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=1794049019; b=4cmdnaN26km4x5VfUD70E632EvGfdKXu/znB1gP/VBMWfCQEPFpLISmhzQqAiNUxjTQ+ A+FJ+GOEkPNQSmeP3imUWAPmQHnt5zLHceeVDy0W4ulA0oJ3mp/kS+CVot42NVeFnM1Ai hUp3CjjWgXxcX8GlgS4SHfgH0jVOU9aqOzB4G0FjwA6SohXW+Z44JCa6lU2L+u8bkH68w +esmgPpamFCy1KBpQ9AxpoxArfaOvuAcbmBygzi1vYeUL0GncOgChwE/tyZxiQrUn7Y8d VQ3lUpNPJ+mx5nYAp21jAxK/aLWdCoviyPUF4mP/2Q2IiS3eATQ7QFHA10F8eDcLWxw== ARC-Message-Signature: i=1; d=subspace.kernel.org; s=arc20261015; a=rsa-sha256; c=relaxed/relaxed; t=1794049019; h=Received:DKIM-Signature:From:To:Cc:Subject:Date:Message-ID:X-Mailer: MIME-Version:Content-Type:Content-Transfer-Encoding; bh=0joekEClLzdpbVYW2DkDXFQp3Xb24A2IVHBskbqEOIk=; b=H7/fujHuWbSb6vl4ISw6W/BMrFvNoMljfh7VRlk/G00rDiL7yc2m7THfmy5adlD1kesQ TQzEQftJ0LcR2vKtngnP9RaXOWCV/YVC/bM/Zit1wYJN/WBJJuKazv0UW28ycDMt+E2RN zbCP0+IFFsguW2HLMsA6DHw0+blSEonHw+FPAdCAAW+WJP9GgwxcujtI9AI3nJMNl2WsH kMkkpP8o1i2s9w50hYNUXXftXiwmhfWoF2IHcWbNb0UKzBk9GLP0916YAS6i+eYdeSnfC bCYK556FhzhTuukvmQcIu7H+vk2j7nLXkM6seKws/rN2tkq/7MziJMal9t7hVL+a9Kg== 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=ZcUy7Wy8; 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 7CA7D606A33E for ; Sat, 7 Nov 2026 10:56:59 +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=ZcUy7Wy8 Received: by smtp.kernel.org (Postfix) with ESMTPSA id AF28A1F008A3; Sat, 7 Nov 2026 10:56:58 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1794049019; bh=0joekEClLzdpbVYW2DkDXFQp3Xb24A2IVHBskbqEOIk=; h=From:To:Cc:Subject:Date; b=ZcUy7Wy8m+rbtl4zClA0zQ7tarRhpEArXWxaR1xBI3+n9jlkyTqSkzvI8EnmmBw7X UU+iavewO5f06x3ZhDIir6oLHOcWpRoDWBT/85Mit1DFR29PtBzBDXaFhlYMPoBZ2K qXqS81zbK5BqdXmO8DdKQqJTmQ9ewsTDHSatDk5q96rpSCi729kdXq21oke0ljQZcE ogxFy3UWdgKGXg0ErDt/sP3Dsmxg/SVrk+5Wq+8jAMV0eAKBHwL36XgW6yerSaoB0Y cwO0FEvOX7UpRdyfOsTP/mhSP/RaatKxg114Ocn2Fs6qp+7WoTjkWU4cRctkmQpQUu KkWw//s8BRFrQ== From: Sasha Levin To: 4ncienth@gmail.com, brauner@kernel.org Cc: stable@vger.kernel.org Subject: FAILED: patch "[PATCH] splice: avoid stale f_pos writeback on error" failed to apply to 6.1-stable tree Date: Sat, 7 Nov 2026 05:56:57 -0500 Message-ID: <20261107055657-failed-6.1-79b496ebe382@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 6.1-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-6.1.y git checkout FETCH_HEAD git cherry-pick -x 79b496ebe382866e3a05090b7dc9ae95e85e65b2 # git commit -s git send-email --to '' --in-reply-to '20261107055657-failed-6.1-79b496ebe382@kernel.org' --subject-prefix 'PATCH 6.1.y' 'HEAD^..' Thanks, Sasha ------------------ original commit in Linus's tree ------------------ >From 79b496ebe382866e3a05090b7dc9ae95e85e65b2 Mon Sep 17 00:00:00 2001 From: Daehyeon Ko <4ncienth@gmail.com> Date: Sun, 18 Oct 2026 14:17:08 +0900 Subject: [PATCH] splice: avoid stale f_pos writeback on error do_splice() snapshots an implicit file position before calling the splice helper. Since splice does not take f_pos_lock, another operation on the same open file description can update f_pos while the helper is blocked. If the helper then fails, the unconditional writeback restores the stale snapshot. For a directory without ->splice_read, a file-to-pipe splice fails with -EINVAL. A concurrent directory mutation and getdents() call can advance f_pos and refresh the filesystem's revalidation cookie before that failure restores only the old position. The next ext2 readdir can then trust an offset inside a directory entry and copy data from the adjacent page to userspace. Only update an implicit file position when splice returns a non-negative result, matching read and write. Keep explicit offset updates unchanged. Fixes: 7995bd287134 ("splice: don't pass the address of ->f_pos to methods") Cc: stable@vger.kernel.org Signed-off-by: Daehyeon Ko <4ncienth@gmail.com> Link: https://patch.msgid.link/20261018051708.2422394-1-4ncienth@gmail.com Signed-off-by: Christian Brauner (Amutable) --- fs/splice.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/fs/splice.c b/fs/splice.c index bc243ab8dc431..f4bce35890671 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1377,10 +1377,10 @@ ssize_t do_splice(struct file *in, loff_t *off_in, struct file *out, ret = do_splice_from(ipipe, out, &offset, len, flags); file_end_write(out); - if (!off_out) - out->f_pos = offset; - else + if (off_out) *off_out = offset; + else if (ret >= 0) + out->f_pos = offset; } else if (opipe) { if (off_out) return -ESPIPE; @@ -1401,10 +1401,10 @@ ssize_t do_splice(struct file *in, loff_t *off_in, struct file *out, ret = splice_file_to_pipe(in, opipe, &offset, len, flags); - if (!off_in) - in->f_pos = offset; - else + if (off_in) *off_in = offset; + else if (ret >= 0) + in->f_pos = offset; } else { ret = -EINVAL; } -- 2.53.0