redhat.com>
Signed-off-by: NYueHaibing <yuehaibing@huawei.com>
Reviewed-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

commit 9180bb4f upstream.

In my latest patch I missed one rcu_read_unlock(), in case
device is down.

Fixes: 4477138f ("tun: properly test for IFF_UP")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 4477138f ]

Same reasons than the ones explained in commit 4179cb5a
("vxlan: test dev->flags & IFF_UP before calling netif_rx()")

netif_rx_ni() or napi_gro_frags() must be called under a strict contract.

At device dismantle phase, core networking clears IFF_UP
and flush_all_backlogs() is called after rcu grace period
to make sure no incoming packet might be in a cpu backlog
and still referencing the device.

A similar protocol is used for gro layer.

Most drivers call netif_rx() from their interrupt handler,
and since the interrupts are disabled at device dismantle,
netif_rx() does not have to check dev->flags & IFF_UP

Virtual drivers do not have this guarantee, and must
therefore make the check themselves.

Fixes: 1bd4978a ("tun: honor IFF_UP in tun_get_user()")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit ecef67cb ]

Replace set_current_state with __set_current_state since no memory
barrier is needed at this point.
Signed-off-by: NTimur Celik <mail@timurcelik.de>
Reviewed-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 71828b22 ]

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: NTimur Celik <mail@timurcelik.de>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

mainline inclusion
from mainline-5.0
commit aa6daaca
category: bugfix
bugzilla: 6169
CVE: NA

-------------------------------------------------

In order to cook skbs in the same way than Ethernet drivers,
it is probably better to not use GFP_KERNEL, but rather
use the GFP_ATOMIC and PFMEMALLOC mechanisms provided by
netdev_alloc_frag().

This would allow to use tun driver even in memory stress
situations, especially if swap is used over this tun channel.

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Cc: Petar Penkov <peterpenkov96@gmail.com>
Cc: Mahesh Bandewar <maheshb@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NLin Miaohe <linmiaohe@huawei.com>
Signed-off-by: NMao Wenan <maowenan@huawei.com>
Reviewed-by: NWei Yongjun <weiyongjun1@huawei.com>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 3a03cb84 ]

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: 0b7959b6 ("tun: publish tfile after it's fully initialized")
Reported-and-tested-by: NGeorge Amanakis <gamanakis@gmail.com>
Signed-off-by: NGeorge Amanakis <gamanakis@gmail.com>
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 0b7959b6 ]

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: Nsyzbot <syzkaller@googlegroups.com>
Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NStanislav Fomichev <sdf@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NYang Yingliang <yangyingliang@huawei.com>

[ Upstream commit 35b827b6d06199841a83839e8bb69c0cd13a28be ]

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: f019a7a5 ("tun: Implement ip link del tunXXX")
CC: Eric W. Biederman <ebiederm@xmission.com>
Signed-off-by: NNicolas Dichtel <nicolas.dichtel@6wind.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit 8ebebcba559a1bfbaec7bbda64feb9870b9c58da ]

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: NMatthew Cover <matthew.cover@stackpath.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

[ Upstream commit df52eab23d703142c766ac00bdb8db19d71238d0 ]

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: f019a7a5 ("tun: Implement ip link del tunXXX")
Signed-off-by: NSerhey Popovych <serhe.popovych@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

Since tun->flags might be shared by multiple tfile structures,
it is better to make sure tun_get_user() is using the flags
for the current tfile.

Presence of the READ_ONCE() in tun_napi_frags_enabled() gave a hint
of what could happen, but we need something stronger to please
syzbot.

kasan: CONFIG_KASAN_INLINE enabled
kasan: GPF could be caused by NULL-ptr deref or user memory access
general protection fault: 0000 [#1] PREEMPT SMP KASAN
CPU: 0 PID: 13647 Comm: syz-executor5 Not tainted 4.19.0-rc5+ #59
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427
Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4
RSP: 0018:ffff8801c400f410 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325
RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0
RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000
R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358
R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004
FS:  00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 napi_gro_frags+0x3f4/0xc90 net/core/dev.c:5715
 tun_get_user+0x31d5/0x42a0 drivers/net/tun.c:1922
 tun_chr_write_iter+0xb9/0x154 drivers/net/tun.c:1967
 call_write_iter include/linux/fs.h:1808 [inline]
 new_sync_write fs/read_write.c:474 [inline]
 __vfs_write+0x6b8/0x9f0 fs/read_write.c:487
 vfs_write+0x1fc/0x560 fs/read_write.c:549
 ksys_write+0x101/0x260 fs/read_write.c:598
 __do_sys_write fs/read_write.c:610 [inline]
 __se_sys_write fs/read_write.c:607 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:607
 do_syscall_64+0x1b9/0x820 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x457579
Code: 1d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 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 0f 83 eb b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fe003614c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457579
RDX: 0000000000000012 RSI: 0000000020000000 RDI: 000000000000000a
RBP: 000000000072c040 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe0036156d4
R13: 00000000004c5574 R14: 00000000004d8e98 R15: 00000000ffffffff
Modules linked in:

RIP: 0010:dev_gro_receive+0x132/0x2720 net/core/dev.c:5427
Code: 48 c1 ea 03 80 3c 02 00 0f 85 6e 20 00 00 48 b8 00 00 00 00 00 fc ff df 4d 8b 6e 10 49 8d bd d0 00 00 00 48 89 fa 48 c1 ea 03 <80> 3c 02 00 0f 85 59 20 00 00 4d 8b a5 d0 00 00 00 31 ff 41 81 e4
RSP: 0018:ffff8801c400f410 EFLAGS: 00010202
RAX: dffffc0000000000 RBX: 0000000000000000 RCX: ffffffff8618d325
RDX: 000000000000001a RSI: ffffffff86189f97 RDI: 00000000000000d0
RBP: ffff8801c400f608 R08: ffff8801c8fb4300 R09: 0000000000000000
R10: ffffed0038801ed7 R11: 0000000000000003 R12: ffff8801d327d358
R13: 0000000000000000 R14: ffff8801c16dd8c0 R15: 0000000000000004
FS:  00007fe003615700(0000) GS:ffff8801dac00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fe1f3c43db8 CR3: 00000001bebb2000 CR4: 00000000001406f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

This is the first part to fix following syzbot report :

console output: https://syzkaller.appspot.com/x/log.txt?x=145378e6400000
kernel config:  https://syzkaller.appspot.com/x/.config?x=443816db871edd66
dashboard link: https://syzkaller.appspot.com/bug?extid=e662df0ac1d753b57e80

Following patch is fixing the race condition, but it seems safer
to initialize this mutex at tfile creation anyway.

Fixes: 90e33d45 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: NEric Dumazet <edumazet@google.com>
Reported-by: syzbot+e662df0ac1d753b57e80@syzkaller.appspotmail.com
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

tun_napi_disable() and tun_napi_del() do not need
a pointer to the tun_struct
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

As diagnosed by Song Liu, ndo_poll_controller() can
be very dangerous on loaded hosts, since the cpu
calling ndo_poll_controller() might steal all NAPI
contexts (for all RX/TX queues of the NIC). This capture
can last for unlimited amount of time, since one
cpu is generally not able to drain all the queues under load.

tun uses NAPI for TX completions, so we better let core
networking stack call the napi->poll() to avoid the capture.
Signed-off-by: NEric Dumazet <edumazet@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

0x3ff in tun_hashfn is mask of TUN_NUM_FLOW_ENTRIES, instead
of hardcode, define a macro to setup the relationship with
TUN_NUM_FLOW_ENTRIES
Signed-off-by: NLi RongQing <lirongqing@baidu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

When f_setown is called a pid and a pid type are stored.  Replace the use
of PIDTYPE_PID with PIDTYPE_TGID as PIDTYPE_TGID goes to the entire thread
group.  Replace the use of PIDTYPE_MAX with PIDTYPE_PID as PIDTYPE_PID now
is only for a thread.

Update the users of __f_setown to use PIDTYPE_TGID instead of
PIDTYPE_PID.

For now the code continues to capture task_pid (when task_tgid would
really be appropriate), and iterate on PIDTYPE_PID (even when type ==
PIDTYPE_TGID) out of an abundance of caution to preserve existing
behavior.

Oleg Nesterov suggested using the test to ensure we use PIDTYPE_PID
for tgid lookup also be used to avoid taking the tasklist lock.
Suggested-by: NOleg Nesterov <oleg@redhat.com>
Signed-off-by: N"Eric W. Biederman" <ebiederm@xmission.com>

On XDP_TX we need to free up the frame only when tun_xdp_tx() returns a
negative value. A positive value indicates that the packet is
successfully enqueued to the ptr_ring, so freeing the page causes
use-after-free.

Fixes: 735fc405 ("xdp: change ndo_xdp_xmit API to support bulking")
Signed-off-by: NToshiaki Makita <makita.toshiaki@lab.ntt.co.jp>
Acked-by: NJason Wang <jasowang@redhat.com>
Acked-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

prog_attached of struct netdev_bpf should have been superseded
by simply setting prog_id long time ago, but we kept it around
to allow offloading drivers to communicate attachment mode (drv
vs hw).  Subsequently drivers were also allowed to report back
attachment flags (prog_flags), and since nowadays only programs
attached will XDP_FLAGS_HW_MODE can get offloaded, we can tell
the attachment mode from the flags driver reports.  Remove
prog_attached member.
Signed-off-by: NJakub Kicinski <jakub.kicinski@netronome.com>
Reviewed-by: NQuentin Monnet <quentin.monnet@netronome.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

This patch makes it so that instead of passing a void pointer as the
accel_priv we instead pass a net_device pointer as sb_dev. Making this
change allows us to pass the subordinate device through to the fallback
function eventually so that we can keep the actual code in the
ndo_select_queue call as focused on possible on the exception cases.
Signed-off-by: NAlexander Duyck <alexander.h.duyck@intel.com>
Tested-by: NAndrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: NJeff Kirsher <jeffrey.t.kirsher@intel.com>

Tun, tap, virtio, packet and uml vector all use struct virtio_net_hdr
to communicate packet metadata to userspace.

For skbuffs with vlan, the first two return the packet as it may have
existed on the wire, inserting the VLAN tag in the user buffer.  Then
virtio_net_hdr.csum_start needs to be adjusted by VLAN_HLEN bytes.

Commit f09e2249 ("macvtap: restore vlan header on user read")
added this feature to macvtap. Commit 3ce9b20f ("macvtap: Fix
csum_start when VLAN tags are present") then fixed up csum_start.

Virtio, packet and uml do not insert the vlan header in the user
buffer.

When introducing virtio_net_hdr_from_skb to deduplicate filling in
the virtio_net_hdr, the variant from macvtap which adds VLAN_HLEN was
applied uniformly, breaking csum offset for packets with vlan on
virtio and packet.

Make insertion of VLAN_HLEN optional. Convert the callers to pass it
when needed.

Fixes: e858fae2 ("virtio_net: use common code for virtio_net_hdr and skb GSO conversion")
Fixes: 1276f24e ("packet: use common code for virtio_net_hdr and skb GSO conversion")
Signed-off-by: NWillem de Bruijn <willemb@google.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

Remove the ndo_xdp_flush call implementation tun_xdp_flush
as no callers of ndo_xdp_flush are left.

The tun drivers XDP_TX implementation also used tun_xdp_flush (and
tun_xdp_xmit).  This is easily solved by passing the XDP_XMIT_FLUSH
flag to tun_xdp_xmit in tun_xdp_tx.
Signed-off-by: NJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: NDaniel Borkmann <daniel@iogearbox.net>

Let user space set whatever it would like to advertise for the
tun interface.  Preserve the existing defaults.
Signed-off-by: NChas Williams <3chas3@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>