Commit 95a22d20 authored Jul 01, 2018 by Richard Weinberger

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: 1e51764a ("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>

parent 08acbdd6

fs/ubifs/journal.c

+10 −1

Original line number	Diff line number	Diff line
		@@ -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);

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