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This is also > required to write safe C code, but as can be seen through the kernel > it's more often that not completely ignored, especially in drivers (just > look at how many drivers that expose a chardev to userspace are happy > using devm_kzalloc() to allocate their private data structure that is > accessible through userspace calls). It may be caused by a combination > of both the compiler an the kernel allowing bad practices (the fact that > devm_kzalloc() exists without a huge flashing red warning around it > shows that we either don't understand the problem or don't care), The answer is that we don't understand the problem. I've been vaguely aware that there is a problem related to this but I've never been clear enough to the point where I could actually tell if code is buggy. It sounds like something which could probably be detected with static analysis. Most of the static analysis devs hang out on kernel-janitors so if you see a bug and you think it might happen more than once then send an email to kernel-janitors@vger.kernel.org. Sometimes if we look at a patch then maybe we can identify several heuristics to spot the bug. regards, dan carpenter