On Wed, Aug 12, 2020 at 09:08:27AM +0200, Greg Kroah-Hartman wrote: > On Wed, Aug 12, 2020 at 02:55:56AM -0400, Peilin Ye wrote: > > Prevent hfs_find_init() from dereferencing `tree` as NULL. > > > > Reported-and-tested-by: syzbot+7ca256d0da4af073b2e2@xxxxxxxxxxxxxxxxxxxxxxxxx > > Signed-off-by: Peilin Ye <yepeilin.cs@xxxxxxxxx> > > --- > > fs/hfs/bfind.c | 3 +++ > > fs/hfsplus/bfind.c | 3 +++ > > 2 files changed, 6 insertions(+) > > > > diff --git a/fs/hfs/bfind.c b/fs/hfs/bfind.c > > index 4af318fbda77..880b7ea2c0fc 100644 > > --- a/fs/hfs/bfind.c > > +++ b/fs/hfs/bfind.c > > @@ -16,6 +16,9 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd) > > { > > void *ptr; > > > > + if (!tree) > > + return -EINVAL; > > + > > fd->tree = tree; > > fd->bnode = NULL; > > ptr = kmalloc(tree->max_key_len * 2 + 4, GFP_KERNEL); > > diff --git a/fs/hfsplus/bfind.c b/fs/hfsplus/bfind.c > > index ca2ba8c9f82e..85bef3e44d7a 100644 > > --- a/fs/hfsplus/bfind.c > > +++ b/fs/hfsplus/bfind.c > > @@ -16,6 +16,9 @@ int hfs_find_init(struct hfs_btree *tree, struct hfs_find_data *fd) > > { > > void *ptr; > > > > + if (!tree) > > + return -EINVAL; > > + > > How can tree ever be NULL in these calls? Shouldn't that be fixed as > the root problem here? I see, I will try to figure out what is going on with the reproducer. Thank you, Peilin Ye