linux-stable.git/net, branch v4.1.8

fs: create and use seq_show_option for escaping

2015-09-21T17:05:45+00:00

commit a068acf2ee77693e0bf39d6e07139ba704f461c3 upstream.

Many file systems that implement the show_options hook fail to correctly
escape their output which could lead to unescaped characters (e.g.  new
lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files.  This
could lead to confusion, spoofed entries (resulting in things like
systemd issuing false d-bus "mount" notifications), and who knows what
else.  This looks like it would only be the root user stepping on
themselves, but it's possible weird things could happen in containers or
in other situations with delegated mount privileges.

Here's an example using overlay with setuid fusermount trusting the
contents of /proc/mounts (via the /etc/mtab symlink).  Imagine the use
of "sudo" is something more sneaky:

  $ BASE="ovl"
  $ MNT="$BASE/mnt"
  $ LOW="$BASE/lower"
  $ UP="$BASE/upper"
  $ WORK="$BASE/work/ 0 0
  none /proc fuse.pwn user_id=1000"
  $ mkdir -p "$LOW" "$UP" "$WORK"
  $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt
  $ cat /proc/mounts
  none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0
  none /proc fuse.pwn user_id=1000 0 0
  $ fusermount -u /proc
  $ cat /proc/mounts
  cat: /proc/mounts: No such file or directory

This fixes the problem by adding new seq_show_option and
seq_show_option_n helpers, and updating the vulnerable show_option
handlers to use them as needed.  Some, like SELinux, need to be open
coded due to unusual existing escape mechanisms.

[akpm@linux-foundation.org: add lost chunk, per Kees]
[keescook@chromium.org: seq_show_option should be using const parameters]
Signed-off-by: Kees Cook 
Acked-by: Serge Hallyn 
Acked-by: Jan Kara 
Acked-by: Paul Moore 
Cc: J. R. Okajima 
Signed-off-by: Kees Cook 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

9p: ensure err is initialized to 0 in p9_client_read/write

2015-09-13T16:07:50+00:00

commit 999b8b88c6060adf7a9b7907740ae86ace65291e upstream.

Some use of those functions were providing unitialized values to those
functions. Notably, when reading 0 bytes from an empty file on a 9P
filesystem, the return code of read() was not 0.

Tested with this simple program:

    #include 
    #include 
    #include 
    #include 
    #include 

    int main(int argc, const char **argv)
    {
        assert(argc == 2);
        char buffer[256];
        int fd = open(argv[1], O_RDONLY|O_NOCTTY);
        assert(fd >= 0);
        assert(read(fd, buffer, 0) == 0);
        return 0;
    }

Signed-off-by: Vincent Bernat 
Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

mac80211: fix invalid read in minstrel_sort_best_tp_rates()

2015-09-13T16:07:48+00:00

commit f5eeb5fa191fd7b634cbc4883ac58f3b2184dbc5 upstream.

At the last iteration of the loop, j may equal zero and thus
tp_list[j - 1] causes an invalid read.
Change the logic of the loop so that j - 1 is always >= 0.

Signed-off-by: Adrien Schildknecht 
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

Bluetooth: Fix NULL pointer dereference in smp_conn_security

2015-08-17T03:52:11+00:00

commit 25ba265390c09b0a2b2f3fd9ba82e37248b7a371 upstream.

The l2cap_conn->smp pointer may be NULL for various valid reasons where SMP has
failed to initialize properly. One such scenario is when crypto support is
missing, another when the adapter has been powered on through a legacy method.
The smp_conn_security() function should have the appropriate check for this
situation to avoid NULL pointer dereferences.

Signed-off-by: Johan Hedberg 
Signed-off-by: Marcel Holtmann 
Signed-off-by: Greg Kroah-Hartman

rds: rds_ib_device.refcount overflow

2015-08-10T19:21:57+00:00

commit 4fabb59449aa44a585b3603ffdadd4c5f4d0c033 upstream.

Fixes: 3e0249f9c05c ("RDS/IB: add refcount tracking to struct rds_ib_device")

There lacks a dropping on rds_ib_device.refcount in case rds_ib_alloc_fmr
failed(mr pool running out). this lead to the refcount overflow.

A complain in line 117(see following) is seen. From vmcore:
s_ib_rdma_mr_pool_depleted is 2147485544 and rds_ibdev->refcount is -2147475448.
That is the evidence the mr pool is used up. so rds_ib_alloc_fmr is very likely
to return ERR_PTR(-EAGAIN).

115 void rds_ib_dev_put(struct rds_ib_device *rds_ibdev)
116 {
117         BUG_ON(atomic_read(&rds_ibdev->refcount) <= 0);
118         if (atomic_dec_and_test(&rds_ibdev->refcount))
119                 queue_work(rds_wq, &rds_ibdev->free_work);
120 }

fix is to drop refcount when rds_ib_alloc_fmr failed.

Signed-off-by: Wengang Wang 
Reviewed-by: Haggai Eran 
Signed-off-by: Doug Ledford 
Signed-off-by: Greg Kroah-Hartman

mac80211: clear subdir_stations when removing debugfs

2015-08-10T19:21:54+00:00

commit 4479004e6409087d1b4986881dc98c6c15dffb28 upstream.

If we don't do this, and we then fail to recreate the debugfs
directory during a mode change, then we will fail later trying
to add stations to this now bogus directory:

BUG: unable to handle kernel NULL pointer dereference at 0000006c
IP: [] mutex_lock+0x12/0x30
Call Trace:
[] start_creating+0x44/0xc0
[] debugfs_create_dir+0x13/0xf0
[] ieee80211_sta_debugfs_add+0x6e/0x490 [mac80211]

Signed-off-by: Tom Hughes 
Signed-off-by: Johannes Berg 
Signed-off-by: Greg Kroah-Hartman

can: replace timestamp as unique skb attribute

2015-08-10T19:21:51+00:00

commit d3b58c47d330de8c29898fe9746f7530408f8a59 upstream.

Commit 514ac99c64b "can: fix multiple delivery of a single CAN frame for
overlapping CAN filters" requires the skb->tstamp to be set to check for
identical CAN skbs.

Without timestamping to be required by user space applications this timestamp
was not generated which lead to commit 36c01245eb8 "can: fix loss of CAN frames
in raw_rcv" - which forces the timestamp to be set in all CAN related skbuffs
by introducing several __net_timestamp() calls.

This forces e.g. out of tree drivers which are not using alloc_can{,fd}_skb()
to add __net_timestamp() after skbuff creation to prevent the frame loss fixed
in mainline Linux.

This patch removes the timestamp dependency and uses an atomic counter to
create an unique identifier together with the skbuff pointer.

Btw: the new skbcnt element introduced in struct can_skb_priv has to be
initialized with zero in out-of-tree drivers which are not using
alloc_can{,fd}_skb() too.

Signed-off-by: Oliver Hartkopp 
Signed-off-by: Marc Kleine-Budde 
Signed-off-by: Greg Kroah-Hartman

p9_client_write(): avoid double p9_free_req()

2015-08-03T16:29:18+00:00

commit 67e808fbb0404a12d9b9830a44bbb48d447d8bc9 upstream.

Braino in "9p: switch p9_client_write() to passing it struct iov_iter *";
if response is impossible to parse and we discard the request, get the
out of the loop right there.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

9p: forgetting to cancel request on interrupted zero-copy RPC

2015-08-03T16:29:18+00:00

commit a84b69cb6e0a41e86bc593904faa6def3b957343 upstream.

If we'd already sent a request and decide to abort it, we *must*
issue TFLUSH properly and not just blindly reuse the tag, or
we'll get seriously screwed when response eventually arrives
and we confuse it for response to later request that had reused
the same tag.

Signed-off-by: Al Viro 
Signed-off-by: Greg Kroah-Hartman

SUNRPC: Fix a memory leak in the backchannel code

2015-08-03T16:29:17+00:00

commit 88de6af24f2b48b06c514d3c3d0a8f22fafe30bd upstream.

req->rq_private_buf isn't initialised when xprt_setup_backchannel calls
xprt_free_allocation.

Fixes: fb7a0b9addbdb ("nfs41: New backchannel helper routines")
Signed-off-by: Trond Myklebust 
Signed-off-by: Greg Kroah-Hartman