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From:   Peilin Ye <yepeilin.cs@gmail.com>
To:     Jan Kara <jack@suse.com>
Cc:     Peilin Ye <yepeilin.cs@gmail.com>,
        Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        linux-kernel-mentees@lists.linuxfoundation.org,
        syzkaller-bugs@googlegroups.com, linux-kernel@vger.kernel.org
Subject: [Linux-kernel-mentees] [PATCH] udf: Fix memory leak in udf_process_sequence()
Date:   Tue, 22 Sep 2020 11:45:31 -0400
Message-Id: <20200922154531.153922-1-yepeilin.cs@gmail.com>
In-Reply-To: <0000000000004c1f4d05afcff2f4@google.com>
References: <0000000000004c1f4d05afcff2f4@google.com>
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udf_process_sequence() is leaking memory. Free `data.part_descs_loc`
before returning.

Cc: stable@vger.kernel.org
Fixes: 7b78fd02fb19 ("udf: Fix handling of Partition Descriptors")
Reported-and-tested-by: syzbot+128f4dd6e796c98b3760@syzkaller.appspotmail.com
Link: https://syzkaller.appspot.com/bug?id=c5ec4e6f5d818f3c4afd4d59342468eec08a38da
Signed-off-by: Peilin Ye <yepeilin.cs@gmail.com>
---
 fs/udf/super.c | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/fs/udf/super.c b/fs/udf/super.c
index 1c42f544096d..b0d862ab3024 100644
--- a/fs/udf/super.c
+++ b/fs/udf/super.c
@@ -1698,7 +1698,8 @@ static noinline int udf_process_sequence(
 					"Pointers (max %u supported)\n",
 					UDF_MAX_TD_NESTING);
 				brelse(bh);
-				return -EIO;
+				ret = -EIO;
+				goto out;
 			}
 
 			vdp = (struct volDescPtr *)bh->b_data;
@@ -1718,7 +1719,8 @@ static noinline int udf_process_sequence(
 			curr = get_volume_descriptor_record(ident, bh, &data);
 			if (IS_ERR(curr)) {
 				brelse(bh);
-				return PTR_ERR(curr);
+				ret = PTR_ERR(curr);
+				goto out;
 			}
 			/* Descriptor we don't care about? */
 			if (!curr)
@@ -1740,28 +1742,32 @@ static noinline int udf_process_sequence(
 	 */
 	if (!data.vds[VDS_POS_PRIMARY_VOL_DESC].block) {
 		udf_err(sb, "Primary Volume Descriptor not found!\n");
-		return -EAGAIN;
+		ret = -EAGAIN;
+		goto out;
 	}
 	ret = udf_load_pvoldesc(sb, data.vds[VDS_POS_PRIMARY_VOL_DESC].block);
 	if (ret < 0)
-		return ret;
+		goto out;
 
 	if (data.vds[VDS_POS_LOGICAL_VOL_DESC].block) {
 		ret = udf_load_logicalvol(sb,
 				data.vds[VDS_POS_LOGICAL_VOL_DESC].block,
 				fileset);
 		if (ret < 0)
-			return ret;
+			goto out;
 	}
 
 	/* Now handle prevailing Partition Descriptors */
 	for (i = 0; i < data.num_part_descs; i++) {
 		ret = udf_load_partdesc(sb, data.part_descs_loc[i].rec.block);
 		if (ret < 0)
-			return ret;
+			goto out;
 	}
 
-	return 0;
+	ret = 0;
+out:
+	kfree(data.part_descs_loc);
+	return ret;
 }
 
 /*
-- 
2.25.1