There could be a deadlock:
1. "nft" process calls request_module() with
nfnl_lock(NFNL_SUBSYS_NFTABLES) taken and waits for its completion:
[UN] PID: 7391 TASK: 939e154bc000 COMMAND: "nft"
wait_for_completion_killable
__call_usermodehelper_exec
__request_module
nf_logger_find_get
On 7/16/20 3:37 PM, Konstantin Khorenko wrote:
>
> +extern struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX]
> __read_mostly;
> +
> +/*
> + * In "nft_log" module we need to drop nfnl lock while performing
> + * request_module(), calls to nf_logger_find_get() in other
> + * m
On 07/16/2020 04:55 PM, Andrey Ryabinin wrote:
On 7/16/20 3:37 PM, Konstantin Khorenko wrote:
+extern struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX]
__read_mostly;
+
+/*
+ * In "nft_log" module we need to drop nfnl lock while performing
+ * request_module(), calls to nf_log
On 07/16/2020 07:47 PM, Konstantin Khorenko wrote:
On 07/16/2020 04:55 PM, Andrey Ryabinin wrote:
On 7/16/20 3:37 PM, Konstantin Khorenko wrote:
+extern struct nf_logger __rcu *loggers[NFPROTO_NUMPROTO][NF_LOG_TYPE_MAX]
__read_mostly;
+
+/*
+ * In "nft_log" module we need to drop nfnl lock wh
On 7/16/20 3:37 PM, Konstantin Khorenko wrote:
> +static int nf_logger_find_get_lock(int pf, enum nf_log_type type)
> +{
> + struct nf_logger *logger;
> + int ret = 0;
> +
> + logger = loggers[pf][type];
> + if (logger == NULL) {
> + nfnl_unlock(NFNL_SUBSYS_NFTABLES);
On 7/16/20 8:21 PM, Konstantin Khorenko wrote:
> If nc->call_batch() == nf_tables_newrule(), it means
> nc == nf_tables_cb[NFT_MSG_NEWRULE]
>
> nc == &ss->cb[cb_id]
> => ss == nf_tables_subsys
>
> and we know that nf_tables_subsys.subsys_id = NFNL_SUBSYS_NFTABLES
>
>
> static const struct nf
On 07/17/2020 03:39 PM, Andrey Ryabinin wrote:
On 7/16/20 3:37 PM, Konstantin Khorenko wrote:
+static int nf_logger_find_get_lock(int pf, enum nf_log_type type)
+{
+ struct nf_logger *logger;
+ int ret = 0;
+
+ logger = loggers[pf][type];
+ if (logger == NULL) {
+
On 07/17/2020 03:41 PM, Andrey Ryabinin wrote:
On 7/16/20 8:21 PM, Konstantin Khorenko wrote:
If nc->call_batch() == nf_tables_newrule(), it means
nc == nf_tables_cb[NFT_MSG_NEWRULE]
nc == &ss->cb[cb_id]
=> ss == nf_tables_subsys
and we know that nf_tables_subsys.subsys_id = NFNL_SUBSYS_NFT
