CVE-2022-50880

In the Linux kernel, the following vulnerability has been resolved:

wifi: ath10k: add peer map clean up for peer delete in ath10k_sta_state()

When peer delete failed in a disconnect operation, use-after-free detected by KFENCE in below log. It is because for each vdev_id and address, it has only one struct ath10k_peer, it is allocated in ath10k_peer_map_event(). When connected to an AP, it has more than one HTT_T2H_MSG_TYPE_PEER_MAP reported from firmware, then the array peer_map of struct ath10k will be set muti-elements to the same ath10k_peer in ath10k_peer_map_event(). When peer delete failed in ath10k_sta_state(), the ath10k_peer will be free for the 1st peer id in array peer_map of struct ath10k, and then use-after-free happened for the 2nd peer id because they map to the same ath10k_peer.

And clean up all peers in array peer_map for the ath10k_peer, then user-after-free disappeared

peer map event log: [ 306.911021] wlan0: authenticate with b0:2a:43:e6:75:0e [ 306.957187] ath10k_pci 0000:01:00.0: mac vdev 0 peer create b0:2a:43:e6:75:0e (new sta) sta 1 / 32 peer 1 / 33 [ 306.957395] ath10k_pci 0000:01:00.0: htt peer map vdev 0 peer b0:2a:43:e6:75:0e id 246 [ 306.957404] ath10k_pci 0000:01:00.0: htt peer map vdev 0 peer b0:2a:43:e6:75:0e id 198 [ 306.986924] ath10k_pci 0000:01:00.0: htt peer map vdev 0 peer b0:2a:43:e6:75:0e id 166

peer unmap event log: [ 435.715691] wlan0: deauthenticating from b0:2a:43:e6:75:0e by local choice (Reason: 3=DEAUTH_LEAVING) [ 435.716802] ath10k_pci 0000:01:00.0: mac vdev 0 peer delete b0:2a:43:e6:75:0e sta ffff990e0e9c2b50 (sta gone) [ 435.717177] ath10k_pci 0000:01:00.0: htt peer unmap vdev 0 peer b0:2a:43:e6:75:0e id 246 [ 435.717186] ath10k_pci 0000:01:00.0: htt peer unmap vdev 0 peer b0:2a:43:e6:75:0e id 198 [ 435.717193] ath10k_pci 0000:01:00.0: htt peer unmap vdev 0 peer b0:2a:43:e6:75:0e id 166

use-after-free log: [21705.888627] wlan0: deauthenticating from d0:76:8f:82:be:75 by local choice (Reason: 3=DEAUTH_LEAVING) [21713.799910] ath10k_pci 0000:01:00.0: failed to delete peer d0:76:8f:82:be:75 for vdev 0: -110 [21713.799925] ath10k_pci 0000:01:00.0: found sta peer d0:76:8f:82:be:75 (ptr 0000000000000000 id 102) entry on vdev 0 after it was supposedly removed [21713.799968] ================================================================== [21713.799991] BUG: KFENCE: use-after-free read in ath10k_sta_state+0x265/0xb8a [ath10k_core] [21713.799991] [21713.799997] Use-after-free read at 0x00000000abe1c75e (in kfence-#69): [21713.800010] ath10k_sta_state+0x265/0xb8a [ath10k_core] [21713.800041] drv_sta_state+0x115/0x677 [mac80211] [21713.800059] __sta_info_destroy_part2+0xb1/0x133 [mac80211] [21713.800076] __sta_info_flush+0x11d/0x162 [mac80211] [21713.800093] ieee80211_set_disassoc+0x12d/0x2f4 [mac80211] [21713.800110] ieee80211_mgd_deauth+0x26c/0x29b [mac80211] [21713.800137] cfg80211_mlme_deauth+0x13f/0x1bb [cfg80211] [21713.800153] nl80211_deauthenticate+0xf8/0x121 [cfg80211] [21713.800161] genl_rcv_msg+0x38e/0x3be [21713.800166] netlink_rcv_skb+0x89/0xf7 [21713.800171] genl_rcv+0x28/0x36 [21713.800176] netlink_unicast+0x179/0x24b [21713.800181] netlink_sendmsg+0x3a0/0x40e [21713.800187] sock_sendmsg+0x72/0x76 [21713.800192] ____sys_sendmsg+0x16d/0x1e3 [21713.800196] ___sys_sendmsg+0x95/0xd1 [21713.800200] __sys_sendmsg+0x85/0xbf [21713.800205] do_syscall_64+0x43/0x55 [21713.800210] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [21713.800213] [21713.800219] kfence-#69: 0x000000009149b0d5-0x000000004c0697fb, size=1064, cache=kmalloc-2k [21713.800219] [21713.800224] allocated by task 13 on cpu 0 at 21705.501373s: [21713.800241] ath10k_peer_map_event+0x7e/0x154 [ath10k_core] [21713.800254] ath10k_htt_t2h_msg_handler+0x586/0x1039 [ath10k_core] [21713.800265] ath10k_htt_htc_t2h_msg_handler+0x12/0x28 [ath10k_core] [21713.800277] ath10k_htc_rx_completion_handler+0x14c/0x1b5 [ath10k_core] [21713.800283] ath10k_pci_process_rx_cb+0x195/0x1d ---truncated---

A use-after-free vulnerability exists in the ath10k Wi-Fi driver when multiple peer IDs in peer_map[] reference the same ath10k_peer object. If firmware peer deletion fails during disconnect, the driver may free the peer while leaving stale references, leading to a UAF read in ath10k_sta_state() and a kernel crash. Exploitability is typically constrained by firmware-dependent behavior and timing, making reliable remote exploitation difficult in practice, with DoS being the most realistic outcome.

The CVSS score(s) listed for this vulnerability do not reflect the associated product's status, and are included for informational purposes to better understand the severity of this vulnerability.