@@ -332,6 +332,12 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
return -EEXIST;
}
+ gact = to_gate(*a);
+ if (ret == ACT_P_CREATED) {
+ gact->param.tcfg_clockid = -1;
+ INIT_LIST_HEAD(&gact->param.entries);
+ }
+
if (tb[TCA_GATE_PRIORITY])
prio = nla_get_s32(tb[TCA_GATE_PRIORITY]);
@@ -366,8 +372,6 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
if (err < 0)
goto release_idr;
- gact = to_gate(*a);
-
spin_lock_bh(&gact->tcf_lock);
p = &gact->param;
@@ -377,7 +381,6 @@ static int tcf_gate_init(struct net *net, struct nlattr *nla,
goto chain_put;
}
- INIT_LIST_HEAD(&p->entries);
if (tb[TCA_GATE_ENTRY_LIST]) {
err = parse_gate_list(tb[TCA_GATE_ENTRY_LIST], p, extack);
if (err < 0)
@@ -449,9 +452,9 @@ static void tcf_gate_cleanup(struct tc_action *a)
struct tcf_gate *gact = to_gate(a);
struct tcf_gate_params *p;
- hrtimer_cancel(&gact->hitimer);
-
p = &gact->param;
+ if (p->tcfg_clockid != -1)
+ hrtimer_cancel(&gact->hitimer);
release_entry_list(&p->entries);
}
trying to configure TC 'act_gate' rules with invalid control actions, the following splat can be observed: # tc action add action gate index 42 clockid CLOCK_TAI goto chain 42 general protection fault, probably for non-canonical address 0xdffffc0000000002: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000010-0x0000000000000017] CPU: 1 PID: 2143 Comm: tc Not tainted 5.7.0-rc6+ #168 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 RIP: 0010:hrtimer_active+0x56/0x290 [...] Call Trace: hrtimer_try_to_cancel+0x6d/0x330 hrtimer_cancel+0x11/0x20 tcf_gate_cleanup+0x15/0x30 [act_gate] tcf_action_cleanup+0x58/0x170 __tcf_action_put+0xb0/0xe0 __tcf_idr_release+0x68/0x90 tcf_gate_init+0x7c7/0x19a0 [act_gate] tcf_action_init_1+0x60f/0x960 tcf_action_init+0x157/0x2a0 tcf_action_add+0xd9/0x2f0 tc_ctl_action+0x2a3/0x39d rtnetlink_rcv_msg+0x5f3/0x920 netlink_rcv_skb+0x121/0x350 netlink_unicast+0x439/0x630 netlink_sendmsg+0x714/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5b4/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x9a/0x370 entry_SYSCALL_64_after_hwframe+0x44/0xa9 this is caused by hrtimer_cancel(), running before hrtimer_init(). Fix it ensuring to call hrtimer_cancel() only if clockid is valid, and the timer has been initialized. After fixing this splat, the same error path causes another problem: general protection fault, probably for non-canonical address 0xdffffc0000000000: 0000 [#1] SMP KASAN NOPTI KASAN: null-ptr-deref in range [0x0000000000000000-0x0000000000000007] CPU: 1 PID: 980 Comm: tc Not tainted 5.7.0-rc6+ #168 Hardware name: Red Hat KVM, BIOS 1.11.1-4.module+el8.1.0+4066+0f1aadab 04/01/2014 RIP: 0010:release_entry_list+0x4a/0x240 [act_gate] [...] Call Trace: tcf_action_cleanup+0x58/0x170 __tcf_action_put+0xb0/0xe0 __tcf_idr_release+0x68/0x90 tcf_gate_init+0x7ab/0x19a0 [act_gate] tcf_action_init_1+0x60f/0x960 tcf_action_init+0x157/0x2a0 tcf_action_add+0xd9/0x2f0 tc_ctl_action+0x2a3/0x39d rtnetlink_rcv_msg+0x5f3/0x920 netlink_rcv_skb+0x121/0x350 netlink_unicast+0x439/0x630 netlink_sendmsg+0x714/0xbf0 sock_sendmsg+0xe2/0x110 ____sys_sendmsg+0x5b4/0x890 ___sys_sendmsg+0xe9/0x160 __sys_sendmsg+0xd3/0x170 do_syscall_64+0x9a/0x370 entry_SYSCALL_64_after_hwframe+0x44/0xa9 the problem is similar: tcf_action_cleanup() was trying to release a list without initializing it first. Ensure that INIT_LIST_HEAD() is called for every newly created 'act_gate' action, same as what was done to 'act_ife' with commit 44c23d71599f ("net/sched: act_ife: initalize ife->metalist earlier"). Changes since v1: - fix typo in the subject (tfc_gate_init->tcf_gate_init) - change commit message to include an example of command that triggers the error path of tcf_gate_init(). Suggested by Po Liu - assign 'gact' earlier to reduce usage of to_gate() Fixes: a51c328df310 ("net: qos: introduce a gate control flow action") CC: Ivan Vecera <ivecera@redhat.com> Signed-off-by: Davide Caratti <dcaratti@redhat.com> --- net/sched/act_gate.c | 13 ++++++++----- 1 file changed, 8 insertions(+), 5 deletions(-)