[PATCH 4.14 23/59] squashfs: fix xattr id and id lookup sanity checks

Greg Kroah-Hartman
2021-03-29T08:08:55Z

From: Phillip Lougher <phillip@squashfs.org.uk>

commit 8b44ca2b634527151af07447a8090a5f3a043321 upstream.

The checks for maximum metadata block size is missing
SQUASHFS_BLOCK_OFFSET (the two byte length count).

Link: https://lkml.kernel.org/r/2069685113.2081245.1614583677427@webmail.123-reg.co.uk
Fixes: f37aa4c7366e23f ("squashfs: add more sanity checks in id lookup")
Signed-off-by: Phillip Lougher <phillip@squashfs.org.uk>
Cc: Sean Nyekjaer <sean@geanix.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/squashfs/id.c | 6 ++++--
fs/squashfs/xattr_id.c | 6 ++++--
2 files changed, 8 insertions(+), 4 deletions(-)

--- a/fs/squashfs/id.c
+++ b/fs/squashfs/id.c
@@ -110,14 +110,16 @@ __le64 *squashfs_read_id_index_table(str
start = le64_to_cpu(table[n]);
end = le64_to_cpu(table[n + 1]);

- if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
+ 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 >= id_table_start || (id_table_start - start) > SQUASHFS_METADATA_SIZE) {
+ if (start >= id_table_start || (id_table_start - start) >
+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
kfree(table);
return ERR_PTR(-EINVAL);
}
--- a/fs/squashfs/xattr_id.c
+++ b/fs/squashfs/xattr_id.c
@@ -122,14 +122,16 @@ __le64 *squashfs_read_xattr_id_table(str
start = le64_to_cpu(table[n]);
end = le64_to_cpu(table[n + 1]);

- if (start >= end || (end - start) > SQUASHFS_METADATA_SIZE) {
+ 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) {
+ if (start >= table_start || (table_start - start) >
+ (SQUASHFS_METADATA_SIZE + SQUASHFS_BLOCK_OFFSET)) {
kfree(table);
return ERR_PTR(-EINVAL);
}