Messages in this thread |  | | From | Denis Vlasenko <> | Subject | Re: AUDIT: copy_from_user is a deathtrap. | Date | Tue, 21 May 2002 08:57:28 -0200 |
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On 20 May 2002 13:22, you wrote: > > Can you tell me what's wrong with copy_from_user? How did you used it > > wrongly? > > Denis, I agree with the essense of Rusty's argument, which is that > copy_to_user is easy to misuse in the following way: > > xxx_ioctl (..., cmd, arg) { > return copy_to_user(....); > } > > Since copy_to_user returns a number of residue bytes instead of > -EINVAL, such statement confuses the caller. > Rusty found something about 54 instances of this.
Oh. Do you think a pair of
copy_to_user_or_EINVAL(...) copy_to_user_return_residue(...)
will help avoid such bugs? It is possible to audit kernel once, move it to new functions and deprecate/delete old one. -- vda - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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