From 5fb1a2133707b418d54c6ee5852bc74efb60279e Mon Sep 17 00:00:00 2001 From: Remi Pommarel Date: Fri, 4 Aug 2023 11:39:36 +0200 Subject: [PATCH] batman-adv: Fix TT global entry leak when client roamed back commit d25ddb7e788d34cf27ff1738d11a87cb4b67d446 upstream. When a client roamed back to a node before it got time to destroy the pending local entry (i.e. within the same originator interval) the old global one is directly removed from hash table and left as such. But because this entry had an extra reference taken at lookup (i.e using batadv_tt_global_hash_find) there is no way its memory will be reclaimed at any time causing the following memory leak: unreferenced object 0xffff0000073c8000 (size 18560): comm "softirq", pid 0, jiffies 4294907738 (age 228.644s) hex dump (first 32 bytes): 06 31 ac 12 c7 7a 05 00 01 00 00 00 00 00 00 00 .1...z.......... 2c ad be 08 00 80 ff ff 6c b6 be 08 00 80 ff ff ,.......l....... backtrace: [<00000000ee6e0ffa>] kmem_cache_alloc+0x1b4/0x300 [<000000000ff2fdbc>] batadv_tt_global_add+0x700/0xe20 [<00000000443897c7>] _batadv_tt_update_changes+0x21c/0x790 [<000000005dd90463>] batadv_tt_update_changes+0x3c/0x110 [<00000000a2d7fc57>] batadv_tt_tvlv_unicast_handler_v1+0xafc/0xe10 [<0000000011793f2a>] batadv_tvlv_containers_process+0x168/0x2b0 [<00000000b7cbe2ef>] batadv_recv_unicast_tvlv+0xec/0x1f4 [<0000000042aef1d8>] batadv_batman_skb_recv+0x25c/0x3a0 [<00000000bbd8b0a2>] __netif_receive_skb_core.isra.0+0x7a8/0xe90 [<000000004033d428>] __netif_receive_skb_one_core+0x64/0x74 [<000000000f39a009>] __netif_receive_skb+0x48/0xe0 [<00000000f2cd8888>] process_backlog+0x174/0x344 [<00000000507d6564>] __napi_poll+0x58/0x1f4 [<00000000b64ef9eb>] net_rx_action+0x504/0x590 [<00000000056fa5e4>] _stext+0x1b8/0x418 [<00000000878879d6>] run_ksoftirqd+0x74/0xa4 unreferenced object 0xffff00000bae1a80 (size 56): comm "softirq", pid 0, jiffies 4294910888 (age 216.092s) hex dump (first 32 bytes): 00 78 b1 0b 00 00 ff ff 0d 50 00 00 00 00 00 00 .x.......P...... 00 00 00 00 00 00 00 00 50 c8 3c 07 00 00 ff ff ........P.<..... backtrace: [<00000000ee6e0ffa>] kmem_cache_alloc+0x1b4/0x300 [<00000000d9aaa49e>] batadv_tt_global_add+0x53c/0xe20 [<00000000443897c7>] _batadv_tt_update_changes+0x21c/0x790 [<000000005dd90463>] batadv_tt_update_changes+0x3c/0x110 [<00000000a2d7fc57>] batadv_tt_tvlv_unicast_handler_v1+0xafc/0xe10 [<0000000011793f2a>] batadv_tvlv_containers_process+0x168/0x2b0 [<00000000b7cbe2ef>] batadv_recv_unicast_tvlv+0xec/0x1f4 [<0000000042aef1d8>] batadv_batman_skb_recv+0x25c/0x3a0 [<00000000bbd8b0a2>] __netif_receive_skb_core.isra.0+0x7a8/0xe90 [<000000004033d428>] __netif_receive_skb_one_core+0x64/0x74 [<000000000f39a009>] __netif_receive_skb+0x48/0xe0 [<00000000f2cd8888>] process_backlog+0x174/0x344 [<00000000507d6564>] __napi_poll+0x58/0x1f4 [<00000000b64ef9eb>] net_rx_action+0x504/0x590 [<00000000056fa5e4>] _stext+0x1b8/0x418 [<00000000878879d6>] run_ksoftirqd+0x74/0xa4 Releasing the extra reference from batadv_tt_global_hash_find even at roam back when batadv_tt_global_free is called fixes this memory leak. Cc: stable@vger.kernel.org Fixes: 068ee6e204e1 ("batman-adv: roaming handling mechanism redesign") Signed-off-by: Remi Pommarel Signed-off-by; Sven Eckelmann Signed-off-by: Simon Wunderlich Signed-off-by: Greg Kroah-Hartman --- net/batman-adv/translation-table.c | 1 - 1 file changed, 1 deletion(-) diff --git a/net/batman-adv/translation-table.c b/net/batman-adv/translation-table.c index 515205d7b650..a01b0277bdb1 100644 --- a/net/batman-adv/translation-table.c +++ b/net/batman-adv/translation-table.c @@ -780,7 +780,6 @@ check_roaming: if (roamed_back) { batadv_tt_global_free(bat_priv, tt_global, "Roaming canceled"); - tt_global = NULL; } else { /* The global entry has to be marked as ROAMING and * has to be kept for consistency purpose