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 AD12F224AFE; Mon, 13 Jan 2025 18:36:41 +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=1736793401; cv=none; b=lnKRSCXYRCaV0hEGx0HFmjg4RNrD/T7jjDe7eexwQ+6SsNJFntjl9Vo+pP6+qHZ7TP+Edh2TxNffttjDFqnY+BxTCHmEVPn14rXVHzqD3Rg0gvibkCKmVvl1/nWv53FPpDnBQiWPj4NbR07P7Vn89U8HbaLCvEcvjNG4YZKWRrI= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736793401; c=relaxed/simple; bh=OSMd6m3CV9jUJ8WykRwJ1KDi0nH2xHT6tg95x+6TSTE=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=OfIIXoHIQpabpGFWyHCYZlQ/LbkYK23d2HyCJ2nSWLb0xZuTHOuev6TjDgak7oVzXa4dEhttPUne1IGhVFyNeM/K/F1W9Qz7yHl/JguMVL4DL4qhk1a99ifOyp7ONnukdxUBqqWPCMSw2jFzjSfAwdA1s+8+F+J0fJDH/yi8ETg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nRG3TzZ7; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nRG3TzZ7" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 638D9C4CED6; Mon, 13 Jan 2025 18:36:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1736793401; bh=OSMd6m3CV9jUJ8WykRwJ1KDi0nH2xHT6tg95x+6TSTE=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=nRG3TzZ7riGviLHQv+8zZWc/liDi0FDgDzd5F+Taro6pfxyMP7luYTY63tsvXlepi d1yN/e55pIvdGZKibkUPG+ZJNVCXl6g71PH1BRPtSLaEtsJgLG1cKp2EgdlmaVr2pD bT8wYAF98LhdKZ9ib8GfO/6Tl4Iu/lKFjztI0HstVNQpcNI6FwZR3sCHpYRnyNjQ/b BF9rs7FfoUPgc+Cz+3LFWwPquks+AmH5pdFqp0WgpUX/P1yw2GGrbQMQskxdizBOSy xnqrSmuLzq9RwE+ELKxopuPa0v9XmxyW3EqGJ7zfiY47skBOevJZwta3ZtiYnRk01n fNX9pMxyeBwFw== From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Leo Stone , syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com, Jan Kara , Christian Brauner , Sasha Levin , quic_jjohnson@quicinc.com, viro@zeniv.linux.org.uk, sandeen@redhat.com, linux-fsdevel@vger.kernel.org Subject: [PATCH AUTOSEL 5.4 2/4] hfs: Sanity check the root record Date: Mon, 13 Jan 2025 13:36:31 -0500 Message-Id: <20250113183633.1784590-2-sashal@kernel.org> X-Mailer: git-send-email 2.39.5 In-Reply-To: <20250113183633.1784590-1-sashal@kernel.org> References: <20250113183633.1784590-1-sashal@kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore X-stable-base: Linux 5.4.289 Content-Transfer-Encoding: 8bit From: Leo Stone [ Upstream commit b905bafdea21a75d75a96855edd9e0b6051eee30 ] In the syzbot reproducer, the hfs_cat_rec for the root dir has type HFS_CDR_FIL after being read with hfs_bnode_read() in hfs_super_fill(). This indicates it should be used as an hfs_cat_file, which is 102 bytes. Only the first 70 bytes of that struct are initialized, however, because the entrylength passed into hfs_bnode_read() is still the length of a directory record. This causes uninitialized values to be used later on, when the hfs_cat_rec union is treated as the larger hfs_cat_file struct. Add a check to make sure the retrieved record has the correct type for the root directory (HFS_CDR_DIR), and make sure we load the correct number of bytes for a directory record. Reported-by: syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=2db3c7526ba68f4ea776 Tested-by: syzbot+2db3c7526ba68f4ea776@syzkaller.appspotmail.com Tested-by: Leo Stone Signed-off-by: Leo Stone Link: https://lore.kernel.org/r/20241201051420.77858-1-leocstone@gmail.com Reviewed-by: Jan Kara Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin --- fs/hfs/super.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/fs/hfs/super.c b/fs/hfs/super.c index bcf820ce0e02..f82444fbbedc 100644 --- a/fs/hfs/super.c +++ b/fs/hfs/super.c @@ -419,11 +419,13 @@ static int hfs_fill_super(struct super_block *sb, void *data, int silent) goto bail_no_root; res = hfs_cat_find_brec(sb, HFS_ROOT_CNID, &fd); if (!res) { - if (fd.entrylength > sizeof(rec) || fd.entrylength < 0) { + if (fd.entrylength != sizeof(rec.dir)) { res = -EIO; goto bail_hfs_find; } hfs_bnode_read(fd.bnode, &rec, fd.entryoffset, fd.entrylength); + if (rec.type != HFS_CDR_DIR) + res = -EIO; } if (res) goto bail_hfs_find; -- 2.39.5