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From: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
To: <ntfs3@lists.linux.dev>
CC: <linux-kernel@vger.kernel.org>, <linux-fsdevel@vger.kernel.org>,
	Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Subject: [PATCH 04/18] fs/ntfs3: Deny getting attr data block in compressed frame
Date: Fri, 7 Jun 2024 15:15:34 +0300
Message-ID: <20240607121548.18818-5-almaz.alexandrovich@paragon-software.com>
In-Reply-To: <20240607121548.18818-1-almaz.alexandrovich@paragon-software.com>
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Attempting to retrieve an attribute data block in a compressed frame
is ignored.

Fixes: be71b5cba2e64 ("fs/ntfs3: Add attrib operations")
Signed-off-by: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
---
 fs/ntfs3/attrib.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/fs/ntfs3/attrib.c b/fs/ntfs3/attrib.c
index 8638248d80d9..7918ab1a3f35 100644
--- a/fs/ntfs3/attrib.c
+++ b/fs/ntfs3/attrib.c
@@ -975,6 +975,19 @@ int attr_data_get_block(struct ntfs_inode *ni, CLST vcn, CLST clen, CLST *lcn,
 	if (err)
 		goto out;
 
+	/* Check for compressed frame. */
+	err = attr_is_frame_compressed(ni, attr, vcn >> NTFS_LZNT_CUNIT, &hint);
+	if (err)
+		goto out;
+
+	if (hint) {
+		/* if frame is compressed - don't touch it. */
+		*lcn = COMPRESSED_LCN;
+		*len = hint;
+		err = -EOPNOTSUPP;
+		goto out;
+	}
+
 	if (!*len) {
 		if (run_lookup_entry(run, vcn, lcn, len, NULL)) {
 			if (*lcn != SPARSE_LCN || !new)
-- 
2.34.1