linux-stable.git/lib, branch v4.13.3

idr: remove WARN_ON_ONCE() when trying to replace negative ID

2017-09-20T06:27:48+00:00

commit a47f68d6a944113bdc8097db6f933c2e17c27bf9 upstream.

IDR only supports non-negative IDs.  There used to be a 'WARN_ON_ONCE(id <
0)' in idr_replace(), but it was intentionally removed by commit
2e1c9b286765 ("idr: remove WARN_ON_ONCE() on negative IDs").

Then it was added back by commit 0a835c4f090a ("Reimplement IDR and IDA
using the radix tree").  However it seems that adding it back was a
mistake, given that some users such as drm_gem_handle_delete()
(DRM_IOCTL_GEM_CLOSE) pass in a value from userspace to idr_replace(),
allowing the WARN_ON_ONCE to be triggered.  drm_gem_handle_delete()
actually just wants idr_replace() to return an error code if the ID is
not allocated, including in the case where the ID is invalid (negative).

So once again remove the bogus WARN_ON_ONCE().

This bug was found by syzkaller, which encountered the following
warning:

    WARNING: CPU: 3 PID: 3008 at lib/idr.c:157 idr_replace+0x1d8/0x240 lib/idr.c:157
    Kernel panic - not syncing: panic_on_warn set ...

    CPU: 3 PID: 3008 Comm: syzkaller218828 Not tainted 4.13.0-rc4-next-20170811 #2
    Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011
    Call Trace:
     fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190
     do_trap_no_signal arch/x86/kernel/traps.c:224 [inline]
     do_trap+0x260/0x390 arch/x86/kernel/traps.c:273
     do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310
     do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323
     invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:930
    RIP: 0010:idr_replace+0x1d8/0x240 lib/idr.c:157
    RSP: 0018:ffff8800394bf9f8 EFLAGS: 00010297
    RAX: ffff88003c6c60c0 RBX: 1ffff10007297f43 RCX: 0000000000000000
    RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8800394bfa78
    RBP: ffff8800394bfae0 R08: ffffffff82856487 R09: 0000000000000000
    R10: ffff8800394bf9a8 R11: ffff88006c8bae28 R12: ffffffffffffffff
    R13: ffff8800394bfab8 R14: dffffc0000000000 R15: ffff8800394bfbc8
     drm_gem_handle_delete+0x33/0xa0 drivers/gpu/drm/drm_gem.c:297
     drm_gem_close_ioctl+0xa1/0xe0 drivers/gpu/drm/drm_gem.c:671
     drm_ioctl_kernel+0x1e7/0x2e0 drivers/gpu/drm/drm_ioctl.c:729
     drm_ioctl+0x72e/0xa50 drivers/gpu/drm/drm_ioctl.c:825
     vfs_ioctl fs/ioctl.c:45 [inline]
     do_vfs_ioctl+0x1b1/0x1520 fs/ioctl.c:685
     SYSC_ioctl fs/ioctl.c:700 [inline]
     SyS_ioctl+0x8f/0xc0 fs/ioctl.c:691
     entry_SYSCALL_64_fastpath+0x1f/0xbe

Here is a C reproducer:

    #include 
    #include 
    #include 
    #include 
    #include 

    int main(void)
    {
            int cardfd = open("/dev/dri/card0", O_RDONLY);

            ioctl(cardfd, DRM_IOCTL_GEM_CLOSE,
                  &(struct drm_gem_close) { .handle = -1 } );
    }

Link: http://lkml.kernel.org/r/20170906235306.20534-1-ebiggers3@gmail.com
Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree")
Signed-off-by: Eric Biggers 
Acked-by: Tejun Heo 
Cc: Dmitry Vyukov 
Cc: Matthew Wilcox 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

radix-tree: must check __radix_tree_preload() return value

2017-09-13T21:20:52+00:00

commit bc9ae2247ac92fd4d962507bafa3afffff6660ff upstream.

__radix_tree_preload() only disables preemption if no error is returned.

So we really need to make sure callers always check the return value.

idr_preload() contract is to always disable preemption, so we need
to add a missing preempt_disable() if an error happened.

Similarly, ida_pre_get() only needs to call preempt_enable() in the
case no error happened.

Link: http://lkml.kernel.org/r/1504637190.15310.62.camel@edumazet-glaptop3.roam.corp.google.com
Fixes: 0a835c4f090a ("Reimplement IDR and IDA using the radix tree")
Fixes: 7ad3d4d85c7a ("ida: Move ida_bitmap to a percpu variable")
Signed-off-by: Eric Dumazet 
Cc: Matthew Wilcox 
Cc: "Kirill A. Shutemov" 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds 
Signed-off-by: Greg Kroah-Hartman

Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6

2017-09-01T17:30:03+00:00

Pull crypto fixes from Herbert Xu:
 "This fixes the following issues:

   - Regression in chacha20 handling of chunked input

   - Crash in algif_skcipher when used with async io

   - Potential bogus pointer dereference in lib/mpi"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: algif_skcipher - only call put_page on referenced and used pages
  crypto: testmgr - add chunked test cases for chacha20
  crypto: chacha20 - fix handling of chunked input
  lib/mpi: kunmap after finishing accessing buffer

lib/mpi: kunmap after finishing accessing buffer

2017-08-22T06:45:01+00:00

Using sg_miter_start and sg_miter_next, the buffer of an SG is kmap'ed
to *buff. The current code calls sg_miter_stop (and thus kunmap) on the
SG entry before the last access of *buff.

The patch moves the sg_miter_stop call after the last access to *buff to
ensure that the memory pointed to by *buff is still mapped.

Fixes: 4816c9406430 ("lib/mpi: Fix SG miter leak")
Cc: 
Signed-off-by: Stephan Mueller 
Signed-off-by: Herbert Xu

kernel/watchdog: Prevent false positives with turbo modes

2017-08-18T10:35:02+00:00

The hardlockup detector on x86 uses a performance counter based on unhalted
CPU cycles and a periodic hrtimer. The hrtimer period is about 2/5 of the
performance counter period, so the hrtimer should fire 2-3 times before the
performance counter NMI fires. The NMI code checks whether the hrtimer
fired since the last invocation. If not, it assumess a hard lockup.

The calculation of those periods is based on the nominal CPU
frequency. Turbo modes increase the CPU clock frequency and therefore
shorten the period of the perf/NMI watchdog. With extreme Turbo-modes (3x
nominal frequency) the perf/NMI period is shorter than the hrtimer period
which leads to false positives.

A simple fix would be to shorten the hrtimer period, but that comes with
the side effect of more frequent hrtimer and softlockup thread wakeups,
which is not desired.

Implement a low pass filter, which checks the perf/NMI period against
kernel time. If the perf/NMI fires before 4/5 of the watchdog period has
elapsed then the event is ignored and postponed to the next perf/NMI.

That solves the problem and avoids the overhead of shorter hrtimer periods
and more frequent softlockup thread wakeups.

Fixes: 58687acba592 ("lockup_detector: Combine nmi_watchdog and softlockup detector")
Reported-and-tested-by: Kan Liang 
Signed-off-by: Thomas Gleixner 
Cc: dzickus@redhat.com
Cc: prarit@redhat.com
Cc: ak@linux.intel.com
Cc: babu.moger@oracle.com
Cc: peterz@infradead.org
Cc: eranian@google.com
Cc: acme@redhat.com
Cc: stable@vger.kernel.org
Cc: atomlin@redhat.com
Cc: akpm@linux-foundation.org
Cc: torvalds@linux-foundation.org
Link: http://lkml.kernel.org/r/alpine.DEB.2.20.1708150931310.1886@nanos

fault-inject: fix wrong should_fail() decision in task context

2017-08-10T22:54:06+00:00

Commit 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
unintentionally broke a conditional statement in should_fail().  Any
faults are not injected in the task context by the change when the
systematic fault injection is not used.

This change restores to the previous correct behaviour.

Link: http://lkml.kernel.org/r/1501633700-3488-1-git-send-email-akinobu.mita@gmail.com
Fixes: 1203c8e6fb0a ("fault-inject: simplify access check for fail-nth")
Signed-off-by: Akinobu Mita 
Reported-by: Lu Fengqi 
Tested-by: Lu Fengqi 
Cc: Dmitry Vyukov 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

test_kmod: fix small memory leak on filesystem tests

2017-08-10T22:54:06+00:00

The break was in the wrong place so file system tests don't work as
intended, leaking memory at each test switch.

[mcgrof@kernel.org: massaged commit subject, noted memory leak issue without the fix]
Link: http://lkml.kernel.org/r/20170802211450.27928-6-mcgrof@kernel.org
Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Dan Carpenter 
Signed-off-by: Luis R. Rodriguez 
Reported-by: David Binderman 
Cc: Colin Ian King 
Cc: Dmitry Torokhov 
Cc: Eric W. Biederman 
Cc: Jessica Yu 
Cc: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Michal Marek 
Cc: Miroslav Benes 
Cc: Petr Mladek 
Cc: Rusty Russell 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

test_kmod: fix the lock in register_test_dev_kmod()

2017-08-10T22:54:06+00:00

We accidentally just drop the lock twice instead of taking it and then
releasing it.  This isn't a big issue unless you are adding more than
one device to test on, and the kmod.sh doesn't do that yet, however this
obviously is the correct thing to do.

[mcgrof@kernel.org: massaged subject, explain what happens]
Link: http://lkml.kernel.org/r/20170802211450.27928-5-mcgrof@kernel.org
Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Dan Carpenter 
Signed-off-by: Luis R. Rodriguez 
Cc: Colin Ian King 
Cc: David Binderman 
Cc: Dmitry Torokhov 
Cc: Eric W. Biederman 
Cc: Jessica Yu 
Cc: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Michal Marek 
Cc: Miroslav Benes 
Cc: Petr Mladek 
Cc: Rusty Russell 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

test_kmod: fix bug which allows negative values on two config options

2017-08-10T22:54:06+00:00

Parsing with kstrtol() enables values to be negative, and we failed to
check for negative values when parsing with test_dev_config_update_uint_sync()
or test_dev_config_update_uint_range().

test_dev_config_update_uint_range() has a minimum check though so an
issue is not present there.  test_dev_config_update_uint_sync() is only
used for the number of threads to use (config_num_threads_store()), and
indeed this would fail with an attempt for a large allocation.

Although the issue is only present in practice with the first fix both
by using kstrtoul() instead of kstrtol().

Link: http://lkml.kernel.org/r/20170802211450.27928-4-mcgrof@kernel.org
Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Luis R. Rodriguez 
Reported-by: Dan Carpenter 
Cc: Colin Ian King 
Cc: David Binderman 
Cc: Dmitry Torokhov 
Cc: Eric W. Biederman 
Cc: Jessica Yu 
Cc: Josh Poimboeuf 
Cc: Kees Cook 
Cc: Michal Marek 
Cc: Miroslav Benes 
Cc: Petr Mladek 
Cc: Rusty Russell 
Cc: Shuah Khan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

test_kmod: fix spelling mistake: "EMTPY" -> "EMPTY"

2017-08-10T22:54:06+00:00

Trivial fix to spelling mistake in snprintf text

[mcgrof@kernel.org: massaged commit message]
Link: http://lkml.kernel.org/r/20170802211450.27928-3-mcgrof@kernel.org
Fixes: 39258f448d71 ("kmod: add test driver to stress test the module loader")
Signed-off-by: Colin Ian King 
Signed-off-by: Luis R. Rodriguez 
Cc: Dmitry Torokhov 
Cc: Kees Cook 
Cc: Jessica Yu 
Cc: Rusty Russell 
Cc: Michal Marek 
Cc: Petr Mladek 
Cc: Miroslav Benes 
Cc: Josh Poimboeuf 
Cc: Eric W. Biederman 
Cc: Shuah Khan 
Cc: Dan Carpenter 
Cc: David Binderman 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds