Find real vulnerabilities before they ship
In the Linux kernel, the following vulnerability has been resolved: interconnect: Fix locking for runpm vs reclaim For cases where icc_bw_set() can be called in callbaths that could deadlock against shrinker/reclaim, such as runpm resume, we need to decouple the icc locking. Introduce a new icc_bw_lock for cases where we need to serialize bw aggregation and update to decouple that from paths that require memory allocation such as node/link creation/ destruction. Fixes this lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 6.2.0-rc8-debug+ #554 Not tainted ------------------------------------------------------ ring0/132 is trying to acquire lock: ffffff80871916d0 (&gmu->lock){+.+.}-{3:3}, at: a6xx_pm_resume+0xf0/0x234 but task is already holding lock: ffffffdb5aee57e8 (dma_fence_map){++++}-{0:0}, at: msm_job_run+0x68/0x150 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (dma_fence_map){++++}-{0:0}: __dma_fence_might_wait+0x74/0xc0 dma_resv_lockdep+0x1f4/0x2f4 do_one_initcall+0x104/0x2bc kernel_init_freeable+0x344/0x34c kernel_init+0x30/0x134 ret_from_fork+0x10/0x20 -> #3 (mmu_notifier_invalidate_range_start){+.+.}-{0:0}: fs_reclaim_acquire+0x80/0xa8 slab_pre_alloc_hook.constprop.0+0x40/0x25c __kmem_cache_alloc_node+0x60/0x1cc __kmalloc+0xd8/0x100 topology_parse_cpu_capacity+0x8c/0x178 get_cpu_for_node+0x88/0xc4 parse_cluster+0x1b0/0x28c parse_cluster+0x8c/0x28c init_cpu_topology+0x168/0x188 smp_prepare_cpus+0x24/0xf8 kernel_init_freeable+0x18c/0x34c kernel_init+0x30/0x134 ret_from_fork+0x10/0x20 -> #2 (fs_reclaim){+.+.}-{0:0}: __fs_reclaim_acquire+0x3c/0x48 fs_reclaim_acquire+0x54/0xa8 slab_pre_alloc_hook.constprop.0+0x40/0x25c __kmem_cache_alloc_node+0x60/0x1cc __kmalloc+0xd8/0x100 kzalloc.constprop.0+0x14/0x20 icc_node_create_nolock+0x4c/0xc4 icc_node_create+0x38/0x58 qcom_icc_rpmh_probe+0x1b8/0x248 platform_probe+0x70/0xc4 really_probe+0x158/0x290 __driver_probe_device+0xc8/0xe0 driver_probe_device+0x44/0x100 __driver_attach+0xf8/0x108 bus_for_each_dev+0x78/0xc4 driver_attach+0x2c/0x38 bus_add_driver+0xd0/0x1d8 driver_register+0xbc/0xf8 __platform_driver_register+0x30/0x3c qnoc_driver_init+0x24/0x30 do_one_initcall+0x104/0x2bc kernel_init_freeable+0x344/0x34c kernel_init+0x30/0x134 ret_from_fork+0x10/0x20 -> #1 (icc_lock){+.+.}-{3:3}: __mutex_lock+0xcc/0x3c8 mutex_lock_nested+0x30/0x44 icc_set_bw+0x88/0x2b4 _set_opp_bw+0x8c/0xd8 _set_opp+0x19c/0x300 dev_pm_opp_set_opp+0x84/0x94 a6xx_gmu_resume+0x18c/0x804 a6xx_pm_resume+0xf8/0x234 adreno_runtime_resume+0x2c/0x38 pm_generic_runtime_resume+0x30/0x44 __rpm_callback+0x15c/0x174 rpm_callback+0x78/0x7c rpm_resume+0x318/0x524 __pm_runtime_resume+0x78/0xbc adreno_load_gpu+0xc4/0x17c msm_open+0x50/0x120 drm_file_alloc+0x17c/0x228 drm_open_helper+0x74/0x118 drm_open+0xa0/0x144 drm_stub_open+0xd4/0xe4 chrdev_open+0x1b8/0x1e4 do_dentry_open+0x2f8/0x38c vfs_open+0x34/0x40 path_openat+0x64c/0x7b4 do_filp_open+0x54/0xc4 do_sys_openat2+0x9c/0x100 do_sys_open+0x50/0x7c __arm64_sys_openat+0x28/0x34 invoke_syscall+0x8c/0x128 el0_svc_common.constprop.0+0xa0/0x11c do_el0_ ---truncated---
