From mboxrd@z Thu Jan 1 00:00:00 1970 Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.remote-ip=100.103.45.18 ARC-Seal: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; cv=none; t=1794274159; b=wpQ6I1ABOj0tLoafSQaqN/32Pjm7GxGxRByO5ODuPWY/sncmF8+6pREVR34AW7Mu5jUQ vMeXyD1cOTTxHGe1mnJb/tq/D1VZ63VXAieWrsuxse+aWEgaeHNizxsNk+6c1nOgCtim7 E/7f8HbSyTXt+9dyPoEfx4GujWsNUEVpzyVBdcoMyVia+AJAansYBazlHIs7RsZ7zZwWZ IiNCnPCgtpkJVStia8vkV1CS4C3fkhj2jQzUbHAAbELQ2povbxgU+6FL8WXxPJJfMu6EO 5xqy5PqP/yW54UWKcB/L1wZeEWqBAJN/kNd+oYETQd9daUPOO4g8D5nz/Uc9v8lt6Vg== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794274159; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=YvEOZFVc5wilbicrnTCzbbbul0UTKzPV0xezc1ffnL0=; b=rxdX55pHSCqHUbc/FuZ6zcIa+d+lHzGUz+ap2djwv20TYEjVyWfHOiewm2itltjkj5g/ tK+Xi3zuNh7EveF2AfdP4hBzUa5yl7htFrtyHlWge+tQl3QgHO5SERgziXSVqgRVIvDCF QMpUqst7gxIaq8/xkHPln52WB9xyf4OLb3v78eaWm6gpyCHTF+aPeABVhU6PtaIupnh07 PuEenjpwLUfOjrz2b/c0VeqT6liJG02UGLr/r/21sySNKUMss3bgvuY1G4UFsgMsJa1qj 10iHlaB4022FdFLn+DXFsxM6ncSMxZyasFfswkVXsjy8D7mnw4jdjg7juwUGvm1JnFw== ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dkim=pass header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VQYRJNnu; arc=none smtp.remote-ip=100.103.45.18 Received: from smtp.kernel.org (quasi.space.kernel.org [100.103.45.18]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (prime256v1)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 17CD1606A325 for ; Tue, 10 Nov 2026 01:29:18 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256 header.s=k20260515 header.b=VQYRJNnu Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C67C1F0089F; Tue, 10 Nov 2026 01:29:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794274158; bh=YvEOZFVc5wilbicrnTCzbbbul0UTKzPV0xezc1ffnL0=; h=From:To:Cc:Subject:Date; b=VQYRJNnuoEZrEjLS7RQFk1QFZ9MRqNZo/s8V81XfozXW1Rly21Oz/1Yhkk+LNPLAa 6WNg/hPNK3VSvW/dANN5HphswSSA1IHYBILJCwdehPq/SQBzEP6zXeuRhWQwn4rgPI 8Fnb2qfHYhxrS2JTEYn0d5Yr4HzawNhZkM/e91K3jtjoD+Ixq7U6AuQG7KV4BeUDpP e3VFudyKoQqR8BJ7h3Sfyih2DJnuXoiWFSBuOrnX8iWNO8dlMO0P5a8x2sHIClRA7V wPQR1HRfz/J0oiVXjaPQkA626Km7+9lfahfve7TN57TGu8YeVqSI2rQcmf6morHsAh DyyzTE+PApYmQ== From: Sasha Levin To: matthias.goergens@gmail.com, jack@suse.cz Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] udf: fix preallocation discarding before an empty allocation extent" failed to apply to 5.10-stable tree Date: Mon, 9 Nov 2026 20:29:17 -0500 Message-ID: <20261109202917-failed-5.10-0c52750caaac@kernel.org> X-Mailer: git-send-email 2.53.0 X-Mailing-List: stable@vger.kernel.org List-Id: List-Post: List-Help: List-Subscribe: List-Unsubscribe: List-Owner: Precedence: list MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit The patch below does not apply to the 5.10-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to . To reproduce the conflict and resubmit, you may use the following commands: git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-5.10.y git checkout FETCH_HEAD git cherry-pick -x 0c52750caaaccee8b0e929450fe6538ec4985722 # git commit -s git send-email --to '' --in-reply-to '20261109202917-failed-5.10-0c52750caaac@kernel.org' --subject-prefix 'PATCH 5.10.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 0c52750caaaccee8b0e929450fe6538ec4985722 Mon Sep 17 00:00:00 2001 From: Matthias Goergens Date: Fri, 30 Oct 2026 22:05:36 +0800 Subject: [PATCH] udf: fix preallocation discarding before an empty allocation extent udf_discard_prealloc() finds the last extent of a file by peeking at the next one with udf_next_aext() and stopping when that returns 0. The peek reads into eloc and elen, and the code then uses them as the last extent. But when udf_next_aext() returns 0 they hold no defined value: if the extent list ends in a continuation descriptor that leads to an empty allocation extent, they describe that continuation, i.e. the block of the empty allocation extent, one block long. The kernel creates such lists itself: when udf_delete_aext() removes the only descriptor of the last allocation extent in a list, it leaves that allocation extent empty and the continuation to it in place. If the last extent is a preallocation, udf_discard_prealloc() deletes it with udf_delete_aext(), which finds the following allocation extent empty, so it also removes the continuation and frees that allocation extent's block. udf_discard_prealloc() then frees eloc and elen: that block a second time, instead of the preallocated blocks. On a space bitmap the preallocated blocks leak and the free block count drifts. On an unallocated space table the second free adds a second free extent for the same block, which is later handed out twice: fsx as run by generic/091 and generic/263 ends up with two parts of its test file in one block and reads back bad data. Peek into separate variables, so that eloc and elen keep the last extent that udf_next_aext() returned with 1. Fixes: cfe4c1b25dd6 ("udf: Fix preallocation discarding at indirect extent boundary") Cc: stable@vger.kernel.org Suggested-by: Jan Kara Signed-off-by: Matthias Goergens Link: https://patch.msgid.link/480eccd1264a4cea5226fc36ed108931b2c403fb.1793349907.git.matthias.goergens@gmail.com Signed-off-by: Jan Kara --- fs/udf/truncate.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/fs/udf/truncate.c b/fs/udf/truncate.c index 0990f94b85518..75151a59f0da6 100644 --- a/fs/udf/truncate.c +++ b/fs/udf/truncate.c @@ -124,8 +124,8 @@ void udf_discard_prealloc(struct inode *inode) { struct extent_position epos = {}; struct extent_position prev_epos = {}; - struct kernel_lb_addr eloc; - uint32_t elen; + struct kernel_lb_addr eloc, tmpeloc; + uint32_t elen, tmpelen; uint64_t lbcount = 0; int8_t etype = -1; struct udf_inode_info *iinfo = UDF_I(inode); @@ -141,7 +141,8 @@ void udf_discard_prealloc(struct inode *inode) /* Find the last extent in the file */ while (1) { - ret = udf_next_aext(inode, &epos, &eloc, &elen, &tmpetype, 0); + ret = udf_next_aext(inode, &epos, &tmpeloc, &tmpelen, + &tmpetype, 0); if (ret < 0) goto out; if (ret == 0) -- 2.53.0