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 F1E9F21423C for ; Wed, 18 Mar 2026 01:06:53 +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=1773796014; cv=none; b=cM/iqBd9KdHnnPRxmi0M6WZkjQrj7bX2yurizbyVhOluW1jRTFOZSgdyqZkF4U0sPLMaFsSX5rXN2/ApUF7sUvAFhEWJVyem2xvcngfpGI52TfOmjk8aqH8efDKa5HLyJNagPk5Z2VfjgUMtV02RtgTTRPCMSq0wfxKeT2PyCOQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773796014; c=relaxed/simple; bh=cfeNsB2ENCgCxoX0gjxMTAFWmh3h3ttbvIznt0GjAWE=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=bGJkAA6UJHkmdjYBIKrlJxjeS17gKKv6tVHLp/XEw02/AA7lKq7YIHYIswSY2Ggt0zeUmk709kDi0kO1utMyJ3ZrGr6UdoJQACjTXHdAo6tB1DyW4J03XzDnn7182FamjBzPPbKs4Lqd3i79EM1jeOxQPw10+S//VMzRFkWAlDc= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=J5qqbjck; 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="J5qqbjck" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DF245C4CEF7; Wed, 18 Mar 2026 01:06:52 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773796013; bh=cfeNsB2ENCgCxoX0gjxMTAFWmh3h3ttbvIznt0GjAWE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=J5qqbjcklWaSTb+goVb/NxvpzIWxw73lRFt6zBLNDB+ESX2Gjnm8IQJaDji2H7btd RjLV8soVanmdfD3LMVkLDOx2q9LaimkUWh5q3znenhfObGvycLavRoNgqGBVEvh5LK 3+Nfgj34uNuXtllZQXzdCvYmHWT/8E8sZud8hHIwtn/lW10Gqp2LsYHr6ZECOG0A2t c6LUzN9tTtmgdqDCaptGNFqLwA56GBZa3sdhUyxOpY9+HaHqdCjbHAPp3PdmwSW9La kjc33wyPDSL4a/OQEucZqDcy0U7iv4fqzeBSlBOS1nZog8X+3jrvaADkAmz0ZwVjXz hdypqpuhdvk5g== From: Sasha Levin To: stable@vger.kernel.org Cc: "Darrick J. Wong" , Christoph Hellwig , Carlos Maiolino , Christian Brauner , Sasha Levin Subject: [PATCH 6.1.y] iomap: reject delalloc mappings during writeback Date: Tue, 17 Mar 2026 21:06:50 -0400 Message-ID: <20260318010650.420596-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2026031713-ride-olympics-fd2c@gregkh> References: <2026031713-ride-olympics-fd2c@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit From: "Darrick J. Wong" [ Upstream commit d320f160aa5ff36cdf83c645cca52b615e866e32 ] Filesystems should never provide a delayed allocation mapping to writeback; they're supposed to allocate the space before replying. This can lead to weird IO errors and crashes in the block layer if the filesystem is being malicious, or if it hadn't set iomap->dev because it's a delalloc mapping. Fix this by failing writeback on delalloc mappings. Currently no filesystems actually misbehave in this manner, but we ought to be stricter about things like that. Cc: stable@vger.kernel.org # v5.5 Fixes: 598ecfbaa742ac ("iomap: lift the xfs writeback code to iomap") Signed-off-by: Darrick J. Wong Link: https://patch.msgid.link/20260302173002.GL13829@frogsfrogsfrogs Reviewed-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Signed-off-by: Christian Brauner [ switch -> if ] Signed-off-by: Sasha Levin --- fs/iomap/buffered-io.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/fs/iomap/buffered-io.c b/fs/iomap/buffered-io.c index e4f58d1e12d48..c3408ba636632 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1620,10 +1620,13 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, if (error) break; trace_iomap_writepage_map(inode, &wpc->iomap); - if (WARN_ON_ONCE(wpc->iomap.type == IOMAP_INLINE)) - continue; if (wpc->iomap.type == IOMAP_HOLE) continue; + if (WARN_ON_ONCE(wpc->iomap.type != IOMAP_MAPPED && + wpc->iomap.type != IOMAP_UNWRITTEN)) { + error = -EIO; + break; + } iomap_add_to_ioend(inode, pos, folio, iop, wpc, wbc, &submit_list); count++; -- 2.51.0