From nobody Wed Oct 1 22:31:20 2025 Received: from sender3-pp-f112.zoho.com (sender3-pp-f112.zoho.com [136.143.184.112]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5512B140E5F; Tue, 30 Sep 2025 00:36:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.184.112 ARC-Seal: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759192604; cv=pass; b=mXx6OPuSJKyyOMvoRkWvc7gUlHLnBQtUh76+sFpNRORonVlHBP1GKizXzhdSfxRlo5ykb+p41sJvpDQoO7lJAV+5QH7i7SrXFm4DfVwe10IO+x6HE36pFw6Wt0jTP5qT+xtZsDcFQP3oYdsCCMWzuJ5wS5wZYqneDjxiurALaG8= ARC-Message-Signature: i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1759192604; c=relaxed/simple; bh=0dmw+NX0SV+++5sYlZaNjj5lFZzOb2zEdPom2w5GJ28=; h=From:To:Cc:Subject:Date:Message-ID:MIME-Version; b=KXfKivLQd/f72G8PeIvKXqBwgNvx/ooZ74DKSQ7FlLHG/FfA4Ucq2/AO4MyNprIeM4MtdJi2/Ft1JNzCBaxeqJvCGLg6twVUFT/p2pVIK8FUC29RJdjnEN5H4MLCiiLWPhLF4QOEblLUthHgsaxvls1QgUByzdkndz2U4lXOewg= ARC-Authentication-Results: i=2; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.beauty; spf=pass smtp.mailfrom=linux.beauty; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b=O3Ji+s0t; arc=pass smtp.client-ip=136.143.184.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=linux.beauty Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.beauty Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.beauty header.i=me@linux.beauty header.b="O3Ji+s0t" ARC-Seal: i=1; a=rsa-sha256; t=1759192572; cv=none; d=zohomail.com; s=zohoarc; b=Gzzvatf2+sOjcLRAR35rfF6PyBpIAs2zctN6lNO2evh/mpIP7fD1GVTcbKuJECN9VPY3dG4T+kgi97611gXES0990c2xlbSrmT9lgscxazjJ3We7DQV7JP6U7hVS1x/mboZp4vRetKQzCYWI0C8SqBV37GMDc4ayN/vN9r9Gsl4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1759192572; h=Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:MIME-Version:Message-ID:Subject:Subject:To:To:Message-Id:Reply-To; bh=hydiAdnjg/6bowrEjqyPCxKqacoOwPu3GjH+2V9IjnI=; b=N072Nz1wP8msVfX2z6Vb4QI8eM7xVRQCzU+3xnOuAiKtpjL1+OszzPlYWmQQMRVJoxi1NdgnR2U2n/6gz3dL8YG2cXqFWo0lv0z8r0KXvKo/Ik2hZc/13/5Xh8/gCSOoETVkLBPpUVVkK5m+tDVjFI2hKPOv+eNnjjBxSctdPlo= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=linux.beauty; spf=pass smtp.mailfrom=me@linux.beauty; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1759192571; s=zmail; d=linux.beauty; i=me@linux.beauty; h=From:From:To:To:Cc:Cc:Subject:Subject:Date:Date:Message-ID:MIME-Version:Content-Transfer-Encoding:Message-Id:Reply-To; bh=hydiAdnjg/6bowrEjqyPCxKqacoOwPu3GjH+2V9IjnI=; b=O3Ji+s0tXa3c2jQrZHN7aZtOznofbmue9EnDAJIFiXn9A16jwC4x8w+bzihQDdwq /QlgieInSYZMTKQMDYqtT4GTl5vJPUpPQ2him4WI4mKmWeGSLHY4e8APRLTjMWlIKCL fbA53BHKKcsPHj9oMc6d43EdZVsdDry9A8LBBq4U= Received: by mx.zohomail.com with SMTPS id 1759192569234211.8709219622018; Mon, 29 Sep 2025 17:36:09 -0700 (PDT) From: Li Chen To: Jens Axboe , Lizhi Xu , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, "Markus Elfring" , "Yang Erkun" , "Ming Lei" , "Yu Kuai" Subject: [PATCH v2] loop: fix backing file reference leak on validation error Date: Tue, 30 Sep 2025 08:35:59 +0800 Message-ID: <20250930003559.708798-1-me@linux.beauty> X-Mailer: git-send-email 2.51.0 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable X-ZohoMailClient: External Content-Type: text/plain; charset="utf-8" loop_change_fd() and loop_configure() call loop_check_backing_file() to validate the new backing file. If validation fails, the reference acquired by fget() was not dropped, leaking a file reference. Fix this by calling fput(file) before returning the error. Cc: stable@vger.kernel.org Cc: "Markus Elfring" CC: "Yang Erkun" Cc: "Ming Lei" Cc: "Yu Kuai" Fixes: f5c84eff634b ("loop: Add sanity check for read/write_iter") Signed-off-by: Li Chen Reviewed-by: Ming Lei Reviewed-by: Yang Erkun --- changelog: v2: add review by, Fixes and cc stable tags. drivers/block/loop.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/drivers/block/loop.c b/drivers/block/loop.c index 053a086d547e..94ec7f747f36 100644 --- a/drivers/block/loop.c +++ b/drivers/block/loop.c @@ -551,8 +551,10 @@ static int loop_change_fd(struct loop_device *lo, stru= ct block_device *bdev, return -EBADF; =20 error =3D loop_check_backing_file(file); - if (error) + if (error) { + fput(file); return error; + } =20 /* suppress uevents while reconfiguring the device */ dev_set_uevent_suppress(disk_to_dev(lo->lo_disk), 1); @@ -993,8 +995,10 @@ static int loop_configure(struct loop_device *lo, blk_= mode_t mode, return -EBADF; =20 error =3D loop_check_backing_file(file); - if (error) + if (error) { + fput(file); return error; + } =20 is_loop =3D is_loop_device(file); =20 --=20 2.51.0