From: Ilya Dryomov <idryomov@gmail.com>
Date: Wed, 20 Nov 2024 15:43:51 +0000 (+0100)
Subject: ceph: validate snapdirname option length when mounting
X-Git-Tag: v6.1.122~7
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=91542d131b41e824d0481aff4c9068500602dbf6;p=thirdparty%2Fkernel%2Fstable.git

ceph: validate snapdirname option length when mounting

commit 12eb22a5a609421b380c3c6ca887474fb2089b2c upstream.

It becomes a path component, so it shouldn't exceed NAME_MAX
characters.  This was hardened in commit c152737be22b ("ceph: Use
strscpy() instead of strcpy() in __get_snap_name()"), but no actual
check was put in place.

Cc: stable@vger.kernel.org
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>
Reviewed-by: Alex Markuze <amarkuze@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---

diff --git a/fs/ceph/super.c b/fs/ceph/super.c
index e292d5c6058ed..bd15991166c27 100644
--- a/fs/ceph/super.c
+++ b/fs/ceph/super.c
@@ -420,6 +420,8 @@ static int ceph_parse_mount_param(struct fs_context *fc,
 
 	switch (token) {
 	case Opt_snapdirname:
+		if (strlen(param->string) > NAME_MAX)
+			return invalfc(fc, "snapdirname too long");
 		kfree(fsopt->snapdir_name);
 		fsopt->snapdir_name = param->string;
 		param->string = NULL;