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  1. 22 Mar, 2014 33 commits
  3. 21 Mar, 2014 2 commits
    • Rob Clark's avatar
      drm/ttm: don't oops if no invalidate_caches() · e00feda0
      Rob Clark authored 
      commit 9ef7506f upstream.

A few of the simpler TTM drivers (cirrus, ast, mgag200) do not implement
this function.  Yet can end up somehow with an evicted bo:

  BUG: unable to handle kernel NULL pointer dereference at           (null)
  IP: [<          (null)>]           (null)
  PGD 16e761067 PUD 16e6cf067 PMD 0
  Oops: 0010 [#1] SMP
  Modules linked in: bnep bluetooth rfkill fuse ip6t_rpfilter ip6t_REJECT ipt_REJECT xt_conntrack ebtable_nat ebtable_broute bridge stp llc ebtable_filter ebtables ip6table_nat nf_conntrack_ipv6 nf_defrag_ipv6 nf_nat_ipv6 ip6table_mangle ip6table_security ip6table_raw ip6table_filter ip6_tables iptable_nat nf_conntrack_ipv4 nf_defrag_ipv4 nf_nat_ipv4 nf_nat nf_conntrack iptable_mangle iptable_security iptable_raw iptable_filter ip_tables sg btrfs zlib_deflate raid6_pq xor dm_queue_length iTCO_wdt iTCO_vendor_support coretemp kvm dcdbas dm_service_time microcode serio_raw pcspkr lpc_ich mfd_core i7core_edac edac_core ses enclosure ipmi_si ipmi_msghandler shpchp acpi_power_meter mperf nfsd auth_rpcgss nfs_acl lockd uinput sunrpc dm_multipath xfs libcrc32c ata_generic pata_acpi sr_mod cdrom
   sd_mod usb_storage mgag200 syscopyarea sysfillrect sysimgblt i2c_algo_bit lpfc drm_kms_helper ttm crc32c_intel ata_piix bfa drm ixgbe libata i2c_core mdio crc_t10dif ptp crct10dif_common pps_core scsi_transport_fc dca scsi_tgt megaraid_sas bnx2 dm_mirror dm_region_hash dm_log dm_mod
  CPU: 16 PID: 2572 Comm: X Not tainted 3.10.0-86.el7.x86_64 #1
  Hardware name: Dell Inc. PowerEdge R810/0H235N, BIOS 0.3.0 11/14/2009
  task: ffff8801799dabc0 ti: ffff88016c884000 task.ti: ffff88016c884000
  RIP: 0010:[<0000000000000000>]  [<          (null)>]           (null)
  RSP: 0018:ffff88016c885ad8  EFLAGS: 00010202
  RAX: ffffffffa04e94c0 RBX: ffff880178937a20 RCX: 0000000000000000
  RDX: 0000000000000000 RSI: 0000000000240004 RDI: ffff880178937a00
  RBP: ffff88016c885b60 R08: 00000000000171a0 R09: ffff88007cf171a0
  R10: ffffea0005842540 R11: ffffffff810487b9 R12: ffff880178937b30
  R13: ffff880178937a00 R14: ffff88016c885b78 R15: ffff880179929400
  FS:  00007f81ba2ef980(0000) GS:ffff88007cf00000(0000) knlGS:0000000000000000
  CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  CR2: 0000000000000000 CR3: 000000016e763000 CR4: 00000000000007e0
  DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400
  Stack:
   ffffffffa0306fae ffff8801799295c0 0000000000260004 0000000000000001
   ffff88016c885b60 ffffffffa0307669 00ff88007cf17738 ffff88017cf17700
   ffff880178937a00 ffff880100000000 ffff880100000000 0000000079929400
  Call Trace:
   [<ffffffffa0306fae>] ? ttm_bo_handle_move_mem+0x54e/0x5b0 [ttm]
   [<ffffffffa0307669>] ? ttm_bo_mem_space+0x169/0x340 [ttm]
   [<ffffffffa0307bd7>] ttm_bo_move_buffer+0x117/0x130 [ttm]
   [<ffffffff81130001>] ? perf_event_init_context+0x141/0x220
   [<ffffffffa0307cb1>] ttm_bo_validate+0xc1/0x130 [ttm]
   [<ffffffffa04e7377>] mgag200_bo_pin+0x87/0xc0 [mgag200]
   [<ffffffffa04e56c4>] mga_crtc_cursor_set+0x474/0xbb0 [mgag200]
   [<ffffffff811971d2>] ? __mem_cgroup_commit_charge+0x152/0x3b0
   [<ffffffff815c4182>] ? mutex_lock+0x12/0x2f
   [<ffffffffa0201433>] drm_mode_cursor_common+0x123/0x170 [drm]
   [<ffffffffa0205231>] drm_mode_cursor_ioctl+0x41/0x50 [drm]
   [<ffffffffa01f5ca2>] drm_ioctl+0x502/0x630 [drm]
   [<ffffffff815cbab4>] ? __do_page_fault+0x1f4/0x510
   [<ffffffff8101cb68>] ? __restore_xstate_sig+0x218/0x4f0
   [<ffffffff811b4445>] do_vfs_ioctl+0x2e5/0x4d0
   [<ffffffff8124488e>] ? file_has_perm+0x8e/0xa0
   [<ffffffff811b46b1>] SyS_ioctl+0x81/0xa0
   [<ffffffff815d05d9>] system_call_fastpath+0x16/0x1b
  Code:  Bad RIP value.
  RIP  [<          (null)>]           (null)
   RSP <ffff88016c885ad8>
  CR2: 0000000000000000
Signed-off-by: default avatarRob Clark <rclark@redhat.com>
Reviewed-by: default avatarJérôme Glisse <jglisse@redhat.com>
Reviewed-by: default avatarThomas Hellstrom <thellstrom@vmware.com>
Cc: stable@vger.kernel.org
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      e00feda0
    • Filipe Brandenburger's avatar
      memcg: reparent charges of children before processing parent · fda958d5
      Filipe Brandenburger authored 
      commit 4fb1a86f upstream.

Sometimes the cleanup after memcg hierarchy testing gets stuck in
mem_cgroup_reparent_charges(), unable to bring non-kmem usage down to 0.

There may turn out to be several causes, but a major cause is this: the
workitem to offline parent can get run before workitem to offline child;
parent's mem_cgroup_reparent_charges() circles around waiting for the
child's pages to be reparented to its lrus, but it's holding
cgroup_mutex which prevents the child from reaching its
mem_cgroup_reparent_charges().

Further testing showed that an ordered workqueue for cgroup_destroy_wq
is not always good enough: percpu_ref_kill_and_confirm's call_rcu_sched
stage on the way can mess up the order before reaching the workqueue.

Instead, when offlining a memcg, call mem_cgroup_reparent_charges() on
all its children (and grandchildren, in the correct order) to have their
charges reparented first.

Fixes: e5fca243 ("cgroup: use a dedicated workqueue for cgroup destruction")
Signed-off-by: default avatarFilipe Brandenburger <filbranden@google.com>
Signed-off-by: default avatarHugh Dickins <hughd@google.com>
Reviewed-by: default avatarTejun Heo <tj@kernel.org>
Acked-by: default avatarMichal Hocko <mhocko@suse.cz>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: <stable@vger.kernel.org>	[v3.10+]
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      fda958d5
  5. 14 Mar, 2014 4 commits
  7. 13 Mar, 2014 1 commit
    • Daniel Borkmann's avatar
      net: sctp: fix sctp_sf_do_5_1D_ce to verify if we/peer is AUTH capable · 00c53b02
      Daniel Borkmann authored 
      [ Upstream commit ec0223ec ]

RFC4895 introduced AUTH chunks for SCTP; during the SCTP
handshake RANDOM; CHUNKS; HMAC-ALGO are negotiated (CHUNKS
being optional though):

  ---------- INIT[RANDOM; CHUNKS; HMAC-ALGO] ---------->
  <------- INIT-ACK[RANDOM; CHUNKS; HMAC-ALGO] ---------
  -------------------- COOKIE-ECHO -------------------->
  <-------------------- COOKIE-ACK ---------------------

A special case is when 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 ---------------------

RFC4895, section 6.3. Receiving Authenticated Chunks says:

  The receiver MUST use the HMAC algorithm indicated in
  the HMAC Identifier field. If this algorithm was not
  specified by the receiver in the HMAC-ALGO parameter in
  the INIT or INIT-ACK chunk during association setup, the
  AUTH chunk and all the chunks after it MUST be discarded
  and an ERROR chunk SHOULD be sent with the error cause
  defined in Section 4.1. [...] If no endpoint pair shared
  key has been configured for that Shared Key Identifier,
  all authenticated chunks MUST be silently discarded. [...]

  When an endpoint requires COOKIE-ECHO chunks to be
  authenticated, some special procedures have to be followed
  because the reception of a COOKIE-ECHO chunk might result
  in the creation of an SCTP association. If a packet arrives
  containing an AUTH chunk as a first chunk, a COOKIE-ECHO
  chunk as the second chunk, and possibly more chunks after
  them, and the receiver does not have an STCB for that
  packet, then authentication is based on the contents of
  the COOKIE-ECHO chunk. In this situation, the receiver MUST
  authenticate the chunks in the packet by using the RANDOM
  parameters, CHUNKS parameters and HMAC_ALGO parameters
  obtained from the COOKIE-ECHO chunk, and possibly a local
  shared secret as inputs to the authentication procedure
  specified in Section 6.3. If authentication fails, then
  the packet is discarded. If the authentication is successful,
  the COOKIE-ECHO and all the chunks after the COOKIE-ECHO
  MUST be processed. If the receiver has an STCB, it MUST
  process the AUTH chunk as described above using the STCB
  from the existing association to authenticate the
  COOKIE-ECHO chunk and all the chunks after it. [...]

Commit bbd0d598 introduced the possibility to receive
and verification of AUTH chunk, including the edge case for
authenticated COOKIE-ECHO. On reception of COOKIE-ECHO,
the function sctp_sf_do_5_1D_ce() handles processing,
unpacks and creates a new association if it passed sanity
checks and also tests for authentication chunks being
present. After a new association has been processed, it
invokes sctp_process_init() on the new association and
walks through the parameter list it received from the INIT
chunk. It checks SCTP_PARAM_RANDOM, SCTP_PARAM_HMAC_ALGO
and SCTP_PARAM_CHUNKS, and copies them into asoc->peer
meta data (peer_random, peer_hmacs, peer_chunks) in case
sysctl -w net.sctp.auth_enable=1 is set. If in INIT's
SCTP_PARAM_SUPPORTED_EXT parameter SCTP_CID_AUTH is set,
peer_random != NULL and peer_hmacs != NULL the peer is to be
assumed asoc->peer.auth_capable=1, in any other case
asoc->peer.auth_capable=0.

Now, if in sctp_sf_do_5_1D_ce() chunk->auth_chunk is
available, we set up a fake auth chunk and pass that on to
sctp_sf_authenticate(), which at latest in
sctp_auth_calculate_hmac() reliably dereferences a NULL pointer
at position 0..0008 when setting up the crypto key in
crypto_hash_setkey() by using asoc->asoc_shared_key that is
NULL as condition key_id == asoc->active_key_id is true if
the AUTH chunk was injected correctly from remote. This
happens no matter what net.sctp.auth_enable sysctl says.

The fix is to check for net->sctp.auth_enable and for
asoc->peer.auth_capable before doing any operations like
sctp_sf_authenticate() as no key is activated in
sctp_auth_asoc_init_active_key() for each case.

Now as RFC4895 section 6.3 states that if the used HMAC-ALGO
passed from the INIT chunk was not used in the AUTH chunk, we
SHOULD send an error; however in this case it would be better
to just silently discard such a maliciously prepared handshake
as we didn't even receive a parameter at all. Also, as our
endpoint has no shared key configured, section 6.3 says that
MUST silently discard, which we are doing from now onwards.

Before calling sctp_sf_pdiscard(), we need not only to free
the association, but also the chunk->auth_chunk skb, as
commit bbd0d598 created a skb clone in that case.

I have tested this locally by using netfilter's nfqueue and
re-injecting packets into the local stack after maliciously
modifying the INIT chunk (removing RANDOM; HMAC-ALGO param)
and the SCTP packet containing the COOKIE_ECHO (injecting
AUTH chunk before COOKIE_ECHO). Fixed with this patch applied.

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>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
Signed-off-by: default avatarJiri Slaby <jslaby@suse.cz>
      00c53b02
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