kasan: remove kasan_find_vm_area() to prevent possible deadlock

Vulnerability Description

In the Linux kernel, the following vulnerability has been resolved: kasan: remove kasan_find_vm_area() to prevent possible deadlock find_vm_area() couldn't be called in atomic_context. If find_vm_area() is called to reports vm area information, kasan can trigger deadlock like: CPU0 CPU1 vmalloc(); alloc_vmap_area(); spin_lock(&vn->busy.lock) spin_lock_bh(&some_lock); <interrupt occurs> <in softirq> spin_lock(&some_lock); <access invalid address> kasan_report(); print_report(); print_address_description(); kasan_find_vm_area(); find_vm_area(); spin_lock(&vn->busy.lock) // deadlock! To prevent possible deadlock while kasan reports, remove kasan_find_vm_area().

References

• https://git.kernel.org/stable/c/595f78d99b9051600233c0a5c4c47e1097e6ed01
• https://git.kernel.org/stable/c/8377d7744bdce5c4b3f1b58924eebd3fdc078dfc
• https://git.kernel.org/stable/c/2d89dab1ea6086e6cbe6fe92531b496fb6808cb9
• https://git.kernel.org/stable/c/0c3566d831def922cd56322c772a7b20d8b0e0c0
• https://git.kernel.org/stable/c/6ee9b3d84775944fb8c8a447961cd01274ac671c