After the conditional that precedes the following code, inode may be an ERR_PTR value. This can eg result from a memory allocation failure via the call to btrfs_iget, and thus does not imply that root is different than sub_root. Thus, an IS_ERR check is added to ensure that there is no dereference of inode in this case. The semantic match that finds this problem is as follows: (http://coccinelle.lip6.fr/) // <smpl> @r@ identifier f; @@ f(...) { ... return ERR_PTR(...); } @@ identifier r.f, fld; expression x; statement S1,S2; @@ x = f(...) ... when != IS_ERR(x) ( if (IS_ERR(x) ||...) S1 else S2 | *x->fld ) // </smpl> Signed-off-by: Julia Lawall <julia@xxxxxxx> --- fs/btrfs/inode.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 160b55b..b322158 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4134,7 +4134,7 @@ struct inode *btrfs_lookup_dentry(struct inode *dir, struct dentry *dentry) } srcu_read_unlock(&root->fs_info->subvol_srcu, index); - if (root != sub_root) { + if (!IS_ERR(inode) && root != sub_root) { down_read(&root->fs_info->cleanup_work_sem); if (!(inode->i_sb->s_flags & MS_RDONLY)) btrfs_orphan_cleanup(sub_root); -- To unsubscribe from this list: send the line "unsubscribe kernel-janitors" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html