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 47F1E31354F; Tue, 31 Mar 2026 17:08:10 +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=1774976890; cv=none; b=M+q2L9d44/vQhCJ0/8KJqXiaUAm0m13HeGZnI5yN4vWTE1HeVa73ytrTfeTK9puhAbcYvTAglU0vuOkz7YvFyaoFk8WQ28k5jNosQ3g8V2fpHxY5Lyd+V06IyPOoEKeAsrJBe3STEjmRUwp6CM19y8YTsJYgn7AQg/c3UsRkqDI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774976890; c=relaxed/simple; bh=d6tYJpu7xTyVPZtpZfGcfIberheStj/Z+RReI6s7heU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tGyKnghHrfAaZ9KiyAzE36NORvL1Z/HamRGlqJjP1vfF+KgZAjEtl4EhE18h543o0hE1IBmU37gl8U526UA66OVpaSZy7d72+uEgeN2Yvg0S785bU8oteo/haLGg5scJzyzzrfSm0TD1bbCkoXwEb8o+AA2gWtxfCwroBHll80M= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=QYRXBG0m; 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="QYRXBG0m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CF6A0C19423; Tue, 31 Mar 2026 17:08:09 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774976890; bh=d6tYJpu7xTyVPZtpZfGcfIberheStj/Z+RReI6s7heU=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=QYRXBG0mdRWTlQDk0PoRTYiNIVw3F1YsT9tuutM3C8iX+lXZmHTDuxbf4uLcYFXiP yZ0feqcA8kLjFKz+QfOUn7fZiJOvUevxa2E3y/OwWTsE87Ej7MWhwu2rD8YYBJcOu/ /GgFPiafVD7fSUf+PBsUfBtgCqLXbgnwilQZCg2w= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Helen Koike , Theodore Tso , syzbot+b73703b873a33d8eb8f6@syzkaller.appspotmail.com, stable@kernel.org Subject: [PATCH 6.18 266/309] ext4: reject mount if bigalloc with s_first_data_block != 0 Date: Tue, 31 Mar 2026 18:22:49 +0200 Message-ID: <20260331161803.355887903@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161753.468533260@linuxfoundation.org> References: <20260331161753.468533260@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.18-stable review patch. If anyone has any objections, please let me know. ------------------ From: Helen Koike commit 3822743dc20386d9897e999dbb990befa3a5b3f8 upstream. bigalloc with s_first_data_block != 0 is not supported, reject mounting it. Signed-off-by: Helen Koike Suggested-by: Theodore Ts'o Reported-by: syzbot+b73703b873a33d8eb8f6@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=b73703b873a33d8eb8f6 Link: https://patch.msgid.link/20260317142325.135074-1-koike@igalia.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org Signed-off-by: Greg Kroah-Hartman --- fs/ext4/super.c | 7 +++++++ 1 file changed, 7 insertions(+) --- a/fs/ext4/super.c +++ b/fs/ext4/super.c @@ -3624,6 +3624,13 @@ int ext4_feature_set_ok(struct super_blo "extents feature\n"); return 0; } + if (ext4_has_feature_bigalloc(sb) && + le32_to_cpu(EXT4_SB(sb)->s_es->s_first_data_block)) { + ext4_msg(sb, KERN_WARNING, + "bad geometry: bigalloc file system with non-zero " + "first_data_block\n"); + return 0; + } #if !IS_ENABLED(CONFIG_QUOTA) || !IS_ENABLED(CONFIG_QFMT_V2) if (!readonly && (ext4_has_feature_quota(sb) ||