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From:   Manas Ghandat <ghandatmanas@gmail.com>
To:     anton@tuxera.com, linkinjeon@kernel.org
Cc:     Manas Ghandat <ghandatmanas@gmail.com>,
        linux-ntfs-dev@lists.sourceforge.net, linux-kernel@vger.kernel.org,
        linux-fsdevel@vger.kernel.org,
        Linux-kernel-mentees@lists.linuxfoundation.org,
        syzbot+4768a8f039aa677897d0@syzkaller.appspotmail.com
Subject: [PATCH] ntfs : fix shift-out-of-bounds in ntfs_iget
Date:   Tue,  8 Aug 2023 10:04:05 +0530
Message-Id: <20230808043404.9028-1-ghandatmanas@gmail.com>
MIME-Version: 1.0
Content-Transfer-Encoding: 8bit
Precedence: bulk

Added a check to the compression_unit so that out of bound doesn't
occur.

Signed-off-by: Manas Ghandat <ghandatmanas@gmail.com>
Reported-by: syzbot+4768a8f039aa677897d0@syzkaller.appspotmail.com
---
 fs/ntfs/inode.c | 11 +++++++++++
 1 file changed, 11 insertions(+)

diff --git a/fs/ntfs/inode.c b/fs/ntfs/inode.c
index 6c3f38d66579..2ee100a7df32 100644
--- a/fs/ntfs/inode.c
+++ b/fs/ntfs/inode.c
@@ -1077,6 +1077,17 @@ static int ntfs_read_locked_inode(struct inode *vi)
 					goto unm_err_out;
 				}
 				if (a->data.non_resident.compression_unit) {
+					if(a->data.non_resident.compression_unit + 
+						vol->cluster_size_bits > 32) {
+							ntfs_error(vi->i_sb, "Found "
+								"non-standard "
+								"compression unit (%u).   "
+								"Cannot handle this.",
+								a->data.non_resident.
+								compression_unit);
+							err = -EOPNOTSUPP;
+							goto unm_err_out;
+						}
 					ni->itype.compressed.block_size = 1U <<
 							(a->data.non_resident.
 							compression_unit +
-- 
2.37.2