Messages in this thread | | | From | Kees Cook <> | Date | Tue, 22 Jan 2019 13:51:20 +1300 | Subject | Re: [PATCH] fs: Allow opening only regular files during execve(). |
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On Tue, Jan 22, 2019 at 10:18 AM Al Viro <viro@zeniv.linux.org.uk> wrote: > > On Mon, Jan 21, 2019 at 07:14:39PM +0900, Tetsuo Handa wrote: > > On Tue, Dec 12, 2017 at 2:06 PM, Eric Biggers <ebiggers3@gmail.com> wrote: > > > I'm not sure what the fix will be. Maybe the proc handlers should take a > > > different lock instead of cred_guard_mutex. Or perhaps execve should check that > > > the file is a regular file before it attempts to open it. > > > > We can easily distinguish open() from execve() and open() from others. ;-) > > > + /* The file or a script interpreter has to be a regular file. */ > > + if (unlikely(current->in_execve && !S_ISREG(inode->i_mode))) { > > + error = -EACCES; > > + goto cleanup_file; > > + } > > We are *NOT* going to use current->in_execve to propagate that information. > Come up with a cleaner solution, if you care, but this one is a non-starter. > Too ugly to live. Sorry.
What would you suggest for a cleaner indication of being in an execve?
-- Kees Cook
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