CVE-2024-40942: wifi: mac80211: mesh: Fix leak of mesh_preq_queue objects

Severity: medium (CVSS 5.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 0.3% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2024-07-12 · updated 2026-10-15
Weakness: CWE-401

Description

In the Linux kernel, the following vulnerability has been resolved: wifi: mac80211: mesh: Fix leak of mesh_preq_queue objects 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

Affected products

Linux kernel: from 2.6.26 before 4.19.317; from 4.20 before 5.4.279; from 5.5 before 5.10.221; from 5.11 before 5.15.162; from 5.16 before 6.1.95; from 6.2 before 6.6.35 — fixed in 4.19.317, 5.10.221, 5.15.162, 5.4.279, 6.1.95, 6.6.35

How to fix

Upgrade to a fixed version: Linux kernel 4.19.317, 5.10.221, 5.15.162, 5.4.279. Check the vendor advisory for mitigations.

References

Get alerted when CVE-2024-40942 or the next vulnerability affects your stack