linux-kernel - [PATCH v2] NFS: suppressing showing of default mount port value in /proc fixed

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Mon, 06 Dec 2010 12:00:31 +0300
From:	Stanislav Kinsbursky <skinsbursky@...allels.com>
To:	Trond.Myklebust@...app.com
Cc:	linux-nfs@...r.kernel.org, linux-kernel@...r.kernel.org
Subject: [PATCH v2] NFS: suppressing showing of default mount port value in
	/proc fixed

Update: added check for zero value as it was before (note: can't simply check
mountd_port for positive value because it's typeof unsigned short)

Default value for mount server port is set to NFS_UNSPEC_PORT (-1) and will not
be changed during parsing mount options for mound data version 6. This default
value will be showed for mountport in /proc/mounts always since current default
check is for zero value. This small mistake leads to big problem, because
during umount.nfs execution from old user-space utils (at least nfs-utils
1.0.9) this value will be used as the server port to connect to. This request
will be rejected (since port is 65535) and thus nfs mount point can't be
unmounted.

Note from Chuck Lever (chuck.lever@...cle.com): this is only possible if
/etc/mtab is a link to /proc/mounts.  Not all systems have this configuration.

---
 fs/nfs/super.c |    4 +++-
 1 files changed, 3 insertions(+), 1 deletions(-)

diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 6d6e21d..449024f 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -681,7 +681,9 @@ static void nfs_show_mountd_options(struct seq_file *m, struct nfs_server *nfss,

 	if (nfss->mountd_version || showdefaults)
 		seq_printf(m, ",mountvers=%u", nfss->mountd_version);
-	if (nfss->mountd_port || showdefaults)
+	if ((nfss->mountd_port &&
+		nfss->mountd_port != (unsigned short)NFS_UNSPEC_PORT) || 
+		showdefaults)
 		seq_printf(m, ",mountport=%u", nfss->mountd_port);

 	nfs_show_mountd_netid(m, nfss, showdefaults);

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/