linux-stable.git/net, branch v5.8.4

can: j1939: add rxtimer for multipacket broadcast session

2020-08-26T09:49:11+00:00

[ Upstream commit 0ae18a82686f9b9965a8ce0dd81371871b306ffe ]

According to SAE J1939/21 (Chapter 5.12.3 and APPENDIX C), for transmit side
the required time interval between packets of a multipacket broadcast message
is 50 to 200 ms, the responder shall use a timeout of 250ms (provides margin
allowing for the maximumm spacing of 200ms). For receive side a timeout will
occur when a time of greater than 750 ms elapsed between two message packets
when more packets were expected.

So this patch fix and add rxtimer for multipacket broadcast session.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong 
Link: https://lore.kernel.org/r/1596599425-5534-5-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: j1939: abort multipacket broadcast session when timeout occurs

2020-08-26T09:49:11+00:00

[ Upstream commit 2b8b2e31555cf55ba3680fb28e2b382e168d7ea1 ]

If timeout occurs, j1939_tp_rxtimer() first calls hrtimer_start() to restart
rxtimer, and then calls __j1939_session_cancel() to set session->state =
J1939_SESSION_WAITING_ABORT. At next timeout expiration, because of the
J1939_SESSION_WAITING_ABORT session state j1939_tp_rxtimer() will call
j1939_session_deactivate_activate_next() to deactivate current session, and
rxtimer won't be set.

But for multipacket broadcast session, __j1939_session_cancel() don't set
session->state = J1939_SESSION_WAITING_ABORT, thus current session won't be
deactivate and hrtimer_start() is called to start new rxtimer again and again.

So fix it by moving session->state = J1939_SESSION_WAITING_ABORT out of if
(!j1939_cb_is_broadcast(&session->skcb)) statement.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong 
Link: https://lore.kernel.org/r/1596599425-5534-4-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: j1939: cancel rxtimer on multipacket broadcast session complete

2020-08-26T09:49:11+00:00

[ Upstream commit e8b17653088f28a87c81845fa41a2d295a3b458c ]

If j1939_xtp_rx_dat_one() receive last frame of multipacket broadcast message,
j1939_session_timers_cancel() should be called to cancel rxtimer.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong 
Link: https://lore.kernel.org/r/1596599425-5534-3-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: j1939: fix support for multipacket broadcast message

2020-08-26T09:49:11+00:00

[ Upstream commit f4fd77fd87e9b214c26bb2ebd4f90055eaea5ade ]

Currently j1939_tp_im_involved_anydir() in j1939_tp_recv() check the previously
set flags J1939_ECU_LOCAL_DST and J1939_ECU_LOCAL_SRC of incoming skb, thus
multipacket broadcast message was aborted by receive side because it may come
from remote ECUs and have no exact dst address. Similarly, j1939_tp_cmd_recv()
and j1939_xtp_rx_dat() didn't process broadcast message.

So fix it by checking and process broadcast message in j1939_tp_recv(),
j1939_tp_cmd_recv() and j1939_xtp_rx_dat().

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Zhang Changzhong 
Link: https://lore.kernel.org/r/1596599425-5534-2-git-send-email-zhangchangzhong@huawei.com
Acked-by: Oleksij Rempel 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: j1939: transport: add j1939_session_skb_find_by_offset() function

2020-08-26T09:49:10+00:00

[ Upstream commit 840835c9281215341d84966a8855f267a971e6a3 ]

Sometimes it makes no sense to search the skb by pkt.dpo, since we need
next the skb within the transaction block. This may happen if we have an
ETP session with CTS set to less than 255 packets.

After this patch, we will be able to work with ETP sessions where the
block size (ETP.CM_CTS byte 2) is less than 255 packets.

Reported-by: Henrique Figueira 
Reported-by: https://github.com/linux-can/can-utils/issues/228
Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel 
Link: https://lore.kernel.org/r/20200807105200.26441-5-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: j1939: transport: j1939_simple_recv(): ignore local J1939 messages send not by J1939 stack

2020-08-26T09:49:10+00:00

[ Upstream commit b43e3a82bc432c1caaed8950e7662c143470c54c ]

In current J1939 stack implementation, we process all locally send
messages as own messages. Even if it was send by CAN_RAW socket.

To reproduce it use following commands:
testj1939 -P -r can0:0x80 &
cansend can0 18238040#0123

This step will trigger false positive not critical warning:
j1939_simple_recv: Received already invalidated message

With this patch we add additional check to make sure, related skb is own
echo message.

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Oleksij Rempel 
Link: https://lore.kernel.org/r/20200807105200.26441-2-o.rempel@pengutronix.de
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

can: j1939: fix kernel-infoleak in j1939_sk_sock2sockaddr_can()

2020-08-26T09:49:09+00:00

[ Upstream commit 38ba8b9241f5848a49b80fddac9ab5f4692e434e ]

syzbot found that at least 2 bytes of kernel information
were leaked during getsockname() on AF_CAN CAN_J1939 socket.

Since struct sockaddr_can has in fact two holes, simply
clear the whole area before filling it with useful data.

BUG: KMSAN: kernel-infoleak in kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:253
CPU: 0 PID: 8466 Comm: syz-executor511 Not tainted 5.8.0-rc5-syzkaller #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+0x21c/0x280 lib/dump_stack.c:118
 kmsan_report+0xf7/0x1e0 mm/kmsan/kmsan_report.c:121
 kmsan_internal_check_memory+0x238/0x3d0 mm/kmsan/kmsan.c:423
 kmsan_copy_to_user+0x81/0x90 mm/kmsan/kmsan_hooks.c:253
 instrument_copy_to_user include/linux/instrumented.h:91 [inline]
 _copy_to_user+0x18e/0x260 lib/usercopy.c:39
 copy_to_user include/linux/uaccess.h:186 [inline]
 move_addr_to_user+0x3de/0x670 net/socket.c:237
 __sys_getsockname+0x407/0x5e0 net/socket.c:1909
 __do_sys_getsockname net/socket.c:1920 [inline]
 __se_sys_getsockname+0x91/0xb0 net/socket.c:1917
 __x64_sys_getsockname+0x4a/0x70 net/socket.c:1917
 do_syscall_64+0xad/0x160 arch/x86/entry/common.c:386
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x440219
Code: Bad RIP value.
RSP: 002b:00007ffe5ee150c8 EFLAGS: 00000246 ORIG_RAX: 0000000000000033
RAX: ffffffffffffffda RBX: 00000000004002c8 RCX: 0000000000440219
RDX: 0000000020000240 RSI: 0000000020000100 RDI: 0000000000000003
RBP: 00000000006ca018 R08: 0000000000000000 R09: 00000000004002c8
R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000401a20
R13: 0000000000401ab0 R14: 0000000000000000 R15: 0000000000000000

Local variable ----address@__sys_getsockname created at:
 __sys_getsockname+0x91/0x5e0 net/socket.c:1894
 __sys_getsockname+0x91/0x5e0 net/socket.c:1894

Bytes 2-3 of 24 are uninitialized
Memory access of size 24 starts at ffff8880ba2c7de8
Data copied to user address 0000000020000100

Fixes: 9d71dd0c7009 ("can: add support of SAE J1939 protocol")
Signed-off-by: Eric Dumazet 
Reported-by: syzbot 
Cc: Robin van der Gracht 
Cc: Oleksij Rempel 
Cc: Pengutronix Kernel Team 
Cc: linux-can@vger.kernel.org
Acked-by: Oleksij Rempel 
Link: https://lore.kernel.org/r/20200813161834.4021638-1-edumazet@google.com
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Sasha Levin

bpf: sock_ops sk access may stomp registers when dst_reg = src_reg

2020-08-26T09:49:09+00:00

[ Upstream commit 84f44df664e9f0e261157e16ee1acd77cc1bb78d ]

Similar to patch ("bpf: sock_ops ctx access may stomp registers") if the
src_reg = dst_reg when reading the sk field of a sock_ops struct we
generate xlated code,

  53: (61) r9 = *(u32 *)(r9 +28)
  54: (15) if r9 == 0x0 goto pc+3
  56: (79) r9 = *(u64 *)(r9 +0)

This stomps on the r9 reg to do the sk_fullsock check and then when
reading the skops->sk field instead of the sk pointer we get the
sk_fullsock. To fix use similar pattern noted in the previous fix
and use the temp field to save/restore a register used to do
sk_fullsock check.

After the fix the generated xlated code reads,

  52: (7b) *(u64 *)(r9 +32) = r8
  53: (61) r8 = *(u32 *)(r9 +28)
  54: (15) if r9 == 0x0 goto pc+3
  55: (79) r8 = *(u64 *)(r9 +32)
  56: (79) r9 = *(u64 *)(r9 +0)
  57: (05) goto pc+1
  58: (79) r8 = *(u64 *)(r9 +32)

Here r9 register was in-use so r8 is chosen as the temporary register.
In line 52 r8 is saved in temp variable and at line 54 restored in case
fullsock != 0. Finally we handle fullsock == 0 case by restoring at
line 58.

This adds a new macro SOCK_OPS_GET_SK it is almost possible to merge
this with SOCK_OPS_GET_FIELD, but I found the extra branch logic a
bit more confusing than just adding a new macro despite a bit of
duplicating code.

Fixes: 1314ef561102e ("bpf: export bpf_sock for BPF_PROG_TYPE_SOCK_OPS prog type")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/159718349653.4728.6559437186853473612.stgit@john-Precision-5820-Tower
Signed-off-by: Sasha Levin

bpf: sock_ops ctx access may stomp registers in corner case

2020-08-26T09:49:09+00:00

[ Upstream commit fd09af010788a884de1c39537c288830c3d305db ]

I had a sockmap program that after doing some refactoring started spewing
this splat at me:

[18610.807284] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001
[...]
[18610.807359] Call Trace:
[18610.807370]  ? 0xffffffffc114d0d5
[18610.807382]  __cgroup_bpf_run_filter_sock_ops+0x7d/0xb0
[18610.807391]  tcp_connect+0x895/0xd50
[18610.807400]  tcp_v4_connect+0x465/0x4e0
[18610.807407]  __inet_stream_connect+0xd6/0x3a0
[18610.807412]  ? __inet_stream_connect+0x5/0x3a0
[18610.807417]  inet_stream_connect+0x3b/0x60
[18610.807425]  __sys_connect+0xed/0x120

After some debugging I was able to build this simple reproducer,

 __section("sockops/reproducer_bad")
 int bpf_reproducer_bad(struct bpf_sock_ops *skops)
 {
        volatile __maybe_unused __u32 i = skops->snd_ssthresh;
        return 0;
 }

And along the way noticed that below program ran without splat,

__section("sockops/reproducer_good")
int bpf_reproducer_good(struct bpf_sock_ops *skops)
{
        volatile __maybe_unused __u32 i = skops->snd_ssthresh;
        volatile __maybe_unused __u32 family;

        compiler_barrier();

        family = skops->family;
        return 0;
}

So I decided to check out the code we generate for the above two
programs and noticed each generates the BPF code you would expect,

0000000000000000 :
;       volatile __maybe_unused __u32 i = skops->snd_ssthresh;
       0:       r1 = *(u32 *)(r1 + 96)
       1:       *(u32 *)(r10 - 4) = r1
;       return 0;
       2:       r0 = 0
       3:       exit

0000000000000000 :
;       volatile __maybe_unused __u32 i = skops->snd_ssthresh;
       0:       r2 = *(u32 *)(r1 + 96)
       1:       *(u32 *)(r10 - 4) = r2
;       family = skops->family;
       2:       r1 = *(u32 *)(r1 + 20)
       3:       *(u32 *)(r10 - 8) = r1
;       return 0;
       4:       r0 = 0
       5:       exit

So we get reasonable assembly, but still something was causing the null
pointer dereference. So, we load the programs and dump the xlated version
observing that line 0 above 'r* = *(u32 *)(r1 +96)' is going to be
translated by the skops access helpers.

int bpf_reproducer_bad(struct bpf_sock_ops * skops):
; volatile __maybe_unused __u32 i = skops->snd_ssthresh;
   0: (61) r1 = *(u32 *)(r1 +28)
   1: (15) if r1 == 0x0 goto pc+2
   2: (79) r1 = *(u64 *)(r1 +0)
   3: (61) r1 = *(u32 *)(r1 +2340)
; volatile __maybe_unused __u32 i = skops->snd_ssthresh;
   4: (63) *(u32 *)(r10 -4) = r1
; return 0;
   5: (b7) r0 = 0
   6: (95) exit

int bpf_reproducer_good(struct bpf_sock_ops * skops):
; volatile __maybe_unused __u32 i = skops->snd_ssthresh;
   0: (61) r2 = *(u32 *)(r1 +28)
   1: (15) if r2 == 0x0 goto pc+2
   2: (79) r2 = *(u64 *)(r1 +0)
   3: (61) r2 = *(u32 *)(r2 +2340)
; volatile __maybe_unused __u32 i = skops->snd_ssthresh;
   4: (63) *(u32 *)(r10 -4) = r2
; family = skops->family;
   5: (79) r1 = *(u64 *)(r1 +0)
   6: (69) r1 = *(u16 *)(r1 +16)
; family = skops->family;
   7: (63) *(u32 *)(r10 -8) = r1
; return 0;
   8: (b7) r0 = 0
   9: (95) exit

Then we look at lines 0 and 2 above. In the good case we do the zero
check in r2 and then load 'r1 + 0' at line 2. Do a quick cross-check
into the bpf_sock_ops check and we can confirm that is the 'struct
sock *sk' pointer field. But, in the bad case,

   0: (61) r1 = *(u32 *)(r1 +28)
   1: (15) if r1 == 0x0 goto pc+2
   2: (79) r1 = *(u64 *)(r1 +0)

Oh no, we read 'r1 +28' into r1, this is skops->fullsock and then in
line 2 we read the 'r1 +0' as a pointer. Now jumping back to our spat,

[18610.807284] BUG: unable to handle kernel NULL pointer dereference at 0000000000000001

The 0x01 makes sense because that is exactly the fullsock value. And
its not a valid dereference so we splat.

To fix we need to guard the case when a program is doing a sock_ops field
access with src_reg == dst_reg. This is already handled in the load case
where the ctx_access handler uses a tmp register being careful to
store the old value and restore it. To fix the get case test if
src_reg == dst_reg and in this case do the is_fullsock test in the
temporary register. Remembering to restore the temporary register before
writing to either dst_reg or src_reg to avoid smashing the pointer into
the struct holding the tmp variable.

Adding this inline code to test_tcpbpf_kern will now be generated
correctly from,

  9: r2 = *(u32 *)(r2 + 96)

to xlated code,

  12: (7b) *(u64 *)(r2 +32) = r9
  13: (61) r9 = *(u32 *)(r2 +28)
  14: (15) if r9 == 0x0 goto pc+4
  15: (79) r9 = *(u64 *)(r2 +32)
  16: (79) r2 = *(u64 *)(r2 +0)
  17: (61) r2 = *(u32 *)(r2 +2348)
  18: (05) goto pc+1
  19: (79) r9 = *(u64 *)(r2 +32)

And in the normal case we keep the original code, because really this
is an edge case. From this,

  9: r2 = *(u32 *)(r6 + 96)

to xlated code,

  22: (61) r2 = *(u32 *)(r6 +28)
  23: (15) if r2 == 0x0 goto pc+2
  24: (79) r2 = *(u64 *)(r6 +0)
  25: (61) r2 = *(u32 *)(r2 +2348)

So three additional instructions if dst == src register, but I scanned
my current code base and did not see this pattern anywhere so should
not be a big deal. Further, it seems no one else has hit this or at
least reported it so it must a fairly rare pattern.

Fixes: 9b1f3d6e5af29 ("bpf: Refactor sock_ops_convert_ctx_access")
Signed-off-by: John Fastabend 
Signed-off-by: Daniel Borkmann 
Acked-by: Song Liu 
Acked-by: Martin KaFai Lau 
Link: https://lore.kernel.org/bpf/159718347772.4728.2781381670567919577.stgit@john-Precision-5820-Tower
Signed-off-by: Sasha Levin

netfilter: nf_tables: nft_exthdr: the presence return value should be little-endian

2020-08-26T09:49:08+00:00

[ Upstream commit b428336676dbca363262cc134b6218205df4f530 ]

On big-endian machine, the returned register data when the exthdr is
present is not being compared correctly because little-endian is
assumed. The function nft_cmp_fast_mask(), called by nft_cmp_fast_eval()
and nft_cmp_fast_init(), calls cpu_to_le32().

The following dump also shows that little endian is assumed:

$ nft --debug=netlink add rule ip recordroute forward ip option rr exists counter
ip
  [ exthdr load ipv4 1b @ 7 + 0 present => reg 1 ]
  [ cmp eq reg 1 0x01000000 ]
  [ counter pkts 0 bytes 0 ]

Lastly, debug print in nft_cmp_fast_init() and nft_cmp_fast_eval() when
RR option exists in the packet shows that the comparison fails because
the assumption:

nft_cmp_fast_init:189 priv->sreg=4 desc.len=8 mask=0xff000000 data.data[0]=0x10003e0
nft_cmp_fast_eval:57 regs->data[priv->sreg=4]=0x1 mask=0xff000000 priv->data=0x1000000

v2: use nft_reg_store8() instead (Florian Westphal). Also to avoid the
    warnings reported by kernel test robot.

Fixes: dbb5281a1f84 ("netfilter: nf_tables: add support for matching IPv4 options")
Fixes: c078ca3b0c5b ("netfilter: nft_exthdr: Add support for existence check")
Signed-off-by: Stephen Suryaputra 
Signed-off-by: Pablo Neira Ayuso 
Signed-off-by: Sasha Levin