Messages in this thread | | | Date | Wed, 22 Oct 2014 16:43:10 -0700 | Subject | Re: [PATCH] sysctl: terminate strings also on \r | From | Kees Cook <> |
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On Wed, Oct 22, 2014 at 4:26 PM, Andrew Morton <akpm@linux-foundation.org> wrote: > On Tue, 21 Oct 2014 13:21:37 -0700 Kees Cook <keescook@chromium.org> wrote: > >> From: Paul Wise <pabs3@bonedaddy.net> >> >> This partially mitigates a common strategy used by attackers for hiding >> the full contents of strings in procfs from naive sysadmins who use cat, >> more or sysctl to inspect the contents of strings in procfs. >> >> ... >> >> --- a/kernel/sysctl.c >> +++ b/kernel/sysctl.c >> @@ -1739,7 +1739,7 @@ static int _proc_do_string(char *data, int maxlen, int write, >> while ((p - buffer) < *lenp && len < maxlen - 1) { >> if (get_user(c, p++)) >> return -EFAULT; >> - if (c == 0 || c == '\n') >> + if (c == 0 || c == '\n' || c == '\r') >> break; >> data[len++] = c; >> } > > There are no valid uses of \r in a procfs write?
I struggle to imagine one; everything I found that uses proc_dostring seems to be names, paths, and commands.
-Kees
-- Kees Cook Chrome OS Security
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