From: Bernard Metzler <bmt@zurich.ibm.com> commit 810dbc69087b08fd53e1cdd6c709f385bc2921ad upstream. The dealloc_work_entries() function must update the work_free_list pointer while freeing its entries, since potentially called again on same list. A second iteration of the work list caused system crash. This happens, if work allocation fails during cma_iw_listen() and free_cm_id() tries to free the list again during cleanup. Fixes: 922a8e9fb2e0 ("RDMA: iWARP Connection Manager.") Link: https://lore.kernel.org/r/20200302181614.17042-1-bmt@zurich.ibm.com Reported-by: syzbot+cb0c054eabfba4342146@syzkaller.appspotmail.com Signed-off-by: Bernard Metzler <bmt@zurich.ibm.com> Reviewed-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Jason Gunthorpe <jgg@mellanox.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Yang Yingliang <yangyingliang@huawei.com> --- drivers/infiniband/core/iwcm.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/drivers/infiniband/core/iwcm.c b/drivers/infiniband/core/iwcm.c index 5d676cf..99dd845 100644 --- a/drivers/infiniband/core/iwcm.c +++ b/drivers/infiniband/core/iwcm.c @@ -158,8 +158,10 @@ static void dealloc_work_entries(struct iwcm_id_private *cm_id_priv) { struct list_head *e, *tmp; - list_for_each_safe(e, tmp, &cm_id_priv->work_free_list) + list_for_each_safe(e, tmp, &cm_id_priv->work_free_list) { + list_del(e); kfree(list_entry(e, struct iwcm_work, free_list)); + } } static int alloc_work_entries(struct iwcm_id_private *cm_id_priv, int count) -- 1.8.3