1. 27 Feb, 2015 11 commits
    • Christoph Hellwig's avatar
      net: don't OOPS on socket aio · db4d24bc
      Christoph Hellwig authored
      [ Upstream commit 06539d30 ]
      Signed-off-by: default avatarChristoph Hellwig <hch@lst.de>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      db4d24bc
    • Govindarajulu Varadarajan's avatar
      bnx2x: fix napi poll return value for repoll · e3b175f6
      Govindarajulu Varadarajan authored
      [ Upstream commit 24e579c8 ]
      
      With the commit d75b1ade ("net: less interrupt masking in NAPI") napi
      repoll is done only when work_done == budget. When in busy_poll is we return 0
      in napi_poll. We should return budget.
      Signed-off-by: default avatarGovindarajulu Varadarajan <_govind@gmx.com>
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e3b175f6
    • Hannes Frederic Sowa's avatar
      ipv6: replacing a rt6_info needs to purge possible propagated rt6_infos too · b0e79166
      Hannes Frederic Sowa authored
      [ Upstream commit 6e9e16e6 ]
      
      Lubomir Rintel reported that during replacing a route the interface
      reference counter isn't correctly decremented.
      
      To quote bug <https://bugzilla.kernel.org/show_bug.cgi?id=91941>:
      | [root@rhel7-5 lkundrak]# sh -x lal
      | + ip link add dev0 type dummy
      | + ip link set dev0 up
      | + ip link add dev1 type dummy
      | + ip link set dev1 up
      | + ip addr add 2001:db8:8086::2/64 dev dev0
      | + ip route add 2001:db8:8086::/48 dev dev0 proto static metric 20
      | + ip route add 2001:db8:8088::/48 dev dev1 proto static metric 10
      | + ip route replace 2001:db8:8086::/48 dev dev1 proto static metric 20
      | + ip link del dev0 type dummy
      | Message from syslogd@rhel7-5 at Jan 23 10:54:41 ...
      |  kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2
      |
      | Message from syslogd@rhel7-5 at Jan 23 10:54:51 ...
      |  kernel:unregister_netdevice: waiting for dev0 to become free. Usage count = 2
      
      During replacement of a rt6_info we must walk all parent nodes and check
      if the to be replaced rt6_info got propagated. If so, replace it with
      an alive one.
      
      Fixes: 4a287eba ("IPv6 routing, NLM_F_* flag support: REPLACE and EXCL flags support, warn about missing CREATE flag")
      Reported-by: default avatarLubomir Rintel <lkundrak@v3.sk>
      Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Tested-by: default avatarLubomir Rintel <lkundrak@v3.sk>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b0e79166
    • subashab@codeaurora.org's avatar
      ping: Fix race in free in receive path · 3a06a68b
      subashab@codeaurora.org authored
      [ Upstream commit fc752f1f ]
      
      An exception is seen in ICMP ping receive path where the skb
      destructor sock_rfree() tries to access a freed socket. This happens
      because ping_rcv() releases socket reference with sock_put() and this
      internally frees up the socket. Later icmp_rcv() will try to free the
      skb and as part of this, skb destructor is called and which leads
      to a kernel panic as the socket is freed already in ping_rcv().
      
      -->|exception
      -007|sk_mem_uncharge
      -007|sock_rfree
      -008|skb_release_head_state
      -009|skb_release_all
      -009|__kfree_skb
      -010|kfree_skb
      -011|icmp_rcv
      -012|ip_local_deliver_finish
      
      Fix this incorrect free by cloning this skb and processing this cloned
      skb instead.
      
      This patch was suggested by Eric Dumazet
      Signed-off-by: default avatarSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
      Cc: Eric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      3a06a68b
    • Herbert Xu's avatar
      udp_diag: Fix socket skipping within chain · faf8cf00
      Herbert Xu authored
      [ Upstream commit 86f3cddb ]
      
      While working on rhashtable walking I noticed that the UDP diag
      dumping code is buggy.  In particular, the socket skipping within
      a chain never happens, even though we record the number of sockets
      that should be skipped.
      
      As this code was supposedly copied from TCP, this patch does what
      TCP does and resets num before we walk a chain.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Acked-by: default avatarPavel Emelyanov <xemul@parallels.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      faf8cf00
    • Hannes Frederic Sowa's avatar
      ipv4: try to cache dst_entries which would cause a redirect · 9ad1a959
      Hannes Frederic Sowa authored
      [ Upstream commit df4d9254 ]
      
      Not caching dst_entries which cause redirects could be exploited by hosts
      on the same subnet, causing a severe DoS attack. This effect aggravated
      since commit f8864972 ("ipv4: fix dst race in sk_dst_get()").
      
      Lookups causing redirects will be allocated with DST_NOCACHE set which
      will force dst_release to free them via RCU.  Unfortunately waiting for
      RCU grace period just takes too long, we can end up with >1M dst_entries
      waiting to be released and the system will run OOM. rcuos threads cannot
      catch up under high softirq load.
      
      Attaching the flag to emit a redirect later on to the specific skb allows
      us to cache those dst_entries thus reducing the pressure on allocation
      and deallocation.
      
      This issue was discovered by Marcelo Leitner.
      
      Cc: Julian Anastasov <ja@ssi.bg>
      Signed-off-by: default avatarMarcelo Leitner <mleitner@redhat.com>
      Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
      Signed-off-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
      Signed-off-by: default avatarJulian Anastasov <ja@ssi.bg>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9ad1a959
    • Daniel Borkmann's avatar
      net: sctp: fix slab corruption from use after free on INIT collisions · c75e4b05
      Daniel Borkmann authored
      [ Upstream commit 600ddd68 ]
      
      When hitting an INIT collision case during the 4WHS with AUTH enabled, as
      already described in detail in commit 1be9a950 ("net: sctp: inherit
      auth_capable on INIT collisions"), it can happen that we occasionally
      still remotely trigger the following panic on server side which seems to
      have been uncovered after the fix from commit 1be9a950 ...
      
      [  533.876389] BUG: unable to handle kernel paging request at 00000000ffffffff
      [  533.913657] IP: [<ffffffff811ac385>] __kmalloc+0x95/0x230
      [  533.940559] PGD 5030f2067 PUD 0
      [  533.957104] Oops: 0000 [#1] SMP
      [  533.974283] Modules linked in: sctp mlx4_en [...]
      [  534.939704] Call Trace:
      [  534.951833]  [<ffffffff81294e30>] ? crypto_init_shash_ops+0x60/0xf0
      [  534.984213]  [<ffffffff81294e30>] crypto_init_shash_ops+0x60/0xf0
      [  535.015025]  [<ffffffff8128c8ed>] __crypto_alloc_tfm+0x6d/0x170
      [  535.045661]  [<ffffffff8128d12c>] crypto_alloc_base+0x4c/0xb0
      [  535.074593]  [<ffffffff8160bd42>] ? _raw_spin_lock_bh+0x12/0x50
      [  535.105239]  [<ffffffffa0418c11>] sctp_inet_listen+0x161/0x1e0 [sctp]
      [  535.138606]  [<ffffffff814e43bd>] SyS_listen+0x9d/0xb0
      [  535.166848]  [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b
      
      ... or depending on the the application, for example this one:
      
      [ 1370.026490] BUG: unable to handle kernel paging request at 00000000ffffffff
      [ 1370.026506] IP: [<ffffffff811ab455>] kmem_cache_alloc+0x75/0x1d0
      [ 1370.054568] PGD 633c94067 PUD 0
      [ 1370.070446] Oops: 0000 [#1] SMP
      [ 1370.085010] Modules linked in: sctp kvm_amd kvm [...]
      [ 1370.963431] Call Trace:
      [ 1370.974632]  [<ffffffff8120f7cf>] ? SyS_epoll_ctl+0x53f/0x960
      [ 1371.000863]  [<ffffffff8120f7cf>] SyS_epoll_ctl+0x53f/0x960
      [ 1371.027154]  [<ffffffff812100d3>] ? anon_inode_getfile+0xd3/0x170
      [ 1371.054679]  [<ffffffff811e3d67>] ? __alloc_fd+0xa7/0x130
      [ 1371.080183]  [<ffffffff816149a9>] system_call_fastpath+0x16/0x1b
      
      With slab debugging enabled, we can see that the poison has been overwritten:
      
      [  669.826368] BUG kmalloc-128 (Tainted: G        W     ): Poison overwritten
      [  669.826385] INFO: 0xffff880228b32e50-0xffff880228b32e50. First byte 0x6a instead of 0x6b
      [  669.826414] INFO: Allocated in sctp_auth_create_key+0x23/0x50 [sctp] age=3 cpu=0 pid=18494
      [  669.826424]  __slab_alloc+0x4bf/0x566
      [  669.826433]  __kmalloc+0x280/0x310
      [  669.826453]  sctp_auth_create_key+0x23/0x50 [sctp]
      [  669.826471]  sctp_auth_asoc_create_secret+0xcb/0x1e0 [sctp]
      [  669.826488]  sctp_auth_asoc_init_active_key+0x68/0xa0 [sctp]
      [  669.826505]  sctp_do_sm+0x29d/0x17c0 [sctp] [...]
      [  669.826629] INFO: Freed in kzfree+0x31/0x40 age=1 cpu=0 pid=18494
      [  669.826635]  __slab_free+0x39/0x2a8
      [  669.826643]  kfree+0x1d6/0x230
      [  669.826650]  kzfree+0x31/0x40
      [  669.826666]  sctp_auth_key_put+0x19/0x20 [sctp]
      [  669.826681]  sctp_assoc_update+0x1ee/0x2d0 [sctp]
      [  669.826695]  sctp_do_sm+0x674/0x17c0 [sctp]
      
      Since this only triggers in some collision-cases with AUTH, the problem at
      heart is that sctp_auth_key_put() on asoc->asoc_shared_key is called twice
      when having refcnt 1, once directly in sctp_assoc_update() and yet again
      from within sctp_auth_asoc_init_active_key() via sctp_assoc_update() on
      the already kzfree'd memory, which is also consistent with the observation
      of the poison decrease from 0x6b to 0x6a (note: the overwrite is detected
      at a later point in time when poison is checked on new allocation).
      
      Reference counting of auth keys revisited:
      
      Shared keys for AUTH chunks are being stored in endpoints and associations
      in endpoint_shared_keys list. On endpoint creation, a null key is being
      added; on association creation, all endpoint shared keys are being cached
      and thus cloned over to the association. struct sctp_shared_key only holds
      a pointer to the actual key bytes, that is, struct sctp_auth_bytes which
      keeps track of users internally through refcounting. Naturally, on assoc
      or enpoint destruction, sctp_shared_key are being destroyed directly and
      the reference on sctp_auth_bytes dropped.
      
      User space can add keys to either list via setsockopt(2) through struct
      sctp_authkey and by passing that to sctp_auth_set_key() which replaces or
      adds a new auth key. There, sctp_auth_create_key() creates a new sctp_auth_bytes
      with refcount 1 and in case of replacement drops the reference on the old
      sctp_auth_bytes. A key can be set active from user space through setsockopt()
      on the id via sctp_auth_set_active_key(), which iterates through either
      endpoint_shared_keys and in case of an assoc, invokes (one of various places)
      sctp_auth_asoc_init_active_key().
      
      sctp_auth_asoc_init_active_key() computes the actual secret from local's
      and peer's random, hmac and shared key parameters and returns a new key
      directly as sctp_auth_bytes, that is asoc->asoc_shared_key, plus drops
      the reference if there was a previous one. The secret, which where we
      eventually double drop the ref comes from sctp_auth_asoc_set_secret() with
      intitial refcount of 1, which also stays unchanged eventually in
      sctp_assoc_update(). This key is later being used for crypto layer to
      set the key for the hash in crypto_hash_setkey() from sctp_auth_calculate_hmac().
      
      To close the loop: asoc->asoc_shared_key is freshly allocated secret
      material and independant of the sctp_shared_key management keeping track
      of only shared keys in endpoints and assocs. Hence, also commit 4184b2a7
      ("net: sctp: fix memory leak in auth key management") is independant of
      this bug here since it concerns a different layer (though same structures
      being used eventually). asoc->asoc_shared_key is reference dropped correctly
      on assoc destruction in sctp_association_free() and when active keys are
      being replaced in sctp_auth_asoc_init_active_key(), it always has a refcount
      of 1. Hence, it's freed prematurely in sctp_assoc_update(). Simple fix is
      to remove that sctp_auth_key_put() from there which fixes these panics.
      
      Fixes: 730fc3d0 ("[SCTP]: Implete SCTP-AUTH parameter processing")
      Signed-off-by: default avatarDaniel Borkmann <dborkman@redhat.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>
      c75e4b05
    • Eric Dumazet's avatar
      netxen: fix netxen_nic_poll() logic · e452612a
      Eric Dumazet authored
      [ Upstream commit 6088beef ]
      
      NAPI poll logic now enforces that a poller returns exactly the budget
      when it wants to be called again.
      
      If a driver limits TX completion, it has to return budget as well when
      the limit is hit, not the number of received packets.
      Reported-and-tested-by: default avatarMike Galbraith <umgwanakikbuti@gmail.com>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Fixes: d75b1ade ("net: less interrupt masking in NAPI")
      Cc: Manish Chopra <manish.chopra@qlogic.com>
      Acked-by: default avatarManish Chopra <manish.chopra@qlogic.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      e452612a
    • Hagen Paul Pfeifer's avatar
      ipv6: stop sending PTB packets for MTU < 1280 · eb489005
      Hagen Paul Pfeifer authored
      [ Upstream commit 9d289715 ]
      
      Reduce the attack vector and stop generating IPv6 Fragment Header for
      paths with an MTU smaller than the minimum required IPv6 MTU
      size (1280 byte) - called atomic fragments.
      
      See IETF I-D "Deprecating the Generation of IPv6 Atomic Fragments" [1]
      for more information and how this "feature" can be misused.
      
      [1] https://tools.ietf.org/html/draft-ietf-6man-deprecate-atomfrag-generation-00Signed-off-by: default avatarFernando Gont <fgont@si6networks.com>
      Signed-off-by: default avatarHagen Paul Pfeifer <hagen@jauu.net>
      Acked-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>
      eb489005
    • Eric Dumazet's avatar
      net: rps: fix cpu unplug · 9e4cc1ed
      Eric Dumazet authored
      [ Upstream commit ac64da0b ]
      
      softnet_data.input_pkt_queue is protected by a spinlock that
      we must hold when transferring packets from victim queue to an active
      one. This is because other cpus could still be trying to enqueue packets
      into victim queue.
      
      A second problem is that when we transfert the NAPI poll_list from
      victim to current cpu, we absolutely need to special case the percpu
      backlog, because we do not want to add complex locking to protect
      process_queue : Only owner cpu is allowed to manipulate it, unless cpu
      is offline.
      
      Based on initial patch from Prasad Sodagudi & Subash Abhinov
      Kasiviswanathan.
      
      This version is better because we do not slow down packet processing,
      only make migration safer.
      Reported-by: default avatarPrasad Sodagudi <psodagud@codeaurora.org>
      Reported-by: default avatarSubash Abhinov Kasiviswanathan <subashab@codeaurora.org>
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Tom Herbert <therbert@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      9e4cc1ed
    • Willem de Bruijn's avatar
      ip: zero sockaddr returned on error queue · 8e9f6bdb
      Willem de Bruijn authored
      [ Upstream commit f812116b ]
      
      The sockaddr is returned in IP(V6)_RECVERR as part of errhdr. That
      structure is defined and allocated on the stack as
      
          struct {
                  struct sock_extended_err ee;
                  struct sockaddr_in(6)    offender;
          } errhdr;
      
      The second part is only initialized for certain SO_EE_ORIGIN values.
      Always initialize it completely.
      
      An MTU exceeded error on a SOCK_RAW/IPPROTO_RAW is one example that
      would return uninitialized bytes.
      Signed-off-by: default avatarWillem de Bruijn <willemb@google.com>
      
      ----
      
      Also verified that there is no padding between errhdr.ee and
      errhdr.offender that could leak additional kernel data.
      Acked-by: default avatarEric Dumazet <edumazet@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      8e9f6bdb
  2. 11 Feb, 2015 29 commits