On Mon, Mar 22, 2021 at 10:02:38PM +0100, Ondrej Mosnacek wrote:
> The code that has been added to strip trailing slashes from path in
> unexportfs_parsed() forgot to account for the case of the root
> directory, which is simply '/'. In that case it accesses path[-1] and
> reduces the path to an empty string, which then fails to match any
> export.
>
> Fix it by stopping the stripping when the path is just a single
> character - it doesn't matter if it's a '/' or not, we want to keep it
> either way in that case.
Makes sense to me.
(Note nfs-exporting / is often a bad idea. I assume you had some good
reason in this case.)
--b.
>
> Reproducer:
>
> exportfs localhost:/
> exportfs -u localhost:/
>
> Without this patch, the unexport step fails with "exportfs: Could not
> find 'localhost:/' to unexport."
>
> Fixes: a9a7728d8743 ("exportfs: Deal with path's trailing "/" in unexportfs_parsed()")
> Link: https://bugzilla.redhat.com/show_bug.cgi?id=1941171
> Signed-off-by: Ondrej Mosnacek <omosnace@xxxxxxxxxx>
> ---
> utils/exportfs/exportfs.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/utils/exportfs/exportfs.c b/utils/exportfs/exportfs.c
> index 262dd19a..1aedd3d6 100644
> --- a/utils/exportfs/exportfs.c
> +++ b/utils/exportfs/exportfs.c
> @@ -383,7 +383,7 @@ unexportfs_parsed(char *hname, char *path, int verbose)
> * so need to deal with it.
> */
> size_t nlen = strlen(path);
> - while (path[nlen - 1] == '/')
> + while (nlen > 1 && path[nlen - 1] == '/')
> nlen--;
>
> for (exp = exportlist[htype].p_head; exp; exp = exp->m_next) {
> --
> 2.30.2
