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authorQu Wenruo <wqu@suse.com>2018-07-03 17:10:07 +0800
committerGreg Kroah-Hartman <gregkh@linuxfoundation.org>2018-09-15 09:40:40 +0200
commit510825b3f8c1f5dc29b81660e1eb68e7fb0b8d50 (patch)
tree7cabc1d9f7f322683925024d34334a536a0cb59d /fs
parentaccb3e424b8b6b9fa51b77fcf7e6673f40d182a6 (diff)
btrfs: relocation: Only remove reloc rb_trees if reloc control has been initialized
[ Upstream commit 389305b2aa68723c754f88d9dbd268a400e10664 ] Invalid reloc tree can cause kernel NULL pointer dereference when btrfs does some cleanup of the reloc roots. It turns out that fs_info::reloc_ctl can be NULL in btrfs_recover_relocation() as we allocate relocation control after all reloc roots have been verified. So when we hit: note, we haven't called set_reloc_control() thus fs_info::reloc_ctl is still NULL. Link: https://bugzilla.kernel.org/show_bug.cgi?id=199833 Reported-by: Xu Wen <wen.xu@gatech.edu> Signed-off-by: Qu Wenruo <wqu@suse.com> Tested-by: Gu Jinxiang <gujx@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Sasha Levin <alexander.levin@microsoft.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
-rw-r--r--fs/btrfs/relocation.c23
1 files changed, 12 insertions, 11 deletions
diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 9ebe027cc4b7..cfe913d2d3df 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1318,18 +1318,19 @@ static void __del_reloc_root(struct btrfs_root *root)
struct mapping_node *node = NULL;
struct reloc_control *rc = root->fs_info->reloc_ctl;
- spin_lock(&rc->reloc_root_tree.lock);
- rb_node = tree_search(&rc->reloc_root_tree.rb_root,
- root->node->start);
- if (rb_node) {
- node = rb_entry(rb_node, struct mapping_node, rb_node);
- rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
+ if (rc) {
+ spin_lock(&rc->reloc_root_tree.lock);
+ rb_node = tree_search(&rc->reloc_root_tree.rb_root,
+ root->node->start);
+ if (rb_node) {
+ node = rb_entry(rb_node, struct mapping_node, rb_node);
+ rb_erase(&node->rb_node, &rc->reloc_root_tree.rb_root);
+ }
+ spin_unlock(&rc->reloc_root_tree.lock);
+ if (!node)
+ return;
+ BUG_ON((struct btrfs_root *)node->data != root);
}
- spin_unlock(&rc->reloc_root_tree.lock);
-
- if (!node)
- return;
- BUG_ON((struct btrfs_root *)node->data != root);
spin_lock(&root->fs_info->trans_lock);
list_del_init(&root->root_list);