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2018-01-17sysrq: Fix warning in sysrq generated crash.Ani Sinha
commit 984cf355aeaa8f2eda3861b50d0e8d3e3f77e83b upstream. Commit 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") replaced spin_lock_irqsave() calls with rcu_read_lock() calls in sysrq. Since rcu_read_lock() does not disable preemption, faulthandler_disabled() in __do_page_fault() in x86/fault.c returns false. When the code later calls might_sleep() in the pagefault handler, we get the following warning: BUG: sleeping function called from invalid context at ../arch/x86/mm/fault.c:1187 in_atomic(): 0, irqs_disabled(): 0, pid: 4706, name: bash Preemption disabled at:[<ffffffff81484339>] printk+0x48/0x4a To fix this, we release the RCU read lock before we crash. Tested this patch on linux 3.18 by booting off one of our boards. Fixes: 984d74a72076a1 ("sysrq: rcu-ify __handle_sysrq") Signed-off-by: Ani Sinha <ani@arista.com> Reviewed-by: Rik van Riel <riel@redhat.com> Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17hwrng: core - sleep interruptible in readJiri Slaby
commit 1ab87298cb59b649d8d648d25dc15b36ab865f5a upstream. hwrng kthread can be waiting via hwrng_fillfn for some data from a rng like virtio-rng: hwrng D ffff880093e17798 0 382 2 0x00000000 ... Call Trace: [<ffffffff817339c6>] wait_for_completion_killable+0x96/0x210 [<ffffffffa00aa1b7>] virtio_read+0x57/0xf0 [virtio_rng] [<ffffffff814f4a35>] hwrng_fillfn+0x75/0x130 [<ffffffff810aa243>] kthread+0xf3/0x110 And when some user program tries to read the /dev node in this state, we get: rngd D ffff880093e17798 0 762 1 0x00000004 ... Call Trace: [<ffffffff817351ac>] mutex_lock_nested+0x15c/0x3e0 [<ffffffff814f478e>] rng_dev_read+0x6e/0x240 [<ffffffff81231958>] __vfs_read+0x28/0xe0 [<ffffffff81232393>] vfs_read+0x83/0x130 And this is indeed unkillable. So use mutex_lock_interruptible instead of mutex_lock in rng_dev_read and exit immediatelly when interrupted. And possibly return already read data, if any (as POSIX allows). v2: use ERESTARTSYS instead of EINTR Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Matt Mackall <mpm@selenic.com> Cc: Herbert Xu <herbert@gondor.apana.org.au> Cc: <linux-crypto@vger.kernel.org> Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17x86/mm/pat, /dev/mem: Remove superfluous error messageJiri Kosina
commit 39380b80d72723282f0ea1d1bbf2294eae45013e upstream. Currently it's possible for broken (or malicious) userspace to flood a kernel log indefinitely with messages a-la Program dmidecode tried to access /dev/mem between f0000->100000 because range_is_allowed() is case of CONFIG_STRICT_DEVMEM being turned on dumps this information each and every time devmem_is_allowed() fails. Reportedly userspace that is able to trigger contignuous flow of these messages exists. It would be possible to rate limit this message, but that'd have a questionable value; the administrator wouldn't get information about all the failing accessess, so then the information would be both superfluous and incomplete at the same time :) Returning EPERM (which is what is actually happening) is enough indication for userspace what has happened; no need to log this particular error as some sort of special condition. Signed-off-by: Jiri Kosina <jkosina@suse.cz> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Andy Lutomirski <luto@kernel.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Brian Gerst <brgerst@gmail.com> Cc: Denys Vlasenko <dvlasenk@redhat.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Josh Poimboeuf <jpoimboe@redhat.com> Cc: Kees Cook <keescook@chromium.org> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Luis R. Rodriguez <mcgrof@suse.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Toshi Kani <toshi.kani@hp.com> Link: http://lkml.kernel.org/r/alpine.LNX.2.00.1607081137020.24757@cbobk.fhfr.pm Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17cx82310_eth: use skb_cow_head() to deal with cloned skbsEric Dumazet
commit a9e840a2081ed28c2b7caa6a9a0041c950b3c37d upstream. We need to ensure there is enough headroom to push extra header, but we also need to check if we are allowed to change headers. skb_cow_head() is the proper helper to deal with this. Fixes: cc28a20e77b2 ("introduce cx82310_eth: Conexant CX82310-based ADSL router USB ethernet driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Hughes <james.hughes@raspberrypi.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17smsc75xx: use skb_cow_head() to deal with cloned skbsEric Dumazet
commit b7c6d2675899cfff0180412c63fc9cbd5bacdb4d upstream. We need to ensure there is enough headroom to push extra header, but we also need to check if we are allowed to change headers. skb_cow_head() is the proper helper to deal with this. Fixes: d0cad871703b ("smsc75xx: SMSC LAN75xx USB gigabit ethernet adapter driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Hughes <james.hughes@raspberrypi.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17sr9700: use skb_cow_head() to deal with cloned skbsEric Dumazet
commit d532c1082f68176363ed766d09bf187616e282fe upstream. We need to ensure there is enough headroom to push extra header, but we also need to check if we are allowed to change headers. skb_cow_head() is the proper helper to deal with this. Fixes: c9b37458e956 ("USB2NET : SR9700 : One chip USB 1.1 USB2NET SR9700Device Driver Support") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Hughes <james.hughes@raspberrypi.org> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17lan78xx: use skb_cow_head() to deal with cloned skbsEric Dumazet
commit d4ca73591916b760478d2b04334d5dcadc028e9c upstream. We need to ensure there is enough headroom to push extra header, but we also need to check if we are allowed to change headers. skb_cow_head() is the proper helper to deal with this. Fixes: 55d7de9de6c3 ("Microchip's LAN7800 family USB 2/3 to 10/100/1000 Ethernet device driver") Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: James Hughes <james.hughes@raspberrypi.org> Cc: Woojung Huh <woojung.huh@microchip.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17r8152: adjust ALDPS functionhayeswang
commit cda9fb01dc3cafd718b2865b447e869bf6624ddd upstream. Replace disable_aldps() and enable_aldps() with aldps_en(). Signed-off-by: Hayes Wang <hayeswang@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17r8152: use test_and_clear_bithayeswang
commit 216a8349d3a0dd1bc2afbcc821e374c8f929bd62 upstream. Replace test_bit() followed by clear_bit() with test_and_clear_bit(). Signed-off-by: Hayes Wang <hayeswang@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17r8152: fix the wake eventhayeswang
commit 5ee3c60c8d3b88cab6496c9b7d49a01576dd9cf9 upstream. When the autosuspend is enabled and occurs before system suspend, we should wake the device before running system syspend. Then, we could change the wake event for system suspend. Otherwise, the device would resume the system when receiving any packet. Signed-off-by: Hayes Wang <hayeswang@realtek.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17usb: musb: ux500: Fix NULL pointer dereference at system PMUlf Hansson
commit 79c5623f1cb85f33403eb9f1e45124e9f56181f8 upstream. The commit 7d32cdef5356 ("usb: musb: fail with error when no DMA controller set"), caused the core platform driver to correctly return an error code when fail probing. Unfurtante it also caused bug for a NULL pointer dereference, during system suspend for the ux500 driver. The reason is a lacking validation of the corresponding ->driver_data pointer, which won't be set when the musb core driver fails to probe (or haven't yet been probed). Fixes: 7d32cdef5356 ("usb: musb: fail with error when no DMA...") Acked-by: Linus Walleij <linus.walleij@linaro.org> Signed-off-by: Ulf Hansson <ulf.hansson@linaro.org> Signed-off-by: Felipe Balbi <balbi@kernel.org> Signed-off-by: Oliver Neukum <oneukum@suse.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17usbvision fix overflow of interfaces arrayOliver Neukum
commit 588afcc1c0e45358159090d95bf7b246fb67565f upstream. This fixes the crash reported in: http://seclists.org/bugtraq/2015/Oct/35 The interface number needs a sanity check. Signed-off-by: Oliver Neukum <oneukum@suse.com> Cc: Vladis Dronov <vdronov@redhat.com> Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17locking/mutex: Allow next waiter lockless wakeupDavidlohr Bueso
commit 1329ce6fbbe4536592dfcfc8d64d61bfeb598fe6 upstream. Make use of wake-queues and enable the wakeup to occur after releasing the wait_lock. This is similar to what we do with rtmutex top waiter, slightly shortening the critical region and allow other waiters to acquire the wait_lock sooner. In low contention cases it can also help the recently woken waiter to find the wait_lock available (fastpath) when it continues execution. Reviewed-by: Waiman Long <Waiman.Long@hpe.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ding Tianhong <dingtianhong@huawei.com> Cc: Jason Low <jason.low2@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Paul E. McKenney <paulmck@us.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Tim Chen <tim.c.chen@linux.intel.com> Cc: Waiman Long <waiman.long@hpe.com> Cc: Will Deacon <Will.Deacon@arm.com> Link: http://lkml.kernel.org/r/20160125022343.GA3322@linux-uzut.site Signed-off-by: Ingo Molnar <mingo@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17futex: Replace barrier() in unqueue_me() with READ_ONCE()Jianyu Zhan
commit 29b75eb2d56a714190a93d7be4525e617591077a upstream. Commit e91467ecd1ef ("bug in futex unqueue_me") introduced a barrier() in unqueue_me() to prevent the compiler from rereading the lock pointer which might change after a check for NULL. Replace the barrier() with a READ_ONCE() for the following reasons: 1) READ_ONCE() is a weaker form of barrier() that affects only the specific load operation, while barrier() is a general compiler level memory barrier. READ_ONCE() was not available at the time when the barrier was added. 2) Aside of that READ_ONCE() is descriptive and self explainatory while a barrier without comment is not clear to the casual reader. No functional change. [ tglx: Massaged changelog ] Signed-off-by: Jianyu Zhan <nasa4836@gmail.com> Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> Acked-by: Darren Hart <dvhart@linux.intel.com> Cc: dave@stgolabs.net Cc: peterz@infradead.org Cc: linux@rasmusvillemoes.dk Cc: akpm@linux-foundation.org Cc: fengguang.wu@intel.com Cc: bigeasy@linutronix.de Link: http://lkml.kernel.org/r/1457314344-5685-1-git-send-email-nasa4836@gmail.com Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17locks: don't check for race with close when setting OFD lockJeff Layton
commit 0752ba807b04ccd69cb4bc8bbf829a80ee208a3c upstream. We don't clean out OFD locks on close(), so there's no need to check for a race with them here. They'll get cleaned out at the same time that flock locks are. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Acked-by: "J. Bruce Fields" <bfields@fieldses.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de>
2018-01-17zswap: don't param_set_charp while holding spinlockDan Streetman
commit fd5bb66cd934987e49557455b6497fc006521940 upstream. Change the zpool/compressor param callback function to release the zswap_pools_lock spinlock before calling param_set_charp, since that function may sleep when it calls kmalloc with GFP_KERNEL. While this problem has existed for a while, I wasn't able to trigger it using a tight loop changing either/both the zpool and compressor params; I think it's very unlikely to be an issue on the stable kernels, especially since most zswap users will change the compressor and/or zpool from sysfs only one time each boot - or zero times, if they add the params to the kernel boot. Fixes: c99b42c3529e ("zswap: use charp for zswap param strings") Link: http://lkml.kernel.org/r/20170126155821.4545-1-ddstreet@ieee.org Signed-off-by: Dan Streetman <dan.streetman@canonical.com> Reported-by: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Minchan Kim <minchan@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17mm/zswap: use workqueue to destroy poolDan Streetman
commit 200867af4dedfe7cb707f96773684de1d1fd21e6 upstream. Add a work_struct to struct zswap_pool, and change __zswap_pool_empty to use the workqueue instead of using call_rcu(). When zswap destroys a pool no longer in use, it uses call_rcu() to perform the destruction/freeing. Since that executes in softirq context, it must not sleep. However, actually destroying the pool involves freeing the per-cpu compressors (which requires locking the cpu_add_remove_lock mutex) and freeing the zpool, for which the implementation may sleep (e.g. zsmalloc calls kmem_cache_destroy, which locks the slab_mutex). So if either mutex is currently taken, or any other part of the compressor or zpool implementation sleeps, it will result in a BUG(). It's not easy to reproduce this when changing zswap's params normally. In testing with a loaded system, this does not fail: $ cd /sys/module/zswap/parameters $ echo lz4 > compressor ; echo zsmalloc > zpool nor does this: $ while true ; do > echo lzo > compressor ; echo zbud > zpool > sleep 1 > echo lz4 > compressor ; echo zsmalloc > zpool > sleep 1 > done although it's still possible either of those might fail, depending on whether anything else besides zswap has locked the mutexes. However, changing a parameter with no delay immediately causes the schedule while atomic BUG: $ while true ; do > echo lzo > compressor ; echo lz4 > compressor > done This is essentially the same as Yu Zhao's proposed patch to zsmalloc, but moved to zswap, to cover compressor and zpool freeing. Fixes: f1c54846ee45 ("zswap: dynamic pool creation") Signed-off-by: Dan Streetman <ddstreet@ieee.org> Reported-by: Yu Zhao <yuzhao@google.com> Reviewed-by: Sergey Senozhatsky <sergey.senozhatsky@gmail.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Dan Streetman <dan.streetman@canonical.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17mm/page-writeback: fix dirty_ratelimit calculationAndrey Ryabinin
commit d59b1087a98e402ed9a7cc577f4da435f9a555f5 upstream. Calculation of dirty_ratelimit sometimes is not correct. E.g. initial values of dirty_ratelimit == INIT_BW and step == 0, lead to the following result: UBSAN: Undefined behaviour in ../mm/page-writeback.c:1286:7 shift exponent 25600 is too large for 64-bit type 'long unsigned int' The fix is straightforward - make step 0 if the shift exponent is too big. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Wu Fengguang <fengguang.wu@intel.com> Cc: Tejun Heo <tj@kernel.org> Cc: Andy Shevchenko <andy.shevchenko@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17mm/compaction: pass only pageblock aligned range to pageblock_pfn_to_pageJoonsoo Kim
commit e1409c325fdc1fef7b3d8025c51892355f065d15 upstream. pageblock_pfn_to_page() is used to check there is valid pfn and all pages in the pageblock is in a single zone. If there is a hole in the pageblock, passing arbitrary position to pageblock_pfn_to_page() could cause to skip whole pageblock scanning, instead of just skipping the hole page. For deterministic behaviour, it's better to always pass pageblock aligned range to pageblock_pfn_to_page(). It will also help further optimization on pageblock_pfn_to_page() in the following patch. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Aaron Lu <aaron.lu@intel.com> Cc: David Rientjes <rientjes@google.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17mm/compaction: fix invalid free_pfn and compact_cached_free_pfnJoonsoo Kim
commit 623446e4dc45b37740268165107cc63abb3022f0 upstream. free_pfn and compact_cached_free_pfn are the pointer that remember restart position of freepage scanner. When they are reset or invalid, we set them to zone_end_pfn because freepage scanner works in reverse direction. But, because zone range is defined as [zone_start_pfn, zone_end_pfn), zone_end_pfn is invalid to access. Therefore, we should not store it to free_pfn and compact_cached_free_pfn. Instead, we need to store zone_end_pfn - 1 to them. There is one more thing we should consider. Freepage scanner scan reversely by pageblock unit. If free_pfn and compact_cached_free_pfn are set to middle of pageblock, it regards that sitiation as that it already scans front part of pageblock so we lose opportunity to scan there. To fix-up, this patch do round_down() to guarantee that reset position will be pageblock aligned. Note that thanks to the current pageblock_pfn_to_page() implementation, actual access to zone_end_pfn doesn't happen until now. But, following patch will change pageblock_pfn_to_page() so this patch is needed from now on. Signed-off-by: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Aaron Lu <aaron.lu@intel.com> Cc: Mel Gorman <mgorman@suse.de> Cc: Rik van Riel <riel@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17x86/acpi: Reduce code duplication in mp_override_legacy_irq()Vikas C Sajjan
commit 4ee2ec1b122599f7b10c849fa7915cebb37b7edb upstream. The new function mp_register_ioapic_irq() is a subset of the code in mp_override_legacy_irq(). Replace the code duplication by invoking mp_register_ioapic_irq() from mp_override_legacy_irq(). Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: linux-pm@vger.kernel.org Cc: kkamagui@gmail.com Cc: linux-acpi@vger.kernel.org Link: https://lkml.kernel.org/r/1510848825-21965-3-git-send-email-vikas.cha.sajjan@hpe.com Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17ALSA: aloop: Fix racy hw constraints adjustmentTakashi Iwai
commit 898dfe4687f460ba337a01c11549f87269a13fa2 upstream. The aloop driver tries to update the hw constraints of the connected target on the cable of the opened PCM substream. This is done by adding the extra hw constraints rules referring to the substream runtime->hw fields, while the other substream may update the runtime hw of another side on the fly. This is, however, racy and may result in the inconsistent values when both PCM streams perform the prepare concurrently. One of the reason is that it overwrites the other's runtime->hw field; which is not only racy but also broken when it's called before the open of another side finishes. And, since the reference to runtime->hw isn't protected, the concurrent write may give the partial value update and become inconsistent. This patch is an attempt to fix and clean up: - The prepare doesn't change the runtime->hw of other side any longer, but only update the cable->hw that is referred commonly. - The extra rules refer to the loopback_pcm object instead of the runtime->hw. The actual hw is deduced from cable->hw. - The extra rules take the cable_lock to protect against the race. Fixes: b1c73fc8e697 ("ALSA: snd-aloop: Fix hw_params restrictions and checking") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17ALSA: aloop: Fix inconsistent format due to incomplete ruleTakashi Iwai
commit b088b53e20c7d09b5ab84c5688e609f478e5c417 upstream. The extra hw constraint rule for the formats the aloop driver introduced has a slight flaw, where it doesn't return a positive value when the mask got changed. It came from the fact that it's basically a copy&paste from snd_hw_constraint_mask64(). The original code is supposed to be a single-shot and it modifies the mask bits only once and never after, while what we need for aloop is the dynamic hw rule that limits the mask bits. This difference results in the inconsistent state, as the hw_refine doesn't apply the dependencies fully. The worse and surprisingly result is that it causes a crash in OSS emulation when multiple full-duplex reads/writes are performed concurrently (I leave why it triggers Oops to readers as a homework). For fixing this, replace a few open-codes with the standard snd_mask_*() macros. Reported-by: syzbot+3902b5220e8ca27889ca@syzkaller.appspotmail.com Fixes: b1c73fc8e697 ("ALSA: snd-aloop: Fix hw_params restrictions and checking") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17ALSA: aloop: Release cable upon open error pathTakashi Iwai
commit 9685347aa0a5c2869058ca6ab79fd8e93084a67f upstream. The aloop runtime object and its assignment in the cable are left even when opening a substream fails. This doesn't mean any memory leak, but it still keeps the invalid pointer that may be referred by the another side of the cable spontaneously, which is a potential Oops cause. Clean up the cable assignment and the empty cable upon the error path properly. Fixes: 597603d615d2 ("ALSA: introduce the snd-aloop module for the PCM loopback") Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17ALSA: pcm: Allow aborting mutex lock at OSS read/write loopsTakashi Iwai
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>
2018-01-17ALSA: pcm: Abort properly at pending signal in OSS read/write loopsTakashi Iwai
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>
2018-01-17ALSA: pcm: Add missing error checks in OSS emulation plugin builderTakashi Iwai
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>
2018-01-17ALSA: pcm: Remove incorrect snd_BUG_ON() usagesTakashi Iwai
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>
2018-01-17iommu/arm-smmu-v3: Don't free page table ops twiceJean-Philippe Brucker
commit 57d72e159b60456c8bb281736c02ddd3164037aa upstream. Kasan reports a double free when finalise_stage_fn fails: the io_pgtable ops are freed by arm_smmu_domain_finalise and then again by arm_smmu_domain_free. Prevent this by leaving pgtbl_ops empty on failure. Fixes: 48ec83bcbcf5 ("iommu/arm-smmu: Add initial driver support for ARM SMMUv3 devices") Reviewed-by: Robin Murphy <robin.murphy@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Will Deacon <will.deacon@arm.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17x86/acpi: Handle SCI interrupts above legacy space gracefullyVikas C Sajjan
commit 252714155f04c5d16989cb3aadb85fd1b5772f99 upstream. Platforms which support only IOAPIC mode, pass the SCI information above the legacy space (0-15) via the FADT mechanism and not via MADT. In such cases mp_override_legacy_irq() which is invoked from acpi_sci_ioapic_setup() to register SCI interrupts fails for interrupts greater equal 16, since it is meant to handle only the legacy space and emits error "Invalid bus_irq %u for legacy override". Add a new function to handle SCI interrupts >= 16 and invoke it conditionally in acpi_sci_ioapic_setup(). The code duplication due to this new function will be cleaned up in a separate patch. Co-developed-by: Sunil V L <sunil.vl@hpe.com> Signed-off-by: Vikas C Sajjan <vikas.cha.sajjan@hpe.com> Signed-off-by: Sunil V L <sunil.vl@hpe.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Tested-by: Abdul Lateef Attar <abdul-lateef.attar@hpe.com> Acked-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com> Cc: linux-pm@vger.kernel.org Cc: kkamagui@gmail.com Cc: linux-acpi@vger.kernel.org Link: https://lkml.kernel.org/r/1510848825-21965-2-git-send-email-vikas.cha.sajjan@hpe.com Cc: Jean Delvare <jdelvare@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17x86/vsdo: Fix build on PARAVIRT_CLOCK=y, KVM_GUEST=nAndy Lutomirski
commit 8705d603edd49f1cff165cd3b7998f4c7f098d27 upstream. arch/x86/built-in.o: In function `arch_setup_additional_pages': (.text+0x587): undefined reference to `pvclock_pvti_cpu0_va' KVM_GUEST selects PARAVIRT_CLOCK, so we can make pvclock_pvti_cpu0_va depend on KVM_GUEST. Signed-off-by: Andy Lutomirski <luto@kernel.org> Tested-by: Borislav Petkov <bp@alien8.de> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Kees Cook <keescook@chromium.org> Link: http://lkml.kernel.org/r/444d38a9bcba832685740ea1401b569861d09a72.1451446564.git.luto@kernel.org Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Cc: James Dingwall <james@dingwall.me.uk> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17kvm: vmx: Scrub hardware GPRs at VM-exitJim Mattson
commit 0cb5b30698fdc8f6b4646012e3acb4ddce430788 upstream. Guest GPR values are live in the hardware GPRs at VM-exit. Do not leave any guest values in hardware GPRs after the guest GPR values are saved to the vcpu_vmx structure. This is a partial mitigation for CVE 2017-5715 and CVE 2017-5753. Specifically, it defeats the Project Zero PoC for CVE 2017-5715. Suggested-by: Eric Northup <digitaleric@google.com> Signed-off-by: Jim Mattson <jmattson@google.com> Reviewed-by: Eric Northup <digitaleric@google.com> Reviewed-by: Benjamin Serebrin <serebrin@google.com> Reviewed-by: Andrew Honig <ahonig@google.com> [Paolo: Add AMD bits, Signed-off-by: Tom Lendacky <thomas.lendacky@amd.com>] Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17net/mac80211/debugfs.c: prevent build failure with CONFIG_UBSAN=yAndrey Ryabinin
commit 68920c973254c5b71a684645c5f6f82d6732c5d6 upstream. With upcoming CONFIG_UBSAN the following BUILD_BUG_ON in net/mac80211/debugfs.c starts to trigger: BUILD_BUG_ON(hw_flag_names[NUM_IEEE80211_HW_FLAGS] != (void *)0x1); It seems, that compiler instrumentation causes some code deoptimizations. Because of that GCC is not being able to resolve condition in BUILD_BUG_ON() at compile time. We could make size of hw_flag_names array unspecified and replace the condition in BUILD_BUG_ON() with following: ARRAY_SIZE(hw_flag_names) != NUM_IEEE80211_HW_FLAGS That will have the same effect as before (adding new flag without updating array will trigger build failure) except it doesn't fail with CONFIG_UBSAN. As a bonus this patch slightly decreases size of hw_flag_names array. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Cc: Johannes Berg <johannes@sipsolutions.net> Cc: "David S. Miller" <davem@davemloft.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> [Daniel: backport to 4.4.] Signed-off-by: Daniel Wagner <daniel.wagner@siemens.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Disallow outsized PTRACE_SETREGSET NT_PRFPREG regset accessesMaciej W. Rozycki
commit c8c5a3a24d395b14447a9a89d61586a913840a3b upstream. Complement commit c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout") and also reject outsized PTRACE_SETREGSET requests to the NT_PRFPREG regset, like with the NT_PRSTATUS regset. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: c23b3d1a5311 ("MIPS: ptrace: Change GP regset to use correct core dump register layout") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17930/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Also verify sizeof `elf_fpreg_t' with PTRACE_SETREGSETMaciej W. Rozycki
commit 006501e039eec411842bb3150c41358867d320c2 upstream. Complement commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") and like with the PTRACE_GETREGSET ptrace(2) request also apply a BUILD_BUG_ON check for the size of the `elf_fpreg_t' type in the PTRACE_SETREGSET request handler. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17929/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Fix an FCSR access API regression with NT_PRFPREG and MSAMaciej W. Rozycki
commit be07a6a1188372b6d19a3307ec33211fc9c9439d upstream. Fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") public API regression, then activated by commit 1db1af84d6df ("MIPS: Basic MSA context switching support"), that caused the FCSR register not to be read or written for CONFIG_CPU_HAS_MSA kernel configurations (regardless of actual presence or absence of the MSA feature in a given processor) with ptrace(2) PTRACE_GETREGSET and PTRACE_SETREGSET requests nor recorded in core dumps. This is because with !CONFIG_CPU_HAS_MSA configurations the whole of `elf_fpregset_t' array is bulk-copied as it is, which includes the FCSR in one half of the last, 33rd slot, whereas with CONFIG_CPU_HAS_MSA configurations array elements are copied individually, and then only the leading 32 FGR slots while the remaining slot is ignored. Correct the code then such that only FGR slots are copied in the respective !MSA and MSA helpers an then the FCSR slot is handled separately in common code. Use `ptrace_setfcr31' to update the FCSR too, so that the read-only mask is respected. Retrieving a correct value of FCSR is important in debugging not only for the human to be able to get the right interpretation of the situation, but for correct operation of GDB as well. This is because the condition code bits in FSCR are used by GDB to determine the location to place a breakpoint at when single-stepping through an FPU branch instruction. If such a breakpoint is placed incorrectly (i.e. with the condition reversed), then it will be missed, likely causing the debuggee to run away from the control of GDB and consequently breaking the process of investigation. Fortunately GDB continues using the older PTRACE_GETFPREGS ptrace(2) request which is unaffected, so the regression only really hits with post-mortem debug sessions using a core dump file, in which case execution, and consequently single-stepping through branches is not possible. Of course core files created by buggy kernels out there will have the value of FCSR recorded clobbered, but such core files cannot be corrected and the person using them simply will have to be aware that the value of FCSR retrieved is not reliable. Which also means we can likely get away without defining a replacement API which would ensure a correct value of FSCR to be retrieved, or none at all. This is based on previous work by Alex Smith, extensively rewritten. Signed-off-by: Alex Smith <alex@alex-smith.me.uk> Signed-off-by: James Hogan <james.hogan@mips.com> Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: Paul Burton <Paul.Burton@mips.com> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17928/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Consistently handle buffer counter with PTRACE_SETREGSETMaciej W. Rozycki
commit 80b3ffce0196ea50068885d085ff981e4b8396f4 upstream. Update commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") bug and consistently consume all data supplied to `fpr_set_msa' with the ptrace(2) PTRACE_SETREGSET request, such that a zero data buffer counter is returned where insufficient data has been given to fill a whole number of FP general registers. In reality this is not going to happen, as the caller is supposed to only supply data covering a whole number of registers and it is verified in `ptrace_regset' and again asserted in `fpr_set', however structuring code such that the presence of trailing partial FP general register data causes `fpr_set_msa' to return with a non-zero data buffer counter makes it appear that this trailing data will be used if there are subsequent writes made to FP registers, which is going to be the case with the FCSR once the missing write to that register has been fixed. Fixes: d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") Signed-off-by: Maciej W. Rozycki <macro@mips.com> Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17927/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Guard against any partial write attempt with PTRACE_SETREGSETMaciej W. Rozycki
commit dc24d0edf33c3e15099688b6bbdf7bdc24bf6e91 upstream. Complement commit d614fd58a283 ("mips/ptrace: Preserve previous registers for short regset write") and ensure that no partial register write attempt is made with PTRACE_SETREGSET, as we do not preinitialize any temporaries used to hold incoming register data and consequently random data could be written. It is the responsibility of the caller, such as `ptrace_regset', to arrange for writes to span whole registers only, so here we only assert that it has indeed happened. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17926/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Factor out NT_PRFPREG regset access helpersMaciej W. Rozycki
commit a03fe72572c12e98f4173f8a535f32468e48b6ec upstream. In preparation to fix a commit 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") FCSR access regression factor out NT_PRFPREG regset access helpers for the non-MSA and the MSA variants respectively, to avoid having to deal with excessive indentation in the actual fix. No functional change, however use `target->thread.fpu.fpr[0]' rather than `target->thread.fpu.fpr[i]' for FGR holding type size determination as there's no `i' variable to refer to anymore, and for the factored out `i' variable declaration use `unsigned int' rather than `unsigned' as its type, following the common style. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 72b22bbad1e7 ("MIPS: Don't assume 64-bit FP registers for FP regset") Cc: James Hogan <james.hogan@mips.com> Cc: Paul Burton <Paul.Burton@mips.com> Cc: Alex Smith <alex@alex-smith.me.uk> Cc: Dave Martin <Dave.Martin@arm.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17925/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17MIPS: Validate PR_SET_FP_MODE prctl(2) requests against the ABI of the taskMaciej W. Rozycki
commit b67336eee3fcb8ecedc6c13e2bf88aacfa3151e2 upstream. Fix an API loophole introduced with commit 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS"), where the caller of prctl(2) is incorrectly allowed to make a change to CP0.Status.FR or CP0.Config5.FRE register bits even if CONFIG_MIPS_O32_FP64_SUPPORT has not been enabled, despite that an executable requesting the mode requested via ELF file annotation would not be allowed to run in the first place, or for n64 and n64 ABI tasks which do not have non-default modes defined at all. Add suitable checks to `mips_set_process_fp_mode' and bail out if an invalid mode change has been requested for the ABI in effect, even if the FPU hardware or emulation would otherwise allow it. Always succeed however without taking any further action if the mode requested is the same as one already in effect, regardless of whether any mode change, should it be requested, would actually be allowed for the task concerned. Signed-off-by: Maciej W. Rozycki <macro@mips.com> Fixes: 9791554b45a2 ("MIPS,prctl: add PR_[GS]ET_FP_MODE prctl options for MIPS") Reviewed-by: Paul Burton <paul.burton@mips.com> Cc: James Hogan <james.hogan@mips.com> Cc: linux-mips@linux-mips.org Cc: linux-kernel@vger.kernel.org Patchwork: https://patchwork.linux-mips.org/patch/17800/ Signed-off-by: Ralf Baechle <ralf@linux-mips.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17IB/srpt: Disable RDMA access by the initiatorBart Van Assche
commit bec40c26041de61162f7be9d2ce548c756ce0f65 upstream. With the SRP protocol all RDMA operations are initiated by the target. Since no RDMA operations are initiated by the initiator, do not grant the initiator permission to submit RDMA reads or writes to the target. Signed-off-by: Bart Van Assche <bart.vanassche@wdc.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17can: gs_usb: fix return value of the "set_bittiming" callbackWolfgang Grandegger
commit d5b42e6607661b198d8b26a0c30969605b1bf5c7 upstream. The "set_bittiming" callback treats a positive return value as error! For that reason "can_changelink()" will quit silently after setting the bittiming values without processing ctrlmode, restart-ms, etc. Signed-off-by: Wolfgang Grandegger <wg@grandegger.com> Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17KVM: Fix stack-out-of-bounds read in write_mmioWanpeng Li
commit e39d200fa5bf5b94a0948db0dae44c1b73b84a56 upstream. Reported by syzkaller: BUG: KASAN: stack-out-of-bounds in write_mmio+0x11e/0x270 [kvm] Read of size 8 at addr ffff8803259df7f8 by task syz-executor/32298 CPU: 6 PID: 32298 Comm: syz-executor Tainted: G OE 4.15.0-rc2+ #18 Hardware name: LENOVO ThinkCentre M8500t-N000/SHARKBAY, BIOS FBKTC1AUS 02/16/2016 Call Trace: dump_stack+0xab/0xe1 print_address_description+0x6b/0x290 kasan_report+0x28a/0x370 write_mmio+0x11e/0x270 [kvm] emulator_read_write_onepage+0x311/0x600 [kvm] emulator_read_write+0xef/0x240 [kvm] emulator_fix_hypercall+0x105/0x150 [kvm] em_hypercall+0x2b/0x80 [kvm] x86_emulate_insn+0x2b1/0x1640 [kvm] x86_emulate_instruction+0x39a/0xb90 [kvm] handle_exception+0x1b4/0x4d0 [kvm_intel] vcpu_enter_guest+0x15a0/0x2640 [kvm] kvm_arch_vcpu_ioctl_run+0x549/0x7d0 [kvm] kvm_vcpu_ioctl+0x479/0x880 [kvm] do_vfs_ioctl+0x142/0x9a0 SyS_ioctl+0x74/0x80 entry_SYSCALL_64_fastpath+0x23/0x9a The path of patched vmmcall will patch 3 bytes opcode 0F 01 C1(vmcall) to the guest memory, however, write_mmio tracepoint always prints 8 bytes through *(u64 *)val since kvm splits the mmio access into 8 bytes. This leaks 5 bytes from the kernel stack (CVE-2017-17741). This patch fixes it by just accessing the bytes which we operate on. Before patch: syz-executor-5567 [007] .... 51370.561696: kvm_mmio: mmio write len 3 gpa 0x10 val 0x1ffff10077c1010f After patch: syz-executor-13416 [002] .... 51302.299573: kvm_mmio: mmio write len 3 gpa 0x10 val 0xc1010f Reported-by: Dmitry Vyukov <dvyukov@google.com> Reviewed-by: Darren Kenny <darren.kenny@oracle.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Marc Zyngier <marc.zyngier@arm.com> Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Marc Zyngier <marc.zyngier@arm.com> Cc: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Cc: Mathieu Desnoyers <mathieu.desnoyers@efficios.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-17dm bufio: fix shrinker scans when (nr_to_scan < retain_target)Suren Baghdasaryan
commit fbc7c07ec23c040179384a1f16b62b6030eb6bdd upstream. When system is under memory pressure it is observed that dm bufio shrinker often reclaims only one buffer per scan. This change fixes the following two issues in dm bufio shrinker that cause this behavior: 1. ((nr_to_scan - freed) <= retain_target) condition is used to terminate slab scan process. This assumes that nr_to_scan is equal to the LRU size, which might not be correct because do_shrink_slab() in vmscan.c calculates nr_to_scan using multiple inputs. As a result when nr_to_scan is less than retain_target (64) the scan will terminate after the first iteration, effectively reclaiming one buffer per scan and making scans very inefficient. This hurts vmscan performance especially because mutex is acquired/released every time dm_bufio_shrink_scan() is called. New implementation uses ((LRU size - freed) <= retain_target) condition for scan termination. LRU size can be safely determined inside __scan() because this function is called after dm_bufio_lock(). 2. do_shrink_slab() uses value returned by dm_bufio_shrink_count() to determine number of freeable objects in the slab. However dm_bufio always retains retain_target buffers in its LRU and will terminate a scan when this mark is reached. Therefore returning the entire LRU size from dm_bufio_shrink_count() is misleading because that does not represent the number of freeable objects that slab will reclaim during a scan. Returning (LRU size - retain_target) better represents the number of freeable objects in the slab. This way do_shrink_slab() returns 0 when (LRU size < retain_target) and vmscan will not try to scan this shrinker avoiding scans that will not reclaim any memory. Test: tested using Android device running <AOSP>/system/extras/alloc-stress that generates memory pressure and causes intensive shrinker scans Signed-off-by: Suren Baghdasaryan <surenb@google.com> Signed-off-by: Mike Snitzer <snitzer@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-10Linux 4.4.111v4.4.111Greg Kroah-Hartman
2018-01-10Fix build error in vma.cGreg Kroah-Hartman
This fixes the following much-reported build issue: arch/x86/entry/vdso/vma.c: In function ‘map_vdso’: arch/x86/entry/vdso/vma.c:175:9: error: implicit declaration of function ‘pvclock_pvti_cpu0_va’ on some arches and configurations. Thanks to Guenter for being persistent enough to get it fixed :) Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-10Map the vsyscall page with _PAGE_USERBorislav Petkov
This needs to happen early in kaiser_pagetable_walk(), before the hierarchy is established so that _PAGE_USER permission can be really set. A proper fix would be to teach kaiser_pagetable_walk() to update those permissions but the vsyscall page is the only exception here so ... Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Hugh Dickins <hughd@google.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-10proc: much faster /proc/vmstatAlexey Dobriyan
commit 68ba0326b4e14988f9e0c24a6e12a85cf2acd1ca upstream. Every current KDE system has process named ksysguardd polling files below once in several seconds: $ strace -e trace=open -p $(pidof ksysguardd) Process 1812 attached open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8 open("/etc/mtab", O_RDONLY|O_CLOEXEC) = 8 open("/proc/net/dev", O_RDONLY) = 8 open("/proc/net/wireless", O_RDONLY) = -1 ENOENT (No such file or directory) open("/proc/stat", O_RDONLY) = 8 open("/proc/vmstat", O_RDONLY) = 8 Hell knows what it is doing but speed up reading /proc/vmstat by 33%! Benchmark is open+read+close 1.000.000 times. BEFORE $ perf stat -r 10 taskset -c 3 ./proc-vmstat Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs): 13146.768464 task-clock (msec) # 0.960 CPUs utilized ( +- 0.60% ) 15 context-switches # 0.001 K/sec ( +- 1.41% ) 1 cpu-migrations # 0.000 K/sec ( +- 11.11% ) 104 page-faults # 0.008 K/sec ( +- 0.57% ) 45,489,799,349 cycles # 3.460 GHz ( +- 0.03% ) 9,970,175,743 stalled-cycles-frontend # 21.92% frontend cycles idle ( +- 0.10% ) 2,800,298,015 stalled-cycles-backend # 6.16% backend cycles idle ( +- 0.32% ) 79,241,190,850 instructions # 1.74 insn per cycle # 0.13 stalled cycles per insn ( +- 0.00% ) 17,616,096,146 branches # 1339.956 M/sec ( +- 0.00% ) 176,106,232 branch-misses # 1.00% of all branches ( +- 0.18% ) 13.691078109 seconds time elapsed ( +- 0.03% ) ^^^^^^^^^^^^ AFTER $ perf stat -r 10 taskset -c 3 ./proc-vmstat Performance counter stats for 'taskset -c 3 ./proc-vmstat' (10 runs): 8688.353749 task-clock (msec) # 0.950 CPUs utilized ( +- 1.25% ) 10 context-switches # 0.001 K/sec ( +- 2.13% ) 1 cpu-migrations # 0.000 K/sec 104 page-faults # 0.012 K/sec ( +- 0.56% ) 30,384,010,730 cycles # 3.497 GHz ( +- 0.07% ) 12,296,259,407 stalled-cycles-frontend # 40.47% frontend cycles idle ( +- 0.13% ) 3,370,668,651 stalled-cycles-backend # 11.09% backend cycles idle ( +- 0.69% ) 28,969,052,879 instructions # 0.95 insn per cycle # 0.42 stalled cycles per insn ( +- 0.01% ) 6,308,245,891 branches # 726.058 M/sec ( +- 0.00% ) 214,685,502 branch-misses # 3.40% of all branches ( +- 0.26% ) 9.146081052 seconds time elapsed ( +- 0.07% ) ^^^^^^^^^^^ vsnprintf() is slow because: 1. format_decode() is busy looking for format specifier: 2 branches per character (not in this case, but in others) 2. approximately million branches while parsing format mini language and everywhere 3. just look at what string() does /proc/vmstat is good case because most of its content are strings Link: http://lkml.kernel.org/r/20160806125455.GA1187@p183.telecom.by Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Joe Perches <joe@perches.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by: Mel Gorman <mgorman@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-10module: Issue warnings when tainting kernelLibor Pechacek
commit 3205c36cf7d96024626f92d65f560035df1abcb2 upstream. While most of the locations where a kernel taint bit is set are accompanied with a warning message, there are two which set their bits silently. If the tainting module gets unloaded later on, it is almost impossible to tell what was the reason for setting the flag. Signed-off-by: Libor Pechacek <lpechacek@suse.com> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2018-01-10module: keep percpu symbols in module's symtabMiroslav Benes
commit e0224418516b4d8a6c2160574bac18447c354ef0 upstream. Currently, percpu symbols from .data..percpu ELF section of a module are not copied over and stored in final symtab array of struct module. Consequently such symbol cannot be returned via kallsyms API (for example kallsyms_lookup_name). This can be especially confusing when the percpu symbol is exported. Only its __ksymtab et al. are present in its symtab. The culprit is in layout_and_allocate() function where SHF_ALLOC flag is dropped for .data..percpu section. There is in fact no need to copy the section to final struct module, because kernel module loader allocates extra percpu section by itself. Unfortunately only symbols from SHF_ALLOC sections are copied due to a check in is_core_symbol(). The patch changes is_core_symbol() function to copy over also percpu symbols (their st_shndx points to .data..percpu ELF section). We do it only if CONFIG_KALLSYMS_ALL is set to be consistent with the rest of the function (ELF section is SHF_ALLOC but !SHF_EXECINSTR). Finally elf_type() returns type 'a' for a percpu symbol because its address is absolute. Signed-off-by: Miroslav Benes <mbenes@suse.cz> Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jiri Kosina <jkosina@suse.cz> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>