ubifs: Check data node size before truncate

Check whether the size is within bounds before using it.
If the size is not correct, abort and dump the bad data node.

Cc: Kees Cook <keescook@chromium.org>
Cc: Silvio Cesare <silvio.cesare@gmail.com>
Cc: stable@vger.kernel.org
Fixes: 1e51764a3c ("UBIFS: add new flash file system")
Reported-by: Silvio Cesare <silvio.cesare@gmail.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
Reviewed-by: Kees Cook <keescook@chromium.org>
Signed-off-by: Richard Weinberger <richard@nod.at>
This commit is contained in:
Richard Weinberger 2018-07-01 23:20:51 +02:00
parent 08acbdd6fd
commit 95a22d2084

View File

@ -1393,7 +1393,16 @@ int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
else if (err)
goto out_free;
else {
if (le32_to_cpu(dn->size) <= dlen)
int dn_len = le32_to_cpu(dn->size);
if (dn_len <= 0 || dn_len > UBIFS_BLOCK_SIZE) {
ubifs_err(c, "bad data node (block %u, inode %lu)",
blk, inode->i_ino);
ubifs_dump_node(c, dn);
goto out_free;
}
if (dn_len <= dlen)
dlen = 0; /* Nothing to do */
else {
err = truncate_data_node(c, inode, blk, dn, &dlen);