From: Joe Thornber Date: Thu, 10 Dec 2015 14:37:53 +0000 (+0000) Subject: dm btree: fix bufio buffer leaks in dm_btree_del() error path X-Git-Tag: v3.12.56~49 X-Git-Url: http://git.hungrycats.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c96f4852b59b919f747a5fba9320a12f23971e8c;p=linux dm btree: fix bufio buffer leaks in dm_btree_del() error path commit ed8b45a3679eb49069b094c0711b30833f27c734 upstream. If dm_btree_del()'s call to push_frame() fails, e.g. due to btree_node_validator finding invalid metadata, the dm_btree_del() error path must unlock all frames (which have active dm-bufio buffers) that were pushed onto the del_stack. Otherwise, dm_bufio_client_destroy() will BUG_ON() because dm-bufio buffers have leaked, e.g.: device-mapper: bufio: leaked buffer 3, hold count 1, list 0 Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Jiri Slaby --- diff --git a/drivers/md/persistent-data/dm-btree.c b/drivers/md/persistent-data/dm-btree.c index 28662bd600e0..67eae74a5525 100644 --- a/drivers/md/persistent-data/dm-btree.c +++ b/drivers/md/persistent-data/dm-btree.c @@ -250,6 +250,16 @@ static void pop_frame(struct del_stack *s) dm_tm_unlock(s->tm, f->b); } +static void unlock_all_frames(struct del_stack *s) +{ + struct frame *f; + + while (unprocessed_frames(s)) { + f = s->spine + s->top--; + dm_tm_unlock(s->tm, f->b); + } +} + int dm_btree_del(struct dm_btree_info *info, dm_block_t root) { int r; @@ -306,9 +316,13 @@ int dm_btree_del(struct dm_btree_info *info, dm_block_t root) pop_frame(s); } } - out: + if (r) { + /* cleanup all frames of del_stack */ + unlock_all_frames(s); + } kfree(s); + return r; } EXPORT_SYMBOL_GPL(dm_btree_del);