From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 11F9A171E43; Sun, 24 Mar 2024 22:39:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711319956; cv=none; b=VtQPyyHXcaJopMxSkcUasQ7f12li3ABdJ4GTo2CgkgOnLT/d3ggsVYqDLTTCRmvUrPF84eBFBsFXAixoDtKq3zM7Lm0F7jQLsWNJQ5gG1krCZCWXGe2IjzpdxHy/hUoIpWjtMkA8KiCggFdG0iwy7igNM7avR28+PtpZGcWs7JE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1711319956; c=relaxed/simple; bh=3ROeb6f/oWDvJLS5zUVN+VKwhzwBKnpR4YsCgI+SwU4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=jNM1vWECROnQqx4uCbCKjr+NvWKSOA3D3eC8ZPw0YVRijxkrE8bV9wpo1IQgib17wk+xrOc7YwnZRrYBYBeFKdYiCjNQY3Upq/iORFy+Dg5GLaiDBVoNRzwghxD5jhzswsPPDWYF3Sg5lpbIZNiLwlVRvkMgxZzGgHuVS10h6Ak= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QoQXtTrs; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="QoQXtTrs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34226C43394; Sun, 24 Mar 2024 22:39:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1711319955; bh=3ROeb6f/oWDvJLS5zUVN+VKwhzwBKnpR4YsCgI+SwU4=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QoQXtTrsagw2AfgSnoN6aZIhyWYS3P04nASwrZXpJhpQkquhQMMFusnaujJFRj10x 6ed1a3/g93OaBO4I23OokJRGoTXrCG/IW0/9Hzm3U3ujmMz/JROQHCLRVgUTQSltf/ A1+ss5Qo2LfMsZJ8OUdBKaAv+IV8ZK6e7TcT2BFt33b1vOTjULwba9ZLv5ZJM9pcHi 7Rezr0kNnnaXtbz+kmfdczdvdFtNnKKst1TQpJCEfWK/QSiJxbJuP7Ph+Se/gWm65/ iutAMB/PlR/eVF6BI+D1l3kM359ryfKg4kp6G3Mrbz5DhO2HbLK4fnXF5yB94umihC +9/DTl6cWbBLA== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Kees Cook , Alexander Viro Subject: [PATCH 6.8 262/715] pstore: inode: Only d_invalidate() is needed Date: Sun, 24 Mar 2024 18:27:21 -0400 Message-ID: <20240324223455.1342824-263-sashal@kernel.org> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240324223455.1342824-1-sashal@kernel.org> References: <20240324223455.1342824-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit 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 unregistered") Signed-off-by: Kees Cook --- 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 d0d9bfdad30cc..56815799ce798 100644 --- a/fs/pstore/inode.c +++ b/fs/pstore/inode.c @@ -307,7 +307,6 @@ int pstore_put_backend_records(struct pstore_info *psi) { struct pstore_private *pos, *tmp; struct dentry *root; - int rc = 0; root = psinfo_lock_root(); if (!root) @@ -317,11 +316,8 @@ int pstore_put_backend_records(struct pstore_info *psi) list_for_each_entry_safe(pos, tmp, &records_list, list) { if (pos->record->psi == psi) { list_del_init(&pos->list); - rc = 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 = NULL; } } @@ -329,7 +325,7 @@ int pstore_put_backend_records(struct pstore_info *psi) inode_unlock(d_inode(root)); - return rc; + return 0; } /* -- 2.43.0