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* ALSA: rawmidi: Fix missing input substream checks in compat ioctlsTakashi Iwai2018-04-241-6/+12
| | | | | | | | | | | | | | | | | | | commit 8a56ef4f3ffba9ebf4967b61ef600b0a7ba10f11 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Fix endless loop for XRUN recovery in OSS emulationTakashi Iwai2018-04-241-2/+3
| | | | | | | | | | | | | | | | | | | | | | | | | | commit e15dc99dbb9cf99f6432e8e3c0b3a8f7a3403a86 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Fix mutex unbalance in OSS emulation ioctlsTakashi Iwai2018-04-241-25/+42
| | | | | | | | | | | | | | | | | | | commit f6d297df4dd47ef949540e4a201230d0c5308325 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Return -EBUSY for OSS ioctls changing busy streamsTakashi Iwai2018-04-241-9/+27
| | | | | | | | | | | | | | | | | | | | | | | | | commit 40cab6e88cb0b6c56d3f30b7491a20e803f948f6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Avoid potential races between OSS ioctls and read/writeTakashi Iwai2018-04-241-28/+106
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 02a5d6925cd34c3b774bdb8eefb057c40a30e870 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Use ERESTARTSYS instead of EINTR in OSS emulationTakashi Iwai2018-04-241-1/+1
| | | | | | | | | | | commit c64ed5dd9feba193c76eb460b451225ac2a0d87b upstream. Fix the last standing EINTR in the whole subsystem. Use more correct ERESTARTSYS for pending signals. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: oss: consolidate kmalloc/memset 0 call to kzallocNicholas Mc Guire2018-04-241-2/+1
| | | | | | | | | | | | commit 46325371b230cc66c743925c930a17e7d0b8211e upstream. This is an API consolidation only. The use of kmalloc + memset to 0 is equivalent to kzalloc. Signed-off-by: Nicholas Mc Guire <hofrat@osadl.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: potential uninitialized return valuesDan Carpenter2018-04-081-2/+2
| | | | | | | | | | | | | | commit 5607dddbfca774fb38bffadcb077fe03aa4ac5c6 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Use dma_bytes as size parameter in dma_mmap_coherent()Stefan Roese2018-04-081-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 9066ae7ff5d89c0b5daa271e2d573540097a94fa upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Clear client entry before deleting else at closingTakashi Iwai2018-03-221-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | commit a2ff19f7b70118ced291a28d5313469914de451b upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix possible UAF in snd_seq_check_queue()Takashi Iwai2018-03-223-37/+25
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit d0f833065221cbfcbadf19fd4102bcfa9330006a upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Fix UAF in snd_pcm_oss_get_formats()Takashi Iwai2018-03-221-4/+6
| | | | | | | | | | | | | | | | commit 01c0b4265cc16bc1f43f475c5944c55c10d5768f upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: More protection for concurrent write and ioctl racesTakashi Iwai2018-03-184-13/+24
| | | | | | | | | | | | | | | | | | | | | | | | | commit 7bd80091567789f1c0cb70eb4737aac8bcd2b6b9 upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Don't allow resizing pool in useTakashi Iwai2018-03-181-0/+3
| | | | | | | | | | | | | | | | | | | | | | commit d85739367c6d56e475c281945c68fdb05ca74b4c upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix racy pool initializationsTakashi Iwai2018-02-251-2/+6
| | | | | | | | | | | | | | | | | | | | | commit d15d662e89fc667b90cd294b0eb45694e33144da upstream. 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> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix regression by incorrect ioctl_mutex usagesTakashi Iwai2018-02-251-8/+7
| | | | | | | | | | | | | | | | | | This is the revised backport of the upstream commit b3defb791b26ea0683a93a4f49c77ec45ec96f10 We had another backport (e.g. 623e5c8ae32b in 4.4.115), but it applies the new mutex also to the code paths that are invoked via faked kernel-to-kernel ioctls. As reported recently, this leads to a deadlock at suspend (or other scenarios triggering the kernel sequencer client). This patch addresses the issue by taking the mutex only in the code paths invoked by user-space, just like the original fix patch does. Reported-and-tested-by: Andres Bertens <abertensu@yahoo.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Make ioctls race-freeTakashi Iwai2018-02-072-2/+9
| | | | | | | | | | | | | | | | | | | | | | | | | commit b3defb791b26ea0683a93a4f49c77ec45ec96f10 upstream. The ALSA sequencer ioctls have no protection against racy calls while the concurrent operations may lead to interfere with each other. As reported recently, for example, the concurrent calls of setting client pool with a combination of write calls may lead to either the unkillable dead-lock or UAF. As a slightly big hammer solution, this patch introduces the mutex to make each ioctl exclusive. Although this may reduce performance via parallel ioctl calls, usually it's not demanded for sequencer usages, hence it should be negligible. Reported-by: Luo Quan <a4651386@163.com> Reviewed-by: Kees Cook <keescook@chromium.org> Reviewed-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> [bwh: Backported to 4.4: ioctl dispatch is done from snd_seq_do_ioctl(); take the mutex and add ret variable there.] Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Remove yet superfluous WARN_ON()Takashi Iwai2018-01-311-1/+0
| | | | | | | | | | | | | | | | | | | | commit 23b19b7b50fe1867da8d431eea9cd3e4b6328c2c upstream. muldiv32() contains a snd_BUG_ON() (which is morphed as WARN_ON() with debug option) for checking the case of 0 / 0. This would be helpful if this happens only as a logical error; however, since the hw refine is performed with any data set provided by user, the inconsistent values that can trigger such a condition might be passed easily. Actually, syzbot caught this by passing some zero'ed old hw_params ioctl. So, having snd_BUG_ON() there is simply superfluous and rather harmful to give unnecessary confusions. Let's get rid of it. Reported-by: syzbot+7e6ee55011deeebce15d@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Allow aborting mutex lock at OSS read/write loopsTakashi Iwai2018-01-171-15/+21
| | | | | | | | | | | | | | | | | | commit 900498a34a3ac9c611e9b425094c8106bdd7dc1c upstream. PCM OSS read/write loops keep taking the mutex lock for the whole read/write, and this might take very long when the exceptionally high amount of data is given. Also, since it invokes with mutex_lock(), the concurrent read/write becomes unbreakable. This patch tries to address these issues by replacing mutex_lock() with mutex_lock_interruptible(), and also splits / re-takes the lock at each read/write period chunk, so that it can switch the context more finely if requested. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Abort properly at pending signal in OSS read/write loopsTakashi Iwai2018-01-171-0/+8
| | | | | | | | | | | | | | | | | | commit 29159a4ed7044c52e3e2cf1a9fb55cec4745c60b upstream. The loops for read and write in PCM OSS emulation have no proper check of pending signals, and they keep processing even after user tries to break. This results in a very long delay, often seen as RCU stall when a huge unprocessed bytes remain queued. The bug could be easily triggered by syzkaller. As a simple workaround, this patch adds the proper check of pending signals and aborts the loop appropriately. Reported-by: syzbot+993cb4cfcbbff3947c21@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Add missing error checks in OSS emulation plugin builderTakashi Iwai2018-01-171-3/+11
| | | | | | | | | | | | | | commit 6708913750344a900f2e73bfe4a4d6dbbce4fe8d upstream. In the OSS emulation plugin builder where the frame size is parsed in the plugin chain, some places miss the possible errors returned from the plugin src_ or dst_frames callback. This patch papers over such places. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: Remove incorrect snd_BUG_ON() usagesTakashi Iwai2018-01-172-3/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit fe08f34d066f4404934a509b6806db1a4f700c86 upstream. syzkaller triggered kernel warnings through PCM OSS emulation at closing a stream: WARNING: CPU: 0 PID: 3502 at sound/core/pcm_lib.c:1635 snd_pcm_hw_param_first+0x289/0x690 sound/core/pcm_lib.c:1635 Call Trace: .... snd_pcm_hw_param_near.constprop.27+0x78d/0x9a0 sound/core/oss/pcm_oss.c:457 snd_pcm_oss_change_params+0x17d3/0x3720 sound/core/oss/pcm_oss.c:969 snd_pcm_oss_make_ready+0xaa/0x130 sound/core/oss/pcm_oss.c:1128 snd_pcm_oss_sync+0x257/0x830 sound/core/oss/pcm_oss.c:1638 snd_pcm_oss_release+0x20b/0x280 sound/core/oss/pcm_oss.c:2431 __fput+0x327/0x7e0 fs/file_table.c:210 .... This happens while it tries to open and set up the aloop device concurrently. The warning above (invoked from snd_BUG_ON() macro) is to detect the unexpected logical error where snd_pcm_hw_refine() call shouldn't fail. The theory is true for the case where the hw_params config rules are static. But for an aloop device, the hw_params rule condition does vary dynamically depending on the connected target; when another device is opened and changes the parameters, the device connected in another side is also affected, and it caused the error from snd_pcm_hw_refine(). That is, the simplest "solution" for this is to remove the incorrect assumption of static rules, and treat such an error as a normal error path. As there are a couple of other places using snd_BUG_ON() incorrectly, this patch removes these spurious snd_BUG_ON() calls. Reported-by: syzbot+6f11c7e2a1b91d466432@syzkaller.appspotmail.com Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: rawmidi: Avoid racy info ioctl via ctl deviceTakashi Iwai2018-01-021-3/+12
| | | | | | | | | | | | | | | | | | | | | commit c1cfd9025cc394fd137a01159d74335c5ac978ce upstream. The rawmidi also allows to obtaining the information via ioctl of ctl API. It means that user can issue an ioctl to the rawmidi device even when it's being removed as long as the control device is present. Although the code has some protection via the global register_mutex, its range is limited to the search of the corresponding rawmidi object, and the mutex is already unlocked at accessing the rawmidi object. This may lead to a use-after-free. For avoiding it, this patch widens the application of register_mutex to the whole snd_rawmidi_info_select() function. We have another mutex per rawmidi object, but this operation isn't very hot path, so it shouldn't matter from the performance POV. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Remove spurious WARN_ON() at timer checkTakashi Iwai2017-12-161-1/+1
| | | | | | | | | | | | | | | | commit 43a3542870328601be02fcc9d27b09db467336ef upstream. The use of snd_BUG_ON() in ALSA sequencer timer may lead to a spurious WARN_ON() when a slave timer is deployed as its backend and a corresponding master timer stops meanwhile. The symptom was triggered by syzkaller spontaneously. Since the NULL timer is valid there, rip off snd_BUG_ON(). Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm: prevent UAF in snd_pcm_infoRobb Glasser2017-12-161-0/+2
| | | | | | | | | | | | | | | | | commit 362bca57f5d78220f8b5907b875961af9436e229 upstream. When the device descriptor is closed, the `substream->runtime` pointer is freed. But another thread may be in the ioctl handler, case SNDRV_CTL_IOCTL_PCM_INFO. This case calls snd_pcm_info_user() which calls snd_pcm_info() which accesses the now freed `substream->runtime`. Note: this fixes CVE-2017-0861 Signed-off-by: Robb Glasser <rglasser@google.com> Signed-off-by: Nick Desaulniers <ndesaulniers@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Remove kernel warning at compat ioctl error pathsTakashi Iwai2017-11-301-6/+6
| | | | | | | | | | | | | | | | | commit 3d4e8303f2c747c8540a0a0126d0151514f6468b upstream. Some timer compat ioctls have NULL checks of timer instance with snd_BUG_ON() that bring up WARN_ON() when the debug option is set. Actually the condition can be met in the normal situation and it's confusing and bad to spew kernel warnings with stack trace there. Let's remove snd_BUG_ON() invocation and replace with the simple checks. Also, correct the error code to EBADFD to follow the native ioctl error handling. Reported-by: syzbot <syzkaller@googlegroups.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix OSS sysex delivery in OSS emulationTakashi Iwai2017-11-153-3/+32
| | | | | | | | | | | | | | | | | | | | | | commit 132d358b183ac6ad8b3fea32ad5e0663456d18d1 upstream. 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: syzbot <syzkaller@googlegroups.com> Reported-by: Mark Salyzyn <salyzyn@android.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix nested rwsem annotation for lockdep splatTakashi Iwai2017-11-081-1/+1
| | | | | | | | | | | | | | | | | | | | | commit 1f20f9ff57ca23b9f5502fca85ce3977e8496cb1 upstream. syzkaller reported the lockdep splat due to the possible deadlock of grp->list_mutex of each sequencer client object. Actually this is rather a false-positive report due to the missing nested lock annotations. The sequencer client may deliver the event directly to another client which takes another own lock. For addressing this issue, this patch replaces the simple down_read() with down_read_nested(). As a lock subclass, the already existing "hop" can be re-used, which indicates the depth of the call. Reference: http://lkml.kernel.org/r/089e082686ac9b482e055c832617@google.com Reported-by: syzbot <bot+7feb8de6b4d6bf810cf098bef942cc387e79d0ad@syzkaller.appspotmail.com> Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Add missing mutex lock for compat ioctlsTakashi Iwai2017-11-081-2/+15
| | | | | | | | | | | | | | | | | | | | commit 79fb0518fec8c8b4ea7f1729f54f293724b3dbb0 upstream. The races among ioctl and other operations were protected by the commit af368027a49a ("ALSA: timer: Fix race among timer ioctls") and later fixes, but one code path was forgotten in the scenario: the 32bit compat ioctl. As syzkaller recently spotted, a very similar use-after-free may happen with the combination of compat ioctls. The fix is simply to apply the same ioctl_lock to the compat_ioctl callback, too. Fixes: af368027a49a ("ALSA: timer: Fix race among timer ioctls") Reference: http://lkml.kernel.org/r/089e082686ac9b482e055c832617@google.com Reported-by: syzbot <bot+e5f3c9783e7048a74233054febbe9f1bdf54b6da@syzkaller.appspotmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Enable 'use' locking in all configurationsBen Hutchings2017-10-272-16/+0
| | | | | | | | | | | | | | commit 8009d506a1dd00cf436b0c4cca0dcec130580a21 upstream. The 'use' locking macros are no-ops if neither SMP or SND_DEBUG is enabled. This might once have been OK in non-preemptible configurations, but even in that case snd_seq_read() may sleep while relying on a 'use' lock. So always use the proper implementations. Signed-off-by: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix missing NULL check at remove_events ioctlTakashi Iwai2017-10-181-1/+1
| | | | | | | | | | | | | | | | | commit 030e2c78d3a91dd0d27fef37e91950dde333eba1 upstream. snd_seq_ioctl_remove_events() calls snd_seq_fifo_clear() unconditionally even if there is no FIFO assigned, and this leads to an Oops due to NULL dereference. The fix is just to add a proper NULL check. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Cc: Mark Salyzyn <salyzyn@google.com> Cc: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix copy_from_user() call inside lockTakashi Iwai2017-10-181-8/+19
| | | | | | | | | | | | | | | | | | | | | | | | commit 5803b023881857db32ffefa0d269c90280a67ee0 upstream. 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: Jia-Ju Bai <baijiaju1990@163.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix use-after-free at creating a portTakashi Iwai2017-10-182-3/+10
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit 71105998845fb012937332fe2e806d443c09e026 upstream. 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: Michael23 Yu <ycqzsy@gmail.com> Suggested-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: core: Fix unexpected error at replacing user TLVTakashi Iwai2017-08-301-1/+1
| | | | | | | | | | | | | | | | | | commit 88c54cdf61f508ebcf8da2d819f5dfc03e954d1d upstream. When user tries to replace the user-defined control TLV, the kernel checks the change of its content via memcmp(). The problem is that the kernel passes the return value from memcmp() as is. memcmp() gives a non-zero negative value depending on the comparison result, and this shall be recognized as an error code. The patch covers that corner-case, return 1 properly for the changed TLV. Fixes: 8aa9b586e420 ("[ALSA] Control API - more robust TLV implementation") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix race between read and ioctlTakashi Iwai2017-06-141-0/+4
| | | | | | | | | | | | | | | | | | | | | commit d11662f4f798b50d8c8743f433842c3e40fe3378 upstream. The read from ALSA timer device, the function snd_timer_user_tread(), may access to an uninitialized struct snd_timer_user fields when the read is concurrently performed while the ioctl like snd_timer_user_tselect() is invoked. We have already fixed the races among ioctls via a mutex, but we seem to have forgotten the race between read vs ioctl. This patch simply applies (more exactly extends the already applied range of) tu->ioctl_lock in snd_timer_user_tread() for closing the race window. Reported-by: Alexander Potapenko <glider@google.com> Tested-by: Alexander Potapenko <glider@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix missing queue indices reset at SNDRV_TIMER_IOCTL_SELECTTakashi Iwai2017-06-141-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | commit ba3021b2c79b2fa9114f92790a99deb27a65b728 upstream. snd_timer_user_tselect() reallocates the queue buffer dynamically, but it forgot to reset its indices. Since the read may happen concurrently with ioctl and snd_timer_user_tselect() allocates the buffer via kmalloc(), this may lead to the leak of uninitialized kernel-space data, as spotted via KMSAN: BUG: KMSAN: use of unitialized memory in snd_timer_user_read+0x6c4/0xa10 CPU: 0 PID: 1037 Comm: probe Not tainted 4.11.0-rc5+ #2739 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:16 dump_stack+0x143/0x1b0 lib/dump_stack.c:52 kmsan_report+0x12a/0x180 mm/kmsan/kmsan.c:1007 kmsan_check_memory+0xc2/0x140 mm/kmsan/kmsan.c:1086 copy_to_user ./arch/x86/include/asm/uaccess.h:725 snd_timer_user_read+0x6c4/0xa10 sound/core/timer.c:2004 do_loop_readv_writev fs/read_write.c:716 __do_readv_writev+0x94c/0x1380 fs/read_write.c:864 do_readv_writev fs/read_write.c:894 vfs_readv fs/read_write.c:908 do_readv+0x52a/0x5d0 fs/read_write.c:934 SYSC_readv+0xb6/0xd0 fs/read_write.c:1021 SyS_readv+0x87/0xb0 fs/read_write.c:1018 This patch adds the missing reset of queue indices. Together with the previous fix for the ioctl/read race, we cover the whole problem. Reported-by: Alexander Potapenko <glider@google.com> Tested-by: Alexander Potapenko <glider@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix leak in events via snd_timer_user_tinterruptKangjie Lu2017-05-201-0/+1
| | | | | | | | | | | | | | commit e4ec8cc8039a7063e24204299b462bd1383184a5 upstream. The stack object “r1” has a total size of 32 bytes. Its field “event” and “val” both contain 4 bytes padding. These 8 bytes padding bytes are sent to user without being initialized. Signed-off-by: Kangjie Lu <kjlu@gatech.edu> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix leak in events via snd_timer_user_ccallbackKangjie Lu2017-05-201-0/+1
| | | | | | | | | | | | | | commit 9a47e9cff994f37f7f0dbd9ae23740d0f64f9fe6 upstream. The stack object “r1” has a total size of 32 bytes. Its field “event” and “val” both contain 4 bytes padding. These 8 bytes padding bytes are sent to user without being initialized. Signed-off-by: Kangjie Lu <kjlu@gatech.edu> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix leak in SNDRV_TIMER_IOCTL_PARAMSKangjie Lu2017-05-201-0/+1
| | | | | | | | | | | | | | commit cec8f96e49d9be372fdb0c3836dcf31ec71e457e upstream. The stack object “tread” has a total size of 32 bytes. Its field “event” and “val” both contain 4 bytes padding. These 8 bytes padding bytes are sent to user without being initialized. Signed-off-by: Kangjie Lu <kjlu@gatech.edu> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix race among timer ioctlsTakashi Iwai2017-05-201-13/+19
| | | | | | | | | | | | | | | | | | | | commit af368027a49a751d6ff4ee9e3f9961f35bb4fede upstream. ALSA timer ioctls have an open race and this may lead to a use-after-free of timer instance object. A simplistic fix is to make each ioctl exclusive. We have already tread_sem for controlling the tread, and extend this as a global mutex to be applied to each ioctl. The downside is, of course, the worse concurrency. But these ioctls aren't to be parallel accessible, in anyway, so it should be fine to serialize there. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix race at timer setup and closeTakashi Iwai2017-05-201-0/+2
| | | | | | | | | | | | | | | | | | commit 3567eb6af614dac436c4b16a8d426f9faed639b3 upstream. ALSA sequencer code has an open race between the timer setup ioctl and the close of the client. This was triggered by syzkaller fuzzer, and a use-after-free was caught there as a result. This patch papers over it by adding a proper queue->timer_mutex lock around the timer-related calls in the relevant code path. Reported-by: Dmitry Vyukov <dvyukov@google.com> Tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: pcm : Call kill_fasync() in stream lockTakashi Iwai2017-05-081-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | commit 3aa02cb664c5fb1042958c8d1aa8c35055a2ebc4 upstream. Currently kill_fasync() is called outside the stream lock in snd_pcm_period_elapsed(). This is potentially racy, since the stream may get released even during the irq handler is running. Although snd_pcm_release_substream() calls snd_pcm_drop(), this doesn't guarantee that the irq handler finishes, thus the kill_fasync() call outside the stream spin lock may be invoked after the substream is detached, as recently reported by KASAN. As a quick workaround, move kill_fasync() call inside the stream lock. The fasync is rarely used interface, so this shouldn't have a big impact from the performance POV. Ideally, we should implement some sync mechanism for the proper finish of stream and irq handler. But this oneliner should suffice for most cases, so far. Reported-by: Baozeng Ding <sploving1@gmail.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Amit Pundir <amit.pundir@linaro.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Don't break snd_use_lock_sync() loop by timeoutTakashi Iwai2017-05-081-6/+3
| | | | | | | | | | | | | | | | | | | | | | | | commit 4e7655fd4f47c23e5249ea260dc802f909a64611 upstream. 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 2d7d54002e39 ("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: Ben Hutchings <ben.hutchings@codethink.co.uk> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix race during FIFO resizeTakashi Iwai2017-04-221-0/+4
| | | | | | | | | | | | | | | | | commit 2d7d54002e396c180db0c800c1046f0a3c471597 upstream. 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: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: seq: Fix racy cell insertions during snd_seq_pool_done()Takashi Iwai2017-04-224-4/+18
| | | | | | | | | | | | | | | | | | | | commit c520ff3d03f0b5db7146d9beed6373ad5d2a5e0e upstream. When snd_seq_pool_done() is called, it marks the closing flag to refuse the further cell insertions. But snd_seq_pool_done() itself doesn't clear the cells but just waits until all cells are cleared by the caller side. That is, it's racy, and this leads to the endless stall as syzkaller spotted. This patch addresses the racy by splitting the setup of pool->closing flag out of snd_seq_pool_done(), and calling it properly before snd_seq_pool_done(). BugLink: http://lkml.kernel.org/r/CACT4Y+aqqy8bZA1fFieifNxR2fAfFQQABcBHj801+u5ePV0URw@mail.gmail.com Reported-and-tested-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
* ALSA: timer: Fix zero-division by continue of uninitialized instanceTakashi Iwai2016-10-051-0/+14
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 9f8a7658bcafb2a7853f7a2eae8a94e87e6e695b ] When a user timer instance is continued without the explicit start beforehand, the system gets eventually zero-division error like: divide error: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN CPU: 1 PID: 27320 Comm: syz-executor Not tainted 4.8.0-rc3-next-20160825+ #8 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 task: ffff88003c9b2280 task.stack: ffff880027280000 RIP: 0010:[<ffffffff858e1a6c>] [< inline >] ktime_divns include/linux/ktime.h:195 RIP: 0010:[<ffffffff858e1a6c>] [<ffffffff858e1a6c>] snd_hrtimer_callback+0x1bc/0x3c0 sound/core/hrtimer.c:62 Call Trace: <IRQ> [< inline >] __run_hrtimer kernel/time/hrtimer.c:1238 [<ffffffff81504335>] __hrtimer_run_queues+0x325/0xe70 kernel/time/hrtimer.c:1302 [<ffffffff81506ceb>] hrtimer_interrupt+0x18b/0x420 kernel/time/hrtimer.c:1336 [<ffffffff8126d8df>] local_apic_timer_interrupt+0x6f/0xe0 arch/x86/kernel/apic/apic.c:933 [<ffffffff86e13056>] smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:957 [<ffffffff86e1210c>] apic_timer_interrupt+0x8c/0xa0 arch/x86/entry/entry_64.S:487 <EOI> ..... Although a similar issue was spotted and a fix patch was merged in commit [6b760bb2c63a: ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUE], it seems covering only a part of iceberg. In this patch, we fix the issue a bit more drastically. Basically the continue of an uninitialized timer is supposed to be a fresh start, so we do it for user timers. For the direct snd_timer_continue() call, there is no way to pass the initial tick value, so we kick out for the uninitialized case. Reported-by: Dmitry Vyukov <dvyukov@google.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
* ALSA: timer: Call notifier in the same spinlockTakashi Iwai2016-10-051-118/+102
| | | | | | | | | | | | | | | [ Upstream commit f65e0d299807d8a11812845c972493c3f9a18e10 ] snd_timer_notify1() is called outside the spinlock and it retakes the lock after the unlock. This is rather racy, and it's safer to move snd_timer_notify() call inside the main spinlock. The patch also contains a slight refactoring / cleanup of the code. Now all start/stop/continue/pause look more symmetric and a bit better readable. Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
* ALSA: timer: fix NULL pointer dereference on memory allocation failureVegard Nossum2016-10-041-2/+15
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 8ddc05638ee42b18ba4fe99b5fb647fa3ad20456 ] I hit this with syzkaller: kasan: CONFIG_KASAN_INLINE enabled kasan: GPF could be caused by NULL-ptr deref or user memory access general protection fault: 0000 [#1] PREEMPT SMP KASAN CPU: 0 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #190 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff88011278d600 task.stack: ffff8801120c0000 RIP: 0010:[<ffffffff82c8ba07>] [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP: 0018:ffff8801120c7a60 EFLAGS: 00010006 RAX: dffffc0000000000 RBX: 0000000000000000 RCX: 0000000000000007 RDX: 0000000000000009 RSI: 1ffff10023483091 RDI: 0000000000000048 RBP: ffff8801120c7a78 R08: ffff88011a5cf768 R09: ffff88011a5ba790 R10: 0000000000000002 R11: ffffed00234b9ef1 R12: ffff880114843980 R13: ffffffff84213c00 R14: ffff880114843ab0 R15: 0000000000000286 FS: 00007f72958f3700(0000) GS:ffff88011aa00000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 00000001126ab000 CR4: 00000000000006f0 Stack: ffff880114843980 ffff880111eb2dc0 ffff880114843a34 ffff8801120c7ad0 ffffffff82c81ab1 0000000000000000 ffffffff842138e0 0000000100000000 ffff880111eb2dd0 ffff880111eb2dc0 0000000000000001 ffff880111eb2dc0 Call Trace: [<ffffffff82c81ab1>] snd_timer_start1+0x331/0x670 [<ffffffff82c85bfd>] snd_timer_start+0x5d/0xa0 [<ffffffff82c8795e>] snd_timer_user_ioctl+0x88e/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff8132762f>] ? put_prev_entity+0x108f/0x21a0 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff813510af>] ? cpuacct_account_field+0x12f/0x1a0 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: c7 c7 c4 b9 c8 82 48 89 d9 4c 89 ee e8 63 88 7f fe e8 7e 46 7b fe 48 8d 7b 48 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 04 02 84 c0 74 04 84 c0 7e 65 80 7b 48 00 74 0e e8 52 46 RIP [<ffffffff82c8ba07>] snd_hrtimer_start+0x77/0x100 RSP <ffff8801120c7a60> ---[ end trace 5955b08db7f2b029 ]--- This can happen if snd_hrtimer_open() fails to allocate memory and returns an error, which is currently not checked by snd_timer_open(): ioctl(SNDRV_TIMER_IOCTL_SELECT) - snd_timer_user_tselect() - snd_timer_close() - snd_hrtimer_close() - (struct snd_timer *) t->private_data = NULL - snd_timer_open() - snd_hrtimer_open() - kzalloc() fails; t->private_data is still NULL ioctl(SNDRV_TIMER_IOCTL_START) - snd_timer_user_start() - snd_timer_start() - snd_timer_start1() - snd_hrtimer_start() - t->private_data == NULL // boom Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
* ALSA: timer: fix division by zero after SNDRV_TIMER_IOCTL_CONTINUEVegard Nossum2016-10-041-0/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | [ Upstream commit 6b760bb2c63a9e322c0e4a0b5daf335ad93d5a33 ] I got this: divide error: 0000 [#1] PREEMPT SMP KASAN CPU: 1 PID: 1327 Comm: a.out Not tainted 4.8.0-rc2+ #189 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 task: ffff8801120a9580 task.stack: ffff8801120b0000 RIP: 0010:[<ffffffff82c8bd9a>] [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0 RSP: 0018:ffff88011aa87da8 EFLAGS: 00010006 RAX: 0000000000004f76 RBX: ffff880112655e88 RCX: 0000000000000000 RDX: 0000000000000000 RSI: ffff880112655ea0 RDI: 0000000000000001 RBP: ffff88011aa87e00 R08: ffff88013fff905c R09: ffff88013fff9048 R10: ffff88013fff9050 R11: 00000001050a7b8c R12: ffff880114778a00 R13: ffff880114778ab4 R14: ffff880114778b30 R15: 0000000000000000 FS: 00007f071647c700(0000) GS:ffff88011aa80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000000603001 CR3: 0000000112021000 CR4: 00000000000006e0 Stack: 0000000000000000 ffff880114778ab8 ffff880112655ea0 0000000000004f76 ffff880112655ec8 ffff880112655e80 ffff880112655e88 ffff88011aa98fc0 00000000b97ccf2b dffffc0000000000 ffff88011aa98fc0 ffff88011aa87ef0 Call Trace: <IRQ> [<ffffffff813abce7>] __hrtimer_run_queues+0x347/0xa00 [<ffffffff82c8bbc0>] ? snd_hrtimer_close+0x130/0x130 [<ffffffff813ab9a0>] ? retrigger_next_event+0x1b0/0x1b0 [<ffffffff813ae1a6>] ? hrtimer_interrupt+0x136/0x4b0 [<ffffffff813ae220>] hrtimer_interrupt+0x1b0/0x4b0 [<ffffffff8120f91e>] local_apic_timer_interrupt+0x6e/0xf0 [<ffffffff81227ad3>] ? kvm_guest_apic_eoi_write+0x13/0xc0 [<ffffffff83c35086>] smp_apic_timer_interrupt+0x76/0xa0 [<ffffffff83c3416c>] apic_timer_interrupt+0x8c/0xa0 <EOI> [<ffffffff83c3239c>] ? _raw_spin_unlock_irqrestore+0x2c/0x60 [<ffffffff82c8185d>] snd_timer_start1+0xdd/0x670 [<ffffffff82c87015>] snd_timer_continue+0x45/0x80 [<ffffffff82c88100>] snd_timer_user_ioctl+0x1030/0x2830 [<ffffffff8159f3a0>] ? __follow_pte.isra.49+0x430/0x430 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff815a26fa>] ? do_wp_page+0x3aa/0x1c90 [<ffffffff815aa4f8>] ? handle_mm_fault+0xbc8/0x27f0 [<ffffffff815a9930>] ? __pmd_alloc+0x370/0x370 [<ffffffff82c870d0>] ? snd_timer_pause+0x80/0x80 [<ffffffff816b0733>] do_vfs_ioctl+0x193/0x1050 [<ffffffff816b05a0>] ? ioctl_preallocate+0x200/0x200 [<ffffffff81002f2f>] ? syscall_trace_enter+0x3cf/0xdb0 [<ffffffff815045ba>] ? __context_tracking_exit.part.4+0x9a/0x1e0 [<ffffffff81002b60>] ? exit_to_usermode_loop+0x190/0x190 [<ffffffff82001a97>] ? check_preemption_disabled+0x37/0x1e0 [<ffffffff81d93889>] ? security_file_ioctl+0x89/0xb0 [<ffffffff816b167f>] SyS_ioctl+0x8f/0xc0 [<ffffffff816b15f0>] ? do_vfs_ioctl+0x1050/0x1050 [<ffffffff81005524>] do_syscall_64+0x1c4/0x4e0 [<ffffffff83c32b2a>] entry_SYSCALL64_slow_path+0x25/0x25 Code: e8 fc 42 7b fe 8b 0d 06 8a 50 03 49 0f af cf 48 85 c9 0f 88 7c 01 00 00 48 89 4d a8 e8 e0 42 7b fe 48 8b 45 c0 48 8b 4d a8 48 99 <48> f7 f9 49 01 c7 e8 cb 42 7b fe 48 8b 55 d0 48 b8 00 00 00 00 RIP [<ffffffff82c8bd9a>] snd_hrtimer_callback+0x1da/0x3f0 RSP <ffff88011aa87da8> ---[ end trace 6aa380f756a21074 ]--- The problem happens when you call ioctl(SNDRV_TIMER_IOCTL_CONTINUE) on a completely new/unused timer -- it will have ->sticks == 0, which causes a divide by 0 in snd_hrtimer_callback(). Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
* ALSA: ctl: Stop notification after disconnectionTakashi Iwai2016-08-071-0/+2
| | | | | | | | | | | | | | | | | | [ Upstream commit f388cdcdd160687c6650833f286b9c89c50960ff ] snd_ctl_remove() has a notification for the removal event. It's superfluous when done during the device got disconnected. Although the notification itself is mostly harmless, it may potentially be harmful, and should be suppressed. Actually some components PCM may free ctl elements during the disconnect or free callbacks, thus it's no theoretical issue. This patch adds the check of card->shutdown flag for avoiding unnecessary notifications after (or during) the disconnect. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
generated by cgit v1.2.3 (git 2.25.1) at 2025-04-09 18:47:38 +0000