From: Taehee Yoo ap420073@gmail.com
[ Upstream commit 9cf1cd8ee3ee09ef2859017df2058e2f53c5347f ]
In order to set/get/dump, the tipc uses the generic netlink infrastructure. So, when tipc module is inserted, init function calls genl_register_family(). After genl_register_family(), set/get/dump commands are immediately allowed and these callbacks internally use the net_generic. net_generic is allocated by register_pernet_device() but this is called after genl_register_family() in the __init function. So, these callbacks would use un-initialized net_generic.
Test commands: #SHELL1 while : do modprobe tipc modprobe -rv tipc done
#SHELL2 while : do tipc link list done
Splat looks like: [ 59.616322][ T2788] kasan: CONFIG_KASAN_INLINE enabled [ 59.617234][ T2788] kasan: GPF could be caused by NULL-ptr deref or user memory access [ 59.618398][ T2788] general protection fault: 0000 [#1] SMP DEBUG_PAGEALLOC KASAN PTI [ 59.619389][ T2788] CPU: 3 PID: 2788 Comm: tipc Not tainted 5.4.0+ #194 [ 59.620231][ T2788] Hardware name: innotek GmbH VirtualBox/VirtualBox, BIOS VirtualBox 12/01/2006 [ 59.621428][ T2788] RIP: 0010:tipc_bcast_get_broadcast_mode+0x131/0x310 [tipc] [ 59.622379][ T2788] Code: c7 c6 ef 8b 38 c0 65 ff 0d 84 83 c9 3f e8 d7 a5 f2 e3 48 8d bb 38 11 00 00 48 b8 00 00 00 00 [ 59.622550][ T2780] NET: Registered protocol family 30 [ 59.624627][ T2788] RSP: 0018:ffff88804b09f578 EFLAGS: 00010202 [ 59.624630][ T2788] RAX: dffffc0000000000 RBX: 0000000000000011 RCX: 000000008bc66907 [ 59.624631][ T2788] RDX: 0000000000000229 RSI: 000000004b3cf4cc RDI: 0000000000001149 [ 59.624633][ T2788] RBP: ffff88804b09f588 R08: 0000000000000003 R09: fffffbfff4fb3df1 [ 59.624635][ T2788] R10: fffffbfff50318f8 R11: ffff888066cadc18 R12: ffffffffa6cc2f40 [ 59.624637][ T2788] R13: 1ffff11009613eba R14: ffff8880662e9328 R15: ffff8880662e9328 [ 59.624639][ T2788] FS: 00007f57d8f7b740(0000) GS:ffff88806cc00000(0000) knlGS:0000000000000000 [ 59.624645][ T2788] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 59.625875][ T2780] tipc: Started in single node mode [ 59.626128][ T2788] CR2: 00007f57d887a8c0 CR3: 000000004b140002 CR4: 00000000000606e0 [ 59.633991][ T2788] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 [ 59.635195][ T2788] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 [ 59.636478][ T2788] Call Trace: [ 59.637025][ T2788] tipc_nl_add_bc_link+0x179/0x1470 [tipc] [ 59.638219][ T2788] ? lock_downgrade+0x6e0/0x6e0 [ 59.638923][ T2788] ? __tipc_nl_add_link+0xf90/0xf90 [tipc] [ 59.639533][ T2788] ? tipc_nl_node_dump_link+0x318/0xa50 [tipc] [ 59.640160][ T2788] ? mutex_lock_io_nested+0x1380/0x1380 [ 59.640746][ T2788] tipc_nl_node_dump_link+0x4fd/0xa50 [tipc] [ 59.641356][ T2788] ? tipc_nl_node_reset_link_stats+0x340/0x340 [tipc] [ 59.642088][ T2788] ? __skb_ext_del+0x270/0x270 [ 59.642594][ T2788] genl_lock_dumpit+0x85/0xb0 [ 59.643050][ T2788] netlink_dump+0x49c/0xed0 [ 59.643529][ T2788] ? __netlink_sendskb+0xc0/0xc0 [ 59.644044][ T2788] ? __netlink_dump_start+0x190/0x800 [ 59.644617][ T2788] ? __mutex_unlock_slowpath+0xd0/0x670 [ 59.645177][ T2788] __netlink_dump_start+0x5a0/0x800 [ 59.645692][ T2788] genl_rcv_msg+0xa75/0xe90 [ 59.646144][ T2788] ? __lock_acquire+0xdfe/0x3de0 [ 59.646692][ T2788] ? genl_family_rcv_msg_attrs_parse+0x320/0x320 [ 59.647340][ T2788] ? genl_lock_dumpit+0xb0/0xb0 [ 59.647821][ T2788] ? genl_unlock+0x20/0x20 [ 59.648290][ T2788] ? genl_parallel_done+0xe0/0xe0 [ 59.648787][ T2788] ? find_held_lock+0x39/0x1d0 [ 59.649276][ T2788] ? genl_rcv+0x15/0x40 [ 59.649722][ T2788] ? lock_contended+0xcd0/0xcd0 [ 59.650296][ T2788] netlink_rcv_skb+0x121/0x350 [ 59.650828][ T2788] ? genl_family_rcv_msg_attrs_parse+0x320/0x320 [ 59.651491][ T2788] ? netlink_ack+0x940/0x940 [ 59.651953][ T2788] ? lock_acquire+0x164/0x3b0 [ 59.652449][ T2788] genl_rcv+0x24/0x40 [ 59.652841][ T2788] netlink_unicast+0x421/0x600 [ ... ]
Fixes: 7e4369057806 ("tipc: fix a slab object leak") Fixes: a62fbccecd62 ("tipc: make subscriber server support net namespace") Signed-off-by: Taehee Yoo ap420073@gmail.com Acked-by: Jon Maloy jon.maloy@ericsson.com Signed-off-by: David S. Miller davem@davemloft.net Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/tipc/core.c | 29 +++++++++++++++-------------- 1 file changed, 15 insertions(+), 14 deletions(-)
--- a/net/tipc/core.c +++ b/net/tipc/core.c @@ -117,14 +117,6 @@ static int __init tipc_init(void) TIPC_CRITICAL_IMPORTANCE; sysctl_tipc_rmem[2] = TIPC_CONN_OVERLOAD_LIMIT;
- err = tipc_netlink_start(); - if (err) - goto out_netlink; - - err = tipc_netlink_compat_start(); - if (err) - goto out_netlink_compat; - err = tipc_register_sysctl(); if (err) goto out_sysctl; @@ -145,8 +137,21 @@ static int __init tipc_init(void) if (err) goto out_bearer;
+ err = tipc_netlink_start(); + if (err) + goto out_netlink; + + err = tipc_netlink_compat_start(); + if (err) + goto out_netlink_compat; + pr_info("Started in single node mode\n"); return 0; + +out_netlink_compat: + tipc_netlink_stop(); +out_netlink: + tipc_bearer_cleanup(); out_bearer: unregister_pernet_device(&tipc_topsrv_net_ops); out_pernet_topsrv: @@ -156,22 +161,18 @@ out_socket: out_pernet: tipc_unregister_sysctl(); out_sysctl: - tipc_netlink_compat_stop(); -out_netlink_compat: - tipc_netlink_stop(); -out_netlink: pr_err("Unable to start in single node mode\n"); return err; }
static void __exit tipc_exit(void) { + tipc_netlink_compat_stop(); + tipc_netlink_stop(); tipc_bearer_cleanup(); unregister_pernet_device(&tipc_topsrv_net_ops); tipc_socket_stop(); unregister_pernet_device(&tipc_net_ops); - tipc_netlink_stop(); - tipc_netlink_compat_stop(); tipc_unregister_sysctl();
pr_info("Deactivated\n");