diff mbox series

[nfs-utils,v2] mount: fix parsing of default options

Message ID 875z3cfklw.fsf@notabene.neil.brown.name (mailing list archive)
State New
Headers show
Series [nfs-utils,v2] mount: fix parsing of default options | expand

Commit Message

NeilBrown Feb. 1, 2021, 5 a.m. UTC
A recent patch to change configfile.c to use parse_opt.c contained code
which was intended to remove all "default*" options from the list before
that could be passed to the kernel.  This code didn't work, so default*
options WERE passed to the kernel, and the kernel complained and failed
the mount attempt.

A more recent patch attempted to fix this by not including the
"default*" options in the option list at all.  This resulting in
global-default defaults over-riding per-mount or per-server defaults.

This patch reverse the "more recent" patch, and fixes the original patch
by providing correct code to remove all "default*" options before the
kernel can see them.

Fixes: 88c22f924f1b ("mount: convert configfile.c to use parse_opt.c")
Fixes: 8142542bda28 ("mount: parse default values correctly")
Signed-off-by: NeilBrown <neilb@suse.de>
---

I realized that po_remove_all() could free 'ptr' and then compare it
against the next option, which would have undefined results.
So best to strdup and free it.


 utils/mount/configfile.c | 9 ++++++---
 1 file changed, 6 insertions(+), 3 deletions(-)

Comments

Steve Dickson Feb. 2, 2021, 5 p.m. UTC | #1
On 2/1/21 12:00 AM, NeilBrown wrote:
> 
> A recent patch to change configfile.c to use parse_opt.c contained code
> which was intended to remove all "default*" options from the list before
> that could be passed to the kernel.  This code didn't work, so default*
> options WERE passed to the kernel, and the kernel complained and failed
> the mount attempt.
> 
> A more recent patch attempted to fix this by not including the
> "default*" options in the option list at all.  This resulting in
> global-default defaults over-riding per-mount or per-server defaults.
> 
> This patch reverse the "more recent" patch, and fixes the original patch
> by providing correct code to remove all "default*" options before the
> kernel can see them.
> 
> Fixes: 88c22f924f1b ("mount: convert configfile.c to use parse_opt.c")
> Fixes: 8142542bda28 ("mount: parse default values correctly")
> Signed-off-by: NeilBrown <neilb@suse.de>
Committed.... (tag: nfs-utils-2-5-3-rc5)

steved.
> ---
> 
> I realized that po_remove_all() could free 'ptr' and then compare it
> against the next option, which would have undefined results.
> So best to strdup and free it.
> 
> 
>  utils/mount/configfile.c | 9 ++++++---
>  1 file changed, 6 insertions(+), 3 deletions(-)
> 
> diff --git a/utils/mount/configfile.c b/utils/mount/configfile.c
> index e865998dd5a9..3d3684efa186 100644
> --- a/utils/mount/configfile.c
> +++ b/utils/mount/configfile.c
> @@ -277,10 +277,9 @@ conf_parse_mntopts(char *section, char *arg, struct mount_options *options)
>  		}
>  		if (buf[0] == '\0')
>  			continue;
> -		if (default_value(buf))
> -			continue;
>  
>  		po_append(options, buf);
> +		default_value(buf);
>  	}
>  	conf_free_list(list);
>  }
> @@ -335,7 +334,11 @@ char *conf_get_mntopts(char *spec, char *mount_point,
>  	 * Strip out defaults, which have already been handled,
>  	 * then join the rest and return.
>  	 */
> -	po_remove_all(options, "default");
> +	while (po_contains_prefix(options, "default", &ptr, 0) == PO_FOUND) {
> +		ptr = strdup(ptr);
> +		po_remove_all(options, ptr);
> +		free(ptr);
> +	}
>  
>  	po_join(options, &mount_opts);
>  	po_destroy(options);
>
diff mbox series

Patch

diff --git a/utils/mount/configfile.c b/utils/mount/configfile.c
index e865998dd5a9..3d3684efa186 100644
--- a/utils/mount/configfile.c
+++ b/utils/mount/configfile.c
@@ -277,10 +277,9 @@  conf_parse_mntopts(char *section, char *arg, struct mount_options *options)
 		}
 		if (buf[0] == '\0')
 			continue;
-		if (default_value(buf))
-			continue;
 
 		po_append(options, buf);
+		default_value(buf);
 	}
 	conf_free_list(list);
 }
@@ -335,7 +334,11 @@  char *conf_get_mntopts(char *spec, char *mount_point,
 	 * Strip out defaults, which have already been handled,
 	 * then join the rest and return.
 	 */
-	po_remove_all(options, "default");
+	while (po_contains_prefix(options, "default", &ptr, 0) == PO_FOUND) {
+		ptr = strdup(ptr);
+		po_remove_all(options, ptr);
+		free(ptr);
+	}
 
 	po_join(options, &mount_opts);
 	po_destroy(options);