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  1. 06 Feb, 2018 2 commits
  3. 02 Feb, 2018 2 commits
    • Chuck Lever's avatar
      xprtrdma: Fix BUG after a device removal · e89e8d8f
      Chuck Lever authored 
      Michal Kalderon reports a BUG that occurs just after device removal:

[  169.112490] rpcrdma: removing device qedr0 for 192.168.110.146:20049
[  169.143909] BUG: unable to handle kernel NULL pointer dereference at 0000000000000010
[  169.181837] IP: rpcrdma_dma_unmap_regbuf+0xa/0x60 [rpcrdma]

The RPC/RDMA client transport attempts to allocate some resources
on demand. Registered buffers are one such resource. These are
allocated (or re-allocated) by xprt_rdma_allocate to hold RPC Call
and Reply messages. A hardware resource is associated with each of
these buffers, as they can be used for a Send or Receive Work
Request.

If a device is removed from under an NFS/RDMA mount, the transport
layer is responsible for releasing all hardware resources before
the device can be finally unplugged. A BUG results when the NFS
mount hasn't yet seen much activity: the transport tries to release
resources that haven't yet been allocated.

rpcrdma_free_regbuf() already checks for this case, so just move
that check to cover the DEVICE_REMOVAL case as well.
Reported-by: default avatarMichal Kalderon <Michal.Kalderon@cavium.com>
Fixes: bebd0318 ("xprtrdma: Support unplugging an HCA ...")
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Tested-by: default avatarMichal Kalderon <Michal.Kalderon@cavium.com>
Cc: stable@vger.kernel.org # v4.12+
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
      e89e8d8f
    • Chuck Lever's avatar
      xprtrdma: Fix calculation of ri_max_send_sges · 1179e2c2
      Chuck Lever authored 
      Commit 16f906d6 ("xprtrdma: Reduce required number of send
SGEs") introduced the rpcrdma_ia::ri_max_send_sges field. This fixes
a problem where xprtrdma would not work if the device's max_sge
capability was small (low single digits).

At least RPCRDMA_MIN_SEND_SGES are needed for the inline parts of
each RPC. ri_max_send_sges is set to this value:

  ia->ri_max_send_sges = max_sge - RPCRDMA_MIN_SEND_SGES;

Then when marshaling each RPC, rpcrdma_args_inline uses that value
to determine whether the device has enough Send SGEs to convey an
NFS WRITE payload inline, or whether instead a Read chunk is
required.

More recently, commit ae72950a ("xprtrdma: Add data structure to
manage RDMA Send arguments") used the ri_max_send_sges value to
calculate the size of an array, but that commit erroneously assumed
ri_max_send_sges contains a value similar to the device's max_sge,
and not one that was reduced by the minimum SGE count.

This assumption results in the calculated size of the sendctx's
Send SGE array to be too small. When the array is used to marshal
an RPC, the code can write Send SGEs into the following sendctx
element in that array, corrupting it. When the device's max_sge is
large, this issue is entirely harmless; but it results in an oops
in the provider's post_send method, if dev.attrs.max_sge is small.

So let's straighten this out: ri_max_send_sges will now contain a
value with the same meaning as dev.attrs.max_sge, which makes
the code easier to understand, and enables rpcrdma_sendctx_create
to calculate the size of the SGE array correctly.
Reported-by: default avatarMichal Kalderon <Michal.Kalderon@cavium.com>
Fixes: 16f906d6 ("xprtrdma: Reduce required number of send SGEs")
Signed-off-by: default avatarChuck Lever <chuck.lever@oracle.com>
Tested-by: default avatarMichal Kalderon <Michal.Kalderon@cavium.com>
Cc: stable@vger.kernel.org # v4.10+
Signed-off-by: default avatarAnna Schumaker <Anna.Schumaker@Netapp.com>
      1179e2c2
  5. 29 Jan, 2018 1 commit
  7. 28 Jan, 2018 1 commit
  9. 25 Jan, 2018 2 commits
  11. 24 Jan, 2018 1 commit
  13. 23 Jan, 2018 20 commits
  15. 22 Jan, 2018 1 commit
    • Eric Biggers's avatar
      NFS: reject request for id_legacy key without auxdata · 49686cbb
      Eric Biggers authored 
      nfs_idmap_legacy_upcall() is supposed to be called with 'aux' pointing
to a 'struct idmap', via the call to request_key_with_auxdata() in
nfs_idmap_request_key().

However it can also be reached via the request_key() system call in
which case 'aux' will be NULL, causing a NULL pointer dereference in
nfs_idmap_prepare_pipe_upcall(), assuming that the key description is
valid enough to get that far.

Fix this by making nfs_idmap_legacy_upcall() negate the key if no
auxdata is provided.

As usual, this bug was found by syzkaller.  A simple reproducer using
the command-line keyctl program is:

    keyctl request2 id_legacy uid:0 '' @s

Fixes: 57e62324 ("NFS: Store the legacy idmapper result in the keyring")
Reported-by: syzbot+5dfdbcf7b3eb5912abbb@syzkaller.appspotmail.com
Cc: <stable@vger.kernel.org> # v3.4+
Signed-off-by: default avatarEric Biggers <ebiggers@google.com>
Signed-off-by: default avatarTrond Myklebust <trondmy@gmail.com>
      49686cbb
  17. 18 Jan, 2018 3 commits
  19. 16 Jan, 2018 7 commits
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