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authorDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
committerDaniel Baumann <daniel.baumann@progress-linux.org>2024-04-07 18:49:45 +0000
commit2c3c1048746a4622d8c89a29670120dc8fab93c4 (patch)
tree848558de17fb3008cdf4d861b01ac7781903ce39 /fs/squashfs/xattr_id.c
parentInitial commit. (diff)
downloadlinux-2c3c1048746a4622d8c89a29670120dc8fab93c4.tar.xz
linux-2c3c1048746a4622d8c89a29670120dc8fab93c4.zip
Adding upstream version 6.1.76.upstream/6.1.76
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'fs/squashfs/xattr_id.c')
-rw-r--r--fs/squashfs/xattr_id.c132
1 files changed, 132 insertions, 0 deletions
diff --git a/fs/squashfs/xattr_id.c b/fs/squashfs/xattr_id.c
new file mode 100644
index 000000000..c8469c656
--- /dev/null
+++ b/fs/squashfs/xattr_id.c
@@ -0,0 +1,132 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/*
+ * Squashfs - a compressed read only filesystem for Linux
+ *
+ * Copyright (c) 2010
+ * Phillip Lougher <phillip@squashfs.org.uk>
+ *
+ * xattr_id.c
+ */
+
+/*
+ * This file implements code to map the 32-bit xattr id stored in the inode
+ * into the on disk location of the xattr data.
+ */
+
+#include <linux/fs.h>
+#include <linux/vfs.h>
+#include <linux/slab.h>
+
+#include "squashfs_fs.h"
+#include "squashfs_fs_sb.h"
+#include "squashfs.h"
+#include "xattr.h"
+
+/*
+ * Map xattr id using the xattr id look up table
+ */
+int squashfs_xattr_lookup(struct super_block *sb, unsigned int index,
+ int *count, unsigned int *size, unsigned long long *xattr)
+{
+ struct squashfs_sb_info *msblk = sb->s_fs_info;
+ int block = SQUASHFS_XATTR_BLOCK(index);
+ int offset = SQUASHFS_XATTR_BLOCK_OFFSET(index);
+ u64 start_block;
+ struct squashfs_xattr_id id;
+ int err;
+
+ if (index >= msblk->xattr_ids)
+ return -EINVAL;
+
+ start_block = le64_to_cpu(msblk->xattr_id_table[block]);
+
+ err = squashfs_read_metadata(sb, &id, &start_block, &offset,
+ sizeof(id));
+ if (err < 0)
+ return err;
+
+ *xattr = le64_to_cpu(id.xattr);
+ *size = le32_to_cpu(id.size);
+ *count = le32_to_cpu(id.count);
+ return 0;
+}
+
+
+/*
+ * Read uncompressed xattr id lookup table indexes from disk into memory
+ */
+__le64 *squashfs_read_xattr_id_table(struct super_block *sb, u64 table_start,
+ u64 *xattr_table_start, unsigned int *xattr_ids)
+{
+ struct squashfs_sb_info *msblk = sb->s_fs_info;
+ unsigned int len, indexes;
+ struct squashfs_xattr_id_table *id_table;
+ __le64 *table;
+ u64 start, end;
+ int n;
+
+ id_table = squashfs_read_table(sb, table_start, sizeof(*id_table));
+ if (IS_ERR(id_table))
+ return (__le64 *) id_table;
+
+ *xattr_table_start = le64_to_cpu(id_table->xattr_table_start);
+ *xattr_ids = le32_to_cpu(id_table->xattr_ids);
+ kfree(id_table);
+
+ /* Sanity check values */
+
+ /* there is always at least one xattr id */
+ if (*xattr_ids == 0)
+ return ERR_PTR(-EINVAL);
+
+ len = SQUASHFS_XATTR_BLOCK_BYTES(*xattr_ids);
+ indexes = SQUASHFS_XATTR_BLOCKS(*xattr_ids);
+
+ /*
+ * The computed size of the index table (len bytes) should exactly
+ * match the table start and end points
+ */
+ start = table_start + sizeof(*id_table);
+ end = msblk->bytes_used;
+
+ if (len != (end - start))
+ return ERR_PTR(-EINVAL);
+
+ table = squashfs_read_table(sb, start, len);
+ if (IS_ERR(table))
+ return table;
+
+ /* table[0], table[1], ... table[indexes - 1] store the locations
+ * of the compressed xattr id blocks. Each entry should be less than
+ * the next (i.e. table[0] < table[1]), and the difference between them
+ * should be SQUASHFS_METADATA_SIZE or less. table[indexes - 1]
+ * should be less than table_start, and again the difference
+ * shouls be SQUASHFS_METADATA_SIZE or less.
+ *
+ * Finally xattr_table_start should be less than table[0].
+ */
+ for (n = 0; n < (indexes - 1); n++) {
+ start = le64_to_cpu(table[n]);
+ end = le64_to_cpu(table[n + 1]);
+
+ if (start >= end || (end - start) >
+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
+ kfree(table);
+ return ERR_PTR(-EINVAL);
+ }
+ }
+
+ start = le64_to_cpu(table[indexes - 1]);
+ if (start >= table_start || (table_start - start) >
+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
+ kfree(table);
+ return ERR_PTR(-EINVAL);
+ }
+
+ if (*xattr_table_start >= le64_to_cpu(table[0])) {
+ kfree(table);
+ return ERR_PTR(-EINVAL);
+ }
+
+ return table;
+}