1. 27 Apr, 2014 2 commits
    • Linus Lüssing's avatar
      bridge: multicast: add sanity check for query source addresses · 098c9960
      Linus Lüssing authored
      [ Upstream commit 6565b9ee ]
      
      MLD queries are supposed to have an IPv6 link-local source address
      according to RFC2710, section 4 and RFC3810, section 5.1.14. This patch
      adds a sanity check to ignore such broken MLD queries.
      
      Without this check, such malformed MLD queries can result in a
      denial of service: The queries are ignored by any MLD listener
      therefore they will not respond with an MLD report. However,
      without this patch these malformed MLD queries would enable the
      snooping part in the bridge code, potentially shutting down the
      according ports towards these hosts for multicast traffic as the
      bridge did not learn about these listeners.
      Reported-by: default avatarJan Stancek <jstancek@redhat.com>
      Signed-off-by: default avatarLinus Lüssing <linus.luessing@web.de>
      Reviewed-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      098c9960
    • Daniel Borkmann's avatar
      net: sctp: fix skb leakage in COOKIE ECHO path of chunk->auth_chunk · 978a9b75
      Daniel Borkmann authored
      [ Upstream commit c485658b ]
      
      While working on ec0223ec ("net: sctp: fix sctp_sf_do_5_1D_ce to
      verify if we/peer is AUTH capable"), we noticed that there's a skb
      memory leakage in the error path.
      
      Running the same reproducer as in ec0223ec and by unconditionally
      jumping to the error label (to simulate an error condition) in
      sctp_sf_do_5_1D_ce() receive path lets kmemleak detector bark about
      the unfreed chunk->auth_chunk skb clone:
      
      Unreferenced object 0xffff8800b8f3a000 (size 256):
        comm "softirq", pid 0, jiffies 4294769856 (age 110.757s)
        hex dump (first 32 bytes):
          00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................
          89 ab 75 5e d4 01 58 13 00 00 00 00 00 00 00 00  ..u^..X.........
        backtrace:
          [<ffffffff816660be>] kmemleak_alloc+0x4e/0xb0
          [<ffffffff8119f328>] kmem_cache_alloc+0xc8/0x210
          [<ffffffff81566929>] skb_clone+0x49/0xb0
          [<ffffffffa0467459>] sctp_endpoint_bh_rcv+0x1d9/0x230 [sctp]
          [<ffffffffa046fdbc>] sctp_inq_push+0x4c/0x70 [sctp]
          [<ffffffffa047e8de>] sctp_rcv+0x82e/0x9a0 [sctp]
          [<ffffffff815abd38>] ip_local_deliver_finish+0xa8/0x210
          [<ffffffff815a64af>] nf_reinject+0xbf/0x180
          [<ffffffffa04b4762>] nfqnl_recv_verdict+0x1d2/0x2b0 [nfnetlink_queue]
          [<ffffffffa04aa40b>] nfnetlink_rcv_msg+0x14b/0x250 [nfnetlink]
          [<ffffffff815a3269>] netlink_rcv_skb+0xa9/0xc0
          [<ffffffffa04aa7cf>] nfnetlink_rcv+0x23f/0x408 [nfnetlink]
          [<ffffffff815a2bd8>] netlink_unicast+0x168/0x250
          [<ffffffff815a2fa1>] netlink_sendmsg+0x2e1/0x3f0
          [<ffffffff8155cc6b>] sock_sendmsg+0x8b/0xc0
          [<ffffffff8155d449>] ___sys_sendmsg+0x369/0x380
      
      What happens is that commit bbd0d598 clones the skb containing
      the AUTH chunk in sctp_endpoint_bh_rcv() when having the edge case
      that an endpoint requires COOKIE-ECHO chunks to be authenticated:
      
        ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
        <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] ---------
        ------------------ AUTH; COOKIE-ECHO ---------------->
        <-------------------- COOKIE-ACK ---------------------
      
      When we enter sctp_sf_do_5_1D_ce() and before we actually get to
      the point where we process (and subsequently free) a non-NULL
      chunk->auth_chunk, we could hit the "goto nomem_init" path from
      an error condition and thus leave the cloned skb around w/o
      freeing it.
      
      The fix is to centrally free such clones in sctp_chunk_destroy()
      handler that is invoked from sctp_chunk_free() after all refs have
      dropped; and also move both kfree_skb(chunk->auth_chunk) there,
      so that chunk->auth_chunk is either NULL (since sctp_chunkify()
      allocs new chunks through kmem_cache_zalloc()) or non-NULL with
      a valid skb pointer. chunk->skb and chunk->auth_chunk are the
      only skbs in the sctp_chunk structure that need to be handeled.
      
      While at it, we should use consume_skb() for both. It is the same
      as dev_kfree_skb() but more appropriately named as we are not
      a device but a protocol. Also, this effectively replaces the
      kfree_skb() from both invocations into consume_skb(). Functions
      are the same only that kfree_skb() assumes that the frame was
      being dropped after a failure (e.g. for tools like drop monitor),
      usage of consume_skb() seems more appropriate in function
      sctp_chunk_destroy() though.
      
      Fixes: bbd0d598 ("[SCTP]: Implement the receive and verification of AUTH chunk")
      Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.com>
      Cc: Vlad Yasevich <yasevich@gmail.com>
      Cc: Neil Horman <nhorman@tuxdriver.com>
      Acked-by: default avatarVlad Yasevich <vyasevich@gmail.com>
      Acked-by: default avatarNeil Horman <nhorman@tuxdriver.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      978a9b75
  2. 14 Apr, 2014 38 commits