linux-stable.git/net/core, branch v4.19.166

lwt: Disable BH too in run_lwt_bpf()

2020-12-30T10:26:06+00:00

[ Upstream commit d9054a1ff585ba01029584ab730efc794603d68f ]

The per-cpu bpf_redirect_info is shared among all skb_do_redirect()
and BPF redirect helpers. Callers on RX path are all in BH context,
disabling preemption is not sufficient to prevent BH interruption.

In production, we observed strange packet drops because of the race
condition between LWT xmit and TC ingress, and we verified this issue
is fixed after we disable BH.

Although this bug was technically introduced from the beginning, that
is commit 3a0af8fd61f9 ("bpf: BPF for lightweight tunnel infrastructure"),
at that time call_rcu() had to be call_rcu_bh() to match the RCU context.
So this patch may not work well before RCU flavor consolidation has been
completed around v5.0.

Update the comments above the code too, as call_rcu() is now BH friendly.

Signed-off-by: Dongdong Wang 
Signed-off-by: Alexei Starovoitov 
Reviewed-by: Cong Wang 
Link: https://lore.kernel.org/bpf/20201205075946.497763-1-xiyou.wangcong@gmail.com
Signed-off-by: Sasha Levin

sock: set sk_err to ee_errno on dequeue from errq

2020-12-08T09:18:52+00:00

[ Upstream commit 985f7337421a811cb354ca93882f943c8335a6f5 ]

When setting sk_err, set it to ee_errno, not ee_origin.

Commit f5f99309fa74 ("sock: do not set sk_err in
sock_dequeue_err_skb") disabled updating sk_err on errq dequeue,
which is correct for most error types (origins):

  -       sk->sk_err = err;

Commit 38b257938ac6 ("sock: reset sk_err when the error queue is
empty") reenabled the behavior for IMCP origins, which do require it:

  +       if (icmp_next)
  +               sk->sk_err = SKB_EXT_ERR(skb_next)->ee.ee_origin;

But read from ee_errno.

Fixes: 38b257938ac6 ("sock: reset sk_err when the error queue is empty")
Reported-by: Ayush Ranjan 
Signed-off-by: Willem de Bruijn 
Acked-by: Soheil Hassas Yeganeh 
Link: https://lore.kernel.org/r/20201126151220.2819322-1-willemdebruijn.kernel@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

net: Have netpoll bring-up DSA management interface

2020-11-24T12:27:17+00:00

[ Upstream commit 1532b9778478577152201adbafa7738b1e844868 ]

DSA network devices rely on having their DSA management interface up and
running otherwise their ndo_open() will return -ENETDOWN. Without doing
this it would not be possible to use DSA devices as netconsole when
configured on the command line. These devices also do not utilize the
upper/lower linking so the check about the netpoll device having upper
is not going to be a problem.

The solution adopted here is identical to the one done for
net/ipv4/ipconfig.c with 728c02089a0e ("net: ipv4: handle DSA enabled
master network devices"), with the network namespace scope being
restricted to that of the process configuring netpoll.

Fixes: 04ff53f96a93 ("net: dsa: Add netconsole support")
Tested-by: Vladimir Oltean 
Signed-off-by: Florian Fainelli 
Link: https://lore.kernel.org/r/20201117035236.22658-1-f.fainelli@gmail.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

devlink: Add missing genlmsg_cancel() in devlink_nl_sb_port_pool_fill()

2020-11-24T12:27:16+00:00

[ Upstream commit 849920c703392957f94023f77ec89ca6cf119d43 ]

If sb_occ_port_pool_get() failed in devlink_nl_sb_port_pool_fill(),
msg should be canceled by genlmsg_cancel().

Fixes: df38dafd2559 ("devlink: implement shared buffer occupancy monitoring interface")
Reported-by: Hulk Robot 
Signed-off-by: Wang Hai 
Link: https://lore.kernel.org/r/20201113111622.11040-1-wanghai38@huawei.com
Signed-off-by: Jakub Kicinski 
Signed-off-by: Greg Kroah-Hartman

bpf: Fix clobbering of r2 in bpf_gen_ld_abs

2020-10-01T11:14:52+00:00

[ Upstream commit e6a18d36118bea3bf497c9df4d9988b6df120689 ]

Bryce reported that he saw the following with:

  0:  r6 = r1
  1:  r1 = 12
  2:  r0 = *(u16 *)skb[r1]

The xlated sequence was incorrectly clobbering r2 with pointer
value of r6 ...

  0: (bf) r6 = r1
  1: (b7) r1 = 12
  2: (bf) r1 = r6
  3: (bf) r2 = r1
  4: (85) call bpf_skb_load_helper_16_no_cache#7692160

... and hence call to the load helper never succeeded given the
offset was too high. Fix it by reordering the load of r6 to r1.

Other than that the insn has similar calling convention than BPF
helpers, that is, r0 - r5 are scratch regs, so nothing else
affected after the insn.

Fixes: e0cea7ce988c ("bpf: implement ld_abs/ld_ind in native bpf")
Reported-by: Bryce Kahle 
Signed-off-by: Daniel Borkmann 
Signed-off-by: Alexei Starovoitov 
Link: https://lore.kernel.org/bpf/cace836e4d07bb63b1a53e49c5dfb238a040c298.1599512096.git.daniel@iogearbox.net
Signed-off-by: Sasha Levin

neigh_stat_seq_next() should increase position index

2020-10-01T11:14:29+00:00

[ Upstream commit 1e3f9f073c47bee7c23e77316b07bc12338c5bba ]

if seq_file .next fuction does not change position index,
read after some lseek can generate unexpected output.

https://bugzilla.kernel.org/show_bug.cgi?id=206283
Signed-off-by: Vasily Averin 
Signed-off-by: David S. Miller 
Signed-off-by: Sasha Levin

net: handle the return value of pskb_carve_frag_list() correctly

2020-09-23T10:10:57+00:00

commit eabe861881a733fc84f286f4d5a1ffaddd4f526f upstream.

pskb_carve_frag_list() may return -ENOMEM in pskb_carve_inside_nonlinear().
we should handle this correctly or we would get wrong sk_buff.

Fixes: 6fa01ccd8830 ("skbuff: Add pskb_extract() helper function")
Signed-off-by: Miaohe Lin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: disable netpoll on fresh napis

2020-09-12T11:40:23+00:00

[ Upstream commit 96e97bc07e90f175a8980a22827faf702ca4cb30 ]

napi_disable() makes sure to set the NAPI_STATE_NPSVC bit to prevent
netpoll from accessing rings before init is complete. However, the
same is not done for fresh napi instances in netif_napi_add(),
even though we expect NAPI instances to be added as disabled.

This causes crashes during driver reconfiguration (enabling XDP,
changing the channel count) - if there is any printk() after
netif_napi_add() but before napi_enable().

To ensure memory ordering is correct we need to use RCU accessors.

Reported-by: Rob Sherwood 
Fixes: 2d8bff12699a ("netpoll: Close race condition between poll_one_napi and napi_disable")
Signed-off-by: Jakub Kicinski 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net: Fix potential wrong skb->protocol in skb_vlan_untag()

2020-09-03T09:24:17+00:00

[ Upstream commit 55eff0eb7460c3d50716ed9eccf22257b046ca92 ]

We may access the two bytes after vlan_hdr in vlan_set_encap_proto(). So
we should pull VLAN_HLEN + sizeof(unsigned short) in skb_vlan_untag() or
we may access the wrong data.

Fixes: 0d5501c1c828 ("net: Always untag vlan-tagged traffic on input.")
Signed-off-by: Miaohe Lin 
Signed-off-by: David S. Miller 
Signed-off-by: Greg Kroah-Hartman

net/compat: Add missing sock updates for SCM_RIGHTS

2020-08-21T09:05:32+00:00

commit d9539752d23283db4692384a634034f451261e29 upstream.

Add missed sock updates to compat path via a new helper, which will be
used more in coming patches. (The net/core/scm.c code is left as-is here
to assist with -stable backports for the compat path.)

Cc: Christoph Hellwig 
Cc: Sargun Dhillon 
Cc: Jakub Kicinski 
Cc: stable@vger.kernel.org
Fixes: 48a87cc26c13 ("net: netprio: fd passed in SCM_RIGHTS datagram not set correctly")
Fixes: d84295067fc7 ("net: net_cls: fd passed in SCM_RIGHTS datagram not set correctly")
Acked-by: Christian Brauner 
Signed-off-by: Kees Cook 
Signed-off-by: Greg Kroah-Hartman