Donate to e Foundation | Murena handsets with /e/OS | Own a part of Murena! Learn more

Commit 4891aca2 authored by David Sterba's avatar David Sterba
Browse files

btrfs: fix dereference before check 



The superblock's ->s_fs_info is properly set in btrfs_fill_super, after
a call to open_ctree, which derefereces it before check. Although
tree_root is set via btrfs_set_super, let's be defensive and leave the
check in place.

Signed-off-by: default avatarDavid Sterba <dsterba@suse.cz>
parent edc95aec

fs/btrfs/disk-io.c

+3 −2
Original line number Diff line number Diff line
@@ -1611,7 +1611,7 @@ struct btrfs_root *open_ctree(struct super_block *sb, 
	struct btrfs_root *csum_root = kzalloc(sizeof(struct btrfs_root),

						 GFP_NOFS);

	struct btrfs_root *tree_root = btrfs_sb(sb);

	struct btrfs_fs_info *fs_info = tree_root->fs_info;

	struct btrfs_fs_info *fs_info = NULL;

	struct btrfs_root *chunk_root = kzalloc(sizeof(struct btrfs_root),

						GFP_NOFS);

	struct btrfs_root *dev_root = kzalloc(sizeof(struct btrfs_root),
@@ -1623,11 +1623,12 @@ struct btrfs_root *open_ctree(struct super_block *sb, 


	struct btrfs_super_block *disk_super;



	if (!extent_root || !tree_root || !fs_info ||

	if (!extent_root || !tree_root || !tree_root->fs_info ||

	    !chunk_root || !dev_root || !csum_root) {

		err = -ENOMEM;

		goto fail;

	}

	fs_info = tree_root->fs_info;



	ret = init_srcu_struct(&fs_info->subvol_srcu);

	if (ret) {