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 AD6E23939AF for ; Wed, 18 Mar 2026 11:31:42 +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=1773833502; cv=none; b=cK+keVZx4ZBnJ+1f3Gv2fmoSAYwfCAIrsIJ0vBfnx2INFOh5T5QgjTye+pn1ibJ/9+U0cfd83YXpA7mUE7lpSExWc1GemU4+Wj+nC6EOkFLYb+XnvfSLDbVJMl4+WgKwx/PdI3jGrqCwgvS2N+BazKOSkHBTym8sEoQuU3ENQz0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1773833502; c=relaxed/simple; bh=MLzekHue3ap7klvEGSohWT262WOq/FUTJNppGRVA5vM=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=f4VX2ozYAA+jhCExm6/QwCRVuA6aD0j1bzjBpYlMXNpEm9xQ/1QKJDyV6U+oA5qgdhuEq958kZHQ1mn2Mmb1BB2RcqVMJhGRWgD+JCK2X/3jxLGUmZ2KmIPAPayKufV3d8u6lQGjBIqqIrBatgPN3DQbWIbQiPkj32gIPN5D474= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=VjEMaCRP; 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="VjEMaCRP" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9AC22C19421; Wed, 18 Mar 2026 11:31:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1773833502; bh=MLzekHue3ap7klvEGSohWT262WOq/FUTJNppGRVA5vM=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=VjEMaCRPIXRNF+19MmBSlXUEjS47MNiUl/VphR9bV2s6jFiCs6H/0UovHO/QbLD2m 0hAEHPT+epodNhg9joOnS4urBiXhglEyNb0kihUDre4suVpnoSIngsYHeDMfniCl+j wzYQLvAcTKFEv+owRLVeD69Lm3azBzvtuTrcRcxtmLFPYAHGH7YiD4eRa58I4K2B/c MJgI52z+jw9nksZaHUkMLi+CmpkbYAUzQq4ponS6TocObuYvuC6380FC5Cbv+zv5Ar zzPo1MzwFLncmgHZtEY03zzq7j+2trY2XIVcs7al4au1BXE+4P6J8ZbYXeaKHalcVk A6zC4vWIy9FPQ== From: Sasha Levin To: stable@vger.kernel.org Cc: "Darrick J. Wong" , Christoph Hellwig , Carlos Maiolino , Christian Brauner , Sasha Levin Subject: [PATCH 5.15.y] iomap: reject delalloc mappings during writeback Date: Wed, 18 Mar 2026 07:31:39 -0400 Message-ID: <20260318113139.627346-1-sashal@kernel.org> X-Mailer: git-send-email 2.51.0 In-Reply-To: <2026031714-renderer-twiddling-44fe@gregkh> References: <2026031714-renderer-twiddling-44fe@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 [ Different error handling structure ] 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 87a4f5a2ded0e..ee22d4ff74a95 100644 --- a/fs/iomap/buffered-io.c +++ b/fs/iomap/buffered-io.c @@ -1320,10 +1320,13 @@ iomap_writepage_map(struct iomap_writepage_ctx *wpc, error = wpc->ops->map_blocks(wpc, inode, file_offset); if (error) break; - 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_UNWRITTEN && + wpc->iomap.type != IOMAP_MAPPED)) { + error = -EIO; + break; + } iomap_add_to_ioend(inode, file_offset, page, iop, wpc, wbc, &submit_list); count++; -- 2.51.0