Comment # 18 on bug 1189469 from Jiri Slaby

[87501.509795] BUG: spinlock bad magic on CPU#8, swapper/8/0
[87501.509804] general protection fault, probably for non-canonical address
0x6b6b6b6b6b6b74c3: 0000 [#1] SMP NOPTI

#define POISON_FREE        0x6b    /* for use-after-free poisoning */

It's clearly a use after free. Using KASAN would catch this. But: does this
still happen?