linux.git/include/net, branch v4.14.34

sch_netem: fix skb leak in netem_enqueue()

2018-03-31T16:10:40+00:00

[ Upstream commit 35d889d10b649fda66121891ec05eca88150059d ]

When we exceed current packets limit and we have more than one
segment in the list returned by skb_gso_segment(), netem drops
only the first one, skipping the rest, hence kmemleak reports:

unreferenced object 0xffff880b5d23b600 (size 1024):
  comm "softirq", pid 0, jiffies 4384527763 (age 2770.629s)
  hex dump (first 32 bytes):
    00 80 23 5d 0b 88 ff ff 00 00 00 00 00 00 00 00  ..#]............
    00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
  backtrace:
    [<00000000d8a19b9d>] __alloc_skb+0xc9/0x520
    [<000000001709b32f>] skb_segment+0x8c8/0x3710
    [<00000000c7b9bb88>] tcp_gso_segment+0x331/0x1830
    [<00000000c921cba1>] inet_gso_segment+0x476/0x1370
    [<000000008b762dd4>] skb_mac_gso_segment+0x1f9/0x510
    [<000000002182660a>] __skb_gso_segment+0x1dd/0x620
    [<00000000412651b9>] netem_enqueue+0x1536/0x2590 [sch_netem]
    [<0000000005d3b2a9>] __dev_queue_xmit+0x1167/0x2120
    [<00000000fc5f7327>] ip_finish_output2+0x998/0xf00
    [<00000000d309e9d3>] ip_output+0x1aa/0x2c0
    [<000000007ecbd3a4>] tcp_transmit_skb+0x18db/0x3670
    [<0000000042d2a45f>] tcp_write_xmit+0x4d4/0x58c0
    [<0000000056a44199>] tcp_tasklet_func+0x3d9/0x540
    [<0000000013d06d02>] tasklet_action+0x1ca/0x250
    [<00000000fcde0b8b>] __do_softirq+0x1b4/0x5a3
    [<00000000e7ed027c>] irq_exit+0x1e2/0x210

Fix it by adding the rest of the segments, if any, to skb 'to_free'
list. Add new __qdisc_drop_all() and qdisc_drop_all() functions
because they can be useful in the future if we need to drop segmented
GSO packets in other places.

Fixes: 6071bd1aa13e ("netem: Segment GSO packets on enqueue")
Signed-off-by: Alexey Kodanev 
Acked-by: Neil Horman 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

tcp: reset sk_send_head in tcp_write_queue_purge

2018-03-31T16:10:38+00:00

tcp_write_queue_purge clears all the SKBs in the write queue
but does not reset the sk_send_head. As a result, we can have
a NULL pointer dereference anywhere that we use tcp_send_head
instead of the tcp_write_queue_tail.

For example, after a27fd7a8ed38 (tcp: purge write queue upon RST),
we can purge the write queue on RST. Prior to
75c119afe14f (tcp: implement rb-tree based retransmit queue),
tcp_push will only check tcp_send_head and then accesses
tcp_write_queue_tail to send the actual SKB. As a result, it will
dereference a NULL pointer.

This has been reported twice for 4.14 where we don't have
75c119afe14f:

By Timofey Titovets:

[  422.081094] BUG: unable to handle kernel NULL pointer dereference
at 0000000000000038
[  422.081254] IP: tcp_push+0x42/0x110
[  422.081314] PGD 0 P4D 0
[  422.081364] Oops: 0002 [#1] SMP PTI

By Yongjian Xu:

BUG: unable to handle kernel NULL pointer dereference at 0000000000000038
IP: tcp_push+0x48/0x120
PGD 80000007ff77b067 P4D 80000007ff77b067 PUD 7fd989067 PMD 0
Oops: 0002 [#18] SMP PTI
Modules linked in: tcp_diag inet_diag tcp_bbr sch_fq iTCO_wdt
iTCO_vendor_support pcspkr ixgbe mdio i2c_i801 lpc_ich joydev input_leds shpchp
e1000e igb dca ptp pps_core hwmon mei_me mei ipmi_si ipmi_msghandler sg ses
scsi_transport_sas enclosure ext4 jbd2 mbcache sd_mod ahci libahci megaraid_sas
wmi ast ttm dm_mirror dm_region_hash dm_log dm_mod dax
CPU: 6 PID: 14156 Comm: [ET_NET 6] Tainted: G D 4.14.26-1.el6.x86_64 #1
Hardware name: LENOVO ThinkServer RD440 /ThinkServer RD440, BIOS A0TS80A
09/22/2014
task: ffff8807d78d8140 task.stack: ffffc9000e944000
RIP: 0010:tcp_push+0x48/0x120
RSP: 0018:ffffc9000e947a88 EFLAGS: 00010246
RAX: 00000000000005b4 RBX: ffff880f7cce9c00 RCX: 0000000000000000
RDX: 0000000000000000 RSI: 0000000000000040 RDI: ffff8807d00f5000
RBP: ffffc9000e947aa8 R08: 0000000000001c84 R09: 0000000000000000
R10: ffff8807d00f5158 R11: 0000000000000000 R12: ffff8807d00f5000
R13: 0000000000000020 R14: 00000000000256d4 R15: 0000000000000000
FS: 00007f5916de9700(0000) GS:ffff88107fd00000(0000) knlGS:0000000000000000
CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000038 CR3: 00000007f8226004 CR4: 00000000001606e0
Call Trace:
tcp_sendmsg_locked+0x33d/0xe50
tcp_sendmsg+0x37/0x60
inet_sendmsg+0x39/0xc0
sock_sendmsg+0x49/0x60
sock_write_iter+0xb6/0x100
do_iter_readv_writev+0xec/0x130
? rw_verify_area+0x49/0xb0
do_iter_write+0x97/0xd0
vfs_writev+0x7e/0xe0
? __wake_up_common_lock+0x80/0xa0
? __fget_light+0x2c/0x70
? __do_page_fault+0x1e7/0x530
do_writev+0x60/0xf0
? inet_shutdown+0xac/0x110
SyS_writev+0x10/0x20
do_syscall_64+0x6f/0x140
? prepare_exit_to_usermode+0x8b/0xa0
entry_SYSCALL_64_after_hwframe+0x3d/0xa2
RIP: 0033:0x3135ce0c57
RSP: 002b:00007f5916de4b00 EFLAGS: 00000293 ORIG_RAX: 0000000000000014
RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000003135ce0c57
RDX: 0000000000000002 RSI: 00007f5916de4b90 RDI: 000000000000606f
RBP: 0000000000000000 R08: 0000000000000000 R09: 00007f5916de8c38
R10: 0000000000000000 R11: 0000000000000293 R12: 00000000000464cc
R13: 00007f5916de8c30 R14: 00007f58d8bef080 R15: 0000000000000002
Code: 48 8b 97 60 01 00 00 4c 8d 97 58 01 00 00 41 b9 00 00 00 00 41 89 f3 4c 39
d2 49 0f 44 d1 41 81 e3 00 80 00 00 0f 85 b0 00 00 00 <80> 4a 38 08 44 8b 8f 74
06 00 00 44 89 8f 7c 06 00 00 83 e6 01
RIP: tcp_push+0x48/0x120 RSP: ffffc9000e947a88
CR2: 0000000000000038
---[ end trace 8d545c2e93515549 ]---

Fixes: a27fd7a8ed38 (tcp: purge write queue upon RST)
Reported-by: Timofey Titovets 
Reported-by: Yongjian Xu 
Signed-off-by: Eric Dumazet 
Signed-off-by: Soheil Hassas Yeganeh 
Tested-by: Yongjian Xu 

Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

udplite: fix partial checksum initialization

2018-03-09T06:41:10+00:00

[ Upstream commit 15f35d49c93f4fa9875235e7bf3e3783d2dd7a1b ]

Since UDP-Lite is always using checksum, the following path is
triggered when calculating pseudo header for it:

  udp4_csum_init() or udp6_csum_init()
    skb_checksum_init_zero_check()
      __skb_checksum_validate_complete()

The problem can appear if skb->len is less than CHECKSUM_BREAK. In
this particular case __skb_checksum_validate_complete() also invokes
__skb_checksum_complete(skb). If UDP-Lite is using partial checksum
that covers only part of a packet, the function will return bad
checksum and the packet will be dropped.

It can be fixed if we skip skb_checksum_init_zero_check() and only
set the required pseudo header checksum for UDP-Lite with partial
checksum before udp4_csum_init()/udp6_csum_init() functions return.

Fixes: ed70fcfcee95 ("net: Call skb_checksum_init in IPv4")
Fixes: e4f45b7f40bd ("net: Call skb_checksum_init in IPv6")
Signed-off-by: Alexey Kodanev 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net_sched: get rid of rcu_barrier() in tcf_block_put_ext()

2018-03-03T09:24:39+00:00

commit efbf78973978b0d25af59bc26c8013a942af6e64 upstream.

Both Eric and Paolo noticed the rcu_barrier() we use in
tcf_block_put_ext() could be a performance bottleneck when
we have a lot of tc classes.

Paolo provided the following to demonstrate the issue:

tc qdisc add dev lo root htb
for I in `seq 1 1000`; do
        tc class add dev lo parent 1: classid 1:$I htb rate 100kbit
        tc qdisc add dev lo parent 1:$I handle $((I + 1)): htb
        for J in `seq 1 10`; do
                tc filter add dev lo parent $((I + 1)): u32 match ip src 1.1.1.$J
        done
done
time tc qdisc del dev root

real    0m54.764s
user    0m0.023s
sys     0m0.000s

The rcu_barrier() there is to ensure we free the block after all chains
are gone, that is, to queue tcf_block_put_final() at the tail of workqueue.
We can achieve this ordering requirement by refcnt'ing tcf block instead,
that is, the tcf block is freed only when the last chain in this block is
gone. This also simplifies the code.

Paolo reported after this patch we get:

real    0m0.017s
user    0m0.000s
sys     0m0.017s

Tested-by: Paolo Abeni 
Cc: Eric Dumazet 
Cc: Jiri Pirko 
Cc: Jamal Hadi Salim 
Signed-off-by: Cong Wang 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

xfrm: Reinject transport-mode packets through tasklet

2018-03-03T09:24:25+00:00

[ Upstream commit acf568ee859f098279eadf551612f103afdacb4e ]

This is an old bugbear of mine:

https://www.mail-archive.com/netdev@vger.kernel.org/msg03894.html

By crafting special packets, it is possible to cause recursion
in our kernel when processing transport-mode packets at levels
that are only limited by packet size.

The easiest one is with DNAT, but an even worse one is where
UDP encapsulation is used in which case you just have to insert
an UDP encapsulation header in between each level of recursion.

This patch avoids this problem by reinjecting tranport-mode packets
through a tasklet.

Fixes: b05e106698d9 ("[IPV4/6]: Netfilter IPsec input hooks")
Signed-off-by: Herbert Xu 
Signed-off-by: Steffen Klassert 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

net_sched: red: Avoid illegal values

2018-02-25T10:07:59+00:00

[ Upstream commit 8afa10cbe281b10371fee5a87ab266e48d71a7f9 ]

Check the qmin & qmax values doesn't overflow for the given Wlog value.
Check that qmin <= qmax.

Fixes: a783474591f2 ("[PKT_SCHED]: Generic RED layer")
Signed-off-by: Nogah Frankel 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

net_sched: red: Avoid devision by zero

2018-02-25T10:07:59+00:00

[ Upstream commit 5c472203421ab4f928aa1ae9e1dbcfdd80324148 ]

Do not allow delta value to be zero since it is used as a divisor.

Fixes: 8af2a218de38 ("sch_red: Adaptative RED AQM")
Signed-off-by: Nogah Frankel 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin 
Signed-off-by: Greg Kroah-Hartman

sctp: set frag_point in sctp_setsockopt_maxseg correctly

2018-02-25T10:07:47+00:00

commit ecca8f88da5c4260cc2bccfefd2a24976704c366 upstream.

Now in sctp_setsockopt_maxseg user_frag or frag_point can be set with
val >= 8 and val <= SCTP_MAX_CHUNK_LEN. But both checks are incorrect.

val >= 8 means frag_point can even be less than SCTP_DEFAULT_MINSEGMENT.
Then in sctp_datamsg_from_user(), when it's value is greater than cookie
echo len and trying to bundle with cookie echo chunk, the first_len will
overflow.

The worse case is when it's value is equal as cookie echo len, first_len
becomes 0, it will go into a dead loop for fragment later on. In Hangbin
syzkaller testing env, oom was even triggered due to consecutive memory
allocation in that loop.

Besides, SCTP_MAX_CHUNK_LEN is the max size of the whole chunk, it should
deduct the data header for frag_point or user_frag check.

This patch does a proper check with SCTP_DEFAULT_MINSEGMENT subtracting
the sctphdr and datahdr, SCTP_MAX_CHUNK_LEN subtracting datahdr when
setting frag_point via sockopt. It also improves sctp_setsockopt_maxseg
codes.

Suggested-by: Marcelo Ricardo Leitner 
Reported-by: Hangbin Liu 
Signed-off-by: Xin Long 
Acked-by: Marcelo Ricardo Leitner 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

mac80211_hwsim: validate number of different channels

2018-02-25T10:07:45+00:00

commit 51a1aaa631c90223888d8beac4d649dc11d2ca55 upstream.

When creating a new radio on the fly, hwsim allows this
to be done with an arbitrary number of channels, but
cfg80211 only supports a limited number of simultaneous
channels, leading to a warning.

Fix this by validating the number - this requires moving
the define for the maximum out to a visible header file.

Reported-by: syzbot+8dd9051ff19940290931@syzkaller.appspotmail.com
Fixes: b59ec8dd4394 ("mac80211_hwsim: fix number of channels in interface combinations")
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

kmemcheck: remove annotations

2018-02-22T14:42:23+00:00

commit 4950276672fce5c241857540f8561c440663673d upstream.

Patch series "kmemcheck: kill kmemcheck", v2.

As discussed at LSF/MM, kill kmemcheck.

KASan is a replacement that is able to work without the limitation of
kmemcheck (single CPU, slow).  KASan is already upstream.

We are also not aware of any users of kmemcheck (or users who don't
consider KASan as a suitable replacement).

The only objection was that since KASAN wasn't supported by all GCC
versions provided by distros at that time we should hold off for 2
years, and try again.

Now that 2 years have passed, and all distros provide gcc that supports
KASAN, kill kmemcheck again for the very same reasons.

This patch (of 4):

Remove kmemcheck annotations, and calls to kmemcheck from the kernel.

[alexander.levin@verizon.com: correctly remove kmemcheck call from dma_map_sg_attrs]
  Link: http://lkml.kernel.org/r/20171012192151.26531-1-alexander.levin@verizon.com
Link: http://lkml.kernel.org/r/20171007030159.22241-2-alexander.levin@verizon.com
Signed-off-by: Sasha Levin 
Cc: Alexander Potapenko 
Cc: Eric W. Biederman 
Cc: Michal Hocko 
Cc: Pekka Enberg 
Cc: Steven Rostedt 
Cc: Tim Hansen 
Cc: Vegard Nossum 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman