@@ -325,9 +325,7 @@ static ssize_t store_enabled(struct netconsole_target *nt,
return -EINVAL;
}
- mutex_lock(&nt->mutex);
if (enabled) { /* 1 */
-
/*
* Skip netpoll_parse_options() -- all the attributes are
* already configured via configfs. Just print them out.
@@ -335,13 +333,10 @@ static ssize_t store_enabled(struct netconsole_target *nt,
netpoll_print_options(&nt->np);
err = netpoll_setup(&nt->np);
- if (err) {
- mutex_unlock(&nt->mutex);
+ if (err)
return err;
- }
printk(KERN_INFO "netconsole: network logging started\n");
-
} else { /* 0 */
/* We need to disable the netconsole before cleaning it up
* otherwise we might end up in write_msg() with
@@ -354,7 +349,6 @@ static ssize_t store_enabled(struct netconsole_target *nt,
}
nt->enabled = enabled;
- mutex_unlock(&nt->mutex);
return strnlen(buf, count);
}
@@ -571,8 +565,10 @@ static ssize_t netconsole_target_attr_store(struct config_item *item,
struct netconsole_target_attr *na =
container_of(attr, struct netconsole_target_attr, attr);
+ mutex_lock(&nt->mutex);
if (na->store)
ret = na->store(nt, buf, count);
+ mutex_unlock(&nt->mutex);
return ret;
}
In every netconsole option that can be set through configfs there's a race when checking for nt->enabled since it can be modified at the same time. Probably the most damage can be done by store_enabled when racing with another instance of itself. Fix all the races with one stone by moving the mutex lock around the ->store call for all options. Signed-off-by: Nikolay Aleksandrov <nikolay@redhat.com> --- Note: this patch is on top of netconsole: fix NULL pointer dereference that I posted yesterday. drivers/net/netconsole.c | 10 +++------- 1 file changed, 3 insertions(+), 7 deletions(-)