n_gsm: avoid accessing freed memory during CMD_FCOFF condition

commit b4338e1efc339986cf6c0a3652906e914a86e2d3 upstream.

gsm_data_kick was recently modified to allow messages on the
tx queue bound for DLCI0 to flow even during FCOFF conditions.
Unfortunately we introduced a bug discovered by code inspection
where subsequent list traversers can access freed memory if
the DLCI0 messages were not all at the head of the list.

Replaced singly linked tx list w/ a list_head and used
provided interfaces for traversing and deleting members.

Change-Id: If28d4546481426696dfd5b31763e817b99102398
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Tested-by: Yin, Fengwei <fengwei.yin@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
n_gsm: replace kfree_skb w/ appropriate dev_* versions

commit 329e56780e514a7ab607bcb51a52ab0dc2669414 upstream.

Drivers are supposed to use the dev_* versions of the kfree_skb
interfaces. In a couple of cases we were called with IRQs
disabled as well which kfree_skb() does not expect.

Replaced kfree_skb calls w/ dev_kfree_skb and dev_kfree_skb_any

Change-Id: I594c1c8a3a7b9f1a16c71f1e93f360cda082326a
Signed-off-by: Russ Gorby <russ.gorby@intel.com>
Tested-by: Yin, Fengwei <fengwei.yin@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
x86 get_unmapped_area: Access mmap_legacy_base through mm_struct member

commit 41aacc1eea645c99edbe8fbcf78a97dc9b862adc upstream.

This is the updated version of df54d6fa5427 ("x86 get_unmapped_area():
use proper mmap base for bottom-up direction") that only randomizes the
mmap base address once.

Change-Id: I38f1032209035b35e909271d4cd6bb6ae6cf7599
Signed-off-by: Radu Caragea <sinaelgl@gmail.com>
Reported-and-tested-by: Jeff Shorey <shoreyjeff@gmail.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Michel Lespinasse <walken@google.com>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Rik van Riel <riel@redhat.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Adrian Sendroiu <molecula2788@gmail.com>
Cc: Greg KH <greg@kroah.com>
Cc: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
[bwh: Backported to 3.2: adjust context]
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
ptrace/x86: Introduce set_task_blockstep() helper

commit 848e8f5f0ad3169560c516fff6471be65f76e69f upstream.

No functional changes, preparation for the next fix and for uprobes
single-step fixes.

Move the code playing with TIF_BLOCKSTEP/DEBUGCTLMSR_BTF into the
new helper, set_task_blockstep().

Change-Id: I07f7960497aa1ad6a2c428b493bc51bf75ffb20b
Signed-off-by: Oleg Nesterov <oleg@redhat.com>
Acked-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
Cc: Rui Xiang <rui.xiang@huawei.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>