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2018-05-18Merge branch 'topic/timer-fixes' into for-nextTakashi Iwai
Pull the fixes for possible races in the resolution callback. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-18ALSA: timer: Assure timer resolution access always lockedTakashi Iwai
There are still many places calling the timer's hw.c_resolution callback without lock, and this may lead to some races, as we faced in the commit a820ccbe21e8 ("ALSA: pcm: Fix UAF at PCM release via PCM timer access"). This patch changes snd_timer_resolution() to take the timer->lock for avoiding the races. A place calling this function already inside the lock (from the notifier) is replaced with the snd_timer_hw_resolution() accordingly, as well as wrapping with the lock around another place calling snd_timer_hw_resolution(), too. Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-18ALSA: seq: Avoid open-code for getting timer resolutionTakashi Iwai
Instead of open-coding for getting the timer resolution, use the standard snd_timer_resolution() helper. The original code falls back to the callback function when the resolution is zero, but it must be always so when the callback function is defined. So this should be no functional change. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-18ALSA: timer: Simplify timer hw resolution callsTakashi Iwai
There multiple open-codes to get the hardware timer resolution. Make a local helper function snd_timer_hw_resolution() and call it from all relevant places. There is no functional change by this, just a preliminary work for the following timer resolution hardening patch. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-18ALSA: timer: Fix pause event notificationBen Hutchings
Commit f65e0d299807 ("ALSA: timer: Call notifier in the same spinlock") combined the start/continue and stop/pause functions, and in doing so changed the event code for the pause case to SNDRV_TIMER_EVENT_CONTINUE. Change it back to SNDRV_TIMER_EVENT_PAUSE. Fixes: f65e0d299807 ("ALSA: timer: Call notifier in the same spinlock") Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Cc: stable@vger.kernel.org Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-17ALSA: core: Assure control device to be registered at lastTakashi Iwai
The commit 289ca025ee1d ("ALSA: Use priority list for managing device list") changed the way to register/disconnect/free devices via a single priority list. This helped to make behavior consistent, but it also changed a slight behavior change: namely, the control device is registered earlier than others, while it was supposed to be the very last one. I've put SNDRV_DEV_CONTROL in the current position as the release of ctl elements often conflict with the private ctl elements some PCM or other components may create, which often leads to a double-free. But, the order of register and disconnect should be indeed fixed as expected in the early days: the control device gets registered at last, and disconnected at first. This patch changes the priority list order to move SNDRV_DEV_CONTROL as the last guy to assure the register / disconnect order. Meanwhile, for keeping the messy resource release order, manually treat the control and lowlevel devices as last freed one. Additional note: The lowlevel device is the device where a card driver creates at probe. And, we still keep the release order control -> lowlevel, as there might be link from a control element back to a lowlevel object. Fixes: 289ca025ee1d ("ALSA: Use priority list for managing device list") Reported-by: Tzung-Bi Shih <tzungbi@google.com> Tested-by: Tzung-Bi Shih <tzungbi@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-15Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge of UAC3 fixes for applying further enhancements. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-14ALSA: vmaster: use position offset macro of TLV dataTakashi Sakamoto
A series of SNDRV_CTL_TLVO_XXX macro was introduced for position offset of TLV data. This commit applies a code optimization. Signed-off-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-13ALSA: control: fix a redundant-copy issueWenwen Wang
In snd_ctl_elem_add_compat(), the fields of the struct 'data' need to be copied from the corresponding fields of the struct 'data32' in userspace. This is achieved by invoking copy_from_user() and get_user() functions. The problem here is that the 'type' field is copied twice. One is by copy_from_user() and one is by get_user(). Given that the 'type' field is not used between the two copies, the second copy is *completely* redundant and should be removed for better performance and cleanup. Also, these two copies can cause inconsistent data: as the struct 'data32' resides in userspace and a malicious userspace process can race to change the 'type' field between the two copies to cause inconsistent data. Depending on how the data is used in the future, such an inconsistency may cause potential security risks. For above reasons, we should take out the second copy. Signed-off-by: Wenwen Wang <wang6495@umn.edu> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-04ALSA: pcm: Hide local_irq_disable/enable() and local_irqsave/restore()Anna-Maria Gleixner
The snd_pcm_stream_lock_irq*() functions decouple disabling interrupts from the actual locking process. This does not work as expected if the locking primitives are replaced like on preempt-rt. Provide one function for locking which uses correct locking primitives. Signed-off-by: Anna-Maria Gleixner <anna-maria@linutronix.de> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-02ALSA: pcm: Check PCM state at xfern compat ioctlTakashi Iwai
Since snd_pcm_ioctl_xfern_compat() has no PCM state check, it may go further and hit the sanity check pcm_sanity_check() when the ioctl is called right after open. It may eventually spew a kernel warning, as triggered by syzbot, depending on kconfig. The lack of PCM state check there was just an oversight. Although it's no real crash, the spurious kernel warning is annoying, so let's add the proper check. Reported-by: syzbot+1dac3a4f6bc9c1c675d4@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-27ALSA: seq: Fix races at MIDI encoding in snd_virmidi_output_trigger()Takashi Iwai
The sequencer virmidi code has an open race at its output trigger callback: namely, virmidi keeps only one event packet for processing while it doesn't protect for concurrent output trigger calls. snd_virmidi_output_trigger() tries to process the previously unfinished event before starting encoding the given MIDI stream, but this is done without any lock. Meanwhile, if another rawmidi stream starts the output trigger, this proceeds further, and overwrites the event package that is being processed in another thread. This eventually corrupts and may lead to the invalid memory access if the event type is like SYSEX. The fix is just to move the spinlock to cover both the pending event and the new stream. The bug was spotted by a new fuzzer, RaceFuzzer. BugLink: http://lkml.kernel.org/r/20180426045223.GA15307@dragonet.kaist.ac.kr Reported-by: DaeRyong Jeong <threeearcat@gmail.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-25Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge 4.17-rc3 fixes for further development. This will bump the base to 4.17-rc2, too. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-25ALSA: seq: oss: Hardening for potential Spectre v1Takashi Iwai
As Smatch recently suggested, a few places in OSS sequencer codes may expand the array directly from the user-space value with speculation, namely there are a significant amount of references to either info->ch[] or dp->synths[] array: sound/core/seq/oss/seq_oss_event.c:315 note_on_event() warn: potential spectre issue 'info->ch' (local cap) sound/core/seq/oss/seq_oss_event.c:362 note_off_event() warn: potential spectre issue 'info->ch' (local cap) sound/core/seq/oss/seq_oss_synth.c:470 snd_seq_oss_synth_load_patch() warn: potential spectre issue 'dp->synths' (local cap) sound/core/seq/oss/seq_oss_event.c:293 note_on_event() warn: potential spectre issue 'dp->synths' sound/core/seq/oss/seq_oss_event.c:353 note_off_event() warn: potential spectre issue 'dp->synths' sound/core/seq/oss/seq_oss_synth.c:506 snd_seq_oss_synth_sysex() warn: potential spectre issue 'dp->synths' sound/core/seq/oss/seq_oss_synth.c:580 snd_seq_oss_synth_ioctl() warn: potential spectre issue 'dp->synths' Although all these seem doing only the first load without further reference, we may want to stay in a safer side, so hardening with array_index_nospec() would still make sense. We may put array_index_nospec() at each place, but here we take a different approach: - For dp->synths[], change the helpers to retrieve seq_oss_synthinfo pointer directly instead of the array expansion at each place - For info->ch[], harden in a normal way, as there are only a couple of places As a result, the existing helper, snd_seq_oss_synth_is_valid() is replaced with snd_seq_oss_synth_info(). Also, we cover MIDI device where a similar array expansion is done, too, although it wasn't reported by Smatch. BugLink: https://marc.info/?l=linux-kernel&m=152411496503418&w=2 Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-25ALSA: seq: oss: Fix unbalanced use lock for synth MIDI deviceTakashi Iwai
When get_synthdev() is called for a MIDI device, it returns the fixed midi_synth_dev without the use refcounting. OTOH, the caller is supposed to unreference unconditionally after the usage, so this would lead to unbalanced refcount. This patch corrects the behavior and keep up the refcount balance also for the MIDI synth device. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-25ALSA: pcm: Change return type to vm_fault_tSouptick Joarder
Use new return type vm_fault_t for fault handler. For now, this is just documenting that the function returns a VM_FAULT value rather than an errno. Once all instances are converted, vm_fault_t will become a distinct type. Commit 1c8f422059ae ("mm: change return type to vm_fault_t") Signed-off-by: Souptick Joarder <jrdr.linux@gmail.com> Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-23ALSA: control: Fix missing __user annotationTakashi Iwai
There is one place missing __user annotation to the pointer used by the recent code refactoring. Reported by sparse. Fixes: 450296f305f1 ("ALSA: control: code refactoring TLV ioctl handler") Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-23ALSA: core: Report audio_tstamp in snd_pcm_sync_ptrDavid Henningsson
It looks like a simple mistake that this struct member was forgotten. Audio_tstamp isn't used much, and on some archs (such as x86) this ioctl is not used by default, so that might be the reason why this has slipped for so long. Fixes: 4eeaaeaea1ce ("ALSA: core: add hooks for audio timestamps") Signed-off-by: David Henningsson <diwic@ubuntu.com> Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Cc: <stable@vger.kernel.org> # v3.8+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-23ALSA: pcm: Return negative delays from SNDRV_PCM_IOCTL_DELAY.Jeffery Miller
The commit c2c86a97175f ("ALSA: pcm: Remove set_fs() in PCM core code") changed SNDRV_PCM_IOCTL_DELAY to return an inconsistent error instead of a negative delay. Originally the call would succeed and return the negative delay. The Chromium OS Audio Server (CRAS) gets confused and hangs when the error is returned instead of the negative delay. Help CRAS avoid the issue by rolling back the behavior to return a negative delay instead of an error. Fixes: c2c86a97175f ("ALSA: pcm: Remove set_fs() in PCM core code") Signed-off-by: Jeffery Miller <jmiller@neverware.com> Cc: <stable@vger.kernel.org> # v4.13+ Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-19ALSA: rawmidi: Fix missing input substream checks in compat ioctlsTakashi Iwai
Some rawmidi compat ioctls lack of the input substream checks (although they do check only for rfile->output). This many eventually lead to an Oops as NULL substream is passed to the rawmidi core functions. Fix it by adding the proper checks before each function call. The bug was spotted by syzkaller. Reported-by: syzbot+f7a0348affc3b67bc617@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-17ALSA: pcm: Unify delay calculation in snd_pcm_status() and snd_pcm_delay()Takashi Iwai
Yet another slight code cleanup: there are two places where calculating the PCM delay, and they can be unified in a single helper. It reduces the multiple open codes. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-17ALSA: pcm: Unify playback and capture poll callbacksTakashi Iwai
The poll callbacks for playback and capture directions are doing fairly similar but with a slight difference. This patch unifies the two functions into a single callback. The advantage of this refactoring is that the direction-specific procedures become clearer. There should be no functional change but only the code cleanup. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-17ALSA: pcm: Clean up with snd_pcm_avail() and snd_pcm_hw_avail() helpersTakashi Iwai
Introduce two new direction-neutral helpers to calculate the avail and hw_avail values, and clean up the code with them. The two separated forward and rewind functions are gathered to the unified functions. No functional change but only code reductions. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-09ALSA: pcm: Remove WARN_ON() at snd_pcm_hw_params() errorTakashi Iwai
snd_pcm_hw_params() (more exactly snd_pcm_hw_params_choose()) contains a check of the return error from snd_pcm_hw_param_first() and _last() with snd_BUG_ON() -- i.e. it may trigger WARN_ON() depending on the kconfig. This was a valid check in the past, as these functions shouldn't return any error if the parameters have been already refined via snd_pcm_hw_refine() beforehand. However, the recent rewrite introduced a kmalloc() in snd_pcm_hw_refine() for removing VLA, and this brought a possibility to trigger an error. As a result, syzbot caught lots of superfluous kernel WARN_ON() and paniced via fault injection. As the WARN_ON() is no longer valid with the introduction of kmalloc(), let's drop snd_BUG_ON() check, in order to make the world peaceful place again. Reported-by: syzbot+803e0047ac3a3096bb4f@syzkaller.appspotmail.com Fixes: 5730f9f744cf ("ALSA: pcm: Remove VLA usage") Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-07ALSA: pcm: Fix endless loop for XRUN recovery in OSS emulationTakashi Iwai
The commit 02a5d6925cd3 ("ALSA: pcm: Avoid potential races between OSS ioctls and read/write") split the PCM preparation code to a locked version, and it added a sanity check of runtime->oss.prepare flag along with the change. This leaded to an endless loop when the stream gets XRUN: namely, snd_pcm_oss_write3() and co call snd_pcm_oss_prepare() without setting runtime->oss.prepare flag and the loop continues until the PCM state reaches to another one. As the function is supposed to execute the preparation unconditionally, drop the invalid state check there. The bug was triggered by syzkaller. Fixes: 02a5d6925cd3 ("ALSA: pcm: Avoid potential races between OSS ioctls and read/write") Reported-by: syzbot+150189c103427d31a053@syzkaller.appspotmail.com Reported-by: syzbot+7e3f31a52646f939c052@syzkaller.appspotmail.com Reported-by: syzbot+4f2016cf5185da7759dc@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-03ALSA: pcm: Fix UAF at PCM release via PCM timer accessTakashi Iwai
The PCM runtime object is created and freed dynamically at PCM stream open / close time. This is tracked via substream->runtime, and it's cleared at snd_pcm_detach_substream(). The runtime object assignment is protected by PCM open_mutex, so for all PCM operations, it's safely handled. However, each PCM substream provides also an ALSA timer interface, and user-space can access to this while closing a PCM substream. This may eventually lead to a UAF, as snd_pcm_timer_resolution() tries to access the runtime while clearing it in other side. Fortunately, it's the only concurrent access from the PCM timer, and it merely reads runtime->timer_resolution field. So, we can avoid the race by reordering kfree() and wrapping the substream->runtime clearance with the corresponding timer lock. Reported-by: syzbot+8e62ff4e07aa2ce87826@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-04-02Merge branch 'for-next' into for-linusTakashi Iwai
Preparation for 4.17 merge. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-27ALSA: pcm: Fix mutex unbalance in OSS emulation ioctlsTakashi Iwai
The previous fix 40cab6e88cb0 ("ALSA: pcm: Return -EBUSY for OSS ioctls changing busy streams") introduced some mutex unbalance; the check of runtime->oss.rw_ref was inserted in a wrong place after the mutex lock. This patch fixes the inconsistency by rewriting with the helper functions to lock/unlock parameters with the stream check. Fixes: 40cab6e88cb0 ("ALSA: pcm: Return -EBUSY for OSS ioctls changing busy streams") Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-27ALSA: pcm: potential uninitialized return valuesDan Carpenter
Smatch complains that "tmp" can be uninitialized if we do a zero size write. Fixes: 02a5d6925cd3 ("ALSA: pcm: Avoid potential races between OSS ioctls and read/write") Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-26ALSA: pcm: Use dma_bytes as size parameter in dma_mmap_coherent()Stefan Roese
When trying to use the driver (e.g. aplay *.wav), the 4MiB DMA buffer will get mmapp'ed in 16KiB chunks. But this fails with the 2nd 16KiB area, as the page offset is outside of the VMA range (size), which is currently used as size parameter in snd_pcm_lib_default_mmap(). By using the DMA buffer size (dma_bytes) instead, the complete DMA buffer can be mmapp'ed and the issue is fixed. This issue was detected on an ARM platform (TI AM57xx) using the RME HDSP MADI PCIe soundcard. Fixes: 657b1989dacf ("ALSA: pcm - Use dma_mmap_coherent() if available") Signed-off-by: Stefan Roese <sr@denx.de> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-23ALSA: pcm: Return -EBUSY for OSS ioctls changing busy streamsTakashi Iwai
OSS PCM stream management isn't modal but it allows ioctls issued at any time for changing the parameters. In the previous hardening patch ("ALSA: pcm: Avoid potential races between OSS ioctls and read/write"), we covered these races and prevent the corruption by protecting the concurrent accesses via params_lock mutex. However, this means that some ioctls that try to change the stream parameter (e.g. channels or format) would be blocked until the read/write finishes, and it may take really long. Basically changing the parameter while reading/writing is an invalid operation, hence it's even more user-friendly from the API POV if it returns -EBUSY in such a situation. This patch adds such checks in the relevant ioctls with the addition of read/write access refcount. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-23ALSA: pcm: Avoid potential races between OSS ioctls and read/writeTakashi Iwai
Although we apply the params_lock mutex to the whole read and write operations as well as snd_pcm_oss_change_params(), we may still face some races. First off, the params_lock is taken inside the read and write loop. This is intentional for avoiding the too long locking, but it allows the in-between parameter change, which might lead to invalid pointers. We check the readiness of the stream and set up via snd_pcm_oss_make_ready() at the beginning of read and write, but it's called only once, by assuming that it remains ready in the rest. Second, many ioctls that may change the actual parameters (i.e. setting runtime->oss.params=1) aren't protected, hence they can be processed in a half-baked state. This patch is an attempt to plug these holes. The stream readiness check is moved inside the read/write inner loop, so that the stream is always set up in a proper state before further processing. Also, each ioctl that may change the parameter is wrapped with the params_lock for avoiding the races. The issues were triggered by syzkaller in a few different scenarios, particularly the one below appearing as GPF in loopback_pos_update. Reported-by: syzbot+c4227aec125487ec3efa@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-19Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge of for-linus branch for applying the further UAC3 patches. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-13ALSA: pcm: Use krealloc() for resizing the rules arrayTakashi Iwai
Just a minor simplification. Change from kcalloc() shouldn't matter as each array element is fully initialized. Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-13ALSA: pcm: Remove VLA usageTakashi Iwai
A helper function used by snd_pcm_hw_refine() still keeps using VLA for timestamps of hw constraint rules that are non-fixed size. Let's replace the VLA with a simple kmalloc() array. Reference: https://lkml.org/lkml/2018/3/7/621 Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-11ALSA: pcm: Fix UAF in snd_pcm_oss_get_formats()Takashi Iwai
snd_pcm_oss_get_formats() has an obvious use-after-free around snd_mask_test() calls, as spotted by syzbot. The passed format_mask argument is a pointer to the hw_params object that is freed before the loop. What a surprise that it has been present since the original code of decades ago... Reported-by: syzbot+4090700a4f13fccaf648@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-10ALSA: seq: Clear client entry before deleting else at closingTakashi Iwai
When releasing a client, we need to clear the clienttab[] entry at first, then call snd_seq_queue_client_leave(). Otherwise, the in-flight cell in the queue might be picked up by the timer interrupt via snd_seq_check_queue() before calling snd_seq_queue_client_leave(), and it's delivered to another queue while the client is clearing queues. This may eventually result in an uncleared cell remaining in a queue, and the later snd_seq_pool_delete() may need to wait for a long time until the event gets really processed. By moving the clienttab[] clearance at the beginning of release, any event delivery of a cell belonging to this client will fail at a later point, since snd_seq_client_ptr() returns NULL. Thus the cell that was picked up by the timer interrupt will be returned immediately without further delivery, and the long stall of snd_seq_delete_pool() can be avoided, too. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-10ALSA: seq: Fix possible UAF in snd_seq_check_queue()Takashi Iwai
Although we've covered the races between concurrent write() and ioctl() in the previous patch series, there is still a possible UAF in the following scenario: A: user client closed B: timer irq -> snd_seq_release() -> snd_seq_timer_interrupt() -> snd_seq_free_client() -> snd_seq_check_queue() -> cell = snd_seq_prioq_cell_peek() -> snd_seq_prioq_leave() .... removing all cells -> snd_seq_pool_done() .... vfree() -> snd_seq_compare_tick_time(cell) ... Oops So the problem is that a cell is peeked and accessed without any protection until it's retrieved from the queue again via snd_seq_prioq_cell_out(). This patch tries to address it, also cleans up the code by a slight refactoring. snd_seq_prioq_cell_out() now receives an extra pointer argument. When it's non-NULL, the function checks the event timestamp with the given pointer. The caller needs to pass the right reference either to snd_seq_tick or snd_seq_realtime depending on the event timestamp type. A good news is that the above change allows us to remove the snd_seq_prioq_cell_peek(), too, thus the patch actually reduces the code size. Reviewed-by: Nicolai Stange <nstange@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-08ALSA: seq: Remove superfluous snd_seq_queue_client_leave_cells() callTakashi Iwai
With the previous two fixes for the write / ioctl races: ALSA: seq: Don't allow resizing pool in use ALSA: seq: More protection for concurrent write and ioctl races the cells aren't any longer in queues at the point calling snd_seq_pool_done() in snd_seq_ioctl_set_client_pool(). Hence the function call snd_seq_queue_client_leave_cells() can be dropped safely from there. Suggested-by: Nicolai Stange <nstange@suse.de> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-08ALSA: seq: More protection for concurrent write and ioctl racesTakashi Iwai
This patch is an attempt for further hardening against races between the concurrent write and ioctls. The previous fix d15d662e89fc ("ALSA: seq: Fix racy pool initializations") covered the race of the pool initialization at writer and the pool resize ioctl by the client->ioctl_mutex (CVE-2018-1000004). However, basically this mutex should be applied more widely to the whole write operation for avoiding the unexpected pool operations by another thread. The only change outside snd_seq_write() is the additional mutex argument to helper functions, so that we can unlock / relock the given mutex temporarily during schedule() call for blocking write. Fixes: d15d662e89fc ("ALSA: seq: Fix racy pool initializations") Reported-by: 范龙飞 <long7573@126.com> Reported-by: Nicolai Stange <nstange@suse.de> Reviewed-and-tested-by: Nicolai Stange <nstange@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-08ALSA: seq: Don't allow resizing pool in useTakashi Iwai
This is a fix for a (sort of) fallout in the recent commit d15d662e89fc ("ALSA: seq: Fix racy pool initializations") for CVE-2018-1000004. As the pool resize deletes the existing cells, it may lead to a race when another thread is writing concurrently, eventually resulting a UAF. A simple workaround is not to allow the pool resizing when the pool is in use. It's an invalid behavior in anyway. Fixes: d15d662e89fc ("ALSA: seq: Fix racy pool initializations") Reported-by: 范龙飞 <long7573@126.com> Reported-by: Nicolai Stange <nstange@suse.de> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-08ALSA: vmaster: Zero-clear ctl before calling slave getTakashi Iwai
Use kzalloc() instead of kmalloc() so that we don't need to rely fully on the slave get() callback to clear the control value that might be copied to user-space. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-03-08ALSA: vmaster: Propagate slave errorTakashi Iwai
In slave_update() of vmaster code ignores the error from the slave get() callback and copies the values. It's not only about the missing error code but also that this may potentially lead to a leak of uninitialized variables when the slave get() don't clear them. This patch fixes slave_update() not to copy the potentially uninitialized values when an error is returned from the slave get() callback, and to propagate the error value properly. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-28ALSA: control: Fix a bunch of whitespace errorsRichard Fitzgerald
Remove a bunch of trailing whitespace errors. They are fairly annoying if you have your editor set to strip trailing whitespace because you find you've introduced more changes than you were trying to make. Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-28Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge for applying a cleanup to core/control Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-28ALSA: control: Fix memory corruption risk in snd_ctl_elem_readRichard Fitzgerald
The patch "ALSA: control: code refactoring for ELEM_READ/ELEM_WRITE operations" introduced a potential for kernel memory corruption due to an incorrect if statement allowing non-readable controls to fall through and call the get function. For TLV controls a driver can omit SNDRV_CTL_ELEM_ACCESS_READ to ensure that only the TLV get function can be called. Instead the normal get() can be invoked unexpectedly and as the driver expects that this will only be called for controls <= 512 bytes, potentially try to copy >512 bytes into the 512 byte return array, so corrupting kernel memory. The problem is an attempt to refactor the snd_ctl_elem_read function to invert the logic so that it conditionally aborted if the control is unreadable instead of conditionally executing. But the if statement wasn't inverted correctly. The correct inversion of if (a && !b) is if (!a || b) Fixes: becf9e5d553c2 ("ALSA: control: code refactoring for ELEM_READ/ELEM_WRITE operations") Signed-off-by: Richard Fitzgerald <rf@opensource.cirrus.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-27ALSA: Use scnprintf() instead of snprintf() for showJaejoong Kim
The show() method should use scnprintf() not snprintf() because snprintf() may returns a value that exceeds its second argument. Signed-off-by: Jaejoong Kim <climbbb.kim@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-14ALSA: seq: Fix racy pool initializationsTakashi Iwai
ALSA sequencer core initializes the event pool on demand by invoking snd_seq_pool_init() when the first write happens and the pool is empty. Meanwhile user can reset the pool size manually via ioctl concurrently, and this may lead to UAF or out-of-bound accesses since the function tries to vmalloc / vfree the buffer. A simple fix is to just wrap the snd_seq_pool_init() call with the recently introduced client->ioctl_mutex; as the calls for snd_seq_pool_init() from other side are always protected with this mutex, we can avoid the race. Reported-by: 范龙飞 <long7573@126.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-02-11vfs: do bulk POLL* -> EPOLL* replacementLinus Torvalds
This is the mindless scripted replacement of kernel use of POLL* variables as described by Al, done by this script: for V in IN OUT PRI ERR RDNORM RDBAND WRNORM WRBAND HUP RDHUP NVAL MSG; do L=`git grep -l -w POLL$V | grep -v '^t' | grep -v /um/ | grep -v '^sa' | grep -v '/poll.h$'|grep -v '^D'` for f in $L; do sed -i "-es/^\([^\"]*\)\(\<POLL$V\>\)/\\1E\\2/" $f; done done with de-mangling cleanups yet to come. NOTE! On almost all architectures, the EPOLL* constants have the same values as the POLL* constants do. But they keyword here is "almost". For various bad reasons they aren't the same, and epoll() doesn't actually work quite correctly in some cases due to this on Sparc et al. The next patch from Al will sort out the final differences, and we should be all done. Scripted-by: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2018-01-31Merge branch 'work.misc' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull misc vfs updates from Al Viro: "All kinds of misc stuff, without any unifying topic, from various people. Neil's d_anon patch, several bugfixes, introduction of kvmalloc analogue of kmemdup_user(), extending bitfield.h to deal with fixed-endians, assorted cleanups all over the place..." * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (28 commits) alpha: osf_sys.c: use timespec64 where appropriate alpha: osf_sys.c: fix put_tv32 regression jffs2: Fix use-after-free bug in jffs2_iget()'s error handling path dcache: delete unused d_hash_mask dcache: subtract d_hash_shift from 32 in advance fs/buffer.c: fold init_buffer() into init_page_buffers() fs: fold __inode_permission() into inode_permission() fs: add RWF_APPEND sctp: use vmemdup_user() rather than badly open-coding memdup_user() snd_ctl_elem_init_enum_names(): switch to vmemdup_user() replace_user_tlv(): switch to vmemdup_user() new primitive: vmemdup_user() memdup_user(): switch to GFP_USER eventfd: fold eventfd_ctx_get() into eventfd_ctx_fileget() eventfd: fold eventfd_ctx_read() into eventfd_read() eventfd: convert to use anon_inode_getfd() nfs4file: get rid of pointless include of btrfs.h uvc_v4l2: clean copyin/copyout up vme_user: don't use __copy_..._user() usx2y: don't bother with memdup_user() for 16-byte structure ...