This is a note to let you know that I've just added the patch titled wifi: mac80211: mesh: Fix leak of mesh_preq_queue objects to the 4.19-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: wifi-mac80211-mesh-fix-leak-of-mesh_preq_queue-objec.patch and it can be found in the queue-4.19 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. commit 9e8df5da4ffa973212c9304987f979d38d8ab24c Author: Nicolas Escande <nico.escande@xxxxxxxxx> Date: Tue May 28 16:26:05 2024 +0200 wifi: mac80211: mesh: Fix leak of mesh_preq_queue objects [ Upstream commit b7d7f11a291830fdf69d3301075dd0fb347ced84 ] The hwmp code use objects of type mesh_preq_queue, added to a list in ieee80211_if_mesh, to keep track of mpath we need to resolve. If the mpath gets deleted, ex mesh interface is removed, the entries in that list will never get cleaned. Fix this by flushing all corresponding items of the preq_queue in mesh_path_flush_pending(). This should take care of KASAN reports like this: unreferenced object 0xffff00000668d800 (size 128): comm "kworker/u8:4", pid 67, jiffies 4295419552 (age 1836.444s) hex dump (first 32 bytes): 00 1f 05 09 00 00 ff ff 00 d5 68 06 00 00 ff ff ..........h..... 8e 97 ea eb 3e b8 01 00 00 00 00 00 00 00 00 00 ....>........... backtrace: [<000000007302a0b6>] __kmem_cache_alloc_node+0x1e0/0x35c [<00000000049bd418>] kmalloc_trace+0x34/0x80 [<0000000000d792bb>] mesh_queue_preq+0x44/0x2a8 [<00000000c99c3696>] mesh_nexthop_resolve+0x198/0x19c [<00000000926bf598>] ieee80211_xmit+0x1d0/0x1f4 [<00000000fc8c2284>] __ieee80211_subif_start_xmit+0x30c/0x764 [<000000005926ee38>] ieee80211_subif_start_xmit+0x9c/0x7a4 [<000000004c86e916>] dev_hard_start_xmit+0x174/0x440 [<0000000023495647>] __dev_queue_xmit+0xe24/0x111c [<00000000cfe9ca78>] batadv_send_skb_packet+0x180/0x1e4 [<000000007bacc5d5>] batadv_v_elp_periodic_work+0x2f4/0x508 [<00000000adc3cd94>] process_one_work+0x4b8/0xa1c [<00000000b36425d1>] worker_thread+0x9c/0x634 [<0000000005852dd5>] kthread+0x1bc/0x1c4 [<000000005fccd770>] ret_from_fork+0x10/0x20 unreferenced object 0xffff000009051f00 (size 128): comm "kworker/u8:4", pid 67, jiffies 4295419553 (age 1836.440s) hex dump (first 32 bytes): 90 d6 92 0d 00 00 ff ff 00 d8 68 06 00 00 ff ff ..........h..... 36 27 92 e4 02 e0 01 00 00 58 79 06 00 00 ff ff 6'.......Xy..... backtrace: [<000000007302a0b6>] __kmem_cache_alloc_node+0x1e0/0x35c [<00000000049bd418>] kmalloc_trace+0x34/0x80 [<0000000000d792bb>] mesh_queue_preq+0x44/0x2a8 [<00000000c99c3696>] mesh_nexthop_resolve+0x198/0x19c [<00000000926bf598>] ieee80211_xmit+0x1d0/0x1f4 [<00000000fc8c2284>] __ieee80211_subif_start_xmit+0x30c/0x764 [<000000005926ee38>] ieee80211_subif_start_xmit+0x9c/0x7a4 [<000000004c86e916>] dev_hard_start_xmit+0x174/0x440 [<0000000023495647>] __dev_queue_xmit+0xe24/0x111c [<00000000cfe9ca78>] batadv_send_skb_packet+0x180/0x1e4 [<000000007bacc5d5>] batadv_v_elp_periodic_work+0x2f4/0x508 [<00000000adc3cd94>] process_one_work+0x4b8/0xa1c [<00000000b36425d1>] worker_thread+0x9c/0x634 [<0000000005852dd5>] kthread+0x1bc/0x1c4 [<000000005fccd770>] ret_from_fork+0x10/0x20 Fixes: 050ac52cbe1f ("mac80211: code for on-demand Hybrid Wireless Mesh Protocol") Signed-off-by: Nicolas Escande <nico.escande@xxxxxxxxx> Link: https://msgid.link/20240528142605.1060566-1-nico.escande@xxxxxxxxx Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx> Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> diff --git a/net/mac80211/mesh_pathtbl.c b/net/mac80211/mesh_pathtbl.c index 8efb2bf08bf48..040f983dea417 100644 --- a/net/mac80211/mesh_pathtbl.c +++ b/net/mac80211/mesh_pathtbl.c @@ -736,10 +736,23 @@ void mesh_path_discard_frame(struct ieee80211_sub_if_data *sdata, */ void mesh_path_flush_pending(struct mesh_path *mpath) { + struct ieee80211_sub_if_data *sdata = mpath->sdata; + struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh; + struct mesh_preq_queue *preq, *tmp; struct sk_buff *skb; while ((skb = skb_dequeue(&mpath->frame_queue)) != NULL) mesh_path_discard_frame(mpath->sdata, skb); + + spin_lock_bh(&ifmsh->mesh_preq_queue_lock); + list_for_each_entry_safe(preq, tmp, &ifmsh->preq_queue.list, list) { + if (ether_addr_equal(mpath->dst, preq->dst)) { + list_del(&preq->list); + kfree(preq); + --ifmsh->preq_queue_len; + } + } + spin_unlock_bh(&ifmsh->mesh_preq_queue_lock); } /**