Re: AUDIT: copy_from_user is a deathtrap.

Rusty Russell (rusty@rustcorp.com.au)
Sun, 19 May 2002 13:38:05 +1000


> Um, what about delivering a SIGSEGV? So, copy_to/from_user always
> returns 0, but a signal is delivered. Then the only places which need
> to be clever are the mount option copying, and the signal delivery
> code for SIGSEGV (which uses copy_to_user).

Sorry, this doesn't work here either: this would return the wrong
value from read.

Of course, everyone who does more than one copy_to_user should be
checking that return value, and not doing:

if (copy_to_user(uptr....)
|| copy_to_user(uptr+10,....)
return -EFAULT

So that such gc schemes actually work,
Rusty.

--
  Anyone who quotes me in their sig is an idiot. -- Rusty Russell.
-
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/