Overview
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().