trying to configure TC 'act_gate' rules with invalid control actions, the
following splat can be observed:
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").
Fixes: a51c328df310 ("net: qos: introduce a gate control flow action")
CC: Ivan Vecera <ivec...@redhat.com>
Signed-off-by: Davide Caratti <dcara...@redhat.com>
---
net/sched/act_gate.c | 9 ++++++---
1 file changed, 6 insertions(+), 3 deletions(-)
diff --git a/net/sched/act_gate.c b/net/sched/act_gate.c
index 35fc48795541c..9c628591f452c 100644
--- a/net/sched/act_gate.c
+++ b/net/sched/act_gate.c
@@ -331,6 +331,10 @@ static int tcf_gate_init(struct net *net, struct nlattr
*nla,
tcf_idr_release(*a, bind);
return -EEXIST;
}
+ if (ret == ACT_P_CREATED) {
+ to_gate(*a)->param.tcfg_clockid = -1;
+ INIT_LIST_HEAD(&(to_gate(*a)->param.entries));
+ }
if (tb[TCA_GATE_PRIORITY])
prio = nla_get_s32(tb[TCA_GATE_PRIORITY]);
@@ -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);
}
--
2.26.2
