lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
Open Source and information security mailing list archives
| ||
|
Message-Id: <20190811073555.27068-4-idosch@idosch.org> Date: Sun, 11 Aug 2019 10:35:48 +0300 From: Ido Schimmel <idosch@...sch.org> To: netdev@...r.kernel.org Cc: davem@...emloft.net, nhorman@...driver.com, jiri@...lanox.com, toke@...hat.com, dsahern@...il.com, roopa@...ulusnetworks.com, nikolay@...ulusnetworks.com, jakub.kicinski@...ronome.com, andy@...yhouse.net, f.fainelli@...il.com, andrew@...n.ch, vivien.didelot@...il.com, mlxsw@...lanox.com, Ido Schimmel <idosch@...lanox.com> Subject: [PATCH net-next v2 03/10] drop_monitor: Reset per-CPU data before starting to trace From: Ido Schimmel <idosch@...lanox.com> The function reset_per_cpu_data() allocates and prepares a new skb for the summary netlink alert message ('NET_DM_CMD_ALERT'). The new skb is stored in the per-CPU 'data' variable and the old is returned. The function is invoked during module initialization and from the workqueue, before an alert is sent. This means that it is possible to receive an alert with stale data, if we stopped tracing when the hysteresis timer ('data->send_timer') was pending. Instead of invoking the function during module initialization, invoke it just before we start tracing and ensure we get a fresh skb. This also allows us to remove the calls to initialize the timer and the work item from the module initialization path, since both could have been triggered by the error paths of reset_per_cpu_data(). Signed-off-by: Ido Schimmel <idosch@...lanox.com> --- net/core/drop_monitor.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) diff --git a/net/core/drop_monitor.c b/net/core/drop_monitor.c index b266dc1660ed..1cf4988de591 100644 --- a/net/core/drop_monitor.c +++ b/net/core/drop_monitor.c @@ -252,9 +252,16 @@ static int net_dm_trace_on_set(struct netlink_ext_ack *extack) for_each_possible_cpu(cpu) { struct per_cpu_dm_data *data = &per_cpu(dm_cpu_data, cpu); + struct sk_buff *skb; INIT_WORK(&data->dm_alert_work, send_dm_alert); timer_setup(&data->send_timer, sched_send_work, 0); + /* Allocate a new per-CPU skb for the summary alert message and + * free the old one which might contain stale data from + * previous tracing. + */ + skb = reset_per_cpu_data(data); + consume_skb(skb); } rc = register_trace_kfree_skb(trace_kfree_skb_hit, NULL); @@ -475,10 +482,7 @@ static int __init init_net_drop_monitor(void) for_each_possible_cpu(cpu) { data = &per_cpu(dm_cpu_data, cpu); - INIT_WORK(&data->dm_alert_work, send_dm_alert); - timer_setup(&data->send_timer, sched_send_work, 0); spin_lock_init(&data->lock); - reset_per_cpu_data(data); } goto out; -- 2.21.0
Powered by blists - more mailing lists