CVE-2024-56607: Vulnerability in Linux Linux

Severity: mediumType: vulnerabilityCVE-2024-56607

In the Linux kernel, the following vulnerability has been resolved: wifi: ath12k: fix atomic calls in ath12k_mac_op_set_bitrate_mask() When I try to manually set bitrates: iw wlan0 set bitrates legacy-2.4 1 I get sleeping from invalid context error, see below. Fix that by switching to use recently introduced ieee80211_iterate_stations_mtx(). Do note that WCN6855 firmware is still crashing, I'm not sure if that firmware even supports bitrate WMI commands and should we consider disabling ath12k_mac_op_set_bitrate_mask() for WCN6855? But that's for another patch. BUG: sleeping function called from invalid context at drivers/net/wireless/ath/ath12k/wmi.c:420 in_atomic(): 0, irqs_disabled(): 0, non_block: 0, pid: 2236, name: iw preempt_count: 0, expected: 0 RCU nest depth: 1, expected: 0 3 locks held by iw/2236: #0: ffffffffabc6f1d8 (cb_lock){++++}-{3:3}, at: genl_rcv+0x14/0x40 #1: ffff888138410810 (&rdev->wiphy.mtx){+.+.}-{3:3}, at: nl80211_pre_doit+0x54d/0x800 [cfg80211] #2: ffffffffab2cfaa0 (rcu_read_lock){....}-{1:2}, at: ieee80211_iterate_stations_atomic+0x2f/0x200 [mac80211] CPU: 3 UID: 0 PID: 2236 Comm: iw Not tainted 6.11.0-rc7-wt-ath+ #1772 Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021 Call Trace: <TASK> dump_stack_lvl+0xa4/0xe0 dump_stack+0x10/0x20 __might_resched+0x363/0x5a0 ? __alloc_skb+0x165/0x340 __might_sleep+0xad/0x160 ath12k_wmi_cmd_send+0xb1/0x3d0 [ath12k] ? ath12k_wmi_init_wcn7850+0xa40/0xa40 [ath12k] ? __netdev_alloc_skb+0x45/0x7b0 ? __asan_memset+0x39/0x40 ? ath12k_wmi_alloc_skb+0xf0/0x150 [ath12k] ? reacquire_held_locks+0x4d0/0x4d0 ath12k_wmi_set_peer_param+0x340/0x5b0 [ath12k] ath12k_mac_disable_peer_fixed_rate+0xa3/0x110 [ath12k] ? ath12k_mac_vdev_stop+0x4f0/0x4f0 [ath12k] ieee80211_iterate_stations_atomic+0xd4/0x200 [mac80211] ath12k_mac_op_set_bitrate_mask+0x5d2/0x1080 [ath12k] ? ath12k_mac_vif_chan+0x320/0x320 [ath12k] drv_set_bitrate_mask+0x267/0x470 [mac80211] ieee80211_set_bitrate_mask+0x4cc/0x8a0 [mac80211] ? __this_cpu_preempt_check+0x13/0x20 nl80211_set_tx_bitrate_mask+0x2bc/0x530 [cfg80211] ? nl80211_parse_tx_bitrate_mask+0x2320/0x2320 [cfg80211] ? trace_contention_end+0xef/0x140 ? rtnl_unlock+0x9/0x10 ? nl80211_pre_doit+0x557/0x800 [cfg80211] genl_family_rcv_msg_doit+0x1f0/0x2e0 ? genl_family_rcv_msg_attrs_parse.isra.0+0x250/0x250 ? ns_capable+0x57/0xd0 genl_family_rcv_msg+0x34c/0x600 ? genl_family_rcv_msg_dumpit+0x310/0x310 ? __lock_acquire+0xc62/0x1de0 ? he_set_mcs_mask.isra.0+0x8d0/0x8d0 [cfg80211] ? nl80211_parse_tx_bitrate_mask+0x2320/0x2320 [cfg80211] ? cfg80211_external_auth_request+0x690/0x690 [cfg80211] genl_rcv_msg+0xa0/0x130 netlink_rcv_skb+0x14c/0x400 ? genl_family_rcv_msg+0x600/0x600 ? netlink_ack+0xd70/0xd70 ? rwsem_optimistic_spin+0x4f0/0x4f0 ? genl_rcv+0x14/0x40 ? down_read_killable+0x580/0x580 ? netlink_deliver_tap+0x13e/0x350 ? __this_cpu_preempt_check+0x13/0x20 genl_rcv+0x23/0x40 netlink_unicast+0x45e/0x790 ? netlink_attachskb+0x7f0/0x7f0 netlink_sendmsg+0x7eb/0xdb0 ? netlink_unicast+0x790/0x790 ? __this_cpu_preempt_check+0x13/0x20 ? selinux_socket_sendmsg+0x31/0x40 ? netlink_unicast+0x790/0x790 __sock_sendmsg+0xc9/0x160 ____sys_sendmsg+0x620/0x990 ? kernel_sendmsg+0x30/0x30 ? __copy_msghdr+0x410/0x410 ? __kasan_check_read+0x11/0x20 ? mark_lock+0xe6/0x1470 ___sys_sendmsg+0xe9/0x170 ? copy_msghdr_from_user+0x120/0x120 ? __lock_acquire+0xc62/0x1de0 ? do_fault_around+0x2c6/0x4e0 ? do_user_addr_fault+0x8c1/0xde0 ? reacquire_held_locks+0x220/0x4d0 ? do_user_addr_fault+0x8c1/0xde0 ? __kasan_check_read+0x11/0x20 ? __fdget+0x4e/0x1d0 ? sockfd_lookup_light+0x1a/0x170 __sys_sendmsg+0xd2/0x180 ? __sys_sendmsg_sock+0x20/0x20 ? reacquire_held_locks+0x4d0/0x4d0 ? debug_smp_processor_id+0x17/0x20 __x64_sys_sendmsg+0x72/0xb0 ? lockdep_hardirqs_on+0x7d/0x100 x64_sys_call+0x894/0x9f0 do_syscall_64+0x64/0x130 entry_SYSCALL_64_after_ ---truncated---

AI Analysis

Technical Summary

CVE-2024-56607 is a vulnerability identified in the Linux kernel specifically within the ath12k wireless driver component. The issue arises in the function ath12k_mac_op_set_bitrate_mask(), which is responsible for setting bitrate masks for wireless transmissions. The vulnerability manifests when manually setting bitrates using commands such as 'iw wlan0 set bitrates legacy-2.4 1', which leads to a 'sleeping function called from invalid context' error. This error indicates that the driver attempts to perform operations that are not allowed in atomic contexts, causing kernel warnings or potential crashes. The root cause is improper handling of atomic calls within the ath12k_mac_op_set_bitrate_mask() function. The fix involves switching to the recently introduced ieee80211_iterate_stations_mtx() API, which correctly manages locking and context requirements. However, there is an outstanding concern regarding the WCN6855 firmware, which may still crash and might not support bitrate WMI commands, suggesting that disabling the problematic function for this firmware could be necessary. The vulnerability is technical and low-level, involving kernel driver internals and wireless firmware interaction. It can lead to kernel instability or crashes when certain wireless bitrate settings are applied, potentially affecting wireless connectivity and system reliability. No known exploits are reported in the wild, and no CVSS score has been assigned yet.

Potential Impact

For European organizations, this vulnerability primarily impacts systems running Linux kernels with the affected ath12k wireless driver, which is common in devices using Qualcomm Atheros Wi-Fi chipsets. The impact includes potential kernel panics or crashes when manipulating wireless bitrate settings, which can disrupt wireless network connectivity. This disruption can affect critical infrastructure relying on stable wireless communications, such as enterprise networks, industrial control systems, and remote access services. Organizations using Linux-based devices for networking, IoT, or embedded systems with affected hardware may experience service interruptions or degraded performance. Although the vulnerability does not directly allow privilege escalation or remote code execution, the resulting instability can be exploited for denial-of-service attacks or cause operational downtime. The lack of known exploits reduces immediate risk, but the vulnerability requires timely patching to prevent potential exploitation or accidental system failures. Given the widespread use of Linux in European IT environments, especially in servers, workstations, and embedded devices, the vulnerability poses a moderate operational risk.

Mitigation Recommendations

1. Apply the official Linux kernel patches that address CVE-2024-56607 as soon as they become available in your distribution's kernel updates. Monitor vendor advisories for updated kernel versions containing the fix. 2. For systems using WCN6855 firmware, consider disabling the ath12k_mac_op_set_bitrate_mask() function or related bitrate mask settings until a stable firmware update or patch is released. 3. Avoid manually setting wireless bitrates using commands that trigger the vulnerability until patched. 4. Implement monitoring for kernel logs to detect occurrences of 'sleeping function called from invalid context' errors or related kernel warnings that may indicate attempts to exploit or trigger the issue. 5. For critical systems, consider isolating affected devices from sensitive networks or limiting wireless configuration changes by non-privileged users to reduce risk. 6. Engage with hardware vendors for firmware updates addressing WCN6855 stability issues. 7. Maintain regular backups and incident response plans to quickly recover from potential service disruptions caused by kernel crashes.