1. 27 Nov, 2017 1 commit
  2. 07 Nov, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix OSS sysex delivery in OSS emulation · 132d358b
      Takashi Iwai authored
      The SYSEX event delivery in OSS sequencer emulation assumed that the
      event is encoded in the variable-length data with the straight
      buffering.  This was the normal behavior in the past, but during the
      development, the chained buffers were introduced for carrying more
      data, while the OSS code was left intact.  As a result, when a SYSEX
      event with the chained buffer data is passed to OSS sequencer port,
      it may end up with the wrong memory access, as if it were having a too
      large buffer.
      
      This patch addresses the bug, by applying the buffer data expansion by
      the generic snd_seq_dump_var_event() helper function.
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Reported-by: default avatarMark Salyzyn <salyzyn@android.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      132d358b
  3. 02 Nov, 2017 1 commit
    • Greg Kroah-Hartman's avatar
      License cleanup: add SPDX GPL-2.0 license identifier to files with no license · b2441318
      Greg Kroah-Hartman authored
      Many source files in the tree are missing licensing information, which
      makes it harder for compliance tools to determine the correct license.
      
      By default all files without license information are under the default
      license of the kernel, which is GPL version 2.
      
      Update the files which contain no license information with the 'GPL-2.0'
      SPDX license identifier.  The SPDX identifier is a legally binding
      shorthand, which can be used instead of the full boiler plate text.
      
      This patch is based on work done by Thomas Gleixner and Kate Stewart and
      Philippe Ombredanne.
      
      How this work was done:
      
      Patches were generated and checked against linux-4.14-rc6 for a subset of
      the use cases:
       - file had no licensing information it it.
       - file was a */uapi/* one with no licensing information in it,
       - file was a */uapi/* one with existing licensing information,
      
      Further patches will be generated in subsequent months to fix up cases
      where non-standard license headers were used, and references to license
      had to be inferred by heuristics based on keywords.
      
      The analysis to determine which SPDX License Identifier to be applied to
      a file was done in a spreadsheet of side by side results from of the
      output of two independent scanners (ScanCode & Windriver) producing SPDX
      tag:value files created by Philippe Ombredanne.  Philippe prepared the
      base worksheet, and did an initial spot review of a few 1000 files.
      
      The 4.13 kernel was the starting point of the analysis with 60,537 files
      assessed.  Kate Stewart did a file by file comparison of the scanner
      results in the spreadsheet to determine which SPDX license identifier(s)
      to be applied to the file. She confirmed any determination that was not
      immediately clear with lawyers working with the Linux Foundation.
      
      Criteria used to select files for SPDX license identifier tagging was:
       - Files considered eligible had to be source code files.
       - Make and config files were included as candidates if they contained >5
         lines of source
       - File already had some variant of a license header in it (even if <5
         lines).
      
      All documentation files were explicitly excluded.
      
      The following heuristics were used to determine which SPDX license
      identifiers to apply.
      
       - when both scanners couldn't find any license traces, file was
         considered to have no license information in it, and the top level
         COPYING file license applied.
      
         For non */uapi/* files that summary was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0                                              11139
      
         and resulted in the first patch in this series.
      
         If that file was a */uapi/* path one, it was "GPL-2.0 WITH
         Linux-syscall-note" otherwise it was "GPL-2.0".  Results of that was:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|-------
         GPL-2.0 WITH Linux-syscall-note                        930
      
         and resulted in the second patch in this series.
      
       - if a file had some form of licensing information in it, and was one
         of the */uapi/* ones, it was denoted with the Linux-syscall-note if
         any GPL family license was found in the file or had no licensing in
         it (per prior point).  Results summary:
      
         SPDX license identifier                            # files
         ---------------------------------------------------|------
         GPL-2.0 WITH Linux-syscall-note                       270
         GPL-2.0+ WITH Linux-syscall-note                      169
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-2-Clause)    21
         ((GPL-2.0 WITH Linux-syscall-note) OR BSD-3-Clause)    17
         LGPL-2.1+ WITH Linux-syscall-note                      15
         GPL-1.0+ WITH Linux-syscall-note                       14
         ((GPL-2.0+ WITH Linux-syscall-note) OR BSD-3-Clause)    5
         LGPL-2.0+ WITH Linux-syscall-note                       4
         LGPL-2.1 WITH Linux-syscall-note                        3
         ((GPL-2.0 WITH Linux-syscall-note) OR MIT)              3
         ((GPL-2.0 WITH Linux-syscall-note) AND MIT)             1
      
         and that resulted in the third patch in this series.
      
       - when the two scanners agreed on the detected license(s), that became
         the concluded license(s).
      
       - when there was disagreement between the two scanners (one detected a
         license but the other didn't, or they both detected different
         licenses) a manual inspection of the file occurred.
      
       - In most cases a manual inspection of the information in the file
         resulted in a clear resolution of the license that should apply (and
         which scanner probably needed to revisit its heuristics).
      
       - When it was not immediately clear, the license identifier was
         confirmed with lawyers working with the Linux Foundation.
      
       - If there was any question as to the appropriate license identifier,
         the file was flagged for further research and to be revisited later
         in time.
      
      In total, over 70 hours of logged manual review was done on the
      spreadsheet to determine the SPDX license identifiers to apply to the
      source files by Kate, Philippe, Thomas and, in some cases, confirmation
      by lawyers working with the Linux Foundation.
      
      Kate also obtained a third independent scan of the 4.13 code base from
      FOSSology, and compared selected files where the other two scanners
      disagreed against that SPDX file, to see if there was new insights.  The
      Windriver scanner is based on an older version of FOSSology in part, so
      they are related.
      
      Thomas did random spot checks in about 500 files from the spreadsheets
      for the uapi headers and agreed with SPDX license identifier in the
      files he inspected. For the non-uapi files Thomas did random spot checks
      in about 15000 files.
      
      In initial set of patches against 4.14-rc6, 3 files were found to have
      copy/paste license identifier errors, and have been fixed to reflect the
      correct identifier.
      
      Additionally Philippe spent 10 hours this week doing a detailed manual
      inspection and review of the 12,461 patched files from the initial patch
      version early this week with:
       - a full scancode scan run, collecting the matched texts, detected
         license ids and scores
       - reviewing anything where there was a license detected (about 500+
         files) to ensure that the applied SPDX license was correct
       - reviewing anything where there was no detection but the patch license
         was not GPL-2.0 WITH Linux-syscall-note to ensure that the applied
         SPDX license was correct
      
      This produced a worksheet with 20 files needing minor correction.  This
      worksheet was then exported into 3 different .csv files for the
      different types of files to be modified.
      
      These .csv files were then reviewed by Greg.  Thomas wrote a script to
      parse the csv files and add the proper SPDX tag to the file, in the
      format that the file expected.  This script was further refined by Greg
      based on the output to detect more types of files automatically and to
      distinguish between header and source .c files (which need different
      comment types.)  Finally Greg ran the script using the .csv files to
      generate the patches.
      Reviewed-by: default avatarKate Stewart <kstewart@linuxfoundation.org>
      Reviewed-by: default avatarPhilippe Ombredanne <pombredanne@nexb.com>
      Reviewed-by: default avatarThomas Gleixner <tglx@linutronix.de>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      b2441318
  4. 31 Oct, 2017 1 commit
  5. 18 Oct, 2017 1 commit
  6. 11 Oct, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix use-after-free at creating a port · 71105998
      Takashi Iwai authored
      There is a potential race window opened at creating and deleting a
      port via ioctl, as spotted by fuzzing.  snd_seq_create_port() creates
      a port object and returns its pointer, but it doesn't take the
      refcount, thus it can be deleted immediately by another thread.
      Meanwhile, snd_seq_ioctl_create_port() still calls the function
      snd_seq_system_client_ev_port_start() with the created port object
      that is being deleted, and this triggers use-after-free like:
      
       BUG: KASAN: use-after-free in snd_seq_ioctl_create_port+0x504/0x630 [snd_seq] at addr ffff8801f2241cb1
       =============================================================================
       BUG kmalloc-512 (Tainted: G    B          ): kasan: bad access detected
       -----------------------------------------------------------------------------
       INFO: Allocated in snd_seq_create_port+0x94/0x9b0 [snd_seq] age=1 cpu=3 pid=4511
       	___slab_alloc+0x425/0x460
       	__slab_alloc+0x20/0x40
        	kmem_cache_alloc_trace+0x150/0x190
      	snd_seq_create_port+0x94/0x9b0 [snd_seq]
      	snd_seq_ioctl_create_port+0xd1/0x630 [snd_seq]
       	snd_seq_do_ioctl+0x11c/0x190 [snd_seq]
       	snd_seq_ioctl+0x40/0x80 [snd_seq]
       	do_vfs_ioctl+0x54b/0xda0
       	SyS_ioctl+0x79/0x90
       	entry_SYSCALL_64_fastpath+0x16/0x75
       INFO: Freed in port_delete+0x136/0x1a0 [snd_seq] age=1 cpu=2 pid=4717
       	__slab_free+0x204/0x310
       	kfree+0x15f/0x180
       	port_delete+0x136/0x1a0 [snd_seq]
       	snd_seq_delete_port+0x235/0x350 [snd_seq]
       	snd_seq_ioctl_delete_port+0xc8/0x180 [snd_seq]
       	snd_seq_do_ioctl+0x11c/0x190 [snd_seq]
       	snd_seq_ioctl+0x40/0x80 [snd_seq]
       	do_vfs_ioctl+0x54b/0xda0
       	SyS_ioctl+0x79/0x90
       	entry_SYSCALL_64_fastpath+0x16/0x75
       Call Trace:
        [<ffffffff81b03781>] dump_stack+0x63/0x82
        [<ffffffff81531b3b>] print_trailer+0xfb/0x160
        [<ffffffff81536db4>] object_err+0x34/0x40
        [<ffffffff815392d3>] kasan_report.part.2+0x223/0x520
        [<ffffffffa07aadf4>] ? snd_seq_ioctl_create_port+0x504/0x630 [snd_seq]
        [<ffffffff815395fe>] __asan_report_load1_noabort+0x2e/0x30
        [<ffffffffa07aadf4>] snd_seq_ioctl_create_port+0x504/0x630 [snd_seq]
        [<ffffffffa07aa8f0>] ? snd_seq_ioctl_delete_port+0x180/0x180 [snd_seq]
        [<ffffffff8136be50>] ? taskstats_exit+0xbc0/0xbc0
        [<ffffffffa07abc5c>] snd_seq_do_ioctl+0x11c/0x190 [snd_seq]
        [<ffffffffa07abd10>] snd_seq_ioctl+0x40/0x80 [snd_seq]
        [<ffffffff8136d433>] ? acct_account_cputime+0x63/0x80
        [<ffffffff815b515b>] do_vfs_ioctl+0x54b/0xda0
        .....
      
      We may fix this in a few different ways, and in this patch, it's fixed
      simply by taking the refcount properly at snd_seq_create_port() and
      letting the caller unref the object after use.  Also, there is another
      potential use-after-free by sprintf() call in snd_seq_create_port(),
      and this is moved inside the lock.
      
      This fix covers CVE-2017-15265.
      Reported-and-tested-by: default avatarMichael23 Yu <ycqzsy@gmail.com>
      Suggested-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      71105998
  7. 10 Oct, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Add sanity check for user-space pointer delivery · 19b592da
      Takashi Iwai authored
      The sequencer event may contain a user-space pointer with its
      SNDRV_SEQ_EXT_USRPTR bit, and we assure that its delivery is limited
      with non-atomic mode.  Otherwise the copy_from_user() may hit the
      fault and cause a problem.  Although the core code doesn't set such a
      flag (only set at snd_seq_write()), any wild driver may set it
      mistakenly and lead to an unexpected crash.
      
      This patch adds a sanity check of such events at the delivery core
      code to filter out the invalid invocation in the atomic mode.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      19b592da
  8. 09 Oct, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix copy_from_user() call inside lock · 5803b023
      Takashi Iwai authored
      The event handler in the virmidi sequencer code takes a read-lock for
      the linked list traverse, while it's calling snd_seq_dump_var_event()
      in the loop.  The latter function may expand the user-space data
      depending on the event type.  It eventually invokes copy_from_user(),
      which might be a potential dead-lock.
      
      The sequencer core guarantees that the user-space data is passed only
      with atomic=0 argument, but snd_virmidi_dev_receive_event() ignores it
      and always takes read-lock().  For avoiding the problem above, this
      patch introduces rwsem for non-atomic case, while keeping rwlock for
      atomic case.
      
      Also while we're at it: the superfluous irq flags is dropped in
      snd_virmidi_input_open().
      Reported-by: default avatarJia-Ju Bai <baijiaju1990@163.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      5803b023
  9. 15 Aug, 2017 1 commit
    • Daniel Mentz's avatar
      ALSA: seq: 2nd attempt at fixing race creating a queue · 7e1d90f6
      Daniel Mentz authored
      commit 4842e98f ("ALSA: seq: Fix race at
      creating a queue") attempted to fix a race reported by syzkaller. That
      fix has been described as follows:
      
      "
      When a sequencer queue is created in snd_seq_queue_alloc(),it adds the
      new queue element to the public list before referencing it.  Thus the
      queue might be deleted before the call of snd_seq_queue_use(), and it
      results in the use-after-free error, as spotted by syzkaller.
      
      The fix is to reference the queue object at the right time.
      "
      
      Even with that fix in place, syzkaller reported a use-after-free error.
      It specifically pointed to the last instruction "return q->queue" in
      snd_seq_queue_alloc(). The pointer q is being used after kfree() has
      been called on it.
      
      It turned out that there is still a small window where a race can
      happen. The window opens at
      snd_seq_ioctl_create_queue()->snd_seq_queue_alloc()->queue_list_add()
      and closes at
      snd_seq_ioctl_create_queue()->queueptr()->snd_use_lock_use(). Between
      these two calls, a different thread could delete the queue and possibly
      re-create a different queue in the same location in queue_list.
      
      This change prevents this situation by calling snd_use_lock_use() from
      snd_seq_queue_alloc() prior to calling queue_list_add(). It is then the
      caller's responsibility to call snd_use_lock_free(&q->use_lock).
      
      Fixes: 4842e98f ("ALSA: seq: Fix race at creating a queue")
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarDaniel Mentz <danielmentz@google.com>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      7e1d90f6
  10. 11 Aug, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix CONFIG_SND_SEQ_MIDI dependency · 4d3a8693
      Takashi Iwai authored
      The commit 0181307a ("ALSA: seq: Reorganize kconfig and build")
      rewrote the dependency of each sequencer module in a standard way, but
      there was one change applied mistakenly: CONFIG_SND_SEQ_MIDI isn't
      enabled properly by CONFIG_SND_RAWMIDI.  I seem to have changed the
      wrong one instead, CONFIG_SND_SEQ_MIDI_EMUL, which is eventually
      reverse-selected by CONFIG_SND_SEQ_MIDI itself.  This ended up the
      lack of snd-seq-midi module as reported below.
      
      The fix is to put def_tristate properly to CONFIG_SND_SEQ_MIDI instead
      of *_MIDI_EMUL entry.
      
      Fixes: 0181307a ("ALSA: seq: Reorganize kconfig and build")
      Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=196633Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      4d3a8693
  11. 20 Jun, 2017 1 commit
    • Ingo Molnar's avatar
      sched/wait: Rename wait_queue_t => wait_queue_entry_t · ac6424b9
      Ingo Molnar authored
      Rename:
      
      	wait_queue_t		=>	wait_queue_entry_t
      
      'wait_queue_t' was always a slight misnomer: its name implies that it's a "queue",
      but in reality it's a queue *entry*. The 'real' queue is the wait queue head,
      which had to carry the name.
      
      Start sorting this out by renaming it to 'wait_queue_entry_t'.
      
      This also allows the real structure name 'struct __wait_queue' to
      lose its double underscore and become 'struct wait_queue_entry',
      which is the more canonical nomenclature for such data types.
      
      Cc: Linus Torvalds <torvalds@linux-foundation.org>
      Cc: Peter Zijlstra <peterz@infradead.org>
      Cc: Thomas Gleixner <tglx@linutronix.de>
      Cc: linux-kernel@vger.kernel.org
      Signed-off-by: default avatarIngo Molnar <mingo@kernel.org>
      ac6424b9
  12. 16 Jun, 2017 1 commit
  13. 12 Jun, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Allow the modular sequencer registration · 111b0cdb
      Takashi Iwai authored
      Many drivers bind the sequencer stuff in off-load by another driver
      module, so that it's loaded only on demand.  In the current code, this
      mechanism doesn't work when the driver is built-in while the sequencer
      is module.  We check with IS_REACHABLE() and enable only when the
      sequencer is in the same level of build.
      
      However, this is basically a overshoot.  The binder code
      (snd-seq-device) is an individual module from the sequencer core
      (snd-seq), and we just have to make the former a built-in while
      keeping the latter a module for allowing the scenario like the above.
      
      This patch achieves that by rewriting Kconfig slightly.  Now, a driver
      that provides the manual sequencer device binding should select
      CONFIG_SND_SEQ_DEVICE in a way as
      	select SND_SEQ_DEVICE if SND_SEQUENCER != n
      
      Note that the "!=n" is needed here to avoid the influence of the
      sequencer core is module while the driver is built-in.
      
      Also, since rawmidi.o may be linked with snd_seq_device.o when
      built-in, we have to shuffle the code to make the linker happy.
      (the kernel linker isn't smart enough yet to handle such a case.)
      That is, snd_seq_device.c is moved to sound/core from sound/core/seq,
      as well as Makefile.
      
      Last but not least, the patch replaces the code using IS_REACHABLE()
      with IS_ENABLED(), since now the condition meets always when enabled.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      111b0cdb
  14. 09 Jun, 2017 2 commits
    • Takashi Iwai's avatar
      ALSA: seq: Reorganize kconfig and build · 0181307a
      Takashi Iwai authored
      This is a slightly intensive rewrite of Kconfig and Makefile about
      ALSA sequencer stuff.
      
      The first major change is that the kconfig items for the sequencer are
      moved to sound/core/seq/Kconfig.  OK, that's easy.
      
      The substantial change is that, instead of hackish top-level module
      selection in Makefile, we define a Kconfig item for each sequencer
      module.  The driver that requires such sequencer components select
      exclusively the kconfig items.  This is more straightforward and
      standard way.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      0181307a
    • Takashi Iwai's avatar
      ALSA: seq: Allow the tristate build of OSS emulation · 3d774d5e
      Takashi Iwai authored
      Currently OSS sequencer emulation is tied with ALSA sequencer core,
      both are built in the same level; i.e. when CONFIG_SND_SEQUENCER=y,
      the OSS sequencer emulation is also always built-in, even though the
      functionality can be built as an individual module.
      
      This patch changes the rule and allows users to build snd-seq-oss
      module while others are built-in.  Essentially, it's just a few simple
      changes in Kconfig and Makefile.  Some driver codes like opl3 need to
      convert from the simple ifdef to IS_ENABLED().  But that's all.
      
      You might wonder how about the dependency: right, it can be messy, but
      it still works.  Since we rewrote the sequencer binding with the
      standard bus, the driver can be bound at any time on demand.  So, the
      synthesizer driver module can be loaded individually from the OSS
      emulation core before/after it.
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      3d774d5e
  15. 13 Apr, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Don't break snd_use_lock_sync() loop by timeout · 4e7655fd
      Takashi Iwai authored
      The snd_use_lock_sync() (thus its implementation
      snd_use_lock_sync_helper()) has the 5 seconds timeout to break out of
      the sync loop.  It was introduced from the beginning, just to be
      "safer", in terms of avoiding the stupid bugs.
      
      However, as Ben Hutchings suggested, this timeout rather introduces a
      potential leak or use-after-free that was apparently fixed by the
      commit 2d7d5400 ("ALSA: seq: Fix race during FIFO resize"):
      for example, snd_seq_fifo_event_in() -> snd_seq_event_dup() ->
      copy_from_user() could block for a long time, and snd_use_lock_sync()
      goes timeout and still leaves the cell at releasing the pool.
      
      For fixing such a problem, we remove the break by the timeout while
      still keeping the warning.
      Suggested-by: default avatarBen Hutchings <ben.hutchings@codethink.co.uk>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      4e7655fd
  16. 24 Mar, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix race during FIFO resize · 2d7d5400
      Takashi Iwai authored
      When a new event is queued while processing to resize the FIFO in
      snd_seq_fifo_clear(), it may lead to a use-after-free, as the old pool
      that is being queued gets removed.  For avoiding this race, we need to
      close the pool to be deleted and sync its usage before actually
      deleting it.
      
      The issue was spotted by syzkaller.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      2d7d5400
  17. 21 Mar, 2017 1 commit
  18. 02 Mar, 2017 1 commit
  19. 28 Feb, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix link corruption by event error handling · f3ac9f73
      Takashi Iwai authored
      The sequencer FIFO management has a bug that may lead to a corruption
      (shortage) of the cell linked list.  When a sequencer client faces an
      error at the event delivery, it tries to put back the dequeued cell.
      When the first queue was put back, this forgot the tail pointer
      tracking, and the link will be screwed up.
      
      Although there is no memory corruption, the sequencer client may stall
      forever at exit while flushing the pending FIFO cells in
      snd_seq_pool_done(), as spotted by syzkaller.
      
      This patch addresses the missing tail pointer tracking at
      snd_seq_fifo_cell_putback().  Also the patch makes sure to clear the
      cell->enxt pointer at snd_seq_fifo_event_in() for avoiding a similar
      mess-up of the FIFO linked list.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      f3ac9f73
  20. 08 Feb, 2017 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: Fix race at creating a queue · 4842e98f
      Takashi Iwai authored
      When a sequencer queue is created in snd_seq_queue_alloc(),it adds the
      new queue element to the public list before referencing it.  Thus the
      queue might be deleted before the call of snd_seq_queue_use(), and it
      results in the use-after-free error, as spotted by syzkaller.
      
      The fix is to reference the queue object at the right time.
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      4842e98f
  21. 06 Feb, 2017 1 commit
  22. 12 Jan, 2017 1 commit
  23. 25 Oct, 2016 1 commit
  24. 12 Oct, 2016 1 commit
  25. 13 Sep, 2016 1 commit
  26. 31 Aug, 2016 1 commit
  27. 22 Aug, 2016 4 commits
  28. 17 Jun, 2016 1 commit
    • Arnd Bergmann's avatar
      ALSA: seq_timer: use monotonic times internally · 3915bf29
      Arnd Bergmann authored
      The sequencer client manager reports timestamps in units of unsigned
      32-bit seconds/nanoseconds, but that does not suffer from the y2038
      overflow because it stores only the delta since the 'last_update'
      time was recorded.
      
      However, the use of the do_gettimeofday() function is problematic
      and we have to replace it to avoid the overflow on on 32-bit
      architectures.
      
      This uses 'struct timespec64' to record 'last_update', and changes
      the code to use monotonic timestamps that do not suffer from leap
      seconds and settimeofday updates.
      
      As a side-effect, the code can now use the timespec64_sub() helper
      and become more readable and also avoid a multiplication to convert
      from microseconds to nanoseconds.
      Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      3915bf29
  29. 15 Jun, 2016 1 commit
  30. 25 Apr, 2016 1 commit
  31. 08 Mar, 2016 1 commit
  32. 01 Mar, 2016 1 commit
    • Takashi Iwai's avatar
      ALSA: seq: oss: Don't drain at closing a client · 197b958c
      Takashi Iwai authored
      The OSS sequencer client tries to drain the pending events at
      releasing.  Unfortunately, as spotted by syzkaller fuzzer, this may
      lead to an unkillable process state when the event has been queued at
      the far future.  Since the process being released can't be signaled
      any longer, it remains and waits for the echo-back event in that far
      future.
      
      Back to history, the draining feature was implemented at the time we
      misinterpreted POSIX definition for blocking file operation.
      Actually, such a behavior is superfluous at release, and we should
      just release the device as is instead of keeping it up forever.
      
      This patch just removes the draining call that may block the release
      for too long time unexpectedly.
      
      BugLink: http://lkml.kernel.org/r/CACT4Y+Y4kD-aBGj37rf-xBw9bH3GMU6P+MYg4W1e-s-paVD2pg@mail.gmail.comReported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      197b958c
  33. 16 Feb, 2016 1 commit
  34. 15 Feb, 2016 1 commit
  35. 03 Feb, 2016 2 commits
    • Takashi Iwai's avatar
      ALSA: seq: Fix lockdep warnings due to double mutex locks · 7f0973e9
      Takashi Iwai authored
      The port subscription code uses double mutex locks for source and
      destination ports, and this may become racy once when wrongly set up.
      It leads to lockdep warning splat, typically triggered by fuzzer like
      syzkaller, although the actual deadlock hasn't been seen, so far.
      
      This patch simplifies the handling by reducing to two single locks, so
      that no lockdep warning will be trigger any longer.
      
      By splitting to two actions, a still-in-progress element shall be
      added in one list while handling another.  For ignoring this element,
      a new check is added in deliver_to_subscribers().
      
      Along with it, the code to add/remove the subscribers list element was
      cleaned up and refactored.
      
      BugLink: http://lkml.kernel.org/r/CACT4Y+aKQXV7xkBW9hpQbzaDO7LrUvohxWh-UwMxXjDy-yBD=A@mail.gmail.comReported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      7f0973e9
    • Takashi Iwai's avatar
      ALSA: rawmidi: Make snd_rawmidi_transmit() race-free · 06ab3003
      Takashi Iwai authored
      A kernel WARNING in snd_rawmidi_transmit_ack() is triggered by
      syzkaller fuzzer:
        WARNING: CPU: 1 PID: 20739 at sound/core/rawmidi.c:1136
      Call Trace:
       [<     inline     >] __dump_stack lib/dump_stack.c:15
       [<ffffffff82999e2d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
       [<ffffffff81352089>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
       [<ffffffff813522b9>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
       [<ffffffff84f80bd5>] snd_rawmidi_transmit_ack+0x275/0x400 sound/core/rawmidi.c:1136
       [<ffffffff84fdb3c1>] snd_virmidi_output_trigger+0x4b1/0x5a0 sound/core/seq/seq_virmidi.c:163
       [<     inline     >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150
       [<ffffffff84f87ed9>] snd_rawmidi_kernel_write1+0x549/0x780 sound/core/rawmidi.c:1223
       [<ffffffff84f89fd3>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1273
       [<ffffffff817b0323>] __vfs_write+0x113/0x480 fs/read_write.c:528
       [<ffffffff817b1db7>] vfs_write+0x167/0x4a0 fs/read_write.c:577
       [<     inline     >] SYSC_write fs/read_write.c:624
       [<ffffffff817b50a1>] SyS_write+0x111/0x220 fs/read_write.c:616
       [<ffffffff86336c36>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185
      
      Also a similar warning is found but in another path:
      Call Trace:
       [<     inline     >] __dump_stack lib/dump_stack.c:15
       [<ffffffff82be2c0d>] dump_stack+0x6f/0xa2 lib/dump_stack.c:50
       [<ffffffff81355139>] warn_slowpath_common+0xd9/0x140 kernel/panic.c:482
       [<ffffffff81355369>] warn_slowpath_null+0x29/0x30 kernel/panic.c:515
       [<ffffffff8527e69a>] rawmidi_transmit_ack+0x24a/0x3b0 sound/core/rawmidi.c:1133
       [<ffffffff8527e851>] snd_rawmidi_transmit_ack+0x51/0x80 sound/core/rawmidi.c:1163
       [<ffffffff852d9046>] snd_virmidi_output_trigger+0x2b6/0x570 sound/core/seq/seq_virmidi.c:185
       [<     inline     >] snd_rawmidi_output_trigger sound/core/rawmidi.c:150
       [<ffffffff85285a0b>] snd_rawmidi_kernel_write1+0x4bb/0x760 sound/core/rawmidi.c:1252
       [<ffffffff85287b73>] snd_rawmidi_write+0x543/0xb30 sound/core/rawmidi.c:1302
       [<ffffffff817ba5f3>] __vfs_write+0x113/0x480 fs/read_write.c:528
       [<ffffffff817bc087>] vfs_write+0x167/0x4a0 fs/read_write.c:577
       [<     inline     >] SYSC_write fs/read_write.c:624
       [<ffffffff817bf371>] SyS_write+0x111/0x220 fs/read_write.c:616
       [<ffffffff86660276>] entry_SYSCALL_64_fastpath+0x16/0x7a arch/x86/entry/entry_64.S:185
      
      In the former case, the reason is that virmidi has an open code
      calling snd_rawmidi_transmit_ack() with the value calculated outside
      the spinlock.   We may use snd_rawmidi_transmit() in a loop just for
      consuming the input data, but even there, there is a race between
      snd_rawmidi_transmit_peek() and snd_rawmidi_tranmit_ack().
      
      Similarly in the latter case, it calls snd_rawmidi_transmit_peek() and
      snd_rawmidi_tranmit_ack() separately without protection, so they are
      racy as well.
      
      The patch tries to address these issues by the following ways:
      - Introduce the unlocked versions of snd_rawmidi_transmit_peek() and
        snd_rawmidi_transmit_ack() to be called inside the explicit lock.
      - Rewrite snd_rawmidi_transmit() to be race-free (the former case).
      - Make the split calls (the latter case) protected in the rawmidi spin
        lock.
      
      BugLink: http://lkml.kernel.org/r/CACT4Y+YPq1+cYLkadwjWa5XjzF1_Vki1eHnVn-Lm0hzhSpu5PA@mail.gmail.com
      BugLink: http://lkml.kernel.org/r/CACT4Y+acG4iyphdOZx47Nyq_VHGbpJQK-6xNpiqUjaZYqsXOGw@mail.gmail.comReported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Tested-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: <stable@vger.kernel.org>
      Signed-off-by: default avatarTakashi Iwai <tiwai@suse.de>
      06ab3003