Re: [PATCH 02/25] vfs: Allow fsinfo() to query what's in an fs_context [ver #13]

On June 21, 2019 3:12:43 PM GMT+02:00, David Howells [off-list ref] wrote:

Christian Brauner [off-list ref] wrote:

quoted

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 static int vfs_fsinfo_fd(unsigned int fd, struct fsinfo_kparams

*params)

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 {
 	struct fd f = fdget_raw(fd);

You're using fdget_raw() which means you want to allow O_PATH fds but
below you're checking whether the f_ops correspond to
fscontext_fops. If it's an O_PATH

It can't be.  The only way to get an fs_context fd is from fsopen() or
fspick() - neither of which allow O_PATH to be specified.

If you tried to go through /proc/pid/fd with open(O_PATH), I think
you'd get
the symlink, not the target.

Then you should use fdget(), no? :)

Christian