| Message ID | 20201214202550.3693-2-yonatanlinik@gmail.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Netdev Maintainers |
| Headers | show |
| Series | net: Fix use of proc_fs | expand |
| Context | Check | Description |
|---|---|---|
| netdev/cover_letter | success | Link |
| netdev/fixes_present | success | Link |
| netdev/patch_count | success | Link |
| netdev/tree_selection | success | Guessed tree name to be net-next |
| netdev/subject_prefix | warning | Target tree name not specified in the subject |
| netdev/source_inline | success | Was 0 now: 0 |
| netdev/verify_signedoff | success | Link |
| netdev/module_param | success | Was 0 now: 0 |
| netdev/build_32bit | success | Errors and warnings before: 2 this patch: 2 |
| netdev/kdoc | success | Errors and warnings before: 0 this patch: 0 |
| netdev/verify_fixes | success | Link |
| netdev/checkpatch | success | total: 0 errors, 0 warnings, 0 checks, 23 lines checked |
| netdev/build_allmodconfig_warn | success | Errors and warnings before: 2 this patch: 2 |
| netdev/header_inline | success | Link |
| netdev/stable | success | Stable not CCed |
On Mon, 14 Dec 2020 22:25:50 +0200 Yonatan Linik wrote: > proc_fs was used, in af_packet, without a surrounding #ifdef, > although there is no hard dependency on proc_fs. > That caused the initialization of the af_packet module to fail > when CONFIG_PROC_FS=n. > > Specifically, proc_create_net() was used in af_packet.c, > and when it fails, packet_net_init() returns -ENOMEM. > It will always fail when the kernel is compiled without proc_fs, > because, proc_create_net() for example always returns NULL. > > The calling order that starts in af_packet.c is as follows: > packet_init() > register_pernet_subsys() > register_pernet_operations() > __register_pernet_operations() > ops_init() > ops->init() (packet_net_ops.init=packet_net_init()) > proc_create_net() > > It worked in the past because register_pernet_subsys()'s return value > wasn't checked before this Commit 36096f2f4fa0 ("packet: Fix error path in > packet_init."). > It always returned an error, but was not checked before, so everything > was working even when CONFIG_PROC_FS=n. > > The fix here is simply to add the necessary #ifdef. > > This also fixes a similar error in tls_proc.c, that was found by Jakub > Kicinski. > > Signed-off-by: Yonatan Linik <yonatanlinik@gmail.com> Applied, and queued for stable, thanks!
diff --git a/net/packet/af_packet.c b/net/packet/af_packet.c index 2b33e977a905..031f2b593720 100644 --- a/net/packet/af_packet.c +++ b/net/packet/af_packet.c @@ -4612,9 +4612,11 @@ static int __net_init packet_net_init(struct net *net) mutex_init(&net->packet.sklist_lock); INIT_HLIST_HEAD(&net->packet.sklist); +#ifdef CONFIG_PROC_FS if (!proc_create_net("packet", 0, net->proc_net, &packet_seq_ops, sizeof(struct seq_net_private))) return -ENOMEM; +#endif /* CONFIG_PROC_FS */ return 0; } diff --git a/net/tls/tls_proc.c b/net/tls/tls_proc.c index 3a5dd1e07233..feeceb0e4cb4 100644 --- a/net/tls/tls_proc.c +++ b/net/tls/tls_proc.c @@ -37,9 +37,12 @@ static int tls_statistics_seq_show(struct seq_file *seq, void *v) int __net_init tls_proc_init(struct net *net) { +#ifdef CONFIG_PROC_FS if (!proc_create_net_single("tls_stat", 0444, net->proc_net, tls_statistics_seq_show, NULL)) return -ENOMEM; +#endif /* CONFIG_PROC_FS */ + return 0; }
proc_fs was used, in af_packet, without a surrounding #ifdef, although there is no hard dependency on proc_fs. That caused the initialization of the af_packet module to fail when CONFIG_PROC_FS=n. Specifically, proc_create_net() was used in af_packet.c, and when it fails, packet_net_init() returns -ENOMEM. It will always fail when the kernel is compiled without proc_fs, because, proc_create_net() for example always returns NULL. The calling order that starts in af_packet.c is as follows: packet_init() register_pernet_subsys() register_pernet_operations() __register_pernet_operations() ops_init() ops->init() (packet_net_ops.init=packet_net_init()) proc_create_net() It worked in the past because register_pernet_subsys()'s return value wasn't checked before this Commit 36096f2f4fa0 ("packet: Fix error path in packet_init."). It always returned an error, but was not checked before, so everything was working even when CONFIG_PROC_FS=n. The fix here is simply to add the necessary #ifdef. This also fixes a similar error in tls_proc.c, that was found by Jakub Kicinski. Signed-off-by: Yonatan Linik <yonatanlinik@gmail.com> --- net/packet/af_packet.c | 2 ++ net/tls/tls_proc.c | 3 +++ 2 files changed, 5 insertions(+)