From: Miaohe Lin <linmiaohe@xxxxxxxxxx> Subject: mm/hugetlb: fix potential double free in hugetlb_register_node() error path In hugetlb_sysfs_add_hstate(), we would do kobject_put() on hstate_kobjs when failed to create sysfs group but forget to set hstate_kobjs to NULL. Then in hugetlb_register_node() error path, we may free it again via hugetlb_unregister_node(). Link: https://lkml.kernel.org/r/20210107123249.36964-1-linmiaohe@xxxxxxxxxx Fixes: a3437870160c ("hugetlb: new sysfs interface") Signed-off-by: Miaohe Lin <linmiaohe@xxxxxxxxxx> Reviewed-by: Mike Kravetz <mike.kravetz@xxxxxxxxxx> Reviewed-by: Muchun Song <smuchun@xxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/hugetlb.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) --- a/mm/hugetlb.c~mm-hugetlb-fix-potential-double-free-in-hugetlb_register_node-error-path +++ a/mm/hugetlb.c @@ -2988,8 +2988,10 @@ static int hugetlb_sysfs_add_hstate(stru return -ENOMEM; retval = sysfs_create_group(hstate_kobjs[hi], hstate_attr_group); - if (retval) + if (retval) { kobject_put(hstate_kobjs[hi]); + hstate_kobjs[hi] = NULL; + } return retval; } _
