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  1. 28 4月, 2018 2 次提交
  3. 26 4月, 2018 2 次提交
  5. 27 3月, 2018 1 次提交
  7. 18 3月, 2018 1 次提交
  9. 15 3月, 2018 4 次提交
  11. 07 3月, 2018 2 次提交
  13. 27 2月, 2018 2 次提交
  15. 16 1月, 2018 1 次提交
    • D
      sctp: Define usercopy region in SCTP proto slab cache · ab9ee8e3
      由 David Windsor 提交于 
      The SCTP socket event notification subscription information need to be
copied to/from userspace. In support of usercopy hardening, this patch
defines a region in the struct proto slab cache in which userspace copy
operations are allowed. Additionally moves the usercopy fields to be
adjacent for the region to cover both.

example usage trace:

    net/sctp/socket.c:
        sctp_getsockopt_events(...):
            ...
            copy_to_user(..., &sctp_sk(sk)->subscribe, len)

        sctp_setsockopt_events(...):
            ...
            copy_from_user(&sctp_sk(sk)->subscribe, ..., optlen)

        sctp_getsockopt_initmsg(...):
            ...
            copy_to_user(..., &sctp_sk(sk)->initmsg, len)

This region is known as the slab cache's usercopy region. Slab caches
can now check that each dynamically sized copy operation involving
cache-managed memory falls entirely within the slab's usercopy region.

This patch is modified from Brad Spengler/PaX Team's PAX_USERCOPY
whitelisting code in the last public patch of grsecurity/PaX based on my
understanding of the code. Changes or omissions from the original code are
mine and don't reflect the original grsecurity/PaX code.
Signed-off-by: NDavid Windsor <dave@nullcore.net>
[kees: split from network patch, move struct members adjacent]
[kees: add SCTPv6 struct whitelist, provide usage trace]
Cc: Vlad Yasevich <vyasevich@gmail.com>
Cc: Neil Horman <nhorman@tuxdriver.com>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: linux-sctp@vger.kernel.org
Cc: netdev@vger.kernel.org
Signed-off-by: NKees Cook <keescook@chromium.org>
      ab9ee8e3
  17. 09 1月, 2018 1 次提交
    • M
      sctp: fix the handling of ICMP Frag Needed for too small MTUs · b6c5734d
      由 Marcelo Ricardo Leitner 提交于 
      syzbot reported a hang involving SCTP, on which it kept flooding dmesg
with the message:
[  246.742374] sctp: sctp_transport_update_pmtu: Reported pmtu 508 too
low, using default minimum of 512

That happened because whenever SCTP hits an ICMP Frag Needed, it tries
to adjust to the new MTU and triggers an immediate retransmission. But
it didn't consider the fact that MTUs smaller than the SCTP minimum MTU
allowed (512) would not cause the PMTU to change, and issued the
retransmission anyway (thus leading to another ICMP Frag Needed, and so
on).

As IPv4 (ip_rt_min_pmtu=556) and IPv6 (IPV6_MIN_MTU=1280) minimum MTU
are higher than that, sctp_transport_update_pmtu() is changed to
re-fetch the PMTU that got set after our request, and with that, detect
if there was an actual change or not.

The fix, thus, skips the immediate retransmission if the received ICMP
resulted in no change, in the hope that SCTP will select another path.

Note: The value being used for the minimum MTU (512,
SCTP_DEFAULT_MINSEGMENT) is not right and instead it should be (576,
SCTP_MIN_PMTU), but such change belongs to another patch.

Changes from v1:
- do not disable PMTU discovery, in the light of commit
06ad3919 ("[SCTP] Don't disable PMTU discovery when mtu is small")
and as suggested by Xin Long.
- changed the way to break the rtx loop by detecting if the icmp
  resulted in a change or not
Changes from v2:
none

See-also: https://lkml.org/lkml/2017/12/22/811Reported-by: Nsyzbot <syzkaller@googlegroups.com>
Signed-off-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      b6c5734d
  19. 16 12月, 2017 5 次提交
  21. 12 12月, 2017 11 次提交
  23. 11 12月, 2017 1 次提交
    • T
      rhashtable: Change rhashtable_walk_start to return void · 97a6ec4a
      由 Tom Herbert 提交于 
      Most callers of rhashtable_walk_start don't care about a resize event
which is indicated by a return value of -EAGAIN. So calls to
rhashtable_walk_start are wrapped wih code to ignore -EAGAIN. Something
like this is common:

       ret = rhashtable_walk_start(rhiter);
       if (ret && ret != -EAGAIN)
               goto out;

Since zero and -EAGAIN are the only possible return values from the
function this check is pointless. The condition never evaluates to true.

This patch changes rhashtable_walk_start to return void. This simplifies
code for the callers that ignore -EAGAIN. For the few cases where the
caller cares about the resize event, particularly where the table can be
walked in mulitple parts for netlink or seq file dump, the function
rhashtable_walk_start_check has been added that returns -EAGAIN on a
resize event.
Signed-off-by: NTom Herbert <tom@quantonium.net>
Acked-by: NHerbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      97a6ec4a
  25. 02 12月, 2017 1 次提交
  27. 29 11月, 2017 2 次提交
  29. 28 11月, 2017 1 次提交
  31. 18 11月, 2017 1 次提交
    • X
      sctp: set frag_point in sctp_setsockopt_maxseg correctly · ecca8f88
      由 Xin Long 提交于 
      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: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Reported-by: NHangbin Liu <liuhangbin@gmail.com>
Signed-off-by: NXin Long <lucien.xin@gmail.com>
Acked-by: NMarcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
      ecca8f88
  33. 29 10月, 2017 1 次提交
  35. 25 10月, 2017 1 次提交