linux-stable.git/drivers/net/tun.c, branch v6.2.7

tun: tun_chr_open(): correctly initialize socket uid

2023-03-10T08:28:16+00:00

[ Upstream commit 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: 86741ec25462 ("net: core: Add a UID field to struct sock.")
Signed-off-by: Pietro Borrello 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

driver/net/tun: Added features for USO.

2022-12-12T09:29:56+00:00

Added support for USO4 and USO6.
For now, to "enable" USO, it's required to set both USO4 and USO6 simultaneously.
USO enables NETIF_F_GSO_UDP_L4.

Signed-off-by: Andrew Melnychenko 
Signed-off-by: David S. Miller

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

2022-11-29T21:04:52+00:00

tools/lib/bpf/ringbuf.c
  927cbb478adf ("libbpf: Handle size overflow for ringbuf mmap")
  b486d19a0ab0 ("libbpf: checkpatch: Fixed code alignments in ringbuf.c")
https://lore.kernel.org/all/20221121122707.44d1446a@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

net: tun: Fix use-after-free in tun_detach()

2022-11-29T11:14:15+00:00

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-gcc675d22e422 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
Call Trace:
 
 __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: 83c1f36f9880 ("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: Shigeru Yoshida 
Link: https://lore.kernel.org/r/20221124175134.1589053-1-syoshida@redhat.com
Signed-off-by: Paolo Abeni

net: tun: rebuild error handling in tun_get_user

2022-11-14T09:52:07+00:00

The error handling in tun_get_user is very scattered.
This patch unifies error handling, reduces duplication of code, and
makes the logic clearer.

Signed-off-by: Chuang Wang 
Signed-off-by: David S. Miller

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

2022-11-11T01:43:53+00:00

drivers/net/can/pch_can.c
  ae64438be192 ("can: dev: fix skb drop check")
  1dd1b521be85 ("can: remove obsolete PCH CAN driver")
https://lore.kernel.org/all/20221110102509.1f7d63cc@canb.auug.org.au/

Signed-off-by: Jakub Kicinski

net: tun: call napi_schedule_prep() to ensure we own a napi

2022-11-09T01:41:11+00:00

A recent patch exposed another issue in napi_get_frags()
caught by syzbot [1]

Before feeding packets to GRO, and calling napi_complete()
we must first grab NAPI_STATE_SCHED.

[1]
WARNING: CPU: 0 PID: 3612 at net/core/dev.c:6076 napi_complete_done+0x45b/0x880 net/core/dev.c:6076
Modules linked in:
CPU: 0 PID: 3612 Comm: syz-executor408 Not tainted 6.1.0-rc3-syzkaller-00175-g1118b2049d77 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/26/2022
RIP: 0010:napi_complete_done+0x45b/0x880 net/core/dev.c:6076
Code: c1 ea 03 0f b6 14 02 4c 89 f0 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 24 04 00 00 41 89 5d 1c e9 73 fc ff ff e8 b5 53 22 fa <0f> 0b e9 82 fe ff ff e8 a9 53 22 fa 48 8b 5c 24 08 31 ff 48 89 de
RSP: 0018:ffffc90003c4f920 EFLAGS: 00010293
RAX: 0000000000000000 RBX: 0000000000000030 RCX: 0000000000000000
RDX: ffff8880251c0000 RSI: ffffffff875a58db RDI: 0000000000000007
RBP: 0000000000000001 R08: 0000000000000007 R09: 0000000000000000
R10: 0000000000000001 R11: 0000000000000001 R12: ffff888072d02628
R13: ffff888072d02618 R14: ffff888072d02634 R15: 0000000000000000
FS: 0000555555f13300(0000) GS:ffff8880b9a00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000055c44d3892b8 CR3: 00000000172d2000 CR4: 00000000003506f0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:

napi_complete include/linux/netdevice.h:510 [inline]
tun_get_user+0x206d/0x3a60 drivers/net/tun.c:1980
tun_chr_write_iter+0xdb/0x200 drivers/net/tun.c:2027
call_write_iter include/linux/fs.h:2191 [inline]
do_iter_readv_writev+0x20b/0x3b0 fs/read_write.c:735
do_iter_write+0x182/0x700 fs/read_write.c:861
vfs_writev+0x1aa/0x630 fs/read_write.c:934
do_writev+0x133/0x2f0 fs/read_write.c:977
do_syscall_x64 arch/x86/entry/common.c:50 [inline]
do_syscall_64+0x35/0xb0 arch/x86/entry/common.c:80
entry_SYSCALL_64_after_hwframe+0x63/0xcd
RIP: 0033:0x7f37021a3c19

Fixes: 1118b2049d77 ("net: tun: Fix memory leaks of napi_get_frags")
Reported-by: syzbot 
Signed-off-by: Eric Dumazet 
Cc: Wang Yufen 
Link: https://lore.kernel.org/r/20221107180011.188437-1-edumazet@google.com
Signed-off-by: Jakub Kicinski

net: tun: Fix memory leaks of napi_get_frags

2022-11-04T10:56:22+00:00

kmemleak reports after running test_progs:

unreferenced object 0xffff8881b1672dc0 (size 232):
  comm "test_progs", pid 394388, jiffies 4354712116 (age 841.975s)
  hex dump (first 32 bytes):
    e0 84 d7 a8 81 88 ff ff 80 2c 67 b1 81 88 ff ff  .........,g.....
    00 40 c5 9b 81 88 ff ff 00 00 00 00 00 00 00 00  .@..............
  backtrace:
    [<00000000c8f01748>] napi_skb_cache_get+0xd4/0x150
    [<0000000041c7fc09>] __napi_build_skb+0x15/0x50
    [<00000000431c7079>] __napi_alloc_skb+0x26e/0x540
    [<000000003ecfa30e>] napi_get_frags+0x59/0x140
    [<0000000099b2199e>] tun_get_user+0x183d/0x3bb0 [tun]
    [<000000008a5adef0>] tun_chr_write_iter+0xc0/0x1b1 [tun]
    [<0000000049993ff4>] do_iter_readv_writev+0x19f/0x320
    [<000000008f338ea2>] do_iter_write+0x135/0x630
    [<000000008a3377a4>] vfs_writev+0x12e/0x440
    [<00000000a6b5639a>] do_writev+0x104/0x280
    [<00000000ccf065d8>] do_syscall_64+0x3b/0x90
    [<00000000d776e329>] entry_SYSCALL_64_after_hwframe+0x63/0xcd

The issue occurs in the following scenarios:
tun_get_user()
  napi_gro_frags()
    napi_frags_finish()
      case GRO_NORMAL:
        gro_normal_one()
          list_add_tail(&skb->list, &napi->rx_list);
          <-- While napi->rx_count < READ_ONCE(gro_normal_batch),
          <-- gro_normal_list() is not called, napi->rx_list is not empty
  <-- not ask to complete the gro work, will cause memory leaks in
  <-- following tun_napi_del()
...
tun_napi_del()
  netif_napi_del()
    __netif_napi_del()
    <-- &napi->rx_list is not empty, which caused memory leaks

To fix, add napi_complete() after napi_gro_frags().

Fixes: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Wang Yufen 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2022-11-03T20:21:54+00:00

No conflicts.

Signed-off-by: Jakub Kicinski

net: tun: bump the link speed from 10Mbps to 10Gbps

2022-11-03T08:33:51+00:00

The 10Mbps link speed was set in 2004 when the ethtool interface was
initially added to the tun driver.  It might have been a good
assumption 18 years ago, but CPUs and network stack came a long way
since then.

Other virtual ports typically report much higher speeds.  For example,
veth reports 10Gbps since its introduction in 2007.

Some userspace applications rely on the current link speed in
certain situations.  For example, Open vSwitch is using link speed
as an upper bound for QoS configuration if user didn't specify the
maximum rate.  Advertised 10Mbps doesn't match reality in a modern
world, so users have to always manually override the value with
something more sensible to avoid configuration issues, e.g. limiting
the traffic too much.  This also creates additional confusion among
users.

Bump the advertised speed to at least match the veth.

Alternative might be to explicitly report UNKNOWN and let the user
decide on a right value for them.  And it is indeed "the right way"
of fixing the problem.  However, that may cause issues with bonding
or with some userspace applications that may rely on speed value to
be reported (even though they should not).  Just changing the speed
value should be a safer option.

Users can still override the speed with ethtool, if necessary.

RFC discussion is linked below.

Link: https://lore.kernel.org/lkml/20221021114921.3705550-1-i.maximets@ovn.org/
Link: https://mail.openvswitch.org/pipermail/ovs-discuss/2022-July/051958.html
Signed-off-by: Ilya Maximets 
Reviewed-by: Nicolas Dichtel 
Link: https://lore.kernel.org/r/20221031173953.614577-1-i.maximets@ovn.org
Signed-off-by: Paolo Abeni