Messages in this thread | | | From | (Eric W. Biederman) | Subject | Re: [PATCH] sysctl: Check length at deprecated_sysctl_warning. | Date | Tue, 13 Nov 2007 06:24:39 -0700 |
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Tetsuo Handa <penguin-kernel@i-love.sakura.ne.jp> writes:
> Hello. > > Andrew Morton wrote: >> I believe (args->nlen > CTL_MAXNAME) was correct. > I'll leave it to you. > But if you want to allow args->nlen == CTL_MAXNAME, > you also need to update do_sysctl().
Which has been that way since before I decided to touch it. 2.6.12-rc1. I haven't tracked it before then as I don't expect to see anything.
And that is why -ENOTDIR. That is the historical error code from sysctl in this case.
> int do_sysctl(int __user *name, int nlen, void __user *oldval, size_t __user > *oldlenp, > void __user *newval, size_t newlen) > { > ... > if (nlen <= 0 || nlen >= CTL_MAXNAME) > return -ENOTDIR; > ... > }
CTL_MAXNAME is fairly arbitrary, and since the set of binary paths is fixed. So it feels to me like the code really should read:
if (nlen <= 0 || nlen > CTL_MAXNAME) return -ENOTDIR;
In both places. Just because that is what the comment describes.
I think in reality CTL_MAXNAME is actually 5 but I would have to look a little more closely to confirm that.
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