linux-stable.git/kernel, branch v4.1.4 Linux kernel stable tree security_syslog() should be called once only 2015-08-03T16:29:15+00:00 Vasily Averin vvs@virtuozzo.com 2015-06-25T22:01:44+00:00 ae41bfc68161ea5d280091ccb9593e9f68d5db44 commit d194e5d666225b04c7754471df0948f645b6ab3a upstream. The final version of commit 637241a900cb ("kmsg: honor dmesg_restrict sysctl on /dev/kmsg") lost few hooks, as result security_syslog() are processed incorrectly: - open of /dev/kmsg checks syslog access permissions by using check_syslog_permissions() where security_syslog() is not called if dmesg_restrict is set. - syslog syscall and /proc/kmsg calls do_syslog() where security_syslog can be executed twice (inside check_syslog_permissions() and then directly in do_syslog()) With this patch security_syslog() is called once only in all syslog-related operations regardless of dmesg_restrict value. Fixes: 637241a900cb ("kmsg: honor dmesg_restrict sysctl on /dev/kmsg") Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Cc: Kees Cook <keescook@chromium.org> Cc: Josh Boyer <jwboyer@redhat.com> Cc: Eric Paris <eparis@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit d194e5d666225b04c7754471df0948f645b6ab3a upstream.

The final version of commit 637241a900cb ("kmsg: honor dmesg_restrict
sysctl on /dev/kmsg") lost few hooks, as result security_syslog() are
processed incorrectly:

- open of /dev/kmsg checks syslog access permissions by using
  check_syslog_permissions() where security_syslog() is not called if
  dmesg_restrict is set.

- syslog syscall and /proc/kmsg calls do_syslog() where security_syslog
  can be executed twice (inside check_syslog_permissions() and then
  directly in do_syslog())

With this patch security_syslog() is called once only in all
syslog-related operations regardless of dmesg_restrict value.

Fixes: 637241a900cb ("kmsg: honor dmesg_restrict sysctl on /dev/kmsg")
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Josh Boyer <jwboyer@redhat.com>
Cc: Eric Paris <eparis@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
PM / sleep: Increase default DPM watchdog timeout to 60 2015-08-03T16:29:15+00:00 Takashi Iwai tiwai@suse.de 2015-06-24T22:35:16+00:00 01fed2338abfbfd9719bc9ae0f2673c145f24955 commit fff3b16d2754a061a3549c4307a186423a0128fd upstream. Many harddisks (mostly WD ones) have firmware problems and take too long, more than 10 seconds, to resume from suspend. And this often exceeds the default DPM watchdog timeout (12 seconds), resulting in a kernel panic out of sudden. Since most distros just take the default as is, we should give a bit more safer value. This patch increases the default value from 12 seconds to one minute, which has been confirmed to be long enough for such problematic disks. Link: https://bugzilla.kernel.org/show_bug.cgi?id=91921 Fixes: 70fea60d888d (PM / Sleep: Detect device suspend/resume lockup and log event) Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit fff3b16d2754a061a3549c4307a186423a0128fd upstream.

Many harddisks (mostly WD ones) have firmware problems and take too
long, more than 10 seconds, to resume from suspend.  And this often
exceeds the default DPM watchdog timeout (12 seconds), resulting in a
kernel panic out of sudden.

Since most distros just take the default as is, we should give a bit
more safer value.  This patch increases the default value from 12
seconds to one minute, which has been confirmed to be long enough for
such problematic disks.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=91921
Fixes: 70fea60d888d (PM / Sleep: Detect device suspend/resume lockup and log event)
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing: Have branch tracer use recursive field of task struct 2015-08-03T16:29:12+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-07-07T19:05:03+00:00 624dda42c3e7a00608ca4532b2f7bc127bc0f740 commit 6224beb12e190ff11f3c7d4bf50cb2922878f600 upstream. Fengguang Wu's tests triggered a bug in the branch tracer's start up test when CONFIG_DEBUG_PREEMPT set. This was because that config adds some debug logic in the per cpu field, which calls back into the branch tracer. The branch tracer has its own recursive checks, but uses a per cpu variable to implement it. If retrieving the per cpu variable calls back into the branch tracer, you can see how things will break. Instead of using a per cpu variable, use the trace_recursion field of the current task struct. Simply set a bit when entering the branch tracing and clear it when leaving. If the bit is set on entry, just don't do the tracing. There's also the case with lockdep, as the local_irq_save() called before the recursion can also trigger code that can call back into the function. Changing that to a raw_local_irq_save() will protect that as well. This prevents the recursion and the inevitable crash that follows. Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com Reported-by: Fengguang Wu <fengguang.wu@intel.com> Tested-by: Fengguang Wu <fengguang.wu@intel.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6224beb12e190ff11f3c7d4bf50cb2922878f600 upstream.

Fengguang Wu's tests triggered a bug in the branch tracer's start up
test when CONFIG_DEBUG_PREEMPT set. This was because that config
adds some debug logic in the per cpu field, which calls back into
the branch tracer.

The branch tracer has its own recursive checks, but uses a per cpu
variable to implement it. If retrieving the per cpu variable calls
back into the branch tracer, you can see how things will break.

Instead of using a per cpu variable, use the trace_recursion field
of the current task struct. Simply set a bit when entering the
branch tracing and clear it when leaving. If the bit is set on
entry, just don't do the tracing.

There's also the case with lockdep, as the local_irq_save() called
before the recursion can also trigger code that can call back into
the function. Changing that to a raw_local_irq_save() will protect
that as well.

This prevents the recursion and the inevitable crash that follows.

Link: http://lkml.kernel.org/r/20150630141803.GA28071@wfg-t540p.sh.intel.com

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Tested-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing: Fix typo from "static inlin" to "static inline" 2015-08-03T16:29:12+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-06-25T22:19:37+00:00 2161c8679389c9008ec7a1c5c279ced37cc07f5e commit cc9e4bde03f2b4cfba52406c021364cbd2a4a0f3 upstream. The trace.h header when called without CONFIG_EVENT_TRACING enabled (seldom done), will not compile because of a typo in the protocol of trace_event_enum_update(). Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit cc9e4bde03f2b4cfba52406c021364cbd2a4a0f3 upstream.

The trace.h header when called without CONFIG_EVENT_TRACING enabled
(seldom done), will not compile because of a typo in the protocol
of trace_event_enum_update().

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing/filter: Do not allow infix to exceed end of string 2015-08-03T16:29:12+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-06-25T22:10:09+00:00 a27274be0112c7d458caba759e1d550fd9985e5f commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 upstream. While debugging a WARN_ON() for filtering, I found that it is possible for the filter string to be referenced after its end. With the filter: # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter The filter_parse() function can call infix_get_op() which calls infix_advance() that updates the infix filter pointers for the cnt and tail without checking if the filter is already at the end, which will put the cnt to zero and the tail beyond the end. The loop then calls infix_next() that has ps->infix.cnt--; return ps->infix.string[ps->infix.tail++]; The cnt will now be below zero, and the tail that is returned is already passed the end of the filter string. So far the allocation of the filter string usually has some buffer that is zeroed out, but if the filter string is of the exact size of the allocated buffer there's no guarantee that the charater after the nul terminating character will be zero. Luckily, only root can write to the filter. Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6b88f44e161b9ee2a803e5b2b1fbcf4e20e8b980 upstream.

While debugging a WARN_ON() for filtering, I found that it is possible
for the filter string to be referenced after its end. With the filter:

 # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter

The filter_parse() function can call infix_get_op() which calls
infix_advance() that updates the infix filter pointers for the cnt
and tail without checking if the filter is already at the end, which
will put the cnt to zero and the tail beyond the end. The loop then calls
infix_next() that has

	ps->infix.cnt--;
	return ps->infix.string[ps->infix.tail++];

The cnt will now be below zero, and the tail that is returned is
already passed the end of the filter string. So far the allocation
of the filter string usually has some buffer that is zeroed out, but
if the filter string is of the exact size of the allocated buffer
there's no guarantee that the charater after the nul terminating
character will be zero.

Luckily, only root can write to the filter.

Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
tracing/filter: Do not WARN on operand count going below zero 2015-08-03T16:29:12+00:00 Steven Rostedt (Red Hat) rostedt@goodmis.org 2015-06-25T22:02:29+00:00 baa7b46259b0dabb66bb4cd0dc28379bc5942c17 commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream. When testing the fix for the trace filter, I could not come up with a scenario where the operand count goes below zero, so I added a WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case that it can happen (although the filter would be wrong). # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter That is, a single operation without any operands will hit the path where the WARN_ON_ONCE() can trigger. Although this is harmless, and the filter is reported as a error. But instead of spitting out a warning to the kernel dmesg, just fail nicely and report it via the proper channels. Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com Reported-by: Vince Weaver <vincent.weaver@maine.edu> Reported-by: Sasha Levin <sasha.levin@oracle.com> Signed-off-by: Steven Rostedt <rostedt@goodmis.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit b4875bbe7e68f139bd3383828ae8e994a0df6d28 upstream.

When testing the fix for the trace filter, I could not come up with
a scenario where the operand count goes below zero, so I added a
WARN_ON_ONCE(cnt < 0) to the logic. But there is legitimate case
that it can happen (although the filter would be wrong).

 # echo '>' > /sys/kernel/debug/events/ext4/ext4_truncate_exit/filter

That is, a single operation without any operands will hit the path
where the WARN_ON_ONCE() can trigger. Although this is harmless,
and the filter is reported as a error. But instead of spitting out
a warning to the kernel dmesg, just fail nicely and report it via
the proper channels.

Link: http://lkml.kernel.org/r/558C6082.90608@oracle.com

Reported-by: Vince Weaver <vincent.weaver@maine.edu>
Reported-by: Sasha Levin <sasha.levin@oracle.com>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
genirq: devres: Fix testing return value of request_any_context_irq() 2015-07-21T17:10:05+00:00 Axel Lin axel.lin@ingics.com 2015-05-11T09:02:58+00:00 25d8f169eee423940158a0ab33ed5dd1dd995cf9 commit 63781394c540dd9e666a6b21d70b64dd52bce76e upstream. request_any_context_irq() returns a negative value on failure. It returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED on success. So fix testing return value of request_any_context_irq(). Also fixup the return value of devm_request_any_context_irq() to make it consistent with request_any_context_irq(). Fixes: 0668d3065128 ("genirq: Add devm_request_any_context_irq()") Signed-off-by: Axel Lin <axel.lin@ingics.com> Reviewed-by: Stephen Boyd <sboyd@codeaurora.org> Link: http://lkml.kernel.org/r/1431334978.17783.4.camel@ingics.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 63781394c540dd9e666a6b21d70b64dd52bce76e upstream.

request_any_context_irq() returns a negative value on failure.
It returns either IRQC_IS_HARDIRQ or IRQC_IS_NESTED on success.
So fix testing return value of request_any_context_irq().

Also fixup the return value of devm_request_any_context_irq() to make it
consistent with request_any_context_irq().

Fixes: 0668d3065128 ("genirq: Add devm_request_any_context_irq()")
Signed-off-by: Axel Lin <axel.lin@ingics.com>
Reviewed-by: Stephen Boyd <sboyd@codeaurora.org>
Link: http://lkml.kernel.org/r/1431334978.17783.4.camel@ingics.com
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
livepatch: add module locking around kallsyms calls 2015-07-21T17:10:04+00:00 Miroslav Benes mbenes@suse.cz 2015-06-01T15:48:37+00:00 9da8e034daa3670221442392ce9ea17474591c34 commit 9a1bd63cdae4b623494c4ebaf723a91c35ec49fb upstream. The list of loaded modules is walked through in module_kallsyms_on_each_symbol (called by kallsyms_on_each_symbol). The module_mutex lock should be acquired to prevent potential corruptions in the list. This was uncovered with new lockdep asserts in module code introduced by the commit 0be964be0d45 ("module: Sanitize RCU usage and locking") in recent next- trees. Signed-off-by: Miroslav Benes <mbenes@suse.cz> Acked-by: Josh Poimboeuf <jpoimboe@redhat.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 9a1bd63cdae4b623494c4ebaf723a91c35ec49fb upstream.

The list of loaded modules is walked through in
module_kallsyms_on_each_symbol (called by kallsyms_on_each_symbol). The
module_mutex lock should be acquired to prevent potential corruptions
in the list.

This was uncovered with new lockdep asserts in module code introduced by
the commit 0be964be0d45 ("module: Sanitize RCU usage and locking") in
recent next- trees.

Signed-off-by: Miroslav Benes <mbenes@suse.cz>
Acked-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
rcu: Correctly handle non-empty Tiny RCU callback list with none ready 2015-07-21T17:10:01+00:00 Paul E. McKenney paulmck@linux.vnet.ibm.com 2015-05-11T18:13:05+00:00 a6556a506ea1c737e8adafd59015786448ffbf3f commit 6e91f8cb138625be96070b778d9ba71ce520ea7e upstream. If, at the time __rcu_process_callbacks() is invoked, there are callbacks in Tiny RCU's callback list, but none of them are ready to be invoked, the current list-management code will knit the non-ready callbacks out of the list. This can result in hangs and possibly worse. This commit therefore inserts a check for there being no callbacks that can be invoked immediately. This bug is unlikely to occur -- you have to get a new callback between the time rcu_sched_qs() or rcu_bh_qs() was called, but before we get to __rcu_process_callbacks(). It was detected by the addition of RCU-bh testing to rcutorture, which in turn was instigated by Iftekhar Ahmed's mutation testing. Although this bug was made much more likely by 915e8a4fe45e (rcu: Remove fastpath from __rcu_process_callbacks()), this did not cause the bug, but rather made it much more probable. That said, it takes more than 40 hours of rcutorture testing, on average, for this bug to appear, so this fix cannot be considered an emergency. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Reviewed-by: Josh Triplett <josh@joshtriplett.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit 6e91f8cb138625be96070b778d9ba71ce520ea7e upstream.

If, at the time __rcu_process_callbacks() is invoked,  there are callbacks
in Tiny RCU's callback list, but none of them are ready to be invoked,
the current list-management code will knit the non-ready callbacks out
of the list.  This can result in hangs and possibly worse.  This commit
therefore inserts a check for there being no callbacks that can be
invoked immediately.

This bug is unlikely to occur -- you have to get a new callback between
the time rcu_sched_qs() or rcu_bh_qs() was called, but before we get to
__rcu_process_callbacks().  It was detected by the addition of RCU-bh
testing to rcutorture, which in turn was instigated by Iftekhar Ahmed's
mutation testing.  Although this bug was made much more likely by
915e8a4fe45e (rcu: Remove fastpath from __rcu_process_callbacks()), this
did not cause the bug, but rather made it much more probable.   That
said, it takes more than 40 hours of rcutorture testing, on average,
for this bug to appear, so this fix cannot be considered an emergency.

Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
sysfs: Create mountpoints with sysfs_create_mount_point 2015-07-21T17:10:01+00:00 Eric W. Biederman ebiederm@xmission.com 2015-05-13T22:35:41+00:00 28dd1f346b2f0fc2ab8285046ed0bd91e9b808d3 commit f9bb48825a6b5d02f4cabcc78967c75db903dcdc upstream. This allows for better documentation in the code and it allows for a simpler and fully correct version of fs_fully_visible to be written. The mount points converted and their filesystems are: /sys/hypervisor/s390/ s390_hypfs /sys/kernel/config/ configfs /sys/kernel/debug/ debugfs /sys/firmware/efi/efivars/ efivarfs /sys/fs/fuse/connections/ fusectl /sys/fs/pstore/ pstore /sys/kernel/tracing/ tracefs /sys/fs/cgroup/ cgroup /sys/kernel/security/ securityfs /sys/fs/selinux/ selinuxfs /sys/fs/smackfs/ smackfs Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> 
commit f9bb48825a6b5d02f4cabcc78967c75db903dcdc upstream.

This allows for better documentation in the code and
it allows for a simpler and fully correct version of
fs_fully_visible to be written.

The mount points converted and their filesystems are:
/sys/hypervisor/s390/       s390_hypfs
/sys/kernel/config/         configfs
/sys/kernel/debug/          debugfs
/sys/firmware/efi/efivars/  efivarfs
/sys/fs/fuse/connections/   fusectl
/sys/fs/pstore/             pstore
/sys/kernel/tracing/        tracefs
/sys/fs/cgroup/             cgroup
/sys/kernel/security/       securityfs
/sys/fs/selinux/            selinuxfs
/sys/fs/smackfs/            smackfs

Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>