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=1793828878; b=nqrQqXoK9EOD1TfZvnunv4kqGfHkZmKZaR7bcovy43uBg/yl75hENa4qWIJ7Q5Vqc4/k 5asMfHseS8nYd2FpBO4Hvxht+aursZOnNxCXHVbD4469c29PVs98bP9WvOjaN0qCLIfZF E3lYYkLXwqRDR2m/jD4khUAU5gDDY2qBxQB+0wOMelLvGz6Oz+N54om/G6Fu25Ss16rFV N7YxMQBprMjXA5/QKA2f6Kzlos/qqGteHJfiDiziSxPTZSuCZRQ5/yjjXuUyAuUdalWQ3 uv0+ftjtcDjnd6m3f4bSFXxKhIcnfWvAB4D0wCxcWlneFttMhC6ZFeoSLAwg2+6mjNg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1793828878; 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=ihLAY5BA7s55rKete/TFzPtxh8eucCl4f0tSRoZIYCo=; b=ad6KoNKZctBGQXd70FDocxHugxWRcwPzeUvX7YWC2EQ9+2z7zEHcCuBFJFq8c25lbymO a7MvWo9tc4laYmbebDHnsPozfUFMEYl5iChhx00AwnjXY3AgyVejiQmXRUCkyK5CKlZjX o79JzxKOdm/Ba7o3UAPu3Ny3aGLld687YenflG3N2D4YXkxKZADOTR5Ctkeie2Oys2rKX vA0c3blHm0wgSJtMMv1nkoyaf8fAyhmpAZe+GbHE8ooGBJm8XTCZPv18b9aA0l0nDtWzD fsFmu9kV6u0YMXSWY8sYFyqnJsrnJXP8VKxiXfGA3e26ZgOcmohssqepnl2F687BqiQ== 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=LYkaMVMe; 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 6EFF16071AC3; Wed, 4 Nov 2026 21:47:58 +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=LYkaMVMe Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0D25D1F000C1; Wed, 4 Nov 2026 21:47:57 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linuxfoundation.org; s=korg; t=1793828878; bh=ihLAY5BA7s55rKete/TFzPtxh8eucCl4f0tSRoZIYCo=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=LYkaMVMefJrUbu1YD4QOs4C6MLg2dDa4A3DaW4t0PJ1tMPxeb4KuO+1LwlDHlk5K5 6Q6aBscXFWzh3CM2HGXXBw2FODYdItYH2ptTvaYLqlyETensqN6xo3PbVMwjMFHmPX zhIEO9sML5ZtOPPsg/9rskNli/MfDtof85SEvvAc= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Josef Bacik , Amir Goldstein Subject: [PATCH 7.3 297/547] ovl: skip copy up of empty security.capability Date: Wed, 4 Nov 2026 16:08:01 -0500 Message-ID: <20261104211046.636587968@linuxfoundation.org> X-Mailer: git-send-email 2.56.0 In-Reply-To: <20261104211038.406938024@linuxfoundation.org> References: <20261104211038.406938024@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 7.3-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; } @@ -1103,9 +1116,9 @@ 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; }