linux.git/net/packet, branch v4.19.145 Clone of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git af_packet: TPACKET_V3: fix fill status rwlock imbalance 2020-08-19T06:15:03+00:00 John Ogness john.ogness@linutronix.de 2020-08-13T19:39:25+00:00 ff00ef9aac0a8e17f52169c25f70e5c7e88c87c9 [ Upstream commit 88fd1cb80daa20af063bce81e1fad14e945a8dc4 ] After @blk_fill_in_prog_lock is acquired there is an early out vnet situation that can occur. In that case, the rwlock needs to be released. Also, since @blk_fill_in_prog_lock is only acquired when @tp_version is exactly TPACKET_V3, only release it on that exact condition as well. And finally, add sparse annotation so that it is clearer that prb_fill_curr_block() and prb_clear_blk_fill_status() are acquiring and releasing @blk_fill_in_prog_lock, respectively. sparse is still unable to understand the balance, but the warnings are now on a higher level that make more sense. Fixes: 632ca50f2cbd ("af_packet: TPACKET_V3: replace busy-wait loop") Signed-off-by: John Ogness <john.ogness@linutronix.de> Reported-by: kernel test robot <lkp@intel.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 88fd1cb80daa20af063bce81e1fad14e945a8dc4 ]

After @blk_fill_in_prog_lock is acquired there is an early out vnet
situation that can occur. In that case, the rwlock needs to be
released.

Also, since @blk_fill_in_prog_lock is only acquired when @tp_version
is exactly TPACKET_V3, only release it on that exact condition as
well.

And finally, add sparse annotation so that it is clearer that
prb_fill_curr_block() and prb_clear_blk_fill_status() are acquiring
and releasing @blk_fill_in_prog_lock, respectively. sparse is still
unable to understand the balance, but the warnings are now on a
higher level that make more sense.

Fixes: 632ca50f2cbd ("af_packet: TPACKET_V3: replace busy-wait loop")
Signed-off-by: John Ogness <john.ogness@linutronix.de>
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/packet: tpacket_rcv: avoid a producer race condition 2020-04-02T13:28:11+00:00 Willem de Bruijn willemb@google.com 2020-03-13T16:18:09+00:00 6fb0e4385928900ccb8697748555b3f54bba5193 [ Upstream commit 61fad6816fc10fb8793a925d5c1256d1c3db0cd2 ] PACKET_RX_RING can cause multiple writers to access the same slot if a fast writer wraps the ring while a slow writer is still copying. This is particularly likely with few, large, slots (e.g., GSO packets). Synchronize kernel thread ownership of rx ring slots with a bitmap. Writers acquire a slot race-free by testing tp_status TP_STATUS_KERNEL while holding the sk receive queue lock. They release this lock before copying and set tp_status to TP_STATUS_USER to release to userspace when done. During copying, another writer may take the lock, also see TP_STATUS_KERNEL, and start writing to the same slot. Introduce a new rx_owner_map bitmap with a bit per slot. To acquire a slot, test and set with the lock held. To release race-free, update tp_status and owner bit as a transaction, so take the lock again. This is the one of a variety of discussed options (see Link below): * instead of a shadow ring, embed the data in the slot itself, such as in tp_padding. But any test for this field may match a value left by userspace, causing deadlock. * avoid the lock on release. This leaves a small race if releasing the shadow slot before setting TP_STATUS_USER. The below reproducer showed that this race is not academic. If releasing the slot after tp_status, the race is more subtle. See the first link for details. * add a new tp_status TP_KERNEL_OWNED to avoid the transactional store of two fields. But, legacy applications may interpret all non-zero tp_status as owned by the user. As libpcap does. So this is possible only opt-in by newer processes. It can be added as an optional mode. * embed the struct at the tail of pg_vec to avoid extra allocation. The implementation proved no less complex than a separate field. The additional locking cost on release adds contention, no different than scaling on multicore or multiqueue h/w. In practice, below reproducer nor small packet tcpdump showed a noticeable change in perf report in cycles spent in spinlock. Where contention is problematic, packet sockets support mitigation through PACKET_FANOUT. And we can consider adding opt-in state TP_KERNEL_OWNED. Easy to reproduce by running multiple netperf or similar TCP_STREAM flows concurrently with `tcpdump -B 129 -n greater 60000`. Based on an earlier patchset by Jon Rosen. See links below. I believe this issue goes back to the introduction of tpacket_rcv, which predates git history. Link: https://www.mail-archive.com/netdev@vger.kernel.org/msg237222.html Suggested-by: Jon Rosen <jrosen@cisco.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Jon Rosen <jrosen@cisco.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 61fad6816fc10fb8793a925d5c1256d1c3db0cd2 ]

PACKET_RX_RING can cause multiple writers to access the same slot if a
fast writer wraps the ring while a slow writer is still copying. This
is particularly likely with few, large, slots (e.g., GSO packets).

Synchronize kernel thread ownership of rx ring slots with a bitmap.

Writers acquire a slot race-free by testing tp_status TP_STATUS_KERNEL
while holding the sk receive queue lock. They release this lock before
copying and set tp_status to TP_STATUS_USER to release to userspace
when done. During copying, another writer may take the lock, also see
TP_STATUS_KERNEL, and start writing to the same slot.

Introduce a new rx_owner_map bitmap with a bit per slot. To acquire a
slot, test and set with the lock held. To release race-free, update
tp_status and owner bit as a transaction, so take the lock again.

This is the one of a variety of discussed options (see Link below):

* instead of a shadow ring, embed the data in the slot itself, such as
in tp_padding. But any test for this field may match a value left by
userspace, causing deadlock.

* avoid the lock on release. This leaves a small race if releasing the
shadow slot before setting TP_STATUS_USER. The below reproducer showed
that this race is not academic. If releasing the slot after tp_status,
the race is more subtle. See the first link for details.

* add a new tp_status TP_KERNEL_OWNED to avoid the transactional store
of two fields. But, legacy applications may interpret all non-zero
tp_status as owned by the user. As libpcap does. So this is possible
only opt-in by newer processes. It can be added as an optional mode.

* embed the struct at the tail of pg_vec to avoid extra allocation.
The implementation proved no less complex than a separate field.

The additional locking cost on release adds contention, no different
than scaling on multicore or multiqueue h/w. In practice, below
reproducer nor small packet tcpdump showed a noticeable change in
perf report in cycles spent in spinlock. Where contention is
problematic, packet sockets support mitigation through PACKET_FANOUT.
And we can consider adding opt-in state TP_KERNEL_OWNED.

Easy to reproduce by running multiple netperf or similar TCP_STREAM
flows concurrently with `tcpdump -B 129 -n greater 60000`.

Based on an earlier patchset by Jon Rosen. See links below.

I believe this issue goes back to the introduction of tpacket_rcv,
which predates git history.

Link: https://www.mail-archive.com/netdev@vger.kernel.org/msg237222.html
Suggested-by: Jon Rosen <jrosen@cisco.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Jon Rosen <jrosen@cisco.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/packet: tpacket_rcv: do not increment ring index on drop 2020-03-18T06:14:12+00:00 Willem de Bruijn willemb@google.com 2020-03-09T15:34:35+00:00 64fabf9bcadfb93fb21fb023a72a2ad8b7a40047 [ Upstream commit 46e4c421a053c36bf7a33dda2272481bcaf3eed3 ] In one error case, tpacket_rcv drops packets after incrementing the ring producer index. If this happens, it does not update tp_status to TP_STATUS_USER and thus the reader is stalled for an iteration of the ring, causing out of order arrival. The only such error path is when virtio_net_hdr_from_skb fails due to encountering an unknown GSO type. Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 46e4c421a053c36bf7a33dda2272481bcaf3eed3 ]

In one error case, tpacket_rcv drops packets after incrementing the
ring producer index.

If this happens, it does not update tp_status to TP_STATUS_USER and
thus the reader is stalled for an iteration of the ring, causing out
of order arrival.

The only such error path is when virtio_net_hdr_from_skb fails due
to encountering an unknown GSO type.

Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
packet: fix data-race in fanout_flow_is_huge() 2020-01-27T13:51:21+00:00 Eric Dumazet edumazet@google.com 2019-11-08T13:07:46+00:00 ab6c0f501d2cecf8c74cf8293fca9c2b780dd55b [ Upstream commit b756ad928d98e5ef0b74af7546a6a31a8dadde00 ] KCSAN reported the following data-race [1] Adding a couple of READ_ONCE()/WRITE_ONCE() should silence it. Since the report hinted about multiple cpus using the history concurrently, I added a test avoiding writing on it if the victim slot already contains the desired value. [1] BUG: KCSAN: data-race in fanout_demux_rollover / fanout_demux_rollover read to 0xffff8880b01786cc of 4 bytes by task 18921 on cpu 1: fanout_flow_is_huge net/packet/af_packet.c:1303 [inline] fanout_demux_rollover+0x33e/0x3f0 net/packet/af_packet.c:1353 packet_rcv_fanout+0x34e/0x490 net/packet/af_packet.c:1453 deliver_skb net/core/dev.c:1888 [inline] dev_queue_xmit_nit+0x15b/0x540 net/core/dev.c:1958 xmit_one net/core/dev.c:3195 [inline] dev_hard_start_xmit+0x3f5/0x430 net/core/dev.c:3215 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311 __sys_sendmmsg+0x123/0x350 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x44/0xa9 write to 0xffff8880b01786cc of 4 bytes by task 18922 on cpu 0: fanout_flow_is_huge net/packet/af_packet.c:1306 [inline] fanout_demux_rollover+0x3a4/0x3f0 net/packet/af_packet.c:1353 packet_rcv_fanout+0x34e/0x490 net/packet/af_packet.c:1453 deliver_skb net/core/dev.c:1888 [inline] dev_queue_xmit_nit+0x15b/0x540 net/core/dev.c:1958 xmit_one net/core/dev.c:3195 [inline] dev_hard_start_xmit+0x3f5/0x430 net/core/dev.c:3215 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530 neigh_output include/net/neighbour.h:511 [inline] ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline] __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152 NF_HOOK_COND include/linux/netfilter.h:294 [inline] ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175 dst_output include/net/dst.h:436 [inline] ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0x9f/0xc0 net/socket.c:657 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311 __sys_sendmmsg+0x123/0x350 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439 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: 0 PID: 18922 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Fixes: 3b3a5b0aab5b ("packet: rollover huge flows before small flows") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b756ad928d98e5ef0b74af7546a6a31a8dadde00 ]

KCSAN reported the following data-race [1]

Adding a couple of READ_ONCE()/WRITE_ONCE() should silence it.

Since the report hinted about multiple cpus using the history
concurrently, I added a test avoiding writing on it if the
victim slot already contains the desired value.

[1]

BUG: KCSAN: data-race in fanout_demux_rollover / fanout_demux_rollover

read to 0xffff8880b01786cc of 4 bytes by task 18921 on cpu 1:
 fanout_flow_is_huge net/packet/af_packet.c:1303 [inline]
 fanout_demux_rollover+0x33e/0x3f0 net/packet/af_packet.c:1353
 packet_rcv_fanout+0x34e/0x490 net/packet/af_packet.c:1453
 deliver_skb net/core/dev.c:1888 [inline]
 dev_queue_xmit_nit+0x15b/0x540 net/core/dev.c:1958
 xmit_one net/core/dev.c:3195 [inline]
 dev_hard_start_xmit+0x3f5/0x430 net/core/dev.c:3215
 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173
 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471
 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
 __sys_sendmmsg+0x123/0x350 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
 do_syscall_64+0xcc/0x370 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

write to 0xffff8880b01786cc of 4 bytes by task 18922 on cpu 0:
 fanout_flow_is_huge net/packet/af_packet.c:1306 [inline]
 fanout_demux_rollover+0x3a4/0x3f0 net/packet/af_packet.c:1353
 packet_rcv_fanout+0x34e/0x490 net/packet/af_packet.c:1453
 deliver_skb net/core/dev.c:1888 [inline]
 dev_queue_xmit_nit+0x15b/0x540 net/core/dev.c:1958
 xmit_one net/core/dev.c:3195 [inline]
 dev_hard_start_xmit+0x3f5/0x430 net/core/dev.c:3215
 __dev_queue_xmit+0x14ab/0x1b40 net/core/dev.c:3792
 dev_queue_xmit+0x21/0x30 net/core/dev.c:3825
 neigh_direct_output+0x1f/0x30 net/core/neighbour.c:1530
 neigh_output include/net/neighbour.h:511 [inline]
 ip6_finish_output2+0x7a2/0xec0 net/ipv6/ip6_output.c:116
 __ip6_finish_output net/ipv6/ip6_output.c:142 [inline]
 __ip6_finish_output+0x2d7/0x330 net/ipv6/ip6_output.c:127
 ip6_finish_output+0x41/0x160 net/ipv6/ip6_output.c:152
 NF_HOOK_COND include/linux/netfilter.h:294 [inline]
 ip6_output+0xf2/0x280 net/ipv6/ip6_output.c:175
 dst_output include/net/dst.h:436 [inline]
 ip6_local_out+0x74/0x90 net/ipv6/output_core.c:179
 ip6_send_skb+0x53/0x110 net/ipv6/ip6_output.c:1795
 udp_v6_send_skb.isra.0+0x3ec/0xa70 net/ipv6/udp.c:1173
 udpv6_sendmsg+0x1906/0x1c20 net/ipv6/udp.c:1471
 inet6_sendmsg+0x6d/0x90 net/ipv6/af_inet6.c:576
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0x9f/0xc0 net/socket.c:657
 ___sys_sendmsg+0x2b7/0x5d0 net/socket.c:2311
 __sys_sendmmsg+0x123/0x350 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x64/0x80 net/socket.c:2439
 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: 0 PID: 18922 Comm: syz-executor.3 Not tainted 5.4.0-rc6+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011

Fixes: 3b3a5b0aab5b ("packet: rollover huge flows before small flows")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
packet: in recvmsg msg_name return at least sizeof sockaddr_ll 2020-01-27T13:50:43+00:00 Willem de Bruijn willemb@google.com 2019-04-29T15:46:55+00:00 abdea7a45abd8841015a3d625a38755defc9c448 [ Upstream commit b2cf86e1563e33a14a1c69b3e508d15dc12f804c ] Packet send checks that msg_name is at least sizeof sockaddr_ll. Packet recv must return at least this length, so that its output can be passed unmodified to packet send. This ceased to be true since adding support for lladdr longer than sll_addr. Since, the return value uses true address length. Always return at least sizeof sockaddr_ll, even if address length is shorter. Zero the padding bytes. Change v1->v2: do not overwrite zeroed padding again. use copy_len. Fixes: 0fb375fb9b93 ("[AF_PACKET]: Allow for > 8 byte hardware addresses.") Suggested-by: David Laight <David.Laight@aculab.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Sasha Levin <sashal@kernel.org> 
[ Upstream commit b2cf86e1563e33a14a1c69b3e508d15dc12f804c ]

Packet send checks that msg_name is at least sizeof sockaddr_ll.
Packet recv must return at least this length, so that its output
can be passed unmodified to packet send.

This ceased to be true since adding support for lladdr longer than
sll_addr. Since, the return value uses true address length.

Always return at least sizeof sockaddr_ll, even if address length
is shorter. Zero the padding bytes.

Change v1->v2: do not overwrite zeroed padding again. use copy_len.

Fixes: 0fb375fb9b93 ("[AF_PACKET]: Allow for > 8 byte hardware addresses.")
Suggested-by: David Laight <David.Laight@aculab.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sasha Levin <sashal@kernel.org>
af_packet: set defaule value for tmo 2019-12-31T15:34:35+00:00 Mao Wenan maowenan@huawei.com 2019-12-09T13:31:25+00:00 e99af2cb552e3fe1ec6157fc15856a89a6388886 [ Upstream commit b43d1f9f7067c6759b1051e8ecb84e82cef569fe ] There is softlockup when using TPACKET_V3: ... NMI watchdog: BUG: soft lockup - CPU#2 stuck for 60010ms! (__irq_svc) from [<c0558a0c>] (_raw_spin_unlock_irqrestore+0x44/0x54) (_raw_spin_unlock_irqrestore) from [<c027b7e8>] (mod_timer+0x210/0x25c) (mod_timer) from [<c0549c30>] (prb_retire_rx_blk_timer_expired+0x68/0x11c) (prb_retire_rx_blk_timer_expired) from [<c027a7ac>] (call_timer_fn+0x90/0x17c) (call_timer_fn) from [<c027ab6c>] (run_timer_softirq+0x2d4/0x2fc) (run_timer_softirq) from [<c021eaf4>] (__do_softirq+0x218/0x318) (__do_softirq) from [<c021eea0>] (irq_exit+0x88/0xac) (irq_exit) from [<c0240130>] (msa_irq_exit+0x11c/0x1d4) (msa_irq_exit) from [<c0209cf0>] (handle_IPI+0x650/0x7f4) (handle_IPI) from [<c02015bc>] (gic_handle_irq+0x108/0x118) (gic_handle_irq) from [<c0558ee4>] (__irq_usr+0x44/0x5c) ... If __ethtool_get_link_ksettings() is failed in prb_calc_retire_blk_tmo(), msec and tmo will be zero, so tov_in_jiffies is zero and the timer expire for retire_blk_timer is turn to mod_timer(&pkc->retire_blk_timer, jiffies + 0), which will trigger cpu usage of softirq is 100%. Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.") Tested-by: Xiao Jiangfeng <xiaojiangfeng@huawei.com> Signed-off-by: Mao Wenan <maowenan@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit b43d1f9f7067c6759b1051e8ecb84e82cef569fe ]

There is softlockup when using TPACKET_V3:
...
NMI watchdog: BUG: soft lockup - CPU#2 stuck for 60010ms!
(__irq_svc) from [<c0558a0c>] (_raw_spin_unlock_irqrestore+0x44/0x54)
(_raw_spin_unlock_irqrestore) from [<c027b7e8>] (mod_timer+0x210/0x25c)
(mod_timer) from [<c0549c30>]
(prb_retire_rx_blk_timer_expired+0x68/0x11c)
(prb_retire_rx_blk_timer_expired) from [<c027a7ac>]
(call_timer_fn+0x90/0x17c)
(call_timer_fn) from [<c027ab6c>] (run_timer_softirq+0x2d4/0x2fc)
(run_timer_softirq) from [<c021eaf4>] (__do_softirq+0x218/0x318)
(__do_softirq) from [<c021eea0>] (irq_exit+0x88/0xac)
(irq_exit) from [<c0240130>] (msa_irq_exit+0x11c/0x1d4)
(msa_irq_exit) from [<c0209cf0>] (handle_IPI+0x650/0x7f4)
(handle_IPI) from [<c02015bc>] (gic_handle_irq+0x108/0x118)
(gic_handle_irq) from [<c0558ee4>] (__irq_usr+0x44/0x5c)
...

If __ethtool_get_link_ksettings() is failed in
prb_calc_retire_blk_tmo(), msec and tmo will be zero, so tov_in_jiffies
is zero and the timer expire for retire_blk_timer is turn to
mod_timer(&pkc->retire_blk_timer, jiffies + 0),
which will trigger cpu usage of softirq is 100%.

Fixes: f6fb8f100b80 ("af-packet: TPACKET_V3 flexible buffer implementation.")
Tested-by: Xiao Jiangfeng <xiaojiangfeng@huawei.com>
Signed-off-by: Mao Wenan <maowenan@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/packet: fix race in tpacket_snd() 2019-08-25T08:48:04+00:00 Eric Dumazet edumazet@google.com 2019-08-14T09:11:57+00:00 154e6bc497c9c4dd4c8ce41a10615dbe474135cf [ Upstream commit 32d3182cd2cd29b2e7e04df7b0db350fbe11289f ] packet_sendmsg() checks tx_ring.pg_vec to decide if it must call tpacket_snd(). Problem is that the check is lockless, meaning another thread can issue a concurrent setsockopt(PACKET_TX_RING ) to flip tx_ring.pg_vec back to NULL. Given that tpacket_snd() grabs pg_vec_lock mutex, we can perform the check again to solve the race. syzbot reported : 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: 1 PID: 11429 Comm: syz-executor394 Not tainted 5.3.0-rc4+ #101 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:packet_lookup_frame+0x8d/0x270 net/packet/af_packet.c:474 Code: c1 ee 03 f7 73 0c 80 3c 0e 00 0f 85 cb 01 00 00 48 8b 0b 89 c0 4c 8d 24 c1 48 b8 00 00 00 00 00 fc ff df 4c 89 e1 48 c1 e9 03 <80> 3c 01 00 0f 85 94 01 00 00 48 8d 7b 10 4d 8b 3c 24 48 b8 00 00 RSP: 0018:ffff88809f82f7b8 EFLAGS: 00010246 RAX: dffffc0000000000 RBX: ffff8880a45c7030 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 1ffff110148b8e06 RDI: ffff8880a45c703c RBP: ffff88809f82f7e8 R08: ffff888087aea200 R09: fffffbfff134ae50 R10: fffffbfff134ae4f R11: ffffffff89a5727f R12: 0000000000000000 R13: 0000000000000001 R14: ffff8880a45c6ac0 R15: 0000000000000000 FS: 00007fa04716f700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa04716edb8 CR3: 0000000091eb4000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: packet_current_frame net/packet/af_packet.c:487 [inline] tpacket_snd net/packet/af_packet.c:2667 [inline] packet_sendmsg+0x590/0x6250 net/packet/af_packet.c:2975 sock_sendmsg_nosec net/socket.c:637 [inline] sock_sendmsg+0xd7/0x130 net/socket.c:657 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413 __do_sys_sendmmsg net/socket.c:2442 [inline] __se_sys_sendmmsg net/socket.c:2439 [inline] __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296 entry_SYSCALL_64_after_hwframe+0x49/0xbe Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap") Signed-off-by: Eric Dumazet <edumazet@google.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 32d3182cd2cd29b2e7e04df7b0db350fbe11289f ]

packet_sendmsg() checks tx_ring.pg_vec to decide
if it must call tpacket_snd().

Problem is that the check is lockless, meaning another thread
can issue a concurrent setsockopt(PACKET_TX_RING ) to flip
tx_ring.pg_vec back to NULL.

Given that tpacket_snd() grabs pg_vec_lock mutex, we can
perform the check again to solve the race.

syzbot reported :

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: 1 PID: 11429 Comm: syz-executor394 Not tainted 5.3.0-rc4+ #101
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
RIP: 0010:packet_lookup_frame+0x8d/0x270 net/packet/af_packet.c:474
Code: c1 ee 03 f7 73 0c 80 3c 0e 00 0f 85 cb 01 00 00 48 8b 0b 89 c0 4c 8d 24 c1 48 b8 00 00 00 00 00 fc ff df 4c 89 e1 48 c1 e9 03 <80> 3c 01 00 0f 85 94 01 00 00 48 8d 7b 10 4d 8b 3c 24 48 b8 00 00
RSP: 0018:ffff88809f82f7b8 EFLAGS: 00010246
RAX: dffffc0000000000 RBX: ffff8880a45c7030 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 1ffff110148b8e06 RDI: ffff8880a45c703c
RBP: ffff88809f82f7e8 R08: ffff888087aea200 R09: fffffbfff134ae50
R10: fffffbfff134ae4f R11: ffffffff89a5727f R12: 0000000000000000
R13: 0000000000000001 R14: ffff8880a45c6ac0 R15: 0000000000000000
FS:  00007fa04716f700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fa04716edb8 CR3: 0000000091eb4000 CR4: 00000000001406e0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Call Trace:
 packet_current_frame net/packet/af_packet.c:487 [inline]
 tpacket_snd net/packet/af_packet.c:2667 [inline]
 packet_sendmsg+0x590/0x6250 net/packet/af_packet.c:2975
 sock_sendmsg_nosec net/socket.c:637 [inline]
 sock_sendmsg+0xd7/0x130 net/socket.c:657
 ___sys_sendmsg+0x3e2/0x920 net/socket.c:2311
 __sys_sendmmsg+0x1bf/0x4d0 net/socket.c:2413
 __do_sys_sendmmsg net/socket.c:2442 [inline]
 __se_sys_sendmmsg net/socket.c:2439 [inline]
 __x64_sys_sendmmsg+0x9d/0x100 net/socket.c:2439
 do_syscall_64+0xfd/0x6a0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Fixes: 69e3c75f4d54 ("net: TX_RING and packet mmap")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
net/packet: fix memory leak in packet_set_ring() 2019-07-03T11:14:47+00:00 Eric Dumazet edumazet@google.com 2019-06-24T09:38:20+00:00 05dceb60e5dd7a40fd9b6c565a62ce272ed4e6a2 [ Upstream commit 55655e3d1197fff16a7a05088fb0e5eba50eac55 ] syzbot found we can leak memory in packet_set_ring(), if user application provides buggy parameters. Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com> Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 55655e3d1197fff16a7a05088fb0e5eba50eac55 ]

syzbot found we can leak memory in packet_set_ring(), if user application
provides buggy parameters.

Fixes: 7f953ab2ba46 ("af_packet: TX_RING support for TPACKET_V3")
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Sowmini Varadhan <sowmini.varadhan@oracle.com>
Reported-by: syzbot <syzkaller@googlegroups.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
af_packet: Block execution of tasks waiting for transmit to complete in AF_PACKET 2019-07-03T11:14:46+00:00 Neil Horman nhorman@tuxdriver.com 2019-06-25T21:57:49+00:00 a4709127e5dd7b3bae9a53b5312d81ce52552a36 [ Upstream commit 89ed5b519004a7706f50b70f611edbd3aaacff2c ] When an application is run that: a) Sets its scheduler to be SCHED_FIFO and b) Opens a memory mapped AF_PACKET socket, and sends frames with the MSG_DONTWAIT flag cleared, its possible for the application to hang forever in the kernel. This occurs because when waiting, the code in tpacket_snd calls schedule, which under normal circumstances allows other tasks to run, including ksoftirqd, which in some cases is responsible for freeing the transmitted skb (which in AF_PACKET calls a destructor that flips the status bit of the transmitted frame back to available, allowing the transmitting task to complete). However, when the calling application is SCHED_FIFO, its priority is such that the schedule call immediately places the task back on the cpu, preventing ksoftirqd from freeing the skb, which in turn prevents the transmitting task from detecting that the transmission is complete. We can fix this by converting the schedule call to a completion mechanism. By using a completion queue, we force the calling task, when it detects there are no more frames to send, to schedule itself off the cpu until such time as the last transmitted skb is freed, allowing forward progress to be made. Tested by myself and the reporter, with good results Change Notes: V1->V2: Enhance the sleep logic to support being interruptible and allowing for honoring to SK_SNDTIMEO (Willem de Bruijn) V2->V3: Rearrage the point at which we wait for the completion queue, to avoid needing to check for ph/skb being null at the end of the loop. Also move the complete call to the skb destructor to avoid needing to modify __packet_set_status. Also gate calling complete on packet_read_pending returning zero to avoid multiple calls to complete. (Willem de Bruijn) Move timeo computation within loop, to re-fetch the socket timeout since we also use the timeo variable to record the return code from the wait_for_complete call (Neil Horman) V3->V4: Willem has requested that the control flow be restored to the previous state. Doing so lets us eliminate the need for the po->wait_on_complete flag variable, and lets us get rid of the packet_next_frame function, but introduces another complexity. Specifically, but using the packet pending count, we can, if an applications calls sendmsg multiple times with MSG_DONTWAIT set, each set of transmitted frames, when complete, will cause tpacket_destruct_skb to issue a complete call, for which there will never be a wait_on_completion call. This imbalance will lead to any future call to wait_for_completion here to return early, when the frames they sent may not have completed. To correct this, we need to re-init the completion queue on every call to tpacket_snd before we enter the loop so as to ensure we wait properly for the frames we send in this iteration. Change the timeout and interrupted gotos to out_put rather than out_status so that we don't try to free a non-existant skb Clean up some extra newlines (Willem de Bruijn) Reviewed-by: Willem de Bruijn <willemb@google.com> Signed-off-by: Neil Horman <nhorman@tuxdriver.com> Reported-by: Matteo Croce <mcroce@redhat.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit 89ed5b519004a7706f50b70f611edbd3aaacff2c ]

When an application is run that:
a) Sets its scheduler to be SCHED_FIFO
and
b) Opens a memory mapped AF_PACKET socket, and sends frames with the
MSG_DONTWAIT flag cleared, its possible for the application to hang
forever in the kernel.  This occurs because when waiting, the code in
tpacket_snd calls schedule, which under normal circumstances allows
other tasks to run, including ksoftirqd, which in some cases is
responsible for freeing the transmitted skb (which in AF_PACKET calls a
destructor that flips the status bit of the transmitted frame back to
available, allowing the transmitting task to complete).

However, when the calling application is SCHED_FIFO, its priority is
such that the schedule call immediately places the task back on the cpu,
preventing ksoftirqd from freeing the skb, which in turn prevents the
transmitting task from detecting that the transmission is complete.

We can fix this by converting the schedule call to a completion
mechanism.  By using a completion queue, we force the calling task, when
it detects there are no more frames to send, to schedule itself off the
cpu until such time as the last transmitted skb is freed, allowing
forward progress to be made.

Tested by myself and the reporter, with good results

Change Notes:

V1->V2:
	Enhance the sleep logic to support being interruptible and
allowing for honoring to SK_SNDTIMEO (Willem de Bruijn)

V2->V3:
	Rearrage the point at which we wait for the completion queue, to
avoid needing to check for ph/skb being null at the end of the loop.
Also move the complete call to the skb destructor to avoid needing to
modify __packet_set_status.  Also gate calling complete on
packet_read_pending returning zero to avoid multiple calls to complete.
(Willem de Bruijn)

	Move timeo computation within loop, to re-fetch the socket
timeout since we also use the timeo variable to record the return code
from the wait_for_complete call (Neil Horman)

V3->V4:
	Willem has requested that the control flow be restored to the
previous state.  Doing so lets us eliminate the need for the
po->wait_on_complete flag variable, and lets us get rid of the
packet_next_frame function, but introduces another complexity.
Specifically, but using the packet pending count, we can, if an
applications calls sendmsg multiple times with MSG_DONTWAIT set, each
set of transmitted frames, when complete, will cause
tpacket_destruct_skb to issue a complete call, for which there will
never be a wait_on_completion call.  This imbalance will lead to any
future call to wait_for_completion here to return early, when the frames
they sent may not have completed.  To correct this, we need to re-init
the completion queue on every call to tpacket_snd before we enter the
loop so as to ensure we wait properly for the frames we send in this
iteration.

	Change the timeout and interrupted gotos to out_put rather than
out_status so that we don't try to free a non-existant skb
	Clean up some extra newlines (Willem de Bruijn)

Reviewed-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: Neil Horman <nhorman@tuxdriver.com>
Reported-by: Matteo Croce <mcroce@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
packet: unconditionally free po->rollover 2019-06-11T10:20:49+00:00 Willem de Bruijn willemb@google.com 2019-05-31T16:37:23+00:00 da096fe1a6a4fe37488423d07836bc701f7c1fe5 [ Upstream commit afa0925c6fcc6a8f610e996ca09bc3215048033c ] Rollover used to use a complex RCU mechanism for assignment, which had a race condition. The below patch fixed the bug and greatly simplified the logic. The feature depends on fanout, but the state is private to the socket. Fanout_release returns f only when the last member leaves and the fanout struct is to be freed. Destroy rollover unconditionally, regardless of fanout state. Fixes: 57f015f5eccf2 ("packet: fix crash in fanout_demux_rollover()") Reported-by: syzbot <syzkaller@googlegroups.com> Diagnosed-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Willem de Bruijn <willemb@google.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
[ Upstream commit afa0925c6fcc6a8f610e996ca09bc3215048033c ]

Rollover used to use a complex RCU mechanism for assignment, which had
a race condition. The below patch fixed the bug and greatly simplified
the logic.

The feature depends on fanout, but the state is private to the socket.
Fanout_release returns f only when the last member leaves and the
fanout struct is to be freed.

Destroy rollover unconditionally, regardless of fanout state.

Fixes: 57f015f5eccf2 ("packet: fix crash in fanout_demux_rollover()")
Reported-by: syzbot <syzkaller@googlegroups.com>
Diagnosed-by: Dmitry Vyukov <dvyukov@google.com>
Signed-off-by: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>