linux-stable.git/kernel, branch v4.14.41

perf/core: Fix possible Spectre-v1 indexing for ->aux_pages[]

2018-05-16T08:10:31+00:00

commit 4411ec1d1993e8dbff2898390e3fed280d88e446 upstream.

> kernel/events/ring_buffer.c:871 perf_mmap_to_page() warn: potential spectre issue 'rb->aux_pages'

Userspace controls @pgoff through the fault address. Sanitize the
array index before doing the array dereference.

Reported-by: Dan Carpenter 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: 
Cc: Alexander Shishkin 
Cc: Arnaldo Carvalho de Melo 
Cc: Jiri Olsa 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Stephane Eranian 
Cc: Thomas Gleixner 
Cc: Vince Weaver 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

tracing/uprobe_event: Fix strncpy corner case

2018-05-16T08:10:31+00:00

commit 50268a3d266ecfdd6c5873d62b2758d9732fc598 upstream.

Fix string fetch function to terminate with NUL.
It is OK to drop the rest of string.

Signed-off-by: Masami Hiramatsu 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Song Liu 
Cc: Thomas Gleixner 
Cc: security@kernel.org
Cc: 范龙飞 
Fixes: 5baaa59ef09e ("tracing/probes: Implement 'memory' fetch method for uprobes")
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

sched/autogroup: Fix possible Spectre-v1 indexing for sched_prio_to_weight[]

2018-05-16T08:10:30+00:00

commit 354d7793070611b4df5a79fbb0f12752d0ed0cc5 upstream.

> kernel/sched/autogroup.c:230 proc_sched_autogroup_set_nice() warn: potential spectre issue 'sched_prio_to_weight'

Userspace controls @nice, sanitize the array index.

Reported-by: Dan Carpenter 
Signed-off-by: Peter Zijlstra (Intel) 
Cc: Linus Torvalds 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: 
Signed-off-by: Ingo Molnar 
Signed-off-by: Greg Kroah-Hartman

cpufreq: schedutil: Avoid using invalid next_freq

2018-05-16T08:10:29+00:00

commit 97739501f207efe33145b918817f305b822987f8 upstream.

If the next_freq field of struct sugov_policy is set to UINT_MAX,
it shouldn't be used for updating the CPU frequency (this is a
special "invalid" value), but after commit b7eaf1aab9f8 (cpufreq:
schedutil: Avoid reducing frequency of busy CPUs prematurely) it
may be passed as the new frequency to sugov_update_commit() in
sugov_update_single().

Fix that by adding an extra check for the special UINT_MAX value
of next_freq to sugov_update_single().

Fixes: b7eaf1aab9f8 (cpufreq: schedutil: Avoid reducing frequency of busy CPUs prematurely)
Reported-by: Viresh Kumar 
Cc: 4.12+  # 4.12+
Signed-off-by: Rafael J. Wysocki 
Acked-by: Viresh Kumar 
Signed-off-by: Rafael J. Wysocki 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix regex_match_front() to not over compare the test string

2018-05-16T08:10:27+00:00

commit dc432c3d7f9bceb3de6f5b44fb9c657c9810ed6d upstream.

The regex match function regex_match_front() in the tracing filter logic,
was fixed to test just the pattern length from testing the entire test
string. That is, it went from strncmp(str, r->pattern, len) to
strcmp(str, r->pattern, r->len).

The issue is that str is not guaranteed to be nul terminated, and if r->len
is greater than the length of str, it can access more memory than is
allocated.

The solution is to add a simple test if (len < r->len) return 0.

Cc: stable@vger.kernel.org
Fixes: 285caad415f45 ("tracing/filters: Fix MATCH_FRONT_ONLY filter matching")
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

compat: fix 4-byte infoleak via uninitialized struct field

2018-05-16T08:10:26+00:00

commit 0a0b98734479aa5b3c671d5190e86273372cab95 upstream.

Commit 3a4d44b61625 ("ntp: Move adjtimex related compat syscalls to
native counterparts") removed the memset() in compat_get_timex().  Since
then, the compat adjtimex syscall can invoke do_adjtimex() with an
uninitialized ->tai.

If do_adjtimex() doesn't write to ->tai (e.g.  because the arguments are
invalid), compat_put_timex() then copies the uninitialized ->tai field
to userspace.

Fix it by adding the memset() back.

Fixes: 3a4d44b61625 ("ntp: Move adjtimex related compat syscalls to native counterparts")
Signed-off-by: Jann Horn 
Acked-by: Kees Cook 
Acked-by: Al Viro 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

perf: Remove superfluous allocation error check

2018-05-16T08:10:24+00:00

commit bfb3d7b8b906b66551424d7636182126e1d134c8 upstream.

If the get_callchain_buffers fails to allocate the buffer it will
decrease the nr_callchain_events right away.

There's no point of checking the allocation error for
nr_callchain_events > 1. Removing that check.

Signed-off-by: Jiri Olsa 
Tested-by: Arnaldo Carvalho de Melo 
Cc: Alexander Shishkin 
Cc: Andi Kleen 
Cc: H. Peter Anvin 
Cc: Namhyung Kim 
Cc: Peter Zijlstra 
Cc: Thomas Gleixner 
Cc: syzkaller-bugs@googlegroups.com
Cc: x86@kernel.org
Link: http://lkml.kernel.org/r/20180415092352.12403-3-jolsa@kernel.org
Signed-off-by: Arnaldo Carvalho de Melo 
Signed-off-by: Greg Kroah-Hartman

tracing: Fix bad use of igrab in trace_uprobe.c

2018-05-09T07:51:56+00:00

commit 0c92c7a3c5d416f47b32c5f20a611dfeca5d5f2e upstream.

As Miklos reported and suggested:

  This pattern repeats two times in trace_uprobe.c and in
  kernel/events/core.c as well:

      ret = kern_path(filename, LOOKUP_FOLLOW, &path);
      if (ret)
          goto fail_address_parse;

      inode = igrab(d_inode(path.dentry));
      path_put(&path);

  And it's wrong.  You can only hold a reference to the inode if you
  have an active ref to the superblock as well (which is normally
  through path.mnt) or holding s_umount.

  This way unmounting the containing filesystem while the tracepoint is
  active will give you the "VFS: Busy inodes after unmount..." message
  and a crash when the inode is finally put.

  Solution: store path instead of inode.

This patch fixes two instances in trace_uprobe.c. struct path is added to
struct trace_uprobe to keep the inode and containing mount point
referenced.

Link: http://lkml.kernel.org/r/20180423172135.4050588-1-songliubraving@fb.com

Fixes: f3f096cfedf8 ("tracing: Provide trace events interface for uprobes")
Fixes: 33ea4b24277b ("perf/core: Implement the 'perf_uprobe' PMU")
Cc: stable@vger.kernel.org
Cc: Ingo Molnar 
Cc: Howard McLauchlan 
Cc: Josef Bacik 
Cc: Srikar Dronamraju 
Acked-by: Miklos Szeredi 
Reported-by: Miklos Szeredi 
Signed-off-by: Song Liu 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tracepoint: Do not warn on ENOMEM

2018-05-09T07:51:50+00:00

commit d66a270be3310d7aa132fec0cea77d3d32a0ff75 upstream.

Tracepoint should only warn when a kernel API user does not respect the
required preconditions (e.g. same tracepoint enabled twice, or called
to remove a tracepoint that does not exist).

Silence warning in out-of-memory conditions, given that the error is
returned to the caller.

This ensures that out-of-memory error-injection testing does not trigger
warnings in tracepoint.c, which were seen by syzbot.

Link: https://lkml.kernel.org/r/001a114465e241a8720567419a72@google.com
Link: https://lkml.kernel.org/r/001a1140e0de15fc910567464190@google.com
Link: http://lkml.kernel.org/r/20180315124424.32319-1-mathieu.desnoyers@efficios.com

CC: Peter Zijlstra 
CC: Jiri Olsa 
CC: Arnaldo Carvalho de Melo 
CC: Alexander Shishkin 
CC: Namhyung Kim 
CC: stable@vger.kernel.org
Fixes: de7b2973903c6 ("tracepoint: Use struct pointer instead of name hash for reg/unreg tracepoints")
Reported-by: syzbot+9c0d616860575a73166a@syzkaller.appspotmail.com
Reported-by: syzbot+4e9ae7fa46233396f64d@syzkaller.appspotmail.com
Signed-off-by: Mathieu Desnoyers 
Signed-off-by: Steven Rostedt (VMware) 
Signed-off-by: Greg Kroah-Hartman

tick/sched: Do not mess with an enqueued hrtimer

2018-05-01T19:58:26+00:00

commit 1f71addd34f4c442bec7d7c749acc1beb58126f2 upstream.

Kaike reported that in tests rdma hrtimers occasionaly stopped working. He
did great debugging, which provided enough context to decode the problem.

CPU 3			     	      	     CPU 2

idle
start sched_timer expires = 712171000000
 queue->next = sched_timer
					    start rdmavt timer. expires = 712172915662
					    lock(baseof(CPU3))
tick_nohz_stop_tick()
tick = 716767000000			    timerqueue_add(tmr)

hrtimer_set_expires(sched_timer, tick);
  sched_timer->expires = 716767000000  <---- FAIL
					     if (tmr->expires < queue->next->expires)
hrtimer_start(sched_timer)		          queue->next = tmr;
lock(baseof(CPU3))
					     unlock(baseof(CPU3))
timerqueue_remove()
timerqueue_add()

ts->sched_timer is queued and queue->next is pointing to it, but then
ts->sched_timer.expires is modified.

This not only corrupts the ordering of the timerqueue RB tree, it also
makes CPU2 see the new expiry time of timerqueue->next->expires when
checking whether timerqueue->next needs to be updated. So CPU2 sees that
the rdma timer is earlier than timerqueue->next and sets the rdma timer as
new next.

Depending on whether it had also seen the new time at RB tree enqueue, it
might have queued the rdma timer at the wrong place and then after removing
the sched_timer the RB tree is completely hosed.

The problem was introduced with a commit which tried to solve inconsistency
between the hrtimer in the tick_sched data and the underlying hardware
clockevent. It split out hrtimer_set_expires() to store the new tick time
in both the NOHZ and the NOHZ + HIGHRES case, but missed the fact that in
the NOHZ + HIGHRES case the hrtimer might still be queued.

Use hrtimer_start(timer, tick...) for the NOHZ + HIGHRES case which sets
timer->expires after canceling the timer and move the hrtimer_set_expires()
invocation into the NOHZ only code path which is not affected as it merily
uses the hrtimer as next event storage so code pathes can be shared with
the NOHZ + HIGHRES case.

Fixes: d4af6d933ccf ("nohz: Fix spurious warning when hrtimer and clockevent get out of sync")
Reported-by: "Wan Kaike" 
Signed-off-by: Thomas Gleixner 
Acked-by: Frederic Weisbecker 
Cc: "Marciniszyn Mike" 
Cc: Anna-Maria Gleixner 
Cc: linux-rdma@vger.kernel.org
Cc: "Dalessandro Dennis" 
Cc: "Fleck John" 
Cc: stable@vger.kernel.org
Cc: Peter Zijlstra 
Cc: Frederic Weisbecker 
Cc: "Weiny Ira" 
Cc: "linux-rdma@vger.kernel.org"
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1804241637390.1679@nanos.tec.linutronix.de
Link: https://lkml.kernel.org/r/alpine.DEB.2.21.1804242119210.1597@nanos.tec.linutronix.de
Signed-off-by: Greg Kroah-Hartman