ext2: Fix oops in ext2_get_block() called from ext2_quota_write()

commit df4e7ac0bb upstream.

ext2_quota_write() doesn't properly setup bh it passes to
ext2_get_block() and thus we hit assertion BUG_ON(maxblocks == 0) in
ext2_get_blocks() (or we could actually ask for mapping arbitrary number
of blocks depending on whatever value was on stack).

Fix ext2_quota_write() to properly fill in number of blocks to map.

Reviewed-by: "Theodore Ts'o" <tytso@mit.edu>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This commit is contained in:
Jan Kara 2013-12-03 11:20:06 +01:00 committed by Greg Kroah-Hartman
parent 4ca178ae0f
commit b083f7cd52

View File

@ -1493,6 +1493,7 @@ static ssize_t ext2_quota_write(struct super_block *sb, int type,
sb->s_blocksize - offset : towrite;
tmp_bh.b_state = 0;
tmp_bh.b_size = sb->s_blocksize;
err = ext2_get_block(inode, blk, &tmp_bh, 1);
if (err < 0)
goto out;