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  1. 05 Sep, 2014 4 commits
    • Daniel Borkmann's avatar
      net: bpf: make eBPF interpreter images read-only · 60a3b225
      Daniel Borkmann authored 
      With eBPF getting more extended and exposure to user space is on it's way,
hardening the memory range the interpreter uses to steer its command flow
seems appropriate.  This patch moves the to be interpreted bytecode to
read-only pages.

In case we execute a corrupted BPF interpreter image for some reason e.g.
caused by an attacker which got past a verifier stage, it would not only
provide arbitrary read/write memory access but arbitrary function calls
as well. After setting up the BPF interpreter image, its contents do not
change until destruction time, thus we can setup the image on immutable
made pages in order to mitigate modifications to that code. The idea
is derived from commit 314beb9b ("x86: bpf_jit_comp: secure bpf jit
against spraying attacks").

This is possible because bpf_prog is not part of sk_filter anymore.
After setup bpf_prog cannot be altered during its life-time. This prevents
any modifications to the entire bpf_prog structure (incl. function/JIT
image pointer).

Every eBPF program (including classic BPF that are migrated) have to call
bpf_prog_select_runtime() to select either interpreter or a JIT image
as a last setup step, and they all are being freed via bpf_prog_free(),
including non-JIT. Therefore, we can easily integrate this into the
eBPF life-time, plus since we directly allocate a bpf_prog, we have no
performance penalty.

Tested with seccomp and test_bpf testsuite in JIT/non-JIT mode and manual
inspection of kernel_page_tables.  Brad Spengler proposed the same idea
via Twitter during development of this patch.

Joint work with Hannes Frederic Sowa.
Suggested-by: default avatarBrad Spengler <spender@grsecurity.net>
Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Cc: Alexei Starovoitov <ast@plumgrid.com>
Cc: Kees Cook <keescook@chromium.org>
Acked-by: default avatarAlexei Starovoitov <ast@plumgrid.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      60a3b225
    • Florian Fainelli's avatar
      net: systemport: update UMAC_CMD only when link is detected · 4a804c01
      Florian Fainelli authored 
      When we bring the interface down, phy_stop() will schedule the PHY
state machine to call our link adjustment callback. By the time we do so,
we may have clock gated off the SYSTEMPORT hardware block, and this will
cause bus errors to happen in bcm_sysport_adj_link():

Make sure that we only touch the UMAC_CMD register when there is an
actual link. This is safe to do for two reasons:

- updating the Ethernet MAC registers only make sense when a physical
  link is present
- the PHY library state machine first set phydev->link = 0 before
  invoking phydev->adjust_link in the PHY_HALTED case

This is a similar fix to the GENET one:
c677ba8b ("net: bcmgenet: update
UMAC_CMD only when link is detected").

Fixes: 80105bef ("net: systemport: add Broadcom SYSTEMPORT Ethernet MAC driver")
Signed-off-by: default avatarFlorian Fainelli <f.fainelli@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      4a804c01
    • Hannes Frederic Sowa's avatar
      ipv4: implement igmp_qrv sysctl to tune igmp robustness variable · a9fe8e29
      Hannes Frederic Sowa authored 
      As in IPv6 people might increase the igmp query robustness variable to
make sure unsolicited state change reports aren't lost on the network. Add
and document this new knob to igmp code.

RFCs allow tuning this parameter back to first IGMP RFC, so we also use
this setting for all counters, including source specific multicast.

Also take over sysctl value when upping the interface and don't reuse
the last one seen on the interface.

Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: default avatarFlavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      a9fe8e29
    • Hannes Frederic Sowa's avatar
      ipv6: add sysctl_mld_qrv to configure query robustness variable · 2f711939
      Hannes Frederic Sowa authored 
      This patch adds a new sysctl_mld_qrv knob to configure the mldv1/v2 query
robustness variable. It specifies how many retransmit of unsolicited mld
retransmit should happen. Admins might want to tune this on lossy links.

Also reset mld state on interface down/up, so we pick up new sysctl
settings during interface up event.

IPv6 certification requests this knob to be available.

I didn't make this knob netns specific, as it is mostly a setting in a
physical environment and should be per host.

Cc: Flavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Acked-by: default avatarFlavio Leitner <fbl@redhat.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      2f711939
  3. 04 Sep, 2014 4 commits
  5. 02 Sep, 2014 32 commits
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