18 Oct, 2018
1 commit
-
[ Upstream commit 2ab2ddd301a22ca3c5f0b743593e4ad2953dfa53 ]
Timer handlers do not imply rcu_read_lock(), so my recent fix
triggered a LOCKDEP warning when SYNACK is retransmit.Lets add rcu_read_lock()/rcu_read_unlock() pairs around ireq->ireq_opt
usages instead of guessing what is done by callers, since it is
not worth the pain.Get rid of ireq_opt_deref() helper since it hides the logic
without real benefit, since it is now a standard rcu_dereference().Fixes: 1ad98e9d1bdf ("tcp/dccp: fix lockdep issue when SYN is backlogged")
Signed-off-by: Eric Dumazet
Reported-by: Willem de Bruijn
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
15 Sep, 2018
1 commit
-
[ Upstream commit 431280eebed9f5079553daf003011097763e71fd ]
tcp uses per-cpu (and per namespace) sockets (net->ipv4.tcp_sk) internally
to send some control packets.1) RST packets, through tcp_v4_send_reset()
2) ACK packets in SYN-RECV and TIME-WAIT state, through tcp_v4_send_ack()These packets assert IP_DF, and also use the hashed IP ident generator
to provide an IPv4 ID number.Geoff Alexander reported this could be used to build off-path attacks.
These packets should not be fragmented, since their size is smaller than
IPV4_MIN_MTU. Only some tunneled paths could eventually have to fragment,
regardless of inner IPID.We really can use zero IPID, to address the flaw, and as a bonus,
avoid a couple of atomic operations in ip_idents_reserve()Signed-off-by: Eric Dumazet
Reported-by: Geoff Alexander
Tested-by: Geoff Alexander
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
26 Jun, 2018
1 commit
-
[ Upstream commit 4fd44a98ffe0d048246efef67ed640fdf2098a62 ]
commit 079096f103fa ("tcp/dccp: install syn_recv requests into ehash
table") introduced an optimization for the handling of child sockets
created for a new TCP connection.But this optimization passes any data associated with the last ACK of the
connection handshake up the stack without verifying its checksum, because it
calls tcp_child_process(), which in turn calls tcp_rcv_state_process()
directly. These lower-level processing functions do not do any checksum
verification.Insert a tcp_checksum_complete call in the TCP_NEW_SYN_RECEIVE path to
fix this.Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Frank van der Linden
Signed-off-by: Eric Dumazet
Tested-by: Balbir Singh
Reviewed-by: Balbir Singh
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
03 Jan, 2018
1 commit
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[ Upstream commit 30791ac41927ebd3e75486f9504b6d2280463bf0 ]
The MD5-key that belongs to a connection is identified by the peer's
IP-address. When we are in tcp_v4(6)_reqsk_send_ack(), we are replying
to an incoming segment from tcp_check_req() that failed the seq-number
checks.Thus, to find the correct key, we need to use the skb's saddr and not
the daddr.This bug seems to have been there since quite a while, but probably got
unnoticed because the consequences are not catastrophic. We will call
tcp_v4_reqsk_send_ack only to send a challenge-ACK back to the peer,
thus the connection doesn't really fail.Fixes: 9501f9722922 ("tcp md5sig: Let the caller pass appropriate key for tcp_v{4,6}_do_calc_md5_hash().")
Signed-off-by: Christoph Paasch
Reviewed-by: Eric Dumazet
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
17 Dec, 2017
1 commit
-
[ Upstream commit eeea10b83a139451130df1594f26710c8fa390c8 ]
James Morris reported kernel stack corruption bug [1] while
running the SELinux testsuite, and bisected to a recent
commit bffa72cf7f9d ("net: sk_buff rbnode reorg")We believe this commit is fine, but exposes an older bug.
SELinux code runs from tcp_filter() and might send an ICMP,
expecting IP options to be found in skb->cb[] using regular IPCB placement.We need to defer TCP mangling of skb->cb[] after tcp_filter() calls.
This patch adds tcp_v4_fill_cb()/tcp_v4_restore_cb() in a very
similar way we added them for IPv6.[1]
[ 339.806024] SELinux: failure in selinux_parse_skb(), unable to parse packet
[ 339.822505] Kernel panic - not syncing: stack-protector: Kernel stack is corrupted in: ffffffff81745af5
[ 339.822505]
[ 339.852250] CPU: 4 PID: 3642 Comm: client Not tainted 4.15.0-rc1-test #15
[ 339.868498] Hardware name: LENOVO 10FGS0VA1L/30BC, BIOS FWKT68A 01/19/2017
[ 339.885060] Call Trace:
[ 339.896875]
[ 339.908103] dump_stack+0x63/0x87
[ 339.920645] panic+0xe8/0x248
[ 339.932668] ? ip_push_pending_frames+0x33/0x40
[ 339.946328] ? icmp_send+0x525/0x530
[ 339.958861] ? kfree_skbmem+0x60/0x70
[ 339.971431] __stack_chk_fail+0x1b/0x20
[ 339.984049] icmp_send+0x525/0x530
[ 339.996205] ? netlbl_skbuff_err+0x36/0x40
[ 340.008997] ? selinux_netlbl_err+0x11/0x20
[ 340.021816] ? selinux_socket_sock_rcv_skb+0x211/0x230
[ 340.035529] ? security_sock_rcv_skb+0x3b/0x50
[ 340.048471] ? sk_filter_trim_cap+0x44/0x1c0
[ 340.061246] ? tcp_v4_inbound_md5_hash+0x69/0x1b0
[ 340.074562] ? tcp_filter+0x2c/0x40
[ 340.086400] ? tcp_v4_rcv+0x820/0xa20
[ 340.098329] ? ip_local_deliver_finish+0x71/0x1a0
[ 340.111279] ? ip_local_deliver+0x6f/0xe0
[ 340.123535] ? ip_rcv_finish+0x3a0/0x3a0
[ 340.135523] ? ip_rcv_finish+0xdb/0x3a0
[ 340.147442] ? ip_rcv+0x27c/0x3c0
[ 340.158668] ? inet_del_offload+0x40/0x40
[ 340.170580] ? __netif_receive_skb_core+0x4ac/0x900
[ 340.183285] ? rcu_accelerate_cbs+0x5b/0x80
[ 340.195282] ? __netif_receive_skb+0x18/0x60
[ 340.207288] ? process_backlog+0x95/0x140
[ 340.218948] ? net_rx_action+0x26c/0x3b0
[ 340.230416] ? __do_softirq+0xc9/0x26a
[ 340.241625] ? do_softirq_own_stack+0x2a/0x40
[ 340.253368]
[ 340.262673] ? do_softirq+0x50/0x60
[ 340.273450] ? __local_bh_enable_ip+0x57/0x60
[ 340.285045] ? ip_finish_output2+0x175/0x350
[ 340.296403] ? ip_finish_output+0x127/0x1d0
[ 340.307665] ? nf_hook_slow+0x3c/0xb0
[ 340.318230] ? ip_output+0x72/0xe0
[ 340.328524] ? ip_fragment.constprop.54+0x80/0x80
[ 340.340070] ? ip_local_out+0x35/0x40
[ 340.350497] ? ip_queue_xmit+0x15c/0x3f0
[ 340.361060] ? __kmalloc_reserve.isra.40+0x31/0x90
[ 340.372484] ? __skb_clone+0x2e/0x130
[ 340.382633] ? tcp_transmit_skb+0x558/0xa10
[ 340.393262] ? tcp_connect+0x938/0xad0
[ 340.403370] ? ktime_get_with_offset+0x4c/0xb0
[ 340.414206] ? tcp_v4_connect+0x457/0x4e0
[ 340.424471] ? __inet_stream_connect+0xb3/0x300
[ 340.435195] ? inet_stream_connect+0x3b/0x60
[ 340.445607] ? SYSC_connect+0xd9/0x110
[ 340.455455] ? __audit_syscall_entry+0xaf/0x100
[ 340.466112] ? syscall_trace_enter+0x1d0/0x2b0
[ 340.476636] ? __audit_syscall_exit+0x209/0x290
[ 340.487151] ? SyS_connect+0xe/0x10
[ 340.496453] ? do_syscall_64+0x67/0x1b0
[ 340.506078] ? entry_SYSCALL64_slow_path+0x25/0x25Fixes: 971f10eca186 ("tcp: better TCP_SKB_CB layout to reduce cache line misses")
Signed-off-by: Eric Dumazet
Reported-by: James Morris
Tested-by: James Morris
Tested-by: Casey Schaufler
Signed-off-by: David S. Miller
Signed-off-by: Greg Kroah-Hartman
26 Oct, 2017
1 commit
-
In my first attempt to fix the lockdep splat, I forgot we could
enter inet_csk_route_req() with a freshly allocated request socket,
for which refcount has not yet been elevated, due to complex
SLAB_TYPESAFE_BY_RCU rules.We either are in rcu_read_lock() section _or_ we own a refcount on the
request.Correct RCU verb to use here is rcu_dereference_check(), although it is
not possible to prove we actually own a reference on a shared
refcount :/In v2, I added ireq_opt_deref() helper and use in three places, to fix other
possible splats.[ 49.844590] lockdep_rcu_suspicious+0xea/0xf3
[ 49.846487] inet_csk_route_req+0x53/0x14d
[ 49.848334] tcp_v4_route_req+0xe/0x10
[ 49.850174] tcp_conn_request+0x31c/0x6a0
[ 49.851992] ? __lock_acquire+0x614/0x822
[ 49.854015] tcp_v4_conn_request+0x5a/0x79
[ 49.855957] ? tcp_v4_conn_request+0x5a/0x79
[ 49.858052] tcp_rcv_state_process+0x98/0xdcc
[ 49.859990] ? sk_filter_trim_cap+0x2f6/0x307
[ 49.862085] tcp_v4_do_rcv+0xfc/0x145
[ 49.864055] ? tcp_v4_do_rcv+0xfc/0x145
[ 49.866173] tcp_v4_rcv+0x5ab/0xaf9
[ 49.868029] ip_local_deliver_finish+0x1af/0x2e7
[ 49.870064] ip_local_deliver+0x1b2/0x1c5
[ 49.871775] ? inet_del_offload+0x45/0x45
[ 49.873916] ip_rcv_finish+0x3f7/0x471
[ 49.875476] ip_rcv+0x3f1/0x42f
[ 49.876991] ? ip_local_deliver_finish+0x2e7/0x2e7
[ 49.878791] __netif_receive_skb_core+0x6d3/0x950
[ 49.880701] ? process_backlog+0x7e/0x216
[ 49.882589] __netif_receive_skb+0x1d/0x5e
[ 49.884122] process_backlog+0x10c/0x216
[ 49.885812] net_rx_action+0x147/0x3dfFixes: a6ca7abe53633 ("tcp/dccp: fix lockdep splat in inet_csk_route_req()")
Fixes: c92e8c02fe66 ("tcp/dccp: fix ireq->opt races")
Signed-off-by: Eric Dumazet
Reported-by: kernel test robot
Reported-by: Maciej Żenczykowski
Signed-off-by: David S. Miller
21 Oct, 2017
1 commit
-
syzkaller found another bug in DCCP/TCP stacks [1]
For the reasons explained in commit ce1050089c96 ("tcp/dccp: fix
ireq->pktopts race"), we need to make sure we do not access
ireq->opt unless we own the request sock.Note the opt field is renamed to ireq_opt to ease grep games.
[1]
BUG: KASAN: use-after-free in ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
Read of size 1 at addr ffff8801c951039c by task syz-executor5/3295CPU: 1 PID: 3295 Comm: syz-executor5 Not tainted 4.14.0-rc4+ #80
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
__dump_stack lib/dump_stack.c:16 [inline]
dump_stack+0x194/0x257 lib/dump_stack.c:52
print_address_description+0x73/0x250 mm/kasan/report.c:252
kasan_report_error mm/kasan/report.c:351 [inline]
kasan_report+0x25b/0x340 mm/kasan/report.c:409
__asan_report_load1_noabort+0x14/0x20 mm/kasan/report.c:427
ip_queue_xmit+0x1687/0x18e0 net/ipv4/ip_output.c:474
tcp_transmit_skb+0x1ab7/0x3840 net/ipv4/tcp_output.c:1135
tcp_send_ack.part.37+0x3bb/0x650 net/ipv4/tcp_output.c:3587
tcp_send_ack+0x49/0x60 net/ipv4/tcp_output.c:3557
__tcp_ack_snd_check+0x2c6/0x4b0 net/ipv4/tcp_input.c:5072
tcp_ack_snd_check net/ipv4/tcp_input.c:5085 [inline]
tcp_rcv_state_process+0x2eff/0x4850 net/ipv4/tcp_input.c:6071
tcp_child_process+0x342/0x990 net/ipv4/tcp_minisocks.c:816
tcp_v4_rcv+0x1827/0x2f80 net/ipv4/tcp_ipv4.c:1682
ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
NF_HOOK include/linux/netfilter.h:249 [inline]
ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
dst_input include/net/dst.h:464 [inline]
ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
NF_HOOK include/linux/netfilter.h:249 [inline]
ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
__netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
__netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
netif_receive_skb+0xae/0x390 net/core/dev.c:4611
tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
call_write_iter include/linux/fs.h:1770 [inline]
new_sync_write fs/read_write.c:468 [inline]
__vfs_write+0x68a/0x970 fs/read_write.c:481
vfs_write+0x18f/0x510 fs/read_write.c:543
SYSC_write fs/read_write.c:588 [inline]
SyS_write+0xef/0x220 fs/read_write.c:580
entry_SYSCALL_64_fastpath+0x1f/0xbe
RIP: 0033:0x40c341
RSP: 002b:00007f469523ec10 EFLAGS: 00000293 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000718000 RCX: 000000000040c341
RDX: 0000000000000037 RSI: 0000000020004000 RDI: 0000000000000015
RBP: 0000000000000086 R08: 0000000000000000 R09: 0000000000000000
R10: 00000000000f4240 R11: 0000000000000293 R12: 00000000004b7fd1
R13: 00000000ffffffff R14: 0000000020000000 R15: 0000000000025000Allocated by task 3295:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x43/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
__do_kmalloc mm/slab.c:3725 [inline]
__kmalloc+0x162/0x760 mm/slab.c:3734
kmalloc include/linux/slab.h:498 [inline]
tcp_v4_save_options include/net/tcp.h:1962 [inline]
tcp_v4_init_req+0x2d3/0x3e0 net/ipv4/tcp_ipv4.c:1271
tcp_conn_request+0xf6d/0x3410 net/ipv4/tcp_input.c:6283
tcp_v4_conn_request+0x157/0x210 net/ipv4/tcp_ipv4.c:1313
tcp_rcv_state_process+0x8ea/0x4850 net/ipv4/tcp_input.c:5857
tcp_v4_do_rcv+0x55c/0x7d0 net/ipv4/tcp_ipv4.c:1482
tcp_v4_rcv+0x2d10/0x2f80 net/ipv4/tcp_ipv4.c:1711
ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
NF_HOOK include/linux/netfilter.h:249 [inline]
ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
dst_input include/net/dst.h:464 [inline]
ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
NF_HOOK include/linux/netfilter.h:249 [inline]
ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
__netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
__netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
netif_receive_skb+0xae/0x390 net/core/dev.c:4611
tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
call_write_iter include/linux/fs.h:1770 [inline]
new_sync_write fs/read_write.c:468 [inline]
__vfs_write+0x68a/0x970 fs/read_write.c:481
vfs_write+0x18f/0x510 fs/read_write.c:543
SYSC_write fs/read_write.c:588 [inline]
SyS_write+0xef/0x220 fs/read_write.c:580
entry_SYSCALL_64_fastpath+0x1f/0xbeFreed by task 3306:
save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
save_stack+0x43/0xd0 mm/kasan/kasan.c:447
set_track mm/kasan/kasan.c:459 [inline]
kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
__cache_free mm/slab.c:3503 [inline]
kfree+0xca/0x250 mm/slab.c:3820
inet_sock_destruct+0x59d/0x950 net/ipv4/af_inet.c:157
__sk_destruct+0xfd/0x910 net/core/sock.c:1560
sk_destruct+0x47/0x80 net/core/sock.c:1595
__sk_free+0x57/0x230 net/core/sock.c:1603
sk_free+0x2a/0x40 net/core/sock.c:1614
sock_put include/net/sock.h:1652 [inline]
inet_csk_complete_hashdance+0xd5/0xf0 net/ipv4/inet_connection_sock.c:959
tcp_check_req+0xf4d/0x1620 net/ipv4/tcp_minisocks.c:765
tcp_v4_rcv+0x17f6/0x2f80 net/ipv4/tcp_ipv4.c:1675
ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
NF_HOOK include/linux/netfilter.h:249 [inline]
ip_local_deliver+0x1ce/0x6e0 net/ipv4/ip_input.c:257
dst_input include/net/dst.h:464 [inline]
ip_rcv_finish+0x887/0x19a0 net/ipv4/ip_input.c:397
NF_HOOK include/linux/netfilter.h:249 [inline]
ip_rcv+0xc3f/0x1820 net/ipv4/ip_input.c:493
__netif_receive_skb_core+0x1a3e/0x34b0 net/core/dev.c:4476
__netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4514
netif_receive_skb_internal+0x10b/0x670 net/core/dev.c:4587
netif_receive_skb+0xae/0x390 net/core/dev.c:4611
tun_rx_batched.isra.50+0x5ed/0x860 drivers/net/tun.c:1372
tun_get_user+0x249c/0x36d0 drivers/net/tun.c:1766
tun_chr_write_iter+0xbf/0x160 drivers/net/tun.c:1792
call_write_iter include/linux/fs.h:1770 [inline]
new_sync_write fs/read_write.c:468 [inline]
__vfs_write+0x68a/0x970 fs/read_write.c:481
vfs_write+0x18f/0x510 fs/read_write.c:543
SYSC_write fs/read_write.c:588 [inline]
SyS_write+0xef/0x220 fs/read_write.c:580
entry_SYSCALL_64_fastpath+0x1f/0xbeFixes: e994b2f0fb92 ("tcp: do not lock listener to process SYN packets")
Fixes: 079096f103fa ("tcp/dccp: install syn_recv requests into ehash table")
Signed-off-by: Eric Dumazet
Signed-off-by: David S. Miller
01 Oct, 2017
1 commit
-
Currently no error is emitted, but this infrastructure will
used by the next patch to allow source address validation
for mcast sockets.
Since early demux can do a route lookup and an ipv4 route
lookup can return an error code this is consistent with the
current ipv4 route infrastructure.Signed-off-by: Paolo Abeni
Signed-off-by: David S. Miller
09 Sep, 2017
1 commit
-
While the cited commit fixed a possible deadlock, it added a leak
of the request socket, since reqsk_put() must be called if the BPF
filter decided the ACK packet must be dropped.Fixes: d624d276d1dd ("tcp: fix possible deadlock in TCP stack vs BPF filter")
Signed-off-by: Eric Dumazet
Acked-by: Alexei Starovoitov
Signed-off-by: David S. Miller
24 Aug, 2017
1 commit
-
When SOF_TIMESTAMPING_RX_SOFTWARE is enabled for tcp sockets, return the
timestamp corresponding to the highest sequence number data returned.Previously the skb->tstamp is overwritten when a TCP packet is placed
in the out of order queue. While the packet is in the ooo queue, save the
timestamp in the TCB_SKB_CB. This space is shared with the gso_*
options which are only used on the tx path, and a previously unused 4
byte hole.When skbs are coalesced either in the sk_receive_queue or the
out_of_order_queue always choose the timestamp of the appended skb to
maintain the invariant of returning the timestamp of the last byte in
the recvmsg buffer.Signed-off-by: Mike Maloney
Acked-by: Willem de Bruijn
Signed-off-by: David S. Miller
16 Aug, 2017
1 commit
15 Aug, 2017
1 commit
-
Filtering the ACK packet was not put at the right place.
At this place, we already allocated a child and put it
into accept queue.We absolutely need to call tcp_child_process() to release
its spinlock, or we will deadlock at accept() or close() time.Found by syzkaller team (Thanks a lot !)
Fixes: 8fac365f63c8 ("tcp: Add a tcp_filter hook before handle ack packet")
Signed-off-by: Eric Dumazet
Reported-by: Dmitry Vyukov
Cc: Chenbo Feng
Signed-off-by: David S. Miller
08 Aug, 2017
1 commit
-
Add a second device index, sdif, to inet socket lookups. sdif is the
index for ingress devices enslaved to an l3mdev. It allows the lookups
to consider the enslaved device as well as the L3 domain when searching
for a socket.TCP moves the data in the cb. Prior to tcp_v4_rcv (e.g., early demux) the
ingress index is obtained from IPCB using inet_sdif and after the cb move
in tcp_v4_rcv the tcp_v4_sdif helper is used.Signed-off-by: David Ahern
Signed-off-by: David S. Miller
07 Aug, 2017
1 commit
-
__ip_options_echo() uses the current network namespace, and
currently retrives it via skb->dst->dev.This commit adds an explicit 'net' argument to __ip_options_echo()
and update all the call sites to provide it, usually via a simpler
sock_net().After this change, __ip_options_echo() no more needs to access
skb->dst and we can drop a couple of hack to preserve such
info in the rx path.Signed-off-by: Paolo Abeni
Signed-off-by: David S. Miller
01 Aug, 2017
2 commits
-
Was only checked by the removed prequeue code.
Signed-off-by: Florian Westphal
Signed-off-by: David S. Miller -
prequeue is a tcp receive optimization that moves part of rx processing
from bh to process context.This only works if the socket being processed belongs to a process that
is blocked in recv on that socket.In practice, this doesn't happen anymore that often because nowadays
servers tend to use an event driven (epoll) model.Even normal client applications (web browsers) commonly use many tcp
connections in parallel.This has measureable impact only in netperf (which uses plain recv and
thus allows prequeue use) from host to locally running vm (~4%), however,
there were no changes when using netperf between two physical hosts with
ixgbe interfaces.Signed-off-by: Florian Westphal
Signed-off-by: David S. Miller
25 Jul, 2017
1 commit
-
The last (4th) argument of tcp_rcv_established() is redundant as it
always equals to skb->len and the skb itself is always passed as 2th
agrument. There is no reason to have it.Signed-off-by: Ilya V. Matveychikov
Signed-off-by: David S. Miller
06 Jul, 2017
1 commit
-
Fixes: 6797318e623d ("tcp: md5: add an address prefix for key lookup")
Signed-off-by: Fengguang Wu
Signed-off-by: David S. Miller
01 Jul, 2017
1 commit
-
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.This patch uses refcount_inc_not_zero() instead of
atomic_inc_not_zero_hint() due to absense of a _hint()
version of refcount API. If the hint() version must
be used, we might need to revisit API.Signed-off-by: Elena Reshetova
Signed-off-by: Hans Liljestrand
Signed-off-by: Kees Cook
Signed-off-by: David Windsor
Signed-off-by: David S. Miller
22 Jun, 2017
1 commit
-
Currently in both ipv4 and ipv6 code path, the ack packet received when
sk at TCP_NEW_SYN_RECV state is not filtered by socket filter or cgroup
filter since it is handled from tcp_child_process and never reaches the
tcp_filter inside tcp_v4_rcv or tcp_v6_rcv. Adding a tcp_filter hooks
here can make sure all the ingress tcp packet can be correctly filtered.Signed-off-by: Chenbo Feng
Signed-off-by: David S. Miller
21 Jun, 2017
1 commit
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Changing from a memcpy to per-member comparison left the
size variable unused:net/ipv4/tcp_ipv4.c: In function 'tcp_md5_do_lookup':
net/ipv4/tcp_ipv4.c:910:15: error: unused variable 'size' [-Werror=unused-variable]This does not show up when CONFIG_IPV6 is enabled, but the
variable can be removed either way, along with the now unused
assignment.Fixes: 6797318e623d ("tcp: md5: add an address prefix for key lookup")
Signed-off-by: Arnd Bergmann
Signed-off-by: David S. Miller
20 Jun, 2017
2 commits
-
Replace first padding in the tcp_md5sig structure with a new flag field
and address prefix length so it can be specified when configuring a new
key for TCP MD5 signature. The tcpm_flags field will only be used if the
socket option is TCP_MD5SIG_EXT to avoid breaking existing programs, and
tcpm_prefixlen only when the TCP_MD5SIG_FLAG_PREFIX flag is set.Signed-off-by: Bob Gilligan
Signed-off-by: Eric Mowat
Signed-off-by: Ivan Delalande
Signed-off-by: David S. Miller -
This allows the keys used for TCP MD5 signature to be used for whole
range of addresses, specified with a prefix length, instead of only one
address as it currently is.Signed-off-by: Bob Gilligan
Signed-off-by: Eric Mowat
Signed-off-by: Ivan Delalande
Signed-off-by: David S. Miller
16 Jun, 2017
1 commit
-
Add the infrustructure for attaching Upper Layer Protocols (ULPs) over TCP
sockets. Based on a similar infrastructure in tcp_cong. The idea is that any
ULP can add its own logic by changing the TCP proto_ops structure to its own
methods.Example usage:
setsockopt(sock, SOL_TCP, TCP_ULP, "tls", sizeof("tls"));
modules will call:
tcp_register_ulp(&tcp_tls_ulp_ops);to register/unregister their ulp, with an init function and name.
A list of registered ulps will be returned by tcp_get_available_ulp, which is
hooked up to /proc. Example:$ cat /proc/sys/net/ipv4/tcp_available_ulp
tlsThere is currently no functionality to remove or chain ULPs, but
it should be possible to add these in the future if needed.Signed-off-by: Boris Pismenny
Signed-off-by: Dave Watson
Signed-off-by: David S. Miller
08 Jun, 2017
4 commits
-
DRAM supply shortage and poor memory pressure tracking in TCP
stack makes any change in SO_SNDBUF/SO_RCVBUF (or equivalent autotuning
limits) and tcp_mem[] quite hazardous.TCPMemoryPressures SNMP counter is an indication of tcp_mem sysctl
limits being hit, but only tracking number of transitions.If TCP stack behavior under stress was perfect :
1) It would maintain memory usage close to the limit.
2) Memory pressure state would be entered for short times.We certainly prefer 100 events lasting 10ms compared to one event
lasting 200 seconds.This patch adds a new SNMP counter tracking cumulative duration of
memory pressure events, given in ms units.$ cat /proc/sys/net/ipv4/tcp_mem
3088 4117 6176
$ grep TCP /proc/net/sockstat
TCP: inuse 180 orphan 0 tw 2 alloc 234 mem 4140
$ nstat -n ; sleep 10 ; nstat |grep Pressure
TcpExtTCPMemoryPressures 1700
TcpExtTCPMemoryPressuresChrono 5209v2: Used EXPORT_SYMBOL_GPL() instead of EXPORT_SYMBOL() as David
instructed.Signed-off-by: Eric Dumazet
Signed-off-by: David S. Miller -
Signed-off-by: Eric Dumazet
Signed-off-by: David S. Miller -
Signed-off-by: Eric Dumazet
Signed-off-by: David S. Miller -
Signed-off-by: Eric Dumazet
Signed-off-by: David S. Miller
18 May, 2017
2 commits
-
TCP Timestamps option is defined in RFC 7323
Traditionally on linux, it has been tied to the internal
'jiffies' variable, because it had been a cheap and good enough
generator.For TCP flows on the Internet, 1 ms resolution would be much better
than 4ms or 10ms (HZ=250 or HZ=100 respectively)For TCP flows in the DC, Google has used usec resolution for more
than two years with great success [1]Receive size autotuning (DRS) is indeed more precise and converges
faster to optimal window size.This patch converts tp->tcp_mstamp to a plain u64 value storing
a 1 usec TCP clock.This choice will allow us to upstream the 1 usec TS option as
discussed in IETF 97.[1] https://www.ietf.org/proceedings/97/slides/slides-97-tcpm-tcp-options-for-low-latency-00.pdf
Signed-off-by: Eric Dumazet
Acked-by: Soheil Hassas Yeganeh
Signed-off-by: David S. Miller -
Idea is to later convert tp->tcp_mstamp to a full u64 counter
using usec resolution, so that we can later have fine
grained TCP TS clock (RFC 7323), regardless of HZ value.We try to refresh tp->tcp_mstamp only when necessary.
Signed-off-by: Eric Dumazet
Acked-by: Soheil Hassas Yeganeh
Signed-off-by: David S. Miller
11 May, 2017
1 commit
-
Pull RCU updates from Ingo Molnar:
"The main changes are:- Debloat RCU headers
- Parallelize SRCU callback handling (plus overlapping patches)
- Improve the performance of Tree SRCU on a CPU-hotplug stress test
- Documentation updates
- Miscellaneous fixes"
* 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (74 commits)
rcu: Open-code the rcu_cblist_n_lazy_cbs() function
rcu: Open-code the rcu_cblist_n_cbs() function
rcu: Open-code the rcu_cblist_empty() function
rcu: Separately compile large rcu_segcblist functions
srcu: Debloat the header
srcu: Adjust default auto-expediting holdoff
srcu: Specify auto-expedite holdoff time
srcu: Expedite first synchronize_srcu() when idle
srcu: Expedited grace periods with reduced memory contention
srcu: Make rcutorture writer stalls print SRCU GP state
srcu: Exact tracking of srcu_data structures containing callbacks
srcu: Make SRCU be built by default
srcu: Fix Kconfig botch when SRCU not selected
rcu: Make non-preemptive schedule be Tasks RCU quiescent state
srcu: Expedite srcu_schedule_cbs_snp() callback invocation
srcu: Parallelize callback handling
kvm: Move srcu_struct fields to end of struct kvm
rcu: Fix typo in PER_RCU_NODE_PERIOD header comment
rcu: Use true/false in assignment to bool
rcu: Use bool value directly
...
06 May, 2017
1 commit
-
Whole point of randomization was to hide server uptime, but an attacker
can simply start a syn flood and TCP generates 'old style' timestamps,
directly revealing server jiffies value.Also, TSval sent by the server to a particular remote address vary
depending on syncookies being sent or not, potentially triggering PAWS
drops for innocent clients.Lets implement proper randomization, including for SYNcookies.
Also we do not need to export sysctl_tcp_timestamps, since it is not
used from a module.In v2, I added Florian feedback and contribution, adding tsoff to
tcp_get_cookie_sock().v3 removed one unused variable in tcp_v4_connect() as Florian spotted.
Fixes: 95a22caee396c ("tcp: randomize tcp timestamp offsets for each connection")
Signed-off-by: Eric Dumazet
Reviewed-by: Florian Westphal
Tested-by: Florian Westphal
Cc: Yuchung Cheng
Signed-off-by: David S. Miller
25 Apr, 2017
1 commit
-
Middlebox firewall issues can potentially cause server's data being
blackholed after a successful 3WHS using TFO. Following are the related
reports from Apple:
https://www.nanog.org/sites/default/files/Paasch_Network_Support.pdf
Slide 31 identifies an issue where the client ACK to the server's data
sent during a TFO'd handshake is dropped.
C ---> syn-data ---> S
C X S
[retry and timeout]https://www.ietf.org/proceedings/94/slides/slides-94-tcpm-13.pdf
Slide 5 shows a similar situation that the server's data gets dropped
after 3WHS.
C ---- syn-data ---> S
C S
S (accept & write)
C? X
Acked-by: Yuchung Cheng
Acked-by: Neal Cardwell
Signed-off-by: David S. Miller
23 Apr, 2017
1 commit
-
…k/linux-rcu into core/rcu
Pull RCU updates from Paul E. McKenney:
- Documentation updates.
- Miscellaneous fixes.
- Parallelize SRCU callback handling (plus overlapping patches).
Signed-off-by: Ingo Molnar <mingo@kernel.org>
19 Apr, 2017
1 commit
-
A group of Linux kernel hackers reported chasing a bug that resulted
from their assumption that SLAB_DESTROY_BY_RCU provided an existence
guarantee, that is, that no block from such a slab would be reallocated
during an RCU read-side critical section. Of course, that is not the
case. Instead, SLAB_DESTROY_BY_RCU only prevents freeing of an entire
slab of blocks.However, there is a phrase for this, namely "type safety". This commit
therefore renames SLAB_DESTROY_BY_RCU to SLAB_TYPESAFE_BY_RCU in order
to avoid future instances of this sort of confusion.Signed-off-by: Paul E. McKenney
Cc: Christoph Lameter
Cc: Pekka Enberg
Cc: David Rientjes
Cc: Joonsoo Kim
Cc: Andrew Morton
Cc:
Acked-by: Johannes Weiner
Acked-by: Vlastimil Babka
[ paulmck: Add comments mentioning the old name, as requested by Eric
Dumazet, in order to help people familiar with the old name find
the new one. ]
Acked-by: David Rientjes
25 Mar, 2017
1 commit
-
While working on some recent busy poll changes we found that child sockets
were being instantiated without NAPI ID being set. In our first attempt to
fix it, it was suggested that we should just pull programming the NAPI ID
into the function itself since all callers will need to have it set.In addition to the NAPI ID change I have dropped the code that was
populating the Rx hash since it was actually being populated in
tcp_get_cookie_sock.Reported-by: Sridhar Samudrala
Signed-off-by: Alexander Duyck
Acked-by: Eric Dumazet
Signed-off-by: David S. Miller
17 Mar, 2017
2 commits
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The tcp_tw_recycle was already broken for connections
behind NAT, since the per-destination timestamp is not
monotonically increasing for multiple machines behind
a single destination address.After the randomization of TCP timestamp offsets
in commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets
for each connection), the tcp_tw_recycle is broken for all
types of connections for the same reason: the timestamps
received from a single machine is not monotonically increasing,
anymore.Remove tcp_tw_recycle, since it is not functional. Also, remove
the PAWSPassive SNMP counter since it is only used for
tcp_tw_recycle, and simplify tcp_v4_route_req and tcp_v6_route_req
since the strict argument is only set when tcp_tw_recycle is
enabled.Signed-off-by: Soheil Hassas Yeganeh
Signed-off-by: Eric Dumazet
Signed-off-by: Neal Cardwell
Signed-off-by: Yuchung Cheng
Cc: Lutz Vieweg
Cc: Florian Westphal
Signed-off-by: David S. Miller -
Commit 8a5bd45f6616 (tcp: randomize tcp timestamp offsets for each connection)
randomizes TCP timestamps per connection. After this commit,
there is no guarantee that the timestamps received from the
same destination are monotonically increasing. As a result,
the per-destination timestamp cache in TCP metrics (i.e., tcpm_ts
in struct tcp_metrics_block) is broken and cannot be relied upon.Remove the per-destination timestamp cache and all related code
paths.Note that this cache was already broken for caching timestamps of
multiple machines behind a NAT sharing the same address.Signed-off-by: Soheil Hassas Yeganeh
Signed-off-by: Eric Dumazet
Signed-off-by: Neal Cardwell
Signed-off-by: Yuchung Cheng
Cc: Lutz Vieweg
Cc: Florian Westphal
Signed-off-by: David S. Miller
16 Mar, 2017
1 commit
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Conflicts:
drivers/net/ethernet/broadcom/genet/bcmgenet.c
net/core/sock.cConflicts were overlapping changes in bcmgenet and the
lockdep handling of sockets.Signed-off-by: David S. Miller
14 Mar, 2017
1 commit
-
As Eric Dumazet pointed out this also needs to be fixed in IPv6.
v2: Contains the IPv6 tcp/Ipv6 dccp patches as well.We have seen a few incidents lately where a dst_enty has been freed
with a dangling TCP socket reference (sk->sk_dst_cache) pointing to that
dst_entry. If the conditions/timings are right a crash then ensues when the
freed dst_entry is referenced later on. A Common crashing back trace is:#8 [] page_fault at ffffffff8163e648
[exception RIP: __tcp_ack_snd_check+74]
.
.
#9 [] tcp_rcv_established at ffffffff81580b64
#10 [] tcp_v4_do_rcv at ffffffff8158b54a
#11 [] tcp_v4_rcv at ffffffff8158cd02
#12 [] ip_local_deliver_finish at ffffffff815668f4
#13 [] ip_local_deliver at ffffffff81566bd9
#14 [] ip_rcv_finish at ffffffff8156656d
#15 [] ip_rcv at ffffffff81566f06
#16 [] __netif_receive_skb_core at ffffffff8152b3a2
#17 [] __netif_receive_skb at ffffffff8152b608
#18 [] netif_receive_skb at ffffffff8152b690
#19 [] vmxnet3_rq_rx_complete at ffffffffa015eeaf [vmxnet3]
#20 [] vmxnet3_poll_rx_only at ffffffffa015f32a [vmxnet3]
#21 [] net_rx_action at ffffffff8152bac2
#22 [] __do_softirq at ffffffff81084b4f
#23 [] call_softirq at ffffffff8164845c
#24 [] do_softirq at ffffffff81016fc5
#25 [] irq_exit at ffffffff81084ee5
#26 [] do_IRQ at ffffffff81648ff8Of course it may happen with other NIC drivers as well.
It's found the freed dst_entry here:
224 static bool tcp_in_quickack_mode(struct sock *sk)↩
225 {↩
226 ▹ const struct inet_connection_sock *icsk = inet_csk(sk);↩
227 ▹ const struct dst_entry *dst = __sk_dst_get(sk);↩
228 ↩
229 ▹ return (dst && dst_metric(dst, RTAX_QUICKACK)) ||↩
230 ▹ ▹ (icsk->icsk_ack.quick && !icsk->icsk_ack.pingpong);↩
231 }↩But there are other backtraces attributed to the same freed dst_entry in
netfilter code as well.All the vmcores showed 2 significant clues:
- Remote hosts behind the default gateway had always been redirected to a
different gateway. A rtable/dst_entry will be added for that host. Making
more dst_entrys with lower reference counts. Making this more probable.- All vmcores showed a postitive LockDroppedIcmps value, e.g:
LockDroppedIcmps 267
A closer look at the tcp_v4_err() handler revealed that do_redirect() will run
regardless of whether user space has the socket locked. This can result in a
race condition where the same dst_entry cached in sk->sk_dst_entry can be
decremented twice for the same socket via:do_redirect()->__sk_dst_check()-> dst_release().
Which leads to the dst_entry being prematurely freed with another socket
pointing to it via sk->sk_dst_cache and a subsequent crash.To fix this skip do_redirect() if usespace has the socket locked. Instead let
the redirect take place later when user space does not have the socket
locked.The dccp/IPv6 code is very similar in this respect, so fixing it there too.
As Eric Garver pointed out the following commit now invalidates routes. Which
can set the dst->obsolete flag so that ipv4_dst_check() returns null and
triggers the dst_release().Fixes: ceb3320610d6 ("ipv4: Kill routes during PMTU/redirect updates.")
Cc: Eric Garver
Cc: Hannes Sowa
Signed-off-by: Jon Maxwell
Signed-off-by: David S. Miller
