The queue handling in the udev daemon assumes that the events are
ordered.
Before this patch uevent_seqnum is incremented under sequence_lock,
than an event is send uner uevent_sock_mutex. I want to say that code
contained a window between incrementing seqnum and sending an event.
This patch locks uevent_sock_mutex before incrementing uevent_seqnum.
Signed-off-by: Andrew Vagin <avagin@xxxxxxxxxx>
---
lib/kobject_uevent.c | 4 +++-
1 files changed, 3 insertions(+), 1 deletions(-)
diff --git a/lib/kobject_uevent.c b/lib/kobject_uevent.c
index e66e9b6..596c40d 100644
--- a/lib/kobject_uevent.c
+++ b/lib/kobject_uevent.c
@@ -243,6 +243,9 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
else if (action == KOBJ_REMOVE)
kobj->state_remove_uevent_sent = 1;
+#if defined(CONFIG_NET)
+ mutex_lock(&uevent_sock_mutex);
+#endif
/* we will send an event, so request a new sequence number */
spin_lock(&sequence_lock);
seq = ++uevent_seqnum;
@@ -253,7 +256,6 @@ int kobject_uevent_env(struct kobject *kobj, enum kobject_action action,
#if defined(CONFIG_NET)
/* send netlink message */
- mutex_lock(&uevent_sock_mutex);
list_for_each_entry(ue_sk, &uevent_sock_list, list) {
struct sock *uevent_sock = ue_sk->sk;
struct sk_buff *skb;
