1#!/bin/sh 2# SPDX-License-Identifier: GPL-2.0-or-later 3# Copyright (c) 2021 FUJITSU LIMITED. All rights reserved. 4# Author: Yang Xu<[email protected]> 5# 6# When using "tc qdisc add dev teql0 root teql0 command", qdisc_create() 7# calls teql_qdisc_init() it imediately fails after check "if (m->dev == dev)" 8# because both devices are teql0, and it does not set qdisc_priv(sch)->m 9# leaving it zero on error path, then qdisc_create() imediately calls 10# teql_destroy() which does not expect zero master pointer and we get OOPS 11# on unpatched kernel. 12# 13# If we enable panic_on_oops, this case may crash. 14# 15# This kernel bug was introduced by 16# commit 87b60cfacf9f ("net_sched: fix error recovery at qdisc creation") 17# and has been fixed by 18# commit 1ffbc7ea9160 ("net: sched: sch_teql: fix null-pointer dereference") 19# 20 21TST_SETUP="setup" 22TST_TESTFUNC="do_test" 23TST_NEEDS_ROOT=1 24TST_NEEDS_DRIVERS="sch_teql" 25TST_NEEDS_CMDS="tc modprobe dmesg grep" 26 27setup() 28{ 29 ROD modprobe $TST_NEEDS_DRIVERS 30} 31 32do_test() 33{ 34 tst_res TINFO "Use tc qdisc command to trigger a null-pointer dereference" 35 36 EXPECT_FAIL tc qdisc add dev teql0 root teql0 37 38 if dmesg | grep -q 'RIP:.*sch_teql'; then 39 tst_res TFAIL "This bug is reproduced." 40 else 41 tst_res TPASS "This bug is not reproduced." 42 fi 43} 44 45. tst_test.sh 46tst_run 47