From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1793831548; b=x3s5Vx5NE7nbupXSKxmUUoz1ZaBYdKVjIynQI5so1+mI1JfrLiQaQLz7QcmSC4WtJsHB oAZOSw/TwgllbRZGhQsFF1gc4ddhtRPboqrTLds5OVrDLr4JEBTAKydQ3KWFfYG5+HYMe hGx6a8Vg28lvKEJUqYq+45xzlIlF6Z3zbn2DN94Ku8shsbP0wdkT1Q04yeP73wqPTOfr+ LlCQswlOuz5OFTGp6ReoAAGF0ZGuq8sVJ8o025pj6zKnHW/UWXEBPkF/e/oL0KSzbkO/O lf2ItUdXMrUQQ65JxCkmL4nILRWkk6cevFCOG5P5alQh1RMA2OkM9hC7lpKF1NNfZkQ== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793831548; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: In-Reply-To:References:User-Agent:X-stable:X-Patchwork-Hint: MIME-Version:Content-Transfer-Encoding; bh=IkAFR7STfNIJPKjkASftk05R8m8vd1fCi3m83M3HXu0=; b=QBQt7OLRD3wSUqVMnt1Hd45hfa7XXfgtn4gaUP5pUJsGp1Q9MnEI+b/OPEcnNs2ljMOO fR0LxrW099Ouu/D6TcV8drmSIdlqkutdQ9WUh7UqmMoNRhsDOwq1buetTSZARwA2GBEv+ gNRasW2FrlH5BLSfJ51et96BycuJ9N9tYwUpkrWMNt8ykGtx69f6+gYsGoKDbh3srjf/e mUz7bv5tzIjvB3ldGDGZMgq3zLZC8TbqzzuV5IVknYx9kONN5swLOgB9EAlBmQCD8cs9X xBJ6EvTsvClxrq/lwDG9Bf7Op6SrH+lezdG9z+/2L1xQD6Sz+8sJLw3OB7YwZOVGhEg== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TSoFEZCl; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 3F333606A85E; Wed, 4 Nov 2026 22:32:28 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key, unprotected) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.a=rsa-sha256 header.s=korg header.b=TSoFEZCl Received: by smtp.kernel.org (Postfix) with ESMTPSA id CCE4C1F00919; Wed, 4 Nov 2026 22:32:27 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793831548; bh=IkAFR7STfNIJPKjkASftk05R8m8vd1fCi3m83M3HXu0=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=TSoFEZCly92CttzxcWuddgiK5JPyla4Ob+CS4G+qXeb/LclnX/i99JqaLhnHTrA8r tcporiANa94B7hgm/q+rYaLpqVzhbsahfHqcUqqJ7Amza/hjxglUSlGUOB3DArTV5b vuvWPtZlltO6BZhoIztjBvVeG0qXMifZFLWjQXrs= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , Amir Goldstein Subject: [PATCH 6.18 0772/1005] ovl: skip copy up of empty security.capability Date: Wed, 4 Nov 2026 16:08:25 -0500 Message-ID: <20261104211105.007764106@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211043.516122098@linuxfoundation.org> References: <20261104211043.516122098@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore X-Mailing-List: patches@lists.linux.dev List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Amir Goldstein commit 50912a1715b8a7c614b654011a0db750e372b43e upstream. ovl_copy_xattr() gives up if it can't read an attribute that listxattr() has named. An empty security.capability, which anybody has been able to store on any file for a long time, is such a case: it is listed, and getxattr() has nothing to return for it. A file in a lower layer that carries one can't be copied up: it can't be written to, renamed or have its mode changed. There is nothing to copy if there are no data. Go on with the next one. Fixes: 8db6c34f1dbc ("Introduce v3 namespaced file capabilities") Cc: stable@vger.kernel.org Signed-off-by: Josef Bacik [amir: treat -EINVAL as no capability too, and do the same in ovl_copy_up_meta_inode_data()] Signed-off-by: Amir Goldstein Signed-off-by: Greg Kroah-Hartman --- fs/overlayfs/copy_up.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) --- a/fs/overlayfs/copy_up.c +++ b/fs/overlayfs/copy_up.c @@ -75,6 +75,15 @@ static int ovl_copy_acl(struct ovl_fs *o static ssize_t ovl_getxattr_value(const struct path *path, char *name, char **value, ssize_t *value_size); +/* + * Any user can store an empty security.capability, which fails to read with + * -EINVAL. It grants no capability, so treat it as none, like no xattr. + */ +static bool ovl_no_fscap(ssize_t err) +{ + return err == -ENODATA || err == -EOPNOTSUPP || err == -EINVAL; +} + int ovl_copy_xattr(struct super_block *sb, const struct path *oldpath, struct dentry *new) { struct dentry *old = oldpath->dentry; @@ -134,6 +143,10 @@ int ovl_copy_xattr(struct super_block *s size = ovl_getxattr_value(oldpath, name, &value, &value_size); if (size < 0) { + if (!strcmp(name, XATTR_NAME_CAPS) && ovl_no_fscap(size)) { + error = 0; + continue; + } error = size; break; } @@ -1115,9 +1128,9 @@ static int ovl_copy_up_meta_inode_data(s if (c->stat.size) { err = cap_size = ovl_getxattr_value(&upperpath, XATTR_NAME_CAPS, &capability, &cap_size); - if (cap_size == -ENODATA || cap_size == -EOPNOTSUPP) + if (ovl_no_fscap(cap_size)) cap_size = 0; - if (cap_size < 0) + else if (cap_size < 0) goto out; }