linux-stable.git, branch v3.0.68 Linux kernel stable tree Linux 3.0.68 2013-03-03T22:09:28+00:00 Greg Kroah-Hartman gregkh@linuxfoundation.org 2013-03-03T22:09:28+00:00 e28c3f2b514b5581e15614f7cf976131092cf4b6 






staging: comedi: check s->async for poll(), read() and write()
2013-03-03T22:09:07+00:00

Ian Abbott
abbotti@mev.co.uk

2013-02-27T10:56:19+00:00

6c80ee53f3737993f693bf2a3b4b3e4bbde9b51f

commit cc400e185c07c15a42d2635995f422de5b94b696 upstream.

Some low-level comedi drivers (incorrectly) point `dev->read_subdev` or
`dev->write_subdev` to a subdevice that does not support asynchronous
commands.  Comedi's poll(), read() and write() file operation handlers
assume these subdevices do support asynchronous commands.  In
particular, they assume `s->async` is valid (where `s` points to the
read or write subdevice), which it won't be if it has been set
incorrectly.  This can lead to a NULL pointer dereference.

Check `s->async` is non-NULL in `comedi_poll()`, `comedi_read()` and
`comedi_write()` to avoid the bug.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit cc400e185c07c15a42d2635995f422de5b94b696 upstream.

Some low-level comedi drivers (incorrectly) point `dev->read_subdev` or
`dev->write_subdev` to a subdevice that does not support asynchronous
commands.  Comedi's poll(), read() and write() file operation handlers
assume these subdevices do support asynchronous commands.  In
particular, they assume `s->async` is valid (where `s` points to the
read or write subdevice), which it won't be if it has been set
incorrectly.  This can lead to a NULL pointer dereference.

Check `s->async` is non-NULL in `comedi_poll()`, `comedi_read()` and
`comedi_write()` to avoid the bug.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








staging: comedi: ni_labpc: set up command4 register *after* command3
2013-03-03T22:09:07+00:00

Ian Abbott
abbotti@mev.co.uk

2013-02-27T12:52:46+00:00

544da4403b05e874e134919db7124def003ef7cf

Commit 22056e2b46246d97ff0f7c6e21a77b8daa07f02c upstream.

Tuomas <tvainikk _at_ gmail _dot_ com> reported problems getting
meaningful output from a Lab-PC+ in differential mode for AI cmds, but
AI insn reads gave correct readings.  He tracked it down to two
problems, one of which is addressed by this patch.

It seems that writing to the command3 register after writing to the
command4 register in `labpc_ai_cmd()` messes up the differential
reference bit setting in the command4 register.  Set up the command4
register after the command3 register (as in `labpc_ai_rinsn()`) to avoid
the problem.

Thanks to Tuomas for suggesting the fix.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






Commit 22056e2b46246d97ff0f7c6e21a77b8daa07f02c upstream.

Tuomas <tvainikk _at_ gmail _dot_ com> reported problems getting
meaningful output from a Lab-PC+ in differential mode for AI cmds, but
AI insn reads gave correct readings.  He tracked it down to two
problems, one of which is addressed by this patch.

It seems that writing to the command3 register after writing to the
command4 register in `labpc_ai_cmd()` messes up the differential
reference bit setting in the command4 register.  Set up the command4
register after the command3 register (as in `labpc_ai_rinsn()`) to avoid
the problem.

Thanks to Tuomas for suggesting the fix.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








staging: comedi: ni_labpc: correct differential channel sequence for AI commands
2013-03-03T22:09:07+00:00

Ian Abbott
abbotti@mev.co.uk

2013-02-27T12:52:45+00:00

5e6af63de116db55be85da4374441f7963d11281

Commit 4c4bc25d0fa6beaf054c0b4c3b324487f266c820 upstream.

Tuomas <tvainikk _at_ gmail _dot_ com> reported problems getting
meaningful output from a Lab-PC+ in differential mode for AI cmds, but
AI insn reads gave correct readings.  He tracked it down to two
problems, one of which is addressed by this patch.

It seems the setting of the channel bits for particular scanning modes
was incorrect for differential mode.  (Only half the number of channels
are available in differential mode; comedi refers to them as channels 0,
1, 2 and 3, but the hardware documentation refers to them as channels 0,
2, 4 and 6.)  In differential mode, the setting of the channel enable
bits in the command1 register should depend on whether the scan enable
bit is set.  Effectively, we need to double the comedi channel number
when the scan enable bit is not set in differential mode.  The scan
enable bit gets set when the AI scan mode is `MODE_MULT_CHAN_UP` or
`MODE_MULT_CHAN_DOWN`, and gets cleared when the AI scan mode is
`MODE_SINGLE_CHAN` or `MODE_SINGLE_CHAN_INTERVAL`.  The existing test
for whether the comedi channel number needs to be doubled in
differential mode is incorrect in `labpc_ai_cmd()`.  This patch corrects
the test.

Thanks to Tuomas for suggesting the fix.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






Commit 4c4bc25d0fa6beaf054c0b4c3b324487f266c820 upstream.

Tuomas <tvainikk _at_ gmail _dot_ com> reported problems getting
meaningful output from a Lab-PC+ in differential mode for AI cmds, but
AI insn reads gave correct readings.  He tracked it down to two
problems, one of which is addressed by this patch.

It seems the setting of the channel bits for particular scanning modes
was incorrect for differential mode.  (Only half the number of channels
are available in differential mode; comedi refers to them as channels 0,
1, 2 and 3, but the hardware documentation refers to them as channels 0,
2, 4 and 6.)  In differential mode, the setting of the channel enable
bits in the command1 register should depend on whether the scan enable
bit is set.  Effectively, we need to double the comedi channel number
when the scan enable bit is not set in differential mode.  The scan
enable bit gets set when the AI scan mode is `MODE_MULT_CHAN_UP` or
`MODE_MULT_CHAN_DOWN`, and gets cleared when the AI scan mode is
`MODE_SINGLE_CHAN` or `MODE_SINGLE_CHAN_INTERVAL`.  The existing test
for whether the comedi channel number needs to be doubled in
differential mode is incorrect in `labpc_ai_cmd()`.  This patch corrects
the test.

Thanks to Tuomas for suggesting the fix.

Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








s390/kvm: Fix store status for ACRS/FPRS fix
2013-03-03T22:09:07+00:00

Jiri Slaby
jslaby@suse.cz

2013-03-03T22:09:07+00:00

d81d788db85abd39fd7753e2482f748c48de202a

In 3.0.67, commit 58c9ce6fad8e00d9726447f939fe7e78e2aec891 (s390/kvm:
Fix store status for ACRS/FPRS), upstream commit
15bc8d8457875f495c59d933b05770ba88d1eacb, added a call to
save_access_regs to save ACRS. But we do not have ARCS in kvm_run in
3.0 yet, so this results in:
arch/s390/kvm/kvm-s390.c: In function 'kvm_s390_vcpu_store_status':
arch/s390/kvm/kvm-s390.c:593: error: 'struct kvm_run' has no member named 's'

Fix it by saving guest_acrs which is where ARCS are in 3.0.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>





In 3.0.67, commit 58c9ce6fad8e00d9726447f939fe7e78e2aec891 (s390/kvm:
Fix store status for ACRS/FPRS), upstream commit
15bc8d8457875f495c59d933b05770ba88d1eacb, added a call to
save_access_regs to save ACRS. But we do not have ARCS in kvm_run in
3.0 yet, so this results in:
arch/s390/kvm/kvm-s390.c: In function 'kvm_s390_vcpu_store_status':
arch/s390/kvm/kvm-s390.c:593: error: 'struct kvm_run' has no member named 's'

Fix it by saving guest_acrs which is where ARCS are in 3.0.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>







dca: check against empty dca_domains list before unregister provider fix
2013-03-03T22:09:07+00:00

Jiri Slaby
jslaby@suse.cz

2013-03-03T22:09:07+00:00

55bce39db26a3b1d6b18fc0ae5d57948946f0c49

In 3.0.67, commit 7a9a20ea77e7508c795dead9ab2f6c98a617762d (dca: check
against empty dca_domains list before unregister provider), upstream
commit c419fcfd071cf34ba00f9f65282583772d2655e7, added a fail path to
unregister_dca_provider. It added there also a call to
raw_spin_unlock_irqrestore. But in 3.0, the lock is not raw, so this
results in:
drivers/dca/dca-core.c: In function 'unregister_dca_provider':
drivers/dca/dca-core.c:413: warning: passing argument 1 of '_raw_spin_unlock_irqrestore' from incompatible pointer type

Fix it by calling spin_unlock_irqrestore properly.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>





In 3.0.67, commit 7a9a20ea77e7508c795dead9ab2f6c98a617762d (dca: check
against empty dca_domains list before unregister provider), upstream
commit c419fcfd071cf34ba00f9f65282583772d2655e7, added a fail path to
unregister_dca_provider. It added there also a call to
raw_spin_unlock_irqrestore. But in 3.0, the lock is not raw, so this
results in:
drivers/dca/dca-core.c: In function 'unregister_dca_provider':
drivers/dca/dca-core.c:413: warning: passing argument 1 of '_raw_spin_unlock_irqrestore' from incompatible pointer type

Fix it by calling spin_unlock_irqrestore properly.

Signed-off-by: Jiri Slaby <jslaby@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>







cgroup: fix exit() vs rmdir() race
2013-03-03T22:09:07+00:00

Li Zefan
lizefan@huawei.com

2013-01-24T06:43:28+00:00

cc0e3e13b0a90e5ff42d5b134939eacf5e7e497c

commit 71b5707e119653039e6e95213f00479668c79b75 upstream.

In cgroup_exit() put_css_set_taskexit() is called without any lock,
which might lead to accessing a freed cgroup:

thread1                           thread2
---------------------------------------------
exit()
  cgroup_exit()
    put_css_set_taskexit()
      atomic_dec(cgrp->count);
                                   rmdir();
      /* not safe !! */
      check_for_release(cgrp);

rcu_read_lock() can be used to make sure the cgroup is alive.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 71b5707e119653039e6e95213f00479668c79b75 upstream.

In cgroup_exit() put_css_set_taskexit() is called without any lock,
which might lead to accessing a freed cgroup:

thread1                           thread2
---------------------------------------------
exit()
  cgroup_exit()
    put_css_set_taskexit()
      atomic_dec(cgrp->count);
                                   rmdir();
      /* not safe !! */
      check_for_release(cgrp);

rcu_read_lock() can be used to make sure the cgroup is alive.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








cpuset: fix cpuset_print_task_mems_allowed() vs rename() race
2013-03-03T22:09:06+00:00

Li Zefan
lizefan@huawei.com

2013-01-25T08:08:01+00:00

6403d47ff9392807fcfa4464527193e0cab65b2a

commit 63f43f55c9bbc14f76b582644019b8a07dc8219a upstream.

rename() will change dentry->d_name. The result of this race can
be worse than seeing partially rewritten name, but we might access
a stale pointer because rename() will re-allocate memory to hold
a longer name.

It's safe in the protection of dentry->d_lock.

v2: check NULL dentry before acquiring dentry lock.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit 63f43f55c9bbc14f76b582644019b8a07dc8219a upstream.

rename() will change dentry->d_name. The result of this race can
be worse than seeing partially rewritten name, but we might access
a stale pointer because rename() will re-allocate memory to hold
a longer name.

It's safe in the protection of dentry->d_lock.

v2: check NULL dentry before acquiring dentry lock.

Signed-off-by: Li Zefan <lizefan@huawei.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








x86/apic: Work around boot failure on HP ProLiant DL980 G7 Server systems
2013-03-03T22:09:06+00:00

Stoney Wang
song-bo.wang@hp.com

2013-02-07T18:53:02+00:00

2212f47b734e5b9461b5c3f555dc653ea7aa212f

commit cb214ede7657db458fd0b2a25ea0b28dbf900ebc upstream.

When a HP ProLiant DL980 G7 Server boots a regular kernel,
there will be intermittent lost interrupts which could
result in a hang or (in extreme cases) data loss.

The reason is that this system only supports x2apic physical
mode, while the kernel boots with a logical-cluster default
setting.

This bug can be worked around by specifying the "x2apic_phys" or
"nox2apic" boot option, but we want to handle this system
without requiring manual workarounds.

The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table.
As all apicids are smaller than 255, BIOS need to pass the
control to the OS with xapic mode, according to x2apic-spec,
chapter 2.9.

Current code handle x2apic when BIOS pass with xapic mode
enabled:

When user specifies x2apic_phys, or FADT indicates PHYSICAL:

1. During madt oem check, apic driver is set with xapic logical
   or xapic phys driver at first.

2. enable_IR_x2apic() will enable x2apic_mode.

3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe()
   will install the correct x2apic phys driver and use x2apic phys mode.
   Otherwise it will skip the driver will let x2apic_cluster_probe to
   take over to install x2apic cluster driver (wrong one) even though FADT
   indicates PHYSICAL, because x2apic_phys_probe does not check
   FADT PHYSICAL.

Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the
problem.

Signed-off-by: Stoney Wang <song-bo.wang@hp.com>
[ updated the changelog and simplified the code ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Zhang Lin-Bao <Linbao.zhang@hp.com>
[ make a patch specially for 3.0.66]
Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit cb214ede7657db458fd0b2a25ea0b28dbf900ebc upstream.

When a HP ProLiant DL980 G7 Server boots a regular kernel,
there will be intermittent lost interrupts which could
result in a hang or (in extreme cases) data loss.

The reason is that this system only supports x2apic physical
mode, while the kernel boots with a logical-cluster default
setting.

This bug can be worked around by specifying the "x2apic_phys" or
"nox2apic" boot option, but we want to handle this system
without requiring manual workarounds.

The BIOS sets ACPI_FADT_APIC_PHYSICAL in FADT table.
As all apicids are smaller than 255, BIOS need to pass the
control to the OS with xapic mode, according to x2apic-spec,
chapter 2.9.

Current code handle x2apic when BIOS pass with xapic mode
enabled:

When user specifies x2apic_phys, or FADT indicates PHYSICAL:

1. During madt oem check, apic driver is set with xapic logical
   or xapic phys driver at first.

2. enable_IR_x2apic() will enable x2apic_mode.

3. if user specifies x2apic_phys on the boot line, x2apic_phys_probe()
   will install the correct x2apic phys driver and use x2apic phys mode.
   Otherwise it will skip the driver will let x2apic_cluster_probe to
   take over to install x2apic cluster driver (wrong one) even though FADT
   indicates PHYSICAL, because x2apic_phys_probe does not check
   FADT PHYSICAL.

Add checking x2apic_fadt_phys in x2apic_phys_probe() to fix the
problem.

Signed-off-by: Stoney Wang <song-bo.wang@hp.com>
[ updated the changelog and simplified the code ]
Signed-off-by: Yinghai Lu <yinghai@kernel.org>
Signed-off-by: Zhang Lin-Bao <Linbao.zhang@hp.com>
[ make a patch specially for 3.0.66]
Link: http://lkml.kernel.org/r/1360263182-16226-1-git-send-email-yinghai@kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>








x86: Do not leak kernel page mapping locations
2013-03-03T22:09:06+00:00

Kees Cook
keescook@chromium.org

2013-02-07T17:44:13+00:00

f39edfbf6dbf8e29cfbafd67d93fa1e30196701c

commit e575a86fdc50d013bf3ad3aa81d9100e8e6cc60d upstream.

Without this patch, it is trivial to determine kernel page
mappings by examining the error code reported to dmesg[1].
Instead, declare the entire kernel memory space as a violation
of a present page.

Additionally, since show_unhandled_signals is enabled by
default, switch branch hinting to the more realistic
expectation, and unobfuscate the setting of the PF_PROT bit to
improve readability.

[1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/

Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Suggested-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>






commit e575a86fdc50d013bf3ad3aa81d9100e8e6cc60d upstream.

Without this patch, it is trivial to determine kernel page
mappings by examining the error code reported to dmesg[1].
Instead, declare the entire kernel memory space as a violation
of a present page.

Additionally, since show_unhandled_signals is enabled by
default, switch branch hinting to the more realistic
expectation, and unobfuscate the setting of the PF_PROT bit to
improve readability.

[1] http://vulnfactory.org/blog/2013/02/06/a-linux-memory-trick/

Reported-by: Dan Rosenberg <dan.j.rosenberg@gmail.com>
Suggested-by: Brad Spengler <spender@grsecurity.net>
Signed-off-by: Kees Cook <keescook@chromium.org>
Acked-by: H. Peter Anvin <hpa@zytor.com>
Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Cc: Eric W. Biederman <ebiederm@xmission.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/r/20130207174413.GA12485@www.outflux.net
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: CAI Qian <caiqian@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>