[PATCH 4.9 034/212] mac80211: mesh: Free pending skb when destroying a mpath

From: Greg Kroah-Hartman
Date: Thu Aug 20 2020 - 05:58:27 EST


From: Remi Pommarel <repk@xxxxxxxxxxxx>

[ Upstream commit 5e43540c2af0a0c0a18e39579b1ad49541f87506 ]

A mpath object can hold reference on a list of skb that are waiting for
mpath resolution to be sent. When destroying a mpath this skb list
should be cleaned up in order to not leak memory.

Fixing that kind of leak:

unreferenced object 0xffff0000181c9300 (size 1088):
comm "openvpn", pid 1782, jiffies 4295071698 (age 80.416s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 f9 80 36 00 00 00 00 00 ..........6.....
02 00 07 40 00 00 00 00 00 00 00 00 00 00 00 00 ...@............
backtrace:
[<000000004bc6a443>] kmem_cache_alloc+0x1a4/0x2f0
[<000000002caaef13>] sk_prot_alloc.isra.39+0x34/0x178
[<00000000ceeaa916>] sk_alloc+0x34/0x228
[<00000000ca1f1d04>] inet_create+0x198/0x518
[<0000000035626b1c>] __sock_create+0x134/0x328
[<00000000a12b3a87>] __sys_socket+0xb0/0x158
[<00000000ff859f23>] __arm64_sys_socket+0x40/0x58
[<00000000263486ec>] el0_svc_handler+0xd0/0x1a0
[<0000000005b5157d>] el0_svc+0x8/0xc
unreferenced object 0xffff000012973a40 (size 216):
comm "openvpn", pid 1782, jiffies 4295082137 (age 38.660s)
hex dump (first 32 bytes):
00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
00 c0 06 16 00 00 ff ff 00 93 1c 18 00 00 ff ff ................
backtrace:
[<000000004bc6a443>] kmem_cache_alloc+0x1a4/0x2f0
[<0000000023c8c8f9>] __alloc_skb+0xc0/0x2b8
[<000000007ad950bb>] alloc_skb_with_frags+0x60/0x320
[<00000000ef90023a>] sock_alloc_send_pskb+0x388/0x3c0
[<00000000104fb1a3>] sock_alloc_send_skb+0x1c/0x28
[<000000006919d2dd>] __ip_append_data+0xba4/0x11f0
[<0000000083477587>] ip_make_skb+0x14c/0x1a8
[<0000000024f3d592>] udp_sendmsg+0xaf0/0xcf0
[<000000005aabe255>] inet_sendmsg+0x5c/0x80
[<000000008651ea08>] __sys_sendto+0x15c/0x218
[<000000003505c99b>] __arm64_sys_sendto+0x74/0x90
[<00000000263486ec>] el0_svc_handler+0xd0/0x1a0
[<0000000005b5157d>] el0_svc+0x8/0xc

Fixes: 2bdaf386f99c (mac80211: mesh: move path tables into if_mesh)
Signed-off-by: Remi Pommarel <repk@xxxxxxxxxxxx>
Link: https://lore.kernel.org/r/20200704135419.27703-1-repk@xxxxxxxxxxxx
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
net/mac80211/mesh_pathtbl.c | 1 +
1 file changed, 1 insertion(+)

diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c
index 8c17d498df301..7c409ba1ddc74 100644
--- a/net/mac80211/mesh_pathtbl.c
+++ b/net/mac80211/mesh_pathtbl.c
@@ -555,6 +555,7 @@ static void mesh_path_free_rcu(struct mesh_table *tbl,
del_timer_sync(&mpath->timer);
atomic_dec(&sdata->u.mesh.mpaths);
atomic_dec(&tbl->entries);
+ mesh_path_flush_pending(mpath);
kfree_rcu(mpath, rcu);
}

--
2.25.1