In the Linux kernel, the following vulnerability has been resolved:

workqueue: Don't call cpumask_test_cpu() with -1 CPU in wq_update_node_max_active()

For wq_update_node_max_active(), @off_cpu of -1 indicates that no CPU is
going down. The function was incorrectly calling cpumask_test_cpu() with -1
CPU leading to oopses like the following on some archs:

  Unable to handle kernel paging request at virtual address ffff0002100296e0
  ..
  pc : wq_update_node_max_active+0x50/0x1fc
  lr : wq_update_node_max_active+0x1f0/0x1fc
  ...
  Call trace:
    wq_update_node_max_active+0x50/0x1fc
    apply_wqattrs_commit+0xf0/0x114
    apply_workqueue_attrs_locked+0x58/0xa0
    alloc_workqueue+0x5ac/0x774
    workqueue_init_early+0x460/0x540
    start_kernel+0x258/0x684
    __primary_switched+0xb8/0xc0
  Code: 9100a273 35000d01 53067f00 d0016dc1 (f8607a60)
  ---[ end trace 0000000000000000 ]---
  Kernel panic - not syncing: Attempted to kill the idle task!
  ---[ end Kernel panic - not syncing: Attempted to kill the idle task! ]---

Fix it.

kernel.org https://git.kernel.org/stable/c/15930da42f8981dc42c19038042947b475b19f47 [No types assigned]

kernel.org https://git.kernel.org/stable/c/38c19c44cc05ec1e84d2e31a9a289b83b6c7ec85 [No types assigned]

kernel.org https://git.kernel.org/stable/c/7df62b8cca38aa452b508b477b16544cba615084 [No types assigned]

kernel.org https://git.kernel.org/stable/c/9fc557d489f8163c1aabcb89114b8eba960f4097 [No types assigned]

kernel.org https://git.kernel.org/stable/c/a75ac2693d734d20724f0e10e039ca85f1fcfc4e [No types assigned]

kernel.org https://git.kernel.org/stable/c/adc646d2126988a64234502f579e4bc2b080d7cf [No types assigned]