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 D5D263E3D82; Tue, 31 Mar 2026 16:29:33 +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=1774974573; cv=none; b=ePC1dFvW5iYEXhbf8de5YcaHm3nvU/IBFKxDCEfkSTxoHzEEhVSywl+nYD01ixS+uEoeLs5F+faW3Q4LGPe/ITud5Hz4OAcpzzhUafEwWyL8CZJzewEuotZFUPm0gQsjWya6IMXihdbH7ecL44PoHEJ6aZABn85ynnqT2vqQNuA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774974573; c=relaxed/simple; bh=0kH3pI92jbYpRpw6ON8Ft4EXEibS1eLOnV7iSSWhvL8=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=OomDyrexAujJqtLYiAKtPahL9GP6b1JvUaKc5XH5FtW8Z7Oln0/1roo6EVt8apXrfWwGD7w/3PpFJTff4EGbXMBEwv9IoWJk5AiMdLzBBatumd+DPPY0kzf5kN17TxJsH0agqR7AfjalEewBsMhC4vG3zYQIBZeZwZhHyxnrsKI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xyBy+pRs; 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="xyBy+pRs" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34989C19423; Tue, 31 Mar 2026 16:29:33 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1774974573; bh=0kH3pI92jbYpRpw6ON8Ft4EXEibS1eLOnV7iSSWhvL8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xyBy+pRsbDPXkdC9aV1WCwGA++CaTX8gllqFabHpiNFWlHVx9I8i9CDSrsE7LsBCc Obz6Sm0q690KmWnue1yREIiomOrULdWSM7qIbJJtL6ZWTkUKvqiz8QO+wPKkq9mGpO 8qVrMBKYMpchbdEpzMLZhydLYTSEUu3aYu8Dp+Lg= 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 6.6 137/175] ext4: reject mount if bigalloc with s_first_data_block != 0 Date: Tue, 31 Mar 2026 18:22:01 +0200 Message-ID: <20260331161734.820830652@linuxfoundation.org> X-Mailer: git-send-email 2.53.0 In-Reply-To: <20260331161729.779738837@linuxfoundation.org> References: <20260331161729.779738837@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 6.6-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 @@ -3655,6 +3655,13 @@ 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) ||