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2020-12-18ALSA: pcm: oss: Fix a few more UBSAN fixesTakashi Iwai
There are a few places that call round{up|down}_pow_of_two() with the value zero, and this causes undefined behavior warnings. Avoid calling those macros if such a nonsense value is passed; it's a minor optimization as well, as we handle it as either an error or a value to be skipped, instead. Reported-by: syzbot+33ef0b6639a8d2d42b4c@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201218161730.26596-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-12-14ALSA: pcm: oss: Fix potential out-of-bounds shiftTakashi Iwai
syzbot spotted a potential out-of-bounds shift in the PCM OSS layer where it calculates the buffer size with the arbitrary shift value given via an ioctl. Add a range check for avoiding the undefined behavior. As the value can be treated by a signed integer, the max shift should be 30. Reported-by: syzbot+df7dc146ebdd6435eea3@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20201209084552.17109-2-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-09-01ALSA: pcm: oss: Remove superfluous WARN_ON() for mulaw sanity checkTakashi Iwai
The PCM OSS mulaw plugin has a check of the format of the counter part whether it's a linear format. The check is with snd_BUG_ON() that emits WARN_ON() when the debug config is set, and it confuses syzkaller as if it were a serious issue. Let's drop snd_BUG_ON() for avoiding that. While we're at it, correct the error code to a more suitable, EINVAL. Reported-by: syzbot+23b22dc2e0b81cbfcc95@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200901131802.18157-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-07-09ALSA: Use fallthrough pseudo-keywordGustavo A. R. Silva
Replace the existing /* fall through */ comments and its variants with the new pseudo-keyword macro fallthrough[1]. Also, remove unnecessary fall-through markings when it is the case. [1] https://www.kernel.org/doc/html/latest/process/deprecated.html?highlight=fallthrough#implicit-switch-case-fall-through Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200708203236.GA5112@embeddedor Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-06-09mmap locking API: convert mmap_sem commentsMichel Lespinasse
Convert comments that reference mmap_sem to reference mmap_lock instead. [akpm@linux-foundation.org: fix up linux-next leftovers] [akpm@linux-foundation.org: s/lockaphore/lock/, per Vlastimil] [akpm@linux-foundation.org: more linux-next fixups, per Michel] Signed-off-by: Michel Lespinasse <walken@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Daniel Jordan <daniel.m.jordan@oracle.com> Cc: Davidlohr Bueso <dbueso@suse.de> Cc: David Rientjes <rientjes@google.com> Cc: Hugh Dickins <hughd@google.com> Cc: Jason Gunthorpe <jgg@ziepe.ca> Cc: Jerome Glisse <jglisse@redhat.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Laurent Dufour <ldufour@linux.ibm.com> Cc: Liam Howlett <Liam.Howlett@oracle.com> Cc: Matthew Wilcox <willy@infradead.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ying Han <yinghan@google.com> Link: http://lkml.kernel.org/r/20200520052908.204642-13-walken@google.com Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-05-28Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge 5.7-devel branch for further development. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-05-07ALSA: Replace zero-length array with flexible-arrayGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertently introduced[3] to the codebase from now on. Also, notice that, dynamic memory allocations won't be affected by this change: "Flexible array members have incomplete type, and so the sizeof operator may not be applied. As a quirk of the original implementation of zero-length arrays, sizeof evaluates to zero."[1] sizeof(flexible-array-member) triggers a warning because flexible array members have incomplete type[1]. There are some instances of code in which the sizeof operator is being incorrectly/erroneously applied to zero-length arrays and the result is zero. Such instances may be hiding some bugs. So, this work (flexible-array member conversions) will also help to get completely rid of those sorts of issues. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavoars@kernel.org> Link: https://lore.kernel.org/r/20200507192223.GA16335@embeddedor Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-04-24ALSA: pcm: oss: Place the plugin buffer overflow checks correctly (for 5.7)Takashi Iwai
[ This is again a forward-port of the fix applied for 5.6-base code (commit 4285de0725b1) to 5.7-base, hence neither Fixes nor Cc-to-stable tags are included here -- tiwai ] The checks of the plugin buffer overflow in the previous fix by commit f2ecf903ef06 ("ALSA: pcm: oss: Avoid plugin buffer overflow") are put in the wrong places mistakenly, which leads to the expected (repeated) sound when the rate plugin is involved. Fix in the right places. Also, at those right places, the zero check is needed for the termination node, so added there as well, and let's get it done, finally. Link: https://lore.kernel.org/r/20200424193843.20397-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-04-03ALSA: pcm: oss: Fix regression by buffer overflow fix (again)Takashi Iwai
[ This is essentially the same fix as commit ae769d355664, but it's adapted to the latest code for 5.7; hence it contains no Fixes or other tags for avoid backport confusion -- tiwai ] The recent fix for the OOB access in PCM OSS plugins (commit f2ecf903ef06: "ALSA: pcm: oss: Avoid plugin buffer overflow") caused a regression on OSS applications. The patch introduced the size check in client and slave size calculations to limit to each plugin's buffer size, but I overlooked that some code paths call those without allocating the buffer but just for estimation. This patch fixes the bug by skipping the size check for those code paths while keeping checking in the actual transfer calls. Link: https://lore.kernel.org/r/20200403073818.27943-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-30Merge branch 'for-next' into for-linusTakashi Iwai
2020-03-12ALSA: pcm: oss: Remove WARNING from snd_pcm_plug_alloc() checksTakashi Iwai
The return value checks in snd_pcm_plug_alloc() are covered with snd_BUG_ON() macro that may trigger a kernel WARNING depending on the kconfig. But since the error condition can be triggered by a weird user space parameter passed to OSS layer, we shouldn't give the kernel stack trace just for that. As it's a normal error condition, let's remove snd_BUG_ON() macro usage there. Reported-by: syzbot+2a59ee7a9831b264f45e@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20200312155730.7520-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-09ALSA: pcm: oss: Simplify plugin frame size calculationsTakashi Iwai
Both snd_pcm_plug_client_size() and snd_pcm_plug_slave_size() do the almost same calculations of calling src_frames() and dst_frames() in the chain, but just to the different directions with each other. This patch simplifies those functions. Now they return -EINVAL for the invalid direction, but practically seen, there is no functional changes at all. Link: https://lore.kernel.org/r/20200309185855.15693-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-09Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge of 5.6 devel branch for further changes in 5.7 cycle Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-03-09ALSA: pcm: oss: Avoid plugin buffer overflowTakashi Iwai
Each OSS PCM plugins allocate its internal buffer per pre-calculation of the max buffer size through the chain of plugins (calling src_frames and dst_frames callbacks). This works for most plugins, but the rate plugin might behave incorrectly. The calculation in the rate plugin involves with the fractional position, i.e. it may vary depending on the input position. Since the buffer size pre-calculation is always done with the offset zero, it may return a shorter size than it might be; this may result in the out-of-bound access as spotted by fuzzer. This patch addresses those possible buffer overflow accesses by simply setting the upper limit per the given buffer size for each plugin before src_frames() and after dst_frames() calls. Reported-by: syzbot+e1fe9f44fb8ecf4fb5dd@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/000000000000b25ea005a02bcf21@google.com Link: https://lore.kernel.org/r/20200309082148.19855-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-02-14ALSA: pcm: oss: Unlock mutex temporarily for sleeping at read/writeTakashi Iwai
ALSA PCM OSS layer calls the generic __snd_pcm_lib_xfer() helper for the actual transfer of the audio data. The xfer helper may sleep long for waiting for the enough space becoming empty for read/write, and it does unlock/relock for the substream lock. This works fine, so far, but a slight problem specific to OSS layer is that OSS layer wraps yet more mutex (runtime->oss.params_lock) over __snd_pcm_lib_xfer() call; so this mutex is still locked during a possible long sleep, and it prevents the whole ioctl and other actions applied to the given stream. This patch adds the temporarily unlock and relock of the mutex around __snd_pcm_lib_xfer() call in the OSS layer to be more friendly to the concurrent accesses. The long mutex protection itself shouldn't be a real issue for the normal systems, and its influence appears only on strange things like fuzzers. Link: https://lore.kernel.org/r/20200214171643.26212-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-02-12ALSA: core: Replace zero-length array with flexible-array memberGustavo A. R. Silva
The current codebase makes use of the zero-length array language extension to the C90 standard, but the preferred mechanism to declare variable-length types such as these ones is a flexible array member[1][2], introduced in C99: struct foo { int stuff; struct boo array[]; }; By making use of the mechanism above, we will get a compiler warning in case the flexible array does not occur last in the structure, which will help us prevent some kind of undefined behavior bugs from being inadvertenly introduced[3] to the codebase from now on. This issue was found with the help of Coccinelle. [1] https://gcc.gnu.org/onlinedocs/gcc/Zero-Length.html [2] https://github.com/KSPP/linux/issues/21 [3] commit 76497732932f ("cxgb3/l2t: Fix undefined behaviour") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Link: https://lore.kernel.org/r/20200211193910.GA4596@embeddedor Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-02-10ALSA: pcm: Use standard macros for fixing PCM format castTakashi Iwai
Simplify the code with the new macros for PCM format type iterations. This fixes the sparse warnings nicely: sound/core/pcm_native.c:2302:26: warning: restricted snd_pcm_format_t degrades to integer sound/core/pcm_native.c:2306:54: warning: incorrect type in argument 1 (different base types) sound/core/pcm_native.c:2306:54: expected restricted snd_pcm_format_t [usertype] format sound/core/pcm_native.c:2306:54: got unsigned int [assigned] k .... No functional changes, just sparse warning fixes. Link: https://lore.kernel.org/r/20200206163945.6797-6-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-05ALSA: oss: More constificationsTakashi Iwai
Apply const prefix to the static tables for strings and formats. Just for minor optimization and no functional changes. Link: https://lore.kernel.org/r/20200105144823.29547-41-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2020-01-03ALSA: mixer: oss: Constify snd_mixer_oss_assign_table definitionTakashi Iwai
The snd_mixer_oss_assign_table is read-only, and can it be declared as const. There should be no functional changes by this patch. Link: https://lore.kernel.org/r/20200103081714.9560-32-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-12-06Merge tag 'sound-fix-5.5-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound Pull more sound updates from Takashi Iwai: "A few last-minute updates, most of them are the regression fixes: - AMD HD-audio HDMI runtime PM improvements - Fixes for HD-audio HDMI regressions wrt DP-MST - A regression fix for the previous aloop enhancement - A fix for a long-time problem in PCM OSS layer that was spotted by fuzzer now - A few HD-audio quirks" * tag 'sound-fix-5.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tiwai/sound: ALSA: pcm: oss: Avoid potential buffer overflows ALSA: hda: hdmi - Keep old slot assignment behavior for Intel platforms ALSA: hda: Modify stream stripe mask only when needed ALSA: hda - fixup for the bass speaker on Lenovo Carbon X1 7th gen ALSA: hda: hdmi - preserve non-MST PCM routing for Intel platforms ALSA: hda: hdmi - fix kernel oops caused by invalid PCM idx ALSA: hda/realtek - Fix inverted bass GPIO pin on Acer 8951G ALSA: hda/realtek - Dell headphone has noise on unmute for ALC236 ALSA: hda: hdmi - fix regression in connect list handling ALSA: aloop: Avoid pointer dereference before null-check ALSA: hda/hdmi - enable automatic runtime pm for AMD HDMI codecs by default ALSA: hda/hdmi - enable runtime pm for newer AMD display audio ALSA: hda/hdmi - Add new pci ids for AMD GPU display audio ALSA: hda/hdmi - fix vgaswitcheroo detection for AMD
2019-12-04ALSA: pcm: oss: Avoid potential buffer overflowsTakashi Iwai
syzkaller reported an invalid access in PCM OSS read, and this seems to be an overflow of the internal buffer allocated for a plugin. Since the rate plugin adjusts its transfer size dynamically, the calculation for the chained plugin might be bigger than the given buffer size in some extreme cases, which lead to such an buffer overflow as caught by KASAN. Fix it by limiting the max transfer size properly by checking against the destination size in each plugin transfer callback. Reported-by: syzbot+f153bde47a62e0b05f83@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Link: https://lore.kernel.org/r/20191204144824.17801-1-tiwai@suse.de Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-10-23compat_ioctl: remove translation for sound ioctlsArnd Bergmann
The SNDCTL_* and SOUND_* commands are the old OSS user interface. I checked all the sound ioctl commands listed in fs/compat_ioctl.c to see if we still need the translation handlers. Here is what I found: - sound/oss/ is (almost) gone from the kernel, this is what actually needed all the translations - The ALSA emulation for OSS correctly handles all compat_ioctl commands already. - sound/oss/dmasound/ is the last holdout of the original OSS code, this is only used on arch/m68k, which has no 64-bit mode and hence needs no compat handlers - arch/um/drivers/hostaudio_kern.c may run in 64-bit mode with 32-bit x86 user space underneath it. This rare corner case is the only one that still needs the compat handlers. By adding a simple redirect of .compat_ioctl to .unlocked_ioctl in the UML driver, we can remove all the COMPATIBLE_IOCTL() annotations without a change in functionality. For completeness, I'm adding the same thing to the dmasound file, knowing that it makes no difference. The compat_ioctl list contains one comment about SNDCTL_DSP_MAPINBUF and SNDCTL_DSP_MAPOUTBUF, which actually would need a translation handler if implemented. However, the native implementation just returns -EINVAL, so we don't care. Reviewed-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
2019-07-08Merge tag 'asoc-v5.3' of ↵Takashi Iwai
https://git.kernel.org/pub/scm/linux/kernel/git/broonie/sound into for-linus ASoC: Updates for v5.3 This is a very big update, mainly thanks to Morimoto-san's refactoring work and some fairly large new drivers. - Lots more work on moving towards a component based framework from Morimoto-san. - Support for force disconnecting muxes from Jerome Brunet. - New drivers for Cirrus Logic CS47L35, CS47L85 and CS47L90, Conexant CX2072X, Realtek RT1011 and RT1308. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-05-30treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 156Thomas Gleixner
Based on 1 normalized pattern(s): this program is free software you can redistribute it and or modify it under the terms of the gnu general public license as published by the free software foundation either version 2 of the license or at your option any later version this program is distributed in the hope that it will be useful but without any warranty without even the implied warranty of merchantability or fitness for a particular purpose see the gnu general public license for more details you should have received a copy of the gnu general public license along with this program if not write to the free software foundation inc 59 temple place suite 330 boston ma 02111 1307 usa extracted by the scancode license scanner the SPDX license identifier GPL-2.0-or-later has been chosen to replace the boilerplate/reference in 1334 file(s). Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Allison Randal <allison@lohutok.net> Reviewed-by: Richard Fontana <rfontana@redhat.com> Cc: linux-spdx@vger.kernel.org Link: https://lkml.kernel.org/r/20190527070033.113240726@linutronix.de Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2019-05-24ALSA: pcm: oss: Use struct_size() helperGustavo A. R. Silva
Make use of the struct_size() helper instead of an open-coded version in order to avoid any potential type mistakes, in particular in the context in which this code is being used. So, replace the following form: sizeof(struct rate_priv) + src_format->channels * sizeof(struct rate_channel) with: struct_size(data, channels, src_format->channels) This code was detected with the help of Coccinelle. Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-04-17ALSA: core: Don't refer to snd_cards array directlyTakashi Iwai
The snd_cards[] array holds the card pointers that have been currently registered, and it's exported for the external modules that may need to refer a card object. But accessing to this array can be racy against the driver probe or removal, as the card registration or free may happen concurrently. This patch gets rid of the direct access to snd_cards[] array and provides a helper function to give the card object from the index number with a refcount management. Then the caller can access to the given card object safely, and releases it via snd_card_unref(). While we're at it, add a proper comment to snd_card_unref() and make it an inlined function for type-safety, too. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-03-22ALSA: pcm: Fix possible OOB access in PCM oss pluginsTakashi Iwai
The PCM OSS emulation converts and transfers the data on the fly via "plugins". The data is converted over the dynamically allocated buffer for each plugin, and recently syzkaller caught OOB in this flow. Although the bisection by syzbot pointed out to the commit 65766ee0bf7f ("ALSA: oss: Use kvzalloc() for local buffer allocations"), this is merely a commit to replace vmalloc() with kvmalloc(), hence it can't be the cause. The further debug action revealed that this happens in the case where a slave PCM doesn't support only the stereo channels while the OSS stream is set up for a mono channel. Below is a brief explanation: At each OSS parameter change, the driver sets up the PCM hw_params again in snd_pcm_oss_change_params_lock(). This is also the place where plugins are created and local buffers are allocated. The problem is that the plugins are created before the final hw_params is determined. Namely, two snd_pcm_hw_param_near() calls for setting the period size and periods may influence on the final result of channels, rates, etc, too, while the current code has already created plugins beforehand with the premature values. So, the plugin believes that channels=1, while the actual I/O is with channels=2, which makes the driver reading/writing over the allocated buffer size. The fix is simply to move the plugin allocation code after the final hw_params call. Reported-by: syzbot+d4503ae45b65c5bc1194@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2019-01-24ALSA: pcm: Drop unused snd_pcm_substream.file fieldTakashi Iwai
It's assigned but nowhere used. Let's remove it. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-11-09ALSA: oss: Use kvzalloc() for local buffer allocationsTakashi Iwai
PCM OSS layer may allocate a few temporary buffers, one for the core read/write and another for the conversions via plugins. Currently both are allocated via vmalloc(). But as the allocation size is equivalent with the PCM period size, the required size might be quite small, depending on the application. This patch replaces these vmalloc() calls with kvzalloc() for covering small period sizes better. Also, we use "z"-alloc variant here for addressing the possible uninitialized access reported by syzkaller. Reported-by: syzbot+1cb36954e127c98dd037@syzkaller.appspotmail.com Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-08-27ALSA: pcm: signedness bug in snd_pcm_plug_alloc()Dan Carpenter
The "frames" variable is unsigned so the error handling doesn't work properly. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-08-01ALSA: pcm: Mark expected switch fall-throughGustavo A. R. Silva
In preparation to enabling -Wimplicit-fallthrough, mark switch cases where we are expecting to fall through. Addresses-Coverity-ID: 1357375 ("Missing break in switch") Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-27ALSA: pcm: Fix sparse warning wrt PCM format typeTakashi Iwai
The PCM format type is with __bitwise, hence it needs the explicit cast with __force. It's ugly, but there is a reason for that cost... This fixes the sparse warning: sound/core/oss/pcm_oss.c:1854:55: warning: incorrect type in argument 1 (different base types) Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-07-26ALSA: pcm: Use standard lower_32_bits() and upper_32_bits()Takashi Iwai
Instead of open codes, use the standard macros for obtaining the lower and upper 32bit values. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-05-28sound: Use octal not symbolic permissionsJoe Perches
Convert the S_<FOO> symbolic permissions to their octal equivalents as using octal and not symbolic permissions is preferred by many as more readable. see: https://lkml.org/lkml/2016/8/2/1945 Done with automated conversion via: $ ./scripts/checkpatch.pl -f --types=SYMBOLIC_PERMS --fix-inplace <files...> Miscellanea: o Wrapped one multi-line call to a single line Signed-off-by: Joe Perches <joe@perches.com> Acked-by: Vinod Koul <vkoul@kernel.org> 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>
2018-04-02Merge 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>
2018-03-23ALSA: 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>
2018-03-11ALSA: 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>
2018-02-11vfs: 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>
2018-01-30Merge branch 'misc.poll' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs Pull poll annotations from Al Viro: "This introduces a __bitwise type for POLL### bitmap, and propagates the annotations through the tree. Most of that stuff is as simple as 'make ->poll() instances return __poll_t and do the same to local variables used to hold the future return value'. Some of the obvious brainos found in process are fixed (e.g. POLLIN misspelled as POLL_IN). At that point the amount of sparse warnings is low and most of them are for genuine bugs - e.g. ->poll() instance deciding to return -EINVAL instead of a bitmap. I hadn't touched those in this series - it's large enough as it is. Another problem it has caught was eventpoll() ABI mess; select.c and eventpoll.c assumed that corresponding POLL### and EPOLL### were equal. That's true for some, but not all of them - EPOLL### are arch-independent, but POLL### are not. The last commit in this series separates userland POLL### values from the (now arch-independent) kernel-side ones, converting between them in the few places where they are copied to/from userland. AFAICS, this is the least disruptive fix preserving poll(2) ABI and making epoll() work on all architectures. As it is, it's simply broken on sparc - try to give it EPOLLWRNORM and it will trigger only on what would've triggered EPOLLWRBAND on other architectures. EPOLLWRBAND and EPOLLRDHUP, OTOH, are never triggered at all on sparc. With this patch they should work consistently on all architectures" * 'misc.poll' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (37 commits) make kernel-side POLL... arch-independent eventpoll: no need to mask the result of epi_item_poll() again eventpoll: constify struct epoll_event pointers debugging printk in sg_poll() uses %x to print POLL... bitmap annotate poll(2) guts 9p: untangle ->poll() mess ->si_band gets POLL... bitmap stored into a user-visible long field ring_buffer_poll_wait() return value used as return value of ->poll() the rest of drivers/*: annotate ->poll() instances media: annotate ->poll() instances fs: annotate ->poll() instances ipc, kernel, mm: annotate ->poll() instances net: annotate ->poll() instances apparmor: annotate ->poll() instances tomoyo: annotate ->poll() instances sound: annotate ->poll() instances acpi: annotate ->poll() instances crypto: annotate ->poll() instances block: annotate ->poll() instances x86: annotate ->poll() instances ...
2018-01-09ALSA: pcm: Use ERESTARTSYS instead of EINTR in OSS emulationTakashi Iwai
Fix the last standing EINTR in the whole subsystem. Use more correct ERESTARTSYS for pending signals. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-09Merge branch 'for-linus' into for-nextTakashi Iwai
Back-merge to continue fixing the OSS emulation code. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-08ALSA: pcm: Allow aborting mutex lock at OSS read/write loopsTakashi Iwai
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. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-08ALSA: pcm: Abort properly at pending signal in OSS read/write loopsTakashi Iwai
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 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-04ALSA: pcm: Add missing error checks in OSS emulation plugin builderTakashi Iwai
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. Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-02ALSA: pcm: Set config update bits only when really changedTakashi Iwai
The PCM config space refine codes touch the parameter rmask and cmask bits when the given config parameter is changed. But in most places it checks only whether the changed value is non-zero or not, and they don't consider whether a negative error value is returned. This will lead to the incorrect update bits set upon the error path. Fix the codes to check properly the return code whether it's really updated or an error. Signed-off-by: Takashi Iwai <tiwai@suse.de>
2018-01-02ALSA: pcm: Remove incorrect snd_BUG_ON() usagesTakashi Iwai
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 Cc: <stable@vger.kernel.org> Signed-off-by: Takashi Iwai <tiwai@suse.de>