Linux Kernel

In the Linux kernel, the following vulnerability has been resolved: perf/x86/intel: Limit the period on Haswell Running the ltp test cve-2015-3290 concurrently reports the following warnings. perfevents: irq loop stuck! WARNING: CPU: 31 PID: 32438 at arch/x86/events/intel/core.c:3174 intel_pmu_handle_irq+0x285/0x370 Call Trace: <NMI> ? __warn+0xa4/0x220 ? intel_pmu_handle_irq+0x285/0x370 ? __report_bug+0x123/0x130 ? intel_pmu_handle_irq+0x285/0x370 ? __report_bug+0x123/0x130 ? intel_pmu_handle_irq+0x285/0x370 ? report_bug+0x3e/0xa0 ? handle_bug+0x3c/0x70 ? exc_invalid_op+0x18/0x50 ? asm_exc_invalid_op+0x1a/0x20 ? irq_work_claim+0x1e/0x40 ? intel_pmu_handle_irq+0x285/0x370 perf_event_nmi_handler+0x3d/0x60 nmi_handle+0x104/0x330 Thanks to Thomas Gleixner's analysis, the issue is caused by the low initial period (1) of the frequency estimation algorithm, which triggers the defects of the HW, specifically erratum HSW11 and HSW143. (For the details, please refer https://lore.kernel.org/lkml/87plq9l5d2.ffs@tglx/) The HSW11 requires a period larger than 100 for the INST_RETIRED.ALL event, but the initial period in the freq mode is 1. The erratum is the same as the BDM11, which has been supported in the kernel. A minimum period of 128 is enforced as well on HSW. HSW143 is regarding that the fixed counter 1 may overcount 32 with the Hyper-Threading is enabled. However, based on the test, the hardware has more issues than it tells. Besides the fixed counter 1, the message 'interrupt took too long' can be observed on any counter which was armed with a period < 32 and two events expired in the same NMI. A minimum period of 32 is enforced for the rest of the events. The recommended workaround code of the HSW143 is not implemented. Because it only addresses the issue for the fixed counter. It brings extra overhead through extra MSR writing. No related overcounting issue has been reported so far.Show less

In the Linux kernel, the following vulnerability has been resolved: mm: vmalloc: ensure vmap_block is initialised before adding to queue Commit 8c61291fd850 ("mm: fix incorrect vbq reference in purge_fragmented_block") extended the 'vmap_block' structure to contain a 'cpu' field which is set at allocation time to the id of the initialising CPU. When a new 'vmap_block' is being instantiated by new_vmap_block(), the partially initialised structure is added to the local 'vmap_block_queue' xarray before the 'cpu' field has been initialised. If another CPU is concurrently walking the xarray (e.g. via vm_unmap_aliases()), then it may perform an out-of-bounds access to the remote queue thanks to an uninitialised index. This has been observed as UBSAN errors in Android: | Internal error: UBSAN: array index out of bounds: 00000000f2005512 [#1] PREEMPT SMP | | Call trace: | purge_fragmented_block+0x204/0x21c | _vm_unmap_aliases+0x170/0x378 | vm_unmap_aliases+0x1c/0x28 | change_memory_common+0x1dc/0x26c | set_memory_ro+0x18/0x24 | module_enable_ro+0x98/0x238 | do_init_module+0x1b0/0x310 Move the initialisation of 'vb->cpu' in new_vmap_block() ahead of the addition to the xarray.Show less

In the Linux kernel, the following vulnerability has been resolved: spi: rockchip: Resolve unbalanced runtime PM / system PM handling Commit e882575efc77 ("spi: rockchip: Suspend and resume the bus during NOIRQ_SYSTEM_SLEEP_PM ops") stopped respecting runtime PM status and simply disabled clocks unconditionally when suspending the system. This causes problems when the device is already runtime suspended when we go to sleep -- in which case we double-disable clocks and produce a WARNing. Switch back to pm_runtime_force_{suspend,resume}(), because that still seems like the right thing to do, and the aforementioned commit makes no explanation why it stopped using it. Also, refactor some of the resume() error handling, because it's not actually a good idea to re-disable clocks on failure.Show less

In the Linux kernel, the following vulnerability has been resolved: tracing/timerlat: Only clear timer if a kthread exists The timerlat tracer can use user space threads to check for osnoise and timer latency. If the program using this is killed via a SIGTERM, the threads are shutdown one at a time and another tracing instance can start up resetting the threads before they are fully closed. That causes the hrtimer assigned to the kthread to be shutdown and freed twice when the dying thread finally closes the file descriptors, causing a use-after-free bug. Only cancel the hrtimer if the associated thread is still around. Also add the interface_lock around the resetting of the tlat_var->kthread. Note, this is just a quick fix that can be backported to stable. A real fix is to have a better synchronization between the shutdown of old threads and the starting of new ones.Show less

In the Linux kernel, the following vulnerability has been resolved: um: line: always fill *error_out in setup_one_line() The pointer isn't initialized by callers, but I have encountered cases where it's still printed; initialize it in all possible cases in setup_one_line().Show less

In the Linux kernel, the following vulnerability has been resolved: scsi: ufs: core: Remove SCSI host only if added If host tries to remove ufshcd driver from a UFS device it would cause a kernel panic if ufshcd_async_scan fails during ufshcd_probe_hba before adding a SCSI host with scsi_add_host and MCQ is enabled since SCSI host has been defered after MCQ configuration introduced by commit 0cab4023ec7b ("scsi: ufs: core: Defer adding host to SCSI if MCQ is supported"). To guarantee that SCSI host is removed only if it has been added, set the scsi_host_added flag to true after adding a SCSI host and check whether it is set or not before removing it.Show less

In the Linux kernel, the following vulnerability has been resolved: scsi: lpfc: Handle mailbox timeouts in lpfc_get_sfp_info The MBX_TIMEOUT return code is not handled in lpfc_get_sfp_info and the routine unconditionally frees submitted mailbox commands regardless of return status. The issue is that for MBX_TIMEOUT cases, when firmware returns SFP information at a later time, that same mailbox memory region references previously freed memory in its cmpl routine. Fix by adding checks for the MBX_TIMEOUT return code. During mailbox resource cleanup, check the mbox flag to make sure that the wait did not timeout. If the MBOX_WAKE flag is not set, then do not free the resources because it will be freed when firmware completes the mailbox at a later time in its cmpl routine. Also, increase the timeout from 30 to 60 seconds to accommodate boot scripts requiring longer timeouts.Show less

In the Linux kernel, the following vulnerability has been resolved: btrfs: don't BUG_ON on ENOMEM from btrfs_lookup_extent_info() in walk_down_proc() We handle errors here properly, ENOMEM isn't fatal, return the error.Show less

In the Linux kernel, the following vulnerability has been resolved: btrfs: clean up our handling of refs == 0 in snapshot delete In reada we BUG_ON(refs == 0), which could be unkind since we aren't holding a lock on the extent leaf and thus could get a transient incorrect answer. In walk_down_proc we also BUG_ON(refs == 0), which could happen if we have extent tree corruption. Change that to return -EUCLEAN. In do_walk_down() we catch this case and handle it correctly, however we return -EIO, which -EUCLEAN is a more appropriate error code. Finally in walk_up_proc we have the same BUG_ON(refs == 0), so convert that to proper error handling. Also adjust the error message so we can actually do something with the information.Show less

In the Linux kernel, the following vulnerability has been resolved: userfaultfd: don't BUG_ON() if khugepaged yanks our page table Since khugepaged was changed to allow retracting page tables in file mappings without holding the mmap lock, these BUG_ON()s are wrong - get rid of them. We could also remove the preceding "if (unlikely(...))" block, but then we could reach pte_offset_map_lock() with transhuge pages not just for file mappings but also for anonymous mappings - which would probably be fine but I think is not necessarily expected.Show less

In the Linux kernel, the following vulnerability has been resolved: drm/panthor: Restrict high priorities on group_create We were allowing any users to create a high priority group without any permission checks. As a result, this was allowing possible denial of service. We now only allow the DRM master or users with the CAP_SYS_NICE capability to set higher priorities than PANTHOR_GROUP_PRIORITY_MEDIUM. As the sole user of that uAPI lives in Mesa and hardcode a value of MEDIUM [1], this should be safe to do. Additionally, as those checks are performed at the ioctl level, panthor_group_create now only check for priority level validity. [1]https://gitlab.freedesktop.org/mesa/mesa/-/blob/f390835074bdf162a63deb0311d1a6de527f9f89/src/gallium/drivers/panfrost/pan_csf.c#L1038Show less

In the Linux kernel, the following vulnerability has been resolved: usb: gadget: aspeed_udc: validate endpoint index for ast udc We should verify the bound of the array to assure that host may not manipulate the index to point past endpoint array. Found by static analysis.Show less

In the Linux kernel, the following vulnerability has been resolved: ethtool: fail closed if we can't get max channel used in indirection tables Commit 0d1b7d6c9274 ("bnxt: fix crashes when reducing ring count with active RSS contexts") proves that allowing indirection table to contain channels with out of bounds IDs may lead to crashes. Currently the max channel check in the core gets skipped if driver can't fetch the indirection table or when we can't allocate memory. Both of those conditions should be extremely rare but if they do happen we should try to be safe and fail the channel change.Show less

In the Linux kernel, the following vulnerability has been resolved: net: hns3: void array out of bound when loop tnl_num When query reg inf of SSU, it loops tnl_num times. However, tnl_num comes from hardware and the length of array is a fixed value. To void array out of bound, make sure the loop time is not greater than the length of arrayShow less

In the Linux kernel, the following vulnerability has been resolved: MIPS: cevt-r4k: Don't call get_c0_compare_int if timer irq is installed This avoids warning: [ 0.118053] BUG: sleeping function called from invalid context at kernel/locking/mutex.c:283 Caused by get_c0_compare_int on secondary CPU. We also skipped saving IRQ number to struct clock_event_device *cd as it's never used by clockevent core, as per comments it's only meant for "non CPU local devices".Show less

In the Linux kernel, the following vulnerability has been resolved: net: microchip: vcap: Fix use-after-free error in kunit test This is a clear use-after-free error. We remove it, and rely on checking the return code of vcap_del_rule.Show less

In the Linux kernel, the following vulnerability has been resolved: KVM: x86: Acquire kvm->srcu when handling KVM_SET_VCPU_EVENTS Grab kvm->srcu when processing KVM_SET_VCPU_EVENTS, as KVM will forcibly leave nested VMX/SVM if SMM mode is being toggled, and leaving nested VMX reads guest memory. Note, kvm_vcpu_ioctl_x86_set_vcpu_events() can also be called from KVM_RUN via sync_regs(), which already holds SRCU. I.e. trying to precisely use kvm_vcpu_srcu_read_lock() around the problematic SMM code would cause problems. Acquiring SRCU isn't all that expensive, so for simplicity, grab it unconditionally for KVM_SET_VCPU_EVENTS. ============================= WARNING: suspicious RCU usage 6.10.0-rc7-332d2c1d713e-next-vm #552 Not tainted ----------------------------- include/linux/kvm_host.h:1027 suspicious rcu_dereference_check() usage! other info that might help us debug this: rcu_scheduler_active = 2, debug_locks = 1 1 lock held by repro/1071: #0: ffff88811e424430 (&vcpu->mutex){+.+.}-{3:3}, at: kvm_vcpu_ioctl+0x7d/0x970 [kvm] stack backtrace: CPU: 15 PID: 1071 Comm: repro Not tainted 6.10.0-rc7-332d2c1d713e-next-vm #552 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Call Trace: <TASK> dump_stack_lvl+0x7f/0x90 lockdep_rcu_suspicious+0x13f/0x1a0 kvm_vcpu_gfn_to_memslot+0x168/0x190 [kvm] kvm_vcpu_read_guest+0x3e/0x90 [kvm] nested_vmx_load_msr+0x6b/0x1d0 [kvm_intel] load_vmcs12_host_state+0x432/0xb40 [kvm_intel] vmx_leave_nested+0x30/0x40 [kvm_intel] kvm_vcpu_ioctl_x86_set_vcpu_events+0x15d/0x2b0 [kvm] kvm_arch_vcpu_ioctl+0x1107/0x1750 [kvm] ? mark_held_locks+0x49/0x70 ? kvm_vcpu_ioctl+0x7d/0x970 [kvm] ? kvm_vcpu_ioctl+0x497/0x970 [kvm] kvm_vcpu_ioctl+0x497/0x970 [kvm] ? lock_acquire+0xba/0x2d0 ? find_held_lock+0x2b/0x80 ? do_user_addr_fault+0x40c/0x6f0 ? lock_release+0xb7/0x270 __x64_sys_ioctl+0x82/0xb0 do_syscall_64+0x6c/0x170 entry_SYSCALL_64_after_hwframe+0x4b/0x53 RIP: 0033:0x7ff11eb1b539 </TASK>Show less

In the Linux kernel, the following vulnerability has been resolved: rtmutex: Drop rt_mutex::wait_lock before scheduling rt_mutex_handle_deadlock() is called with rt_mutex::wait_lock held. In the good case it returns with the lock held and in the deadlock case it emits a warning and goes into an endless scheduling loop with the lock held, which triggers the 'scheduling in atomic' warning. Unlock rt_mutex::wait_lock in the dead lock case before issuing the warning and dropping into the schedule for ever loop. [ tglx: Moved unlock before the WARN(), removed the pointless comment, massaged changelog, added Fixes tag ]Show less

In the Linux kernel, the following vulnerability has been resolved: sched: sch_cake: fix bulk flow accounting logic for host fairness In sch_cake, we keep track of the count of active bulk flows per host, when running in dst/src host fairness mode, which is used as the round-robin weight when iterating through flows. The count of active bulk flows is updated whenever a flow changes state. This has a peculiar interaction with the hash collision handling: when a hash collision occurs (after the set-associative hashing), the state of the hash bucket is simply updated to match the new packet that collided, and if host fairness is enabled, that also means assigning new per-host state to the flow. For this reason, the bulk flow counters of the host(s) assigned to the flow are decremented, before new state is assigned (and the counters, which may not belong to the same host anymore, are incremented again). Back when this code was introduced, the host fairness mode was always enabled, so the decrement was unconditional. When the configuration flags were introduced the *increment* was made conditional, but the *decrement* was not. Which of course can lead to a spurious decrement (and associated wrap-around to U16_MAX). AFAICT, when host fairness is disabled, the decrement and wrap-around happens as soon as a hash collision occurs (which is not that common in itself, due to the set-associative hashing). However, in most cases this is harmless, as the value is only used when host fairness mode is enabled. So in order to trigger an array overflow, sch_cake has to first be configured with host fairness disabled, and while running in this mode, a hash collision has to occur to cause the overflow. Then, the qdisc has to be reconfigured to enable host fairness, which leads to the array out-of-bounds because the wrapped-around value is retained and used as an array index. It seems that syzbot managed to trigger this, which is quite impressive in its own right. This patch fixes the issue by introducing the same conditional check on decrement as is used on increment. The original bug predates the upstreaming of cake, but the commit listed in the Fixes tag touched that code, meaning that this patch won't apply before that.Show less