user/sven/linux.git/include, branch v4.11.8

netfilter: xtables: zero padding in data_to_user

2017-06-29T11:02:55Z

commit 324318f0248c31be8a08984146e7e4dd7cdd091d upstream. When looking up an iptables rule, the iptables binary compares the aligned match and target data (XT_ALIGN). In some cases this can exceed the actual data size to include padding bytes. Before commit f77bc5b23fb1 ("iptables: use match, target and data copy_to_user helpers") the malloc()ed bytes were overwritten by the kernel with kzalloced contents, zeroing the padding and making the comparison succeed. After this patch, the kernel copies and clears only data, leaving the padding bytes undefined. Extend the clear operation from data size to aligned data size to include the padding bytes, if any. Padding bytes can be observed in both match and target, and the bug triggered, by issuing a rule with match icmp and target ACCEPT: iptables -t mangle -A INPUT -i lo -p icmp --icmp-type 1 -j ACCEPT iptables -t mangle -D INPUT -i lo -p icmp --icmp-type 1 -j ACCEPT Fixes: f77bc5b23fb1 ("iptables: use match, target and data copy_to_user helpers") Reported-by: Paul Moore Reported-by: Richard Guy Briggs Signed-off-by: Willem de Bruijn Signed-off-by: Pablo Neira Ayuso Cc: Florian Westphal Signed-off-by: Greg Kroah-Hartman

ACPI / scan: Fix enumeration for special SPI and I2C devices

2017-06-29T11:02:54Z

commit e4330d8bf669139a983255d1801733b64c2ae841 upstream. Commit f406270bf73d ("ACPI / scan: Set the visited flag for all enumerated devices") caused that two group of special SPI or I2C devices do not enumerate. SPI and I2C devices are expected to be enumerated by the SPI and I2C subsystems but change caused that acpi_bus_attach() marks those devices with acpi_device_set_enumerated(). First group of devices are matched using Device Tree compatible property with special _HID "PRP0001". Those devices have matched scan handler, acpi_scan_attach_handler() retuns 1 and acpi_bus_attach() marks them with acpi_device_set_enumerated(). Second group of devices without valid _HID such as "LNXVIDEO" have device->pnp.type.platform_id set to zero and change again marks them with acpi_device_set_enumerated(). Fix this by flagging the SPI and I2C devices during struct acpi_device object initialization time and let the code in acpi_bus_attach() to go through the device_attach() and acpi_default_enumeration() path for all SPI and I2C devices. Fixes: f406270bf73d (ACPI / scan: Set the visited flag for all enumerated devices) Signed-off-by: Jarkko Nikula Acked-by: Mika Westerberg Signed-off-by: Rafael J. Wysocki Signed-off-by: Greg Kroah-Hartman

time: Fix CLOCK_MONOTONIC_RAW sub-nanosecond accounting

2017-06-29T11:02:52Z

commit 3d88d56c5873f6eebe23e05c3da701960146b801 upstream. Due to how the MONOTONIC_RAW accumulation logic was handled, there is the potential for a 1ns discontinuity when we do accumulations. This small discontinuity has for the most part gone un-noticed, but since ARM64 enabled CLOCK_MONOTONIC_RAW in their vDSO clock_gettime implementation, we've seen failures with the inconsistency-check test in kselftest. This patch addresses the issue by using the same sub-ns accumulation handling that CLOCK_MONOTONIC uses, which avoids the issue for in-kernel users. Since the ARM64 vDSO implementation has its own clock_gettime calculation logic, this patch reduces the frequency of errors, but failures are still seen. The ARM64 vDSO will need to be updated to include the sub-nanosecond xtime_nsec values in its calculation for this issue to be completely fixed. Signed-off-by: John Stultz Tested-by: Daniel Mentz Cc: Prarit Bhargava Cc: Kevin Brodsky Cc: Richard Cochran Cc: Stephen Boyd Cc: Will Deacon Cc: Miroslav Lichvar Link: http://lkml.kernel.org/r/1496965462-20003-3-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

time: Fix clock->read(clock) race around clocksource changes

2017-06-29T11:02:51Z

commit ceea5e3771ed2378668455fa21861bead7504df5 upstream. In tests, which excercise switching of clocksources, a NULL pointer dereference can be observed on AMR64 platforms in the clocksource read() function: u64 clocksource_mmio_readl_down(struct clocksource *c) { return ~(u64)readl_relaxed(to_mmio_clksrc(c)->reg) & c->mask; } This is called from the core timekeeping code via: cycle_now = tkr->read(tkr->clock); tkr->read is the cached tkr->clock->read() function pointer. When the clocksource is changed then tkr->clock and tkr->read are updated sequentially. The code above results in a sequential load operation of tkr->read and tkr->clock as well. If the store to tkr->clock hits between the loads of tkr->read and tkr->clock, then the old read() function is called with the new clock pointer. As a consequence the read() function dereferences a different data structure and the resulting 'reg' pointer can point anywhere including NULL. This problem was introduced when the timekeeping code was switched over to use struct tk_read_base. Before that, it was theoretically possible as well when the compiler decided to reload clock in the code sequence: now = tk->clock->read(tk->clock); Add a helper function which avoids the issue by reading tk_read_base->clock once into a local variable clk and then issue the read function via clk->read(clk). This guarantees that the read() function always gets the proper clocksource pointer handed in. Since there is now no use for the tkr.read pointer, this patch also removes it, and to address stopping the fast timekeeper during suspend/resume, it introduces a dummy clocksource to use rather then just a dummy read function. Signed-off-by: John Stultz Acked-by: Ingo Molnar Cc: Prarit Bhargava Cc: Richard Cochran Cc: Stephen Boyd Cc: Miroslav Lichvar Cc: Daniel Mentz Link: http://lkml.kernel.org/r/1496965462-20003-2-git-send-email-john.stultz@linaro.org Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

mm: larger stack guard gap, between vmas

2017-06-24T05:06:22Z

commit 1be7107fbe18eed3e319a6c3e83c78254b693acb upstream. Stack guard page is a useful feature to reduce a risk of stack smashing into a different mapping. We have been using a single page gap which is sufficient to prevent having stack adjacent to a different mapping. But this seems to be insufficient in the light of the stack usage in userspace. E.g. glibc uses as large as 64kB alloca() in many commonly used functions. Others use constructs liks gid_t buffer[NGROUPS_MAX] which is 256kB or stack strings with MAX_ARG_STRLEN. This will become especially dangerous for suid binaries and the default no limit for the stack size limit because those applications can be tricked to consume a large portion of the stack and a single glibc call could jump over the guard page. These attacks are not theoretical, unfortunatelly. Make those attacks less probable by increasing the stack guard gap to 1MB (on systems with 4k pages; but make it depend on the page size because systems with larger base pages might cap stack allocations in the PAGE_SIZE units) which should cover larger alloca() and VLA stack allocations. It is obviously not a full fix because the problem is somehow inherent, but it should reduce attack space a lot. One could argue that the gap size should be configurable from userspace, but that can be done later when somebody finds that the new 1MB is wrong for some special case applications. For now, add a kernel command line option (stack_guard_gap) to specify the stack gap size (in page units). Implementation wise, first delete all the old code for stack guard page: because although we could get away with accounting one extra page in a stack vma, accounting a larger gap can break userspace - case in point, a program run with "ulimit -S -v 20000" failed when the 1MB gap was counted for RLIMIT_AS; similar problems could come with RLIMIT_MLOCK and strict non-overcommit mode. Instead of keeping gap inside the stack vma, maintain the stack guard gap as a gap between vmas: using vm_start_gap() in place of vm_start (or vm_end_gap() in place of vm_end if VM_GROWSUP) in just those few places which need to respect the gap - mainly arch_get_unmapped_area(), and and the vma tree's subtree_gap support for that. Original-patch-by: Oleg Nesterov Original-patch-by: Michal Hocko Signed-off-by: Hugh Dickins Acked-by: Michal Hocko Tested-by: Helge Deller # parisc Signed-off-by: Linus Torvalds [wt: backport to 4.11: adjust context] Signed-off-by: Willy Tarreau Signed-off-by: Greg Kroah-Hartman

USB: hub: fix SS max number of ports

2017-06-24T05:06:19Z

commit 93491ced3c87c94b12220dbac0527e1356702179 upstream. Add define for the maximum number of ports on a SuperSpeed hub as per USB 3.1 spec Table 10-5, and use it when verifying the retrieved hub descriptor. This specifically avoids benign attempts to update the DeviceRemovable mask for non-existing ports (should we get that far). Fixes: dbe79bbe9dcb ("USB 3.0 Hub Changes") Acked-by: Alan Stern Signed-off-by: Johan Hovold Signed-off-by: Greg Kroah-Hartman

PCI/PM: Add needs_resume flag to avoid suspend complete optimization

2017-06-17T04:44:17Z

commit 4d071c3238987325b9e50e33051a40d1cce311cc upstream. Some drivers - like i915 - may not support the system suspend direct complete optimization due to differences in their runtime and system suspend sequence. Add a flag that when set resumes the device before calling the driver's system suspend handlers which effectively disables the optimization. Needed by a future patch fixing suspend/resume on i915. Suggested by Rafael. Signed-off-by: Imre Deak Signed-off-by: Bjorn Helgaas Acked-by: Rafael J. Wysocki Cc: stable@vger.kernel.org (rebased on v4.8, added kernel version to commit message stable tag) Signed-off-by: Imre Deak Signed-off-by: Greg Kroah-Hartman

drm/i915/skl: Add missing SKL ID

2017-06-14T13:07:50Z

commit ca7a45ba6fb9e7ceca56d10b91db29c2f3451a2e upstream. Used by production device: Intel(R) Iris(TM) Graphics P555 Cc: Mika Kuoppala Cc: Rodrigo Vivi Signed-off-by: Michał Winiarski Reviewed-by: Rodrigo Vivi Reviewed-by: Mika Kuoppala Signed-off-by: Mika Kuoppala Link: http://patchwork.freedesktop.org/patch/msgid/20170227112256.20060-1-michal.winiarski@intel.com Signed-off-by: Greg Kroah-Hartman

srcu: Allow use of Classic SRCU from both process and interrupt context

2017-06-14T13:07:48Z

commit 1123a6041654e8f889014659593bad4168e542c2 upstream. Linu Cherian reported a WARN in cleanup_srcu_struct() when shutting down a guest running iperf on a VFIO assigned device. This happens because irqfd_wakeup() calls srcu_read_lock(&kvm->irq_srcu) in interrupt context, while a worker thread does the same inside kvm_set_irq(). If the interrupt happens while the worker thread is executing __srcu_read_lock(), updates to the Classic SRCU ->lock_count[] field or the Tree SRCU ->srcu_lock_count[] field can be lost. The docs say you are not supposed to call srcu_read_lock() and srcu_read_unlock() from irq context, but KVM interrupt injection happens from (host) interrupt context and it would be nice if SRCU supported the use case. KVM is using SRCU here not really for the "sleepable" part, but rather due to its IPI-free fast detection of grace periods. It is therefore not desirable to switch back to RCU, which would effectively revert commit 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING", 2014-01-16). However, the docs are overly conservative. You can have an SRCU instance only has users in irq context, and you can mix process and irq context as long as process context users disable interrupts. In addition, __srcu_read_unlock() actually uses this_cpu_dec() on both Tree SRCU and Classic SRCU. For those two implementations, only srcu_read_lock() is unsafe. When Classic SRCU's __srcu_read_unlock() was changed to use this_cpu_dec(), in commit 5a41344a3d83 ("srcu: Simplify __srcu_read_unlock() via this_cpu_dec()", 2012-11-29), __srcu_read_lock() did two increments. Therefore it kept __this_cpu_inc(), with preempt_disable/enable in the caller. Tree SRCU however only does one increment, so on most architectures it is more efficient for __srcu_read_lock() to use this_cpu_inc(), and any performance differences appear to be down in the noise. Fixes: 719d93cd5f5c ("kvm/irqchip: Speed up KVM_SET_GSI_ROUTING") Reported-by: Linu Cherian Suggested-by: Linu Cherian Cc: kvm@vger.kernel.org Signed-off-by: Paolo Bonzini Cc: Linus Torvalds Signed-off-by: Paul E. McKenney Signed-off-by: Greg Kroah-Hartman

cpuset: consider dying css as offline

2017-06-14T13:07:45Z

commit 41c25707d21716826e3c1f60967f5550610ec1c9 upstream. In most cases, a cgroup controller don't care about the liftimes of cgroups. For the controller, a css becomes online when ->css_online() is called on it and offline when ->css_offline() is called. However, cpuset is special in that the user interface it exposes cares whether certain cgroups exist or not. Combined with the RCU delay between cgroup removal and css offlining, this can lead to user visible behavior oddities where operations which should succeed after cgroup removals fail for some time period. The effects of cgroup removals are delayed when seen from userland. This patch adds css_is_dying() which tests whether offline is pending and updates is_cpuset_online() so that the function returns false also while offline is pending. This gets rid of the userland visible delays. Signed-off-by: Tejun Heo Reported-by: Daniel Jordan Link: http://lkml.kernel.org/r/327ca1f5-7957-fbb9-9e5f-9ba149d40ba2@oracle.com Signed-off-by: Tejun Heo Signed-off-by: Greg Kroah-Hartman