From nobody Tue Apr 7 01:13:29 2026 Received: from m16.mail.163.com (m16.mail.163.com [220.197.31.5]) (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 4F0AB199949; Tue, 17 Mar 2026 02:56:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=220.197.31.5 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773716211; cv=none; b=ZQDx1ZCPpdLrPgCB/ViQuXfTK1g+rYrqKnKQvsPp8WS0KgDDP75NqGTyprso7czLRo28VWovxlWRz8X4jMueoPtqJT/6pVCxsOivpFuP8uvB5VhPWlkxN+3VARhIlURhqvzPs9ZXItfrMbvFqFd0cNKQpYZCLRmAuSnHEUGFmXs= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773716211; c=relaxed/simple; bh=5idiaM5ya0ZMcmh4ZOciWJkmKYgEJKIeAs3Tkdo/yrw=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=CPhQbCWw/W/6dUY5+J1mXBpKD56HNRHNdwywhpwJ1pcm21NRF27K9mC1BHoEzH32bPYWa0811H9ZDr53mdpXA/hzkek7yhO9rluVzgms2clJrTdBl5baN1O3X3YuSV0tKlhHQtugazi4sWNrcX5t0WqmJ0l0v5cNvgw+/Z30rgo= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com; spf=pass smtp.mailfrom=163.com; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b=JSt0fYRQ; arc=none smtp.client-ip=220.197.31.5 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=163.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=163.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=163.com header.i=@163.com header.b="JSt0fYRQ" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=163.com; s=s110527; h=From:To:Subject:Date:Message-Id:MIME-Version; bh=fl keyKELInxzqtQjTpvZ9iQ7lXdYqruNsdCwFkYgqcY=; b=JSt0fYRQKlXAbDM6x6 Gm4dzWkMV6CHbqnpeNGTgZX/tKxPDjUFLXZ1XHZQfRylBjlz2ZDIUUj2fqJSmwyD bo/Vnkyq/q/NZMyectN09bBRkQmVsck8oLfxJRCg7L6zyIXdu3Ld4qK5njycu7l1 GOPj38a18WwZJ/P+0BBpQtSDQ= Received: from pek-lpg-core5.wrs.com (unknown []) by gzga-smtp-mtada-g0-0 (Coremail) with SMTP id _____wD3u1C+wrhphmaaBQ--.42197S2; Tue, 17 Mar 2026 10:55:59 +0800 (CST) From: Robert Garcia To: stable@vger.kernel.org, Kees Cook Cc: "Guilherme G . Piccoli" , Tony Luck , linux-hardening@vger.kernel.org, Robert Garcia , Anton Vorontsov , Colin Cross , linux-kernel@vger.kernel.org Subject: [PATCH 5.15.y] pstore: inode: Only d_invalidate() is needed Date: Tue, 17 Mar 2026 10:55:58 +0800 Message-Id: <20260317025558.1666400-1-rob_garcia@163.com> X-Mailer: git-send-email 2.34.1 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-CM-TRANSID: _____wD3u1C+wrhphmaaBQ--.42197S2 X-Coremail-Antispam: 1Uf129KBjvJXoW7ur17CF17trWDWw4kuFy8Krg_yoW8Zw47pr nxCw45ArW8Ka4Sgw48XF45Z345uFsYgw45XrZ7Ga1ftrnxKw4FqF43tFnIvFyrJrWruFZY qr10kr1YvFyYyaUanT9S1TB71UUUUU7qnTZGkaVYY2UrUUUUjbIjqfuFe4nvWSU5nxnvy2 9KBjDUYxBIdaVFxhVjvjDU0xZFpf9x0pRpVbDUUUUU= X-CM-SenderInfo: 5uresw5dufxti6rwjhhfrp/xtbDAR9o02m4wr9emAAA3P Content-Type: text/plain; charset="utf-8" From: Kees Cook [ Upstream commit a43e0fc5e9134a46515de2f2f8d4100b74e50de3 ] Unloading a modular pstore backend with records in pstorefs would trigger the dput() double-drop warning: WARNING: CPU: 0 PID: 2569 at fs/dcache.c:762 dput.part.0+0x3f3/0x410 Using the combo of d_drop()/dput() (as mentioned in Documentation/filesystems/vfs.rst) isn't the right approach here, and leads to the reference counting problem seen above. Use d_invalidate() and update the code to not bother checking for error codes that can never happen. Suggested-by: Alexander Viro Fixes: 609e28bb139e ("pstore: Remove filesystem records when backend is unr= egistered") Signed-off-by: Kees Cook --- Cc: "Guilherme G. Piccoli" Cc: Tony Luck Cc: linux-hardening@vger.kernel.org [ Minor context change fixed. ] Signed-off-by: Robert Garcia --- fs/pstore/inode.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-) diff --git a/fs/pstore/inode.c b/fs/pstore/inode.c index 14658b009f1b..f56e0b105be7 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -312,7 +312,6 @@ int pstore_put_backend_records(struct pstore_info *psi) { struct pstore_private *pos, *tmp; struct dentry *root; - int rc =3D 0; =20 root =3D psinfo_lock_root(); if (!root) @@ -322,11 +321,8 @@ int pstore_put_backend_records(struct pstore_info *psi) list_for_each_entry_safe(pos, tmp, &records_list, list) { if (pos->record->psi =3D=3D psi) { list_del_init(&pos->list); - rc =3D simple_unlink(d_inode(root), pos->dentry); - if (WARN_ON(rc)) - break; - d_drop(pos->dentry); - dput(pos->dentry); + d_invalidate(pos->dentry); + simple_unlink(d_inode(root), pos->dentry); pos->dentry =3D NULL; } } @@ -334,7 +330,7 @@ int pstore_put_backend_records(struct pstore_info *psi) =20 inode_unlock(d_inode(root)); =20 - return rc; + return 0; } =20 /* --=20 2.34.1