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  1. 09 Sep, 2017 11 commits
    • John Fastabend's avatar
      net: rcu lock and preempt disable missing around generic xdp · bbbe211c
      John Fastabend authored 
      do_xdp_generic must be called inside rcu critical section with preempt
disabled to ensure BPF programs are valid and per-cpu variables used
for redirect operations are consistent. This patch ensures this is true
and fixes the splat below.

The netif_receive_skb_internal() code path is now broken into two rcu
critical sections. I decided it was better to limit the preempt_enable/disable
block to just the xdp static key portion and the fallout is more
rcu_read_lock/unlock calls. Seems like the best option to me.

[  607.596901] =============================
[  607.596906] WARNING: suspicious RCU usage
[  607.596912] 4.13.0-rc4+ #570 Not tainted
[  607.596917] -----------------------------
[  607.596923] net/core/dev.c:3948 suspicious rcu_dereference_check() usage!
[  607.596927]
[  607.596927] other info that might help us debug this:
[  607.596927]
[  607.596933]
[  607.596933] rcu_scheduler_active = 2, debug_locks = 1
[  607.596938] 2 locks held by pool/14624:
[  607.596943]  #0:  (rcu_read_lock_bh){......}, at: [<ffffffff95445ffd>] ip_finish_output2+0x14d/0x890
[  607.596973]  #1:  (rcu_read_lock_bh){......}, at: [<ffffffff953c8e3a>] __dev_queue_xmit+0x14a/0xfd0
[  607.597000]
[  607.597000] stack backtrace:
[  607.597006] CPU: 5 PID: 14624 Comm: pool Not tainted 4.13.0-rc4+ #570
[  607.597011] Hardware name: Dell Inc. Precision Tower 5810/0HHV7N, BIOS A17 03/01/2017
[  607.597016] Call Trace:
[  607.597027]  dump_stack+0x67/0x92
[  607.597040]  lockdep_rcu_suspicious+0xdd/0x110
[  607.597054]  do_xdp_generic+0x313/0xa50
[  607.597068]  ? time_hardirqs_on+0x5b/0x150
[  607.597076]  ? mark_held_locks+0x6b/0xc0
[  607.597088]  ? netdev_pick_tx+0x150/0x150
[  607.597117]  netif_rx_internal+0x205/0x3f0
[  607.597127]  ? do_xdp_generic+0xa50/0xa50
[  607.597144]  ? lock_downgrade+0x2b0/0x2b0
[  607.597158]  ? __lock_is_held+0x93/0x100
[  607.597187]  netif_rx+0x119/0x190
[  607.597202]  loopback_xmit+0xfd/0x1b0
[  607.597214]  dev_hard_start_xmit+0x127/0x4e0

Fixes: d4455169 ("net: xdp: support xdp generic on virtual devices")
Fixes: b5cdae32 ("net: Generic XDP")
Acked-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      bbbe211c
    • Daniel Borkmann's avatar
      bpf: don't select potentially stale ri->map from buggy xdp progs · 109980b8
      Daniel Borkmann authored 
      We can potentially run into a couple of issues with the XDP
bpf_redirect_map() helper. The ri->map in the per CPU storage
can become stale in several ways, mostly due to misuse, where
we can then trigger a use after free on the map:

i) prog A is calling bpf_redirect_map(), returning XDP_REDIRECT
and running on a driver not supporting XDP_REDIRECT yet. The
ri->map on that CPU becomes stale when the XDP program is unloaded
on the driver, and a prog B loaded on a different driver which
supports XDP_REDIRECT return code. prog B would have to omit
calling to bpf_redirect_map() and just return XDP_REDIRECT, which
would then access the freed map in xdp_do_redirect() since not
cleared for that CPU.

ii) prog A is calling bpf_redirect_map(), returning a code other
than XDP_REDIRECT. prog A is then detached, which triggers release
of the map. prog B is attached which, similarly as in i), would
just return XDP_REDIRECT without having called bpf_redirect_map()
and thus be accessing the freed map in xdp_do_redirect() since
not cleared for that CPU.

iii) prog A is attached to generic XDP, calling the bpf_redirect_map()
helper and returning XDP_REDIRECT. xdp_do_generic_redirect() is
currently not handling ri->map (will be fixed by Jesper), so it's
not being reset. Later loading a e.g. native prog B which would,
say, call bpf_xdp_redirect() and then returns XDP_REDIRECT would
find in xdp_do_redirect() that a map was set and uses that causing
use after free on map access.

Fix thus needs to avoid accessing stale ri->map pointers, naive
way would be to call a BPF function from drivers that just resets
it to NULL for all XDP return codes but XDP_REDIRECT and including
XDP_REDIRECT for drivers not supporting it yet (and let ri->map
being handled in xdp_do_generic_redirect()). There is a less
intrusive way w/o letting drivers call a reset for each BPF run.

The verifier knows we're calling into bpf_xdp_redirect_map()
helper, so it can do a small insn rewrite transparent to the prog
itself in the sense that it fills R4 with a pointer to the own
bpf_prog. We have that pointer at verification time anyway and
R4 is allowed to be used as per calling convention we scratch
R0 to R5 anyway, so they become inaccessible and program cannot
read them prior to a write. Then, the helper would store the prog
pointer in the current CPUs struct redirect_info. Later in
xdp_do_*_redirect() we check whether the redirect_info's prog
pointer is the same as passed xdp_prog pointer, and if that's
the case then all good, since the prog holds a ref on the map
anyway, so it is always valid at that point in time and must
have a reference count of at least 1. If in the unlikely case
they are not equal, it means we got a stale pointer, so we clear
and bail out right there. Also do reset map and the owning prog
in bpf_xdp_redirect(), so that bpf_xdp_redirect_map() and
bpf_xdp_redirect() won't get mixed up, only the last call should
take precedence. A tc bpf_redirect() doesn't use map anywhere
yet, so no need to clear it there since never accessed in that
layer.

Note that in case the prog is released, and thus the map as
well we're still under RCU read critical section at that time
and have preemption disabled as well. Once we commit with the
__dev_map_insert_ctx() from xdp_do_redirect_map() and set the
map to ri->map_to_flush, we still wait for a xdp_do_flush_map()
to finish in devmap dismantle time once flush_needed bit is set,
so that is fine.

Fixes: 97f91a7c ("bpf: add bpf_redirect_map helper routine")
Reported-by: default avatarJesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: default avatarDaniel Borkmann <daniel@iogearbox.net>
Signed-off-by: default avatarJohn Fastabend <john.fastabend@gmail.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      109980b8
    • Kees Cook's avatar
      net: tulip: Constify tulip_tbl · 9a486c9d
      Kees Cook authored 
      It looks like all users of tulip_tbl are reads, so mark this table
as read-only.

$ git grep tulip_tbl  # edited to avoid line-wraps...
interrupt.c: iowrite32(tulip_tbl[tp->chip_id].valid_intrs, ...
interrupt.c: iowrite32(tulip_tbl[tp->chip_id].valid_intrs&~RxPollInt, ...
interrupt.c: iowrite32(tulip_tbl[tp->chip_id].valid_intrs, ...
interrupt.c: iowrite32(tulip_tbl[tp->chip_id].valid_intrs | TimerInt,
pnic.c:      iowrite32(tulip_tbl[tp->chip_id].valid_intrs, ioaddr + CSR7);
tulip.h:     extern struct tulip_chip_table tulip_tbl[];
tulip_core.c:struct tulip_chip_table tulip_tbl[] = {
tulip_core.c:iowrite32(tulip_tbl[tp->chip_id].valid_intrs, ioaddr + CSR5);
tulip_core.c:iowrite32(tulip_tbl[tp->chip_id].valid_intrs, ioaddr + CSR7);
tulip_core.c:setup_timer(&tp->timer, tulip_tbl[tp->chip_id].media_timer,
tulip_core.c:const char *chip_name = tulip_tbl[chip_idx].chip_name;
tulip_core.c:if (pci_resource_len (pdev, 0) < tulip_tbl[chip_idx].io_size)
tulip_core.c:ioaddr =  pci_iomap(..., tulip_tbl[chip_idx].io_size);
tulip_core.c:tp->flags = tulip_tbl[chip_idx].flags;
tulip_core.c:setup_timer(&tp->timer, tulip_tbl[tp->chip_id].media_timer,
tulip_core.c:INIT_WORK(&tp->media_work, tulip_tbl[tp->chip_id].media_task);

Cc: "David S. Miller" <davem@davemloft.net>
Cc: Jarod Wilson <jarod@redhat.com>
Cc: "Gustavo A. R. Silva" <gustavo@embeddedor.com>
Cc: netdev@vger.kernel.org
Cc: linux-parisc@vger.kernel.org
Signed-off-by: default avatarKees Cook <keescook@chromium.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      9a486c9d
    • Ivan Khoronzhuk's avatar
      net: ethernet: ti: netcp_core: no need in netif_napi_del · e333ac1f
      Ivan Khoronzhuk authored 
      Don't remove rx_napi specifically just before free_netdev(),
it's supposed to be done in it and is confusing w/o tx_napi deletion.
Signed-off-by: default avatarIvan Khoronzhuk <ivan.khoronzhuk@linaro.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      e333ac1f
    • Mathieu Malaterre's avatar
      davicom: Display proper debug level up to 6 · 0fdbedc7
      Mathieu Malaterre authored 
      This will make it explicit some messages are of the form:
dm9000_dbg(db, 5, ...
Signed-off-by: default avatarMathieu Malaterre <malat@debian.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0fdbedc7
    • Baruch Siach's avatar
      net: phy: sfp: rename dt properties to match the binding · 25ee0793
      Baruch Siach authored 
      Make the Rx rate select control gpio property name match the documented
binding. This would make the addition of 'rate-select1-gpios' for SFP+
support more natural.

Also, make the MOD-DEF0 gpio property name match the documentation.
Signed-off-by: default avatarBaruch Siach <baruch@tkos.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      25ee0793
    • Baruch Siach's avatar
      dt-binding: net: sfp binding documentation · 3ef37140
      Baruch Siach authored 
      Add device-tree binding documentation SFP transceivers. Support for SFP
transceivers has been recently introduced (drivers/net/phy/sfp.c).
Signed-off-by: default avatarBaruch Siach <baruch@tkos.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      3ef37140
    • Baruch Siach's avatar
      dt-bindings: add SFF vendor prefix · 165da358
      Baruch Siach authored 
      Acked-by: default avatarRob Herring <robh@kernel.org>
Signed-off-by: default avatarBaruch Siach <baruch@tkos.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      165da358
    • Baruch Siach's avatar
      dt-bindings: net: don't confuse with generic PHY property · c43593d8
      Baruch Siach authored 
      This complements commit 9a94b3a4 (dt-binding: phy: don't confuse with
Ethernet phy properties).

The generic PHY 'phys' property sometime appears in the same node with
the Ethernet PHY 'phy' or 'phy-handle' properties. Add a warning in
ethernet.txt to reduce confusion.
Signed-off-by: default avatarBaruch Siach <baruch@tkos.co.il>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      c43593d8
    • Haishuang Yan's avatar
      ip6_tunnel: fix setting hop_limit value for ipv6 tunnel · 18e1173d
      Haishuang Yan authored 
      Similar to vxlan/geneve tunnel, if hop_limit is zero, it should fall
back to ip6_dst_hoplimt().
Signed-off-by: default avatarHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      18e1173d
    • Haishuang Yan's avatar
      ip_tunnel: fix setting ttl and tos value in collect_md mode · 0f693f19
      Haishuang Yan authored 
      ttl and tos variables are declared and assigned, but are not used in
iptunnel_xmit() function.

Fixes: cfc7381b ("ip_tunnel: add collect_md mode to IPIP tunnel")
Cc: Alexei Starovoitov <ast@fb.com>
Signed-off-by: default avatarHaishuang Yan <yanhaishuang@cmss.chinamobile.com>
Acked-by: default avatarAlexei Starovoitov <ast@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      0f693f19
  3. 08 Sep, 2017 21 commits
  5. 07 Sep, 2017 8 commits
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