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  1. 27 Oct, 2015 35 commits
  3. 26 Oct, 2015 4 commits
    • Sabrina Dubroca's avatar
      [stable-only] net: add length argument to skb_copy_and_csum_datagram_iovec · 1837825e
      Sabrina Dubroca authored 
      Without this length argument, we can read past the end of the iovec in
memcpy_toiovec because we have no way of knowing the total length of the
iovec's buffers.

This is needed for stable kernels where 89c22d8c ("net: Fix skb
csum races when peeking") has been backported but that don't have the
ioviter conversion, which is almost all the stable trees <= 3.18.

This also fixes a kernel crash for NFS servers when the client uses
 -onfsvers=3,proto=udp to mount the export.
Signed-off-by: default avatarSabrina Dubroca <sd@queasysnail.net>
Reviewed-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      1837825e
    • David Howells's avatar
      KEYS: Don't permit request_key() to construct a new keyring · 35552610
      David Howells authored 
      commit 911b79cd upstream.

If request_key() is used to find a keyring, only do the search part - don't
do the construction part if the keyring was not found by the search.  We
don't really want keyrings in the negative instantiated state since the
rejected/negative instantiation error value in the payload is unioned with
keyring metadata.

Now the kernel gives an error:

	request_key("keyring", "#selinux,bdekeyring", "keyring", KEY_SPEC_USER_SESSION_KEYRING) = -1 EPERM (Operation not permitted)
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      35552610
    • David Howells's avatar
      KEYS: Fix crash when attempt to garbage collect an uninstantiated keyring · 1881b6b8
      David Howells authored 
      commit f05819df upstream.

The following sequence of commands:

    i=`keyctl add user a a @s`
    keyctl request2 keyring foo bar @t
    keyctl unlink $i @s

tries to invoke an upcall to instantiate a keyring if one doesn't already
exist by that name within the user's keyring set.  However, if the upcall
fails, the code sets keyring->type_data.reject_error to -ENOKEY or some
other error code.  When the key is garbage collected, the key destroy
function is called unconditionally and keyring_destroy() uses list_empty()
on keyring->type_data.link - which is in a union with reject_error.
Subsequently, the kernel tries to unlink the keyring from the keyring names
list - which oopses like this:

	BUG: unable to handle kernel paging request at 00000000ffffff8a
	IP: [<ffffffff8126e051>] keyring_destroy+0x3d/0x88
	...
	Workqueue: events key_garbage_collector
	...
	RIP: 0010:[<ffffffff8126e051>] keyring_destroy+0x3d/0x88
	RSP: 0018:ffff88003e2f3d30  EFLAGS: 00010203
	RAX: 00000000ffffff82 RBX: ffff88003bf1a900 RCX: 0000000000000000
	RDX: 0000000000000000 RSI: 000000003bfc6901 RDI: ffffffff81a73a40
	RBP: ffff88003e2f3d38 R08: 0000000000000152 R09: 0000000000000000
	R10: ffff88003e2f3c18 R11: 000000000000865b R12: ffff88003bf1a900
	R13: 0000000000000000 R14: ffff88003bf1a908 R15: ffff88003e2f4000
	...
	CR2: 00000000ffffff8a CR3: 000000003e3ec000 CR4: 00000000000006f0
	...
	Call Trace:
	 [<ffffffff8126c756>] key_gc_unused_keys.constprop.1+0x5d/0x10f
	 [<ffffffff8126ca71>] key_garbage_collector+0x1fa/0x351
	 [<ffffffff8105ec9b>] process_one_work+0x28e/0x547
	 [<ffffffff8105fd17>] worker_thread+0x26e/0x361
	 [<ffffffff8105faa9>] ? rescuer_thread+0x2a8/0x2a8
	 [<ffffffff810648ad>] kthread+0xf3/0xfb
	 [<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2
	 [<ffffffff815f2ccf>] ret_from_fork+0x3f/0x70
	 [<ffffffff810647ba>] ? kthread_create_on_node+0x1c2/0x1c2

Note the value in RAX.  This is a 32-bit representation of -ENOKEY.

The solution is to only call ->destroy() if the key was successfully
instantiated.
Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      1881b6b8
    • David Howells's avatar
      KEYS: Fix race between key destruction and finding a keyring by name · 348fce88
      David Howells authored 
      commit 94c4554b upstream.

There appears to be a race between:

 (1) key_gc_unused_keys() which frees key->security and then calls
     keyring_destroy() to unlink the name from the name list

 (2) find_keyring_by_name() which calls key_permission(), thus accessing
     key->security, on a key before checking to see whether the key usage is 0
     (ie. the key is dead and might be cleaned up).

Fix this by calling ->destroy() before cleaning up the core key data -
including key->security.
Reported-by: default avatarPetr Matousek <pmatouse@redhat.com>
Signed-off-by: default avatarDavid Howells <dhowells@redhat.com>
Signed-off-by: default avatarKamal Mostafa <kamal@canonical.com>
      348fce88
  5. 23 Oct, 2015 1 commit
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