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 3CA6E1D5CE8 for ; Thu, 16 Oct 2025 14:14:48 +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=1760624089; cv=none; b=LBDoS4so/NIXZ+D2uaW10uZGdbIlKUYDtQcpu4Bfek7zm0sLVT1oc4IZyaGyG5kMzvUlxZAR3NCJ0aAkOe/pPUUKRApLfEP+TOWSgCq7k3/bzYNEdZ2IeEZyyDcnwf09m+snjmftM1Bm42UiTOWvrzdoFznHcrPYqXmY07H5pFE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760624089; c=relaxed/simple; bh=em3R7shSQq4FjfqYK/uTMwMpvpwmFNJyF2w2/+rBdQQ=; h=Subject:To:Cc:From:Date:Message-ID:MIME-Version:Content-Type; b=LZigopOexK8FfKDYY5q+pRF8p1sinSWNPfAUX0v82UCjhRcsWf8JYCrrG/W7wEDggOH3emAz4fslyj3iz9b//uL+TNGklJ6jrUJb+eot1AkEEXeE33j7kqpozHksXFepJiYbQZb9bt4HQ4K9mSbjnH97gau+yasd03QgvpOAfCA= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=Oly42VDw; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="Oly42VDw" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 66CD2C4CEF1; Thu, 16 Oct 2025 14:14:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1760624088; bh=em3R7shSQq4FjfqYK/uTMwMpvpwmFNJyF2w2/+rBdQQ=; h=Subject:To:Cc:From:Date:From; b=Oly42VDw9aLGKSip8emuKKbrl9UP203T0Mwuv1V3fbl37I7Mry8dN2zeF22JtC03z D9Di+dWMA0YtB555i1CiFMLprJPWpIWcg0cs710ZIlnTZ+NqR/N1ssP/YbuTJDjpzU G0fo/fOzmLi6N//oLzRnKEQdasoO1gOMAsciQ3H8= Subject: FAILED: patch "[PATCH] ext4: avoid potential buffer over-read in" failed to apply to 5.10-stable tree To: tytso@mit.edu,djwong@kernel.org,jack@suse.cz Cc: From: Date: Thu, 16 Oct 2025 16:14:35 +0200 Message-ID: <2025101635-unbuckled-masses-9441@gregkh> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 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 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 # git commit -s git send-email --to '' --in-reply-to '2025101635-unbuckled-masses-9441@gregkh' --subject-prefix 'PATCH 5.10.y' HEAD^.. Possible dependencies: thanks, greg k-h ------------------ original commit in Linus's tree ------------------ >From 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8 Mon Sep 17 00:00:00 2001 From: Theodore Ts'o Date: Tue, 16 Sep 2025 23:22:47 -0400 Subject: [PATCH] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Unlike other strings in the ext4 superblock, we rely on tune2fs to make sure s_mount_opts is NUL terminated. Harden parse_apply_sb_mount_options() by treating s_mount_opts as a potential __nonstring. Cc: stable@vger.kernel.org Fixes: 8b67f04ab9de ("ext4: Add mount options in superblock") Reviewed-by: Jan Kara Reviewed-by: Darrick J. Wong Signed-off-by: Theodore Ts'o Message-ID: <20250916-tune2fs-v2-1-d594dc7486f0@mit.edu> Signed-off-by: Theodore Ts'o diff --git a/fs/ext4/super.c b/fs/ext4/super.c index d26e5c0731e5..488f4c281a3f 100644 --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -2469,7 +2469,7 @@ static int parse_apply_sb_mount_options(struct super_block *sb, struct ext4_fs_context *m_ctx) { struct ext4_sb_info *sbi = EXT4_SB(sb); - char *s_mount_opts = NULL; + char s_mount_opts[65]; struct ext4_fs_context *s_ctx = NULL; struct fs_context *fc = NULL; int ret = -ENOMEM; @@ -2477,15 +2477,11 @@ static int parse_apply_sb_mount_options(struct super_block *sb, if (!sbi->s_es->s_mount_opts[0]) return 0; - s_mount_opts = kstrndup(sbi->s_es->s_mount_opts, - sizeof(sbi->s_es->s_mount_opts), - GFP_KERNEL); - if (!s_mount_opts) - return ret; + strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts); fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL); if (!fc) - goto out_free; + return -ENOMEM; s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL); if (!s_ctx) @@ -2517,11 +2513,8 @@ static int parse_apply_sb_mount_options(struct super_block *sb, ret = 0; out_free: - if (fc) { - ext4_fc_free(fc); - kfree(fc); - } - kfree(s_mount_opts); + ext4_fc_free(fc); + kfree(fc); return ret; }