linux-stable.git/drivers/net/tun.c, branch v5.6

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

2020-01-26T09:40:21+00:00

Minor conflict in mlx5 because changes happened to code that has
moved meanwhile.

Signed-off-by: David S. Miller

tun: add mutex_unlock() call and napi.skb clearing in tun_get_user()

2020-01-23T10:42:44+00:00

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: 90e33d459407 ("tun: enable napi_gro_frags() for TUN/TAP driver")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Cc: Petar Penkov 
Cc: Willem de Bruijn 
Signed-off-by: David S. Miller

xdp: Use bulking for non-map XDP_REDIRECT and consolidate code paths

2020-01-17T04:03:34+00:00

Since the bulk queue used by XDP_REDIRECT now lives in struct net_device,
we can re-use the bulking for the non-map version of the bpf_redirect()
helper. This is a simple matter of having xdp_do_redirect_slow() queue the
frame on the bulk queue instead of sending it out with __bpf_tx_xdp().

Unfortunately we can't make the bpf_redirect() helper return an error if
the ifindex doesn't exit (as bpf_redirect_map() does), because we don't
have a reference to the network namespace of the ingress device at the time
the helper is called. So we have to leave it as-is and keep the device
lookup in xdp_do_redirect_slow().

Since this leaves less reason to have the non-map redirect code in a
separate function, so we get rid of the xdp_do_redirect_slow() function
entirely. This does lose us the tracepoint disambiguation, but fortunately
the xdp_redirect and xdp_redirect_map tracepoints use the same tracepoint
entry structures. This means both can contain a map index, so we can just
amend the tracepoint definitions so we always emit the xdp_redirect(_err)
tracepoints, but with the map ID only populated if a map is present. This
means we retire the xdp_redirect_map(_err) tracepoints entirely, but keep
the definitions around in case someone is still listening for them.

With this change, the performance of the xdp_redirect sample program goes
from 5Mpps to 8.4Mpps (a 68% increase).

Since the flush functions are no longer map-specific, rename the flush()
functions to drop _map from their names. One of the renamed functions is
the xdp_do_flush_map() callback used in all the xdp-enabled drivers. To
keep from having to update all drivers, use a #define to keep the old name
working, and only update the virtual drivers in this patch.

Signed-off-by: Toke Høiland-Jørgensen 
Signed-off-by: Alexei Starovoitov 
Acked-by: John Fastabend 
Link: https://lore.kernel.org/bpf/157918768505.1458396.17518057312953572912.stgit@toke.dk

tun: fix data-race in gro_normal_list()

2019-11-15T20:46:49+00:00

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 
Reported-by: syzbot 
Reviewed-by: Eric Dumazet 
Signed-off-by: David S. Miller

tun: switch to u64_stats_t

2019-11-08T04:03:08+00:00

In order to fix this data-race found by KCSAN [1],
switch to u64_stats_t helpers. They provide all
the needed annotations, without adding extra cost.

[1]
BUG: KCSAN: data-race in tun_get_user / tun_net_get_stats64

read to 0xffffe8ffffd8aca8 of 8 bytes by task 4882 on cpu 0:
 tun_net_get_stats64+0x9b/0x230 drivers/net/tun.c:1171
 dev_get_stats+0x89/0x1e0 net/core/dev.c:9103
 rtnl_fill_stats+0x56/0x370 net/core/rtnetlink.c:1177
 rtnl_fill_ifinfo+0xd3b/0x2100 net/core/rtnetlink.c:1667
 rtmsg_ifinfo_build_skb+0xb0/0x150 net/core/rtnetlink.c:3472
 rtmsg_ifinfo_event.part.0+0x4e/0xb0 net/core/rtnetlink.c:3504
 rtmsg_ifinfo_event net/core/rtnetlink.c:3515 [inline]
 rtmsg_ifinfo+0x85/0x90 net/core/rtnetlink.c:3513
 __dev_notify_flags+0x18b/0x200 net/core/dev.c:7649
 dev_change_flags+0xb8/0xe0 net/core/dev.c:7691
 dev_ifsioc+0x201/0x6a0 net/core/dev_ioctl.c:237
 dev_ioctl+0x149/0x660 net/core/dev_ioctl.c:489
 sock_do_ioctl+0xdb/0x230 net/socket.c:1061
 sock_ioctl+0x3a3/0x5e0 net/socket.c:1189
 vfs_ioctl fs/ioctl.c:46 [inline]
 file_ioctl fs/ioctl.c:509 [inline]
 do_vfs_ioctl+0x991/0xc60 fs/ioctl.c:696

write to 0xffffe8ffffd8aca8 of 8 bytes by task 4883 on cpu 1:
 tun_get_user+0x1d94/0x2ba0 drivers/net/tun.c:2002
 tun_chr_write_iter+0x79/0xd0 drivers/net/tun.c:2022
 call_write_iter include/linux/fs.h:1895 [inline]
 new_sync_write+0x388/0x4a0 fs/read_write.c:483
 __vfs_write+0xb1/0xc0 fs/read_write.c:496
 __kernel_write+0xb8/0x240 fs/read_write.c:515
 write_pipe_buf+0xb6/0xf0 fs/splice.c:794
 splice_from_pipe_feed fs/splice.c:500 [inline]
 __splice_from_pipe+0x248/0x480 fs/splice.c:624
 splice_from_pipe+0xbb/0x100 fs/splice.c:659
 default_file_splice_write+0x45/0x90 fs/splice.c:806
 do_splice_from fs/splice.c:848 [inline]
 direct_splice_actor+0xa0/0xc0 fs/splice.c:1020
 splice_direct_to_actor+0x215/0x510 fs/splice.c:975
 do_splice_direct+0x161/0x1e0 fs/splice.c:1063
 do_sendfile+0x384/0x7f0 fs/read_write.c:1464

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 4883 Comm: syz-executor.1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Signed-off-by: Eric Dumazet 
Signed-off-by: David S. Miller

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

2019-10-20T17:43:00+00:00

Several cases of overlapping changes which were for the most
part trivially resolvable.

Signed-off-by: David S. Miller

tun: remove possible false sharing in tun_flow_update()

2019-10-10T04:29:33+00:00

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 
Cc: Zhang Yu 
Cc: Wang Li 
Cc: Li RongQing 
Acked-by: Jason Wang 
Signed-off-by: Jakub Kicinski

Revert "tun: call dev_get_valid_name() before register_netdevice()"

2019-10-09T03:49:15+00:00

This reverts commit 0ad646c81b2182f7fa67ec0c8c825e0ee165696d.

As noticed by Jakub, this is no longer needed after
commit 11fc7d5a0a2d ("tun: fix memory leak in error path")

This no longer exports dev_get_valid_name() for the exclusive
use of tun driver.

Suggested-by: Jakub Kicinski 
Signed-off-by: Eric Dumazet 
Signed-off-by: Jakub Kicinski

tun: fix memory leak in error path

2019-10-08T20:06:11+00:00

syzbot reported a warning [1] that triggered after recent Jiri patch.

This exposes a bug that we hit already in the past (see commit
ff244c6b29b1 ("tun: handle register_netdevice() failures properly")
for details)

tun uses priv->destructor without an ndo_init() method.

register_netdevice() can return an error, but will
not call priv->destructor() in some cases. Jiri recent
patch added one more.

A long term fix would be to transfer the initialization
of what we destroy in ->destructor() in the ndo_init()

This looks a bit risky given the complexity of tun driver.

A simpler fix is to detect after the failed register_netdevice()
if the tun_free_netdev() function was called already.

[1]
ODEBUG: free active (active state 0) object type: timer_list hint: tun_flow_cleanup+0x0/0x280 drivers/net/tun.c:457
WARNING: CPU: 0 PID: 8653 at lib/debugobjects.c:481 debug_print_object+0x168/0x250 lib/debugobjects.c:481
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 8653 Comm: syz-executor976 Not tainted 5.4.0-rc1-next-20191004 #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 panic+0x2dc/0x755 kernel/panic.c:220
 __warn.cold+0x2f/0x3c kernel/panic.c:581
 report_bug+0x289/0x300 lib/bug.c:195
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 fixup_bug arch/x86/kernel/traps.c:169 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:267
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:286
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1028
RIP: 0010:debug_print_object+0x168/0x250 lib/debugobjects.c:481
Code: dd 80 b9 e6 87 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b5 00 00 00 48 8b 14 dd 80 b9 e6 87 48 c7 c7 e0 ae e6 87 e8 80 84 ff fd <0f> 0b 83 05 e3 ee 80 06 01 48 83 c4 20 5b 41 5c 41 5d 41 5e 5d c3
RSP: 0018:ffff888095997a28 EFLAGS: 00010082
RAX: 0000000000000000 RBX: 0000000000000003 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815cb526 RDI: ffffed1012b32f37
RBP: ffff888095997a68 R08: ffff8880a92ac580 R09: ffffed1015d04101
R10: ffffed1015d04100 R11: ffff8880ae820807 R12: 0000000000000001
R13: ffffffff88fb5340 R14: ffffffff81627110 R15: ffff8880aa41eab8
 __debug_check_no_obj_freed lib/debugobjects.c:963 [inline]
 debug_check_no_obj_freed+0x2d4/0x43f lib/debugobjects.c:994
 kfree+0xf8/0x2c0 mm/slab.c:3755
 kvfree+0x61/0x70 mm/util.c:593
 netdev_freemem net/core/dev.c:9384 [inline]
 free_netdev+0x39d/0x450 net/core/dev.c:9533
 tun_set_iff drivers/net/tun.c:2871 [inline]
 __tun_chr_ioctl+0x317b/0x3f30 drivers/net/tun.c:3075
 tun_chr_ioctl+0x2b/0x40 drivers/net/tun.c:3355
 vfs_ioctl fs/ioctl.c:47 [inline]
 file_ioctl fs/ioctl.c:539 [inline]
 do_vfs_ioctl+0xdb6/0x13e0 fs/ioctl.c:726
 ksys_ioctl+0xab/0xd0 fs/ioctl.c:743
 __do_sys_ioctl fs/ioctl.c:750 [inline]
 __se_sys_ioctl fs/ioctl.c:748 [inline]
 __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:748
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x441439
Code: e8 9c ae 02 00 48 83 c4 18 c3 0f 1f 80 00 00 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 0f 83 3b 0a fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fff61c37438 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000441439
RDX: 0000000020000400 RSI: 00000000400454ca RDI: 0000000000000004
RBP: 00007fff61c37470 R08: 0000000000000001 R09: 0000000100000000
R10: 0000000000000000 R11: 0000000000000246 R12: ffffffffffffffff
R13: 0000000000000005 R14: 0000000000000000 R15: 0000000000000000
Kernel Offset: disabled
Rebooting in 86400 seconds..

Fixes: ff92741270bf ("net: introduce name_node struct to be used in hashlist")
Signed-off-by: Eric Dumazet 
Cc: Jiri Pirko 
Reported-by: syzbot 
Signed-off-by: Jakub Kicinski

netfilter: drop bridge nf reset from nf_reset

2019-10-01T16:42:15+00:00

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 
Signed-off-by: Florian Westphal 
Signed-off-by: Pablo Neira Ayuso