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Subject: [REPOST PATCH] nfs: fix port value parsing
From:   Ian Kent <raven@themaw.net>
To:     Trond Myklebust <trond.myklebust@hammerspace.com>,
        Anna Schumaker <Anna.Schumaker@Netapp.com>
Cc:     linux-nfs-list <linux-nfs@vger.kernel.org>,
        linux-fsdevel <linux-fsdevel@vger.kernel.org>,
        David Howells <dhowells@redhat.com>,
        Steve Dickson <SteveD@redhat.com>,
        Benjamin Coddington <bcodding@redhat.com>
Date:   Tue, 28 Jun 2022 08:25:07 +0800
Message-ID: <165637590710.37553.7481596265813355098.stgit@donald.themaw.net>
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The valid values of nfs options port and mountport are 0 to USHRT_MAX.

The fs parser will return a fail for port values that are negative
and the sloppy option handling then returns success.

But the sloppy option handling is meant to return success for invalid
options not valid options with invalid values.

Parsing these values as s32 rather than u32 prevents the parser from
returning a parse fail allowing the later USHRT_MAX option check to
correctly return a fail in this case. The result check could be changed
to use the int_32 union variant as well but leaving it as a uint_32
check avoids using two logical compares instead of one.

Signed-off-by: Ian Kent <raven@themaw.net>
---
 fs/nfs/fs_context.c |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/nfs/fs_context.c b/fs/nfs/fs_context.c
index 9a16897e8dc6..f4da1d2be616 100644
--- a/fs/nfs/fs_context.c
+++ b/fs/nfs/fs_context.c
@@ -156,14 +156,14 @@ static const struct fs_parameter_spec nfs_fs_parameters[] = {
 	fsparam_u32   ("minorversion",	Opt_minorversion),
 	fsparam_string("mountaddr",	Opt_mountaddr),
 	fsparam_string("mounthost",	Opt_mounthost),
-	fsparam_u32   ("mountport",	Opt_mountport),
+	fsparam_s32   ("mountport",	Opt_mountport),
 	fsparam_string("mountproto",	Opt_mountproto),
 	fsparam_u32   ("mountvers",	Opt_mountvers),
 	fsparam_u32   ("namlen",	Opt_namelen),
 	fsparam_u32   ("nconnect",	Opt_nconnect),
 	fsparam_u32   ("max_connect",	Opt_max_connect),
 	fsparam_string("nfsvers",	Opt_vers),
-	fsparam_u32   ("port",		Opt_port),
+	fsparam_s32   ("port",		Opt_port),
 	fsparam_flag_no("posix",	Opt_posix),
 	fsparam_string("proto",		Opt_proto),
 	fsparam_flag_no("rdirplus",	Opt_rdirplus),