CVE-2022-49328

A vulnerability was found in the Linux kernel's mt76 wi-fi driver. A concurrency bug causes the `mtxq` TX queue to maintain a raw pointer to a `wcid` structure (`mtxq->wcid`) that might be freed by the time it is accessed. This issue can lead to a use-after-free scenario, leading to system instability, memory corruption, and potentially arbitrary code execution.

In the Linux kernel, the following vulnerability has been resolved: mt76: fix use-after-free by removing a non-RCU wcid pointer Fixes an issue caught by KASAN about use-after-free in mt76_txq_schedule by protecting mtxq->wcid with rcu_lock between mt76_txq_schedule and sta_info_[alloc, free]. [18853.876689] ================================================================== [18853.876751] BUG: KASAN: use-after-free in mt76_txq_schedule+0x204/0xaf8 [mt76] [18853.876773] Read of size 8 at addr ffffffaf989a2138 by task mt76-tx phy0/883 [18853.876786] [18853.876810] CPU: 5 PID: 883 Comm: mt76-tx phy0 Not tainted 5.10.100-fix-510-56778d365941-kasan #5 0b01fbbcf41a530f52043508fec2e31a4215 [18853.876840] Call trace: [18853.876861] dump_backtrace+0x0/0x3ec [18853.876878] show_stack+0x20/0x2c [18853.876899] dump_stack+0x11c/0x1ac [18853.876918] print_address_description+0x74/0x514 [18853.876934] kasan_report+0x134/0x174 [18853.876948] __asan_report_load8_noabort+0x44/0x50 [18853.876976] mt76_txq_schedule+0x204/0xaf8 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877002] mt76_txq_schedule_all+0x2c/0x48 [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877030] mt7921_tx_worker+0xa0/0x1cc [mt7921_common f0875ebac9d7b4754e1010549e7db50fbd90a047] [18853.877054] __mt76_worker_fn+0x190/0x22c [mt76 074e03e4640e97fe7405ee1fab547b81c4fa45d2] [18853.877071] kthread+0x2f8/0x3b8 [18853.877087] ret_from_fork+0x10/0x30 [18853.877098] [18853.877112] Allocated by task 941: [18853.877131] kasan_save_stack+0x38/0x68 [18853.877147] __kasan_kmalloc+0xd4/0xfc [18853.877163] kasan_kmalloc+0x10/0x1c [18853.877177] __kmalloc+0x264/0x3c4 [18853.877294] sta_info_alloc+0x460/0xf88 [mac80211] [18853.877410] ieee80211_prep_connection+0x204/0x1ee0 [mac80211] [18853.877523] ieee80211_mgd_auth+0x6c4/0xa4c [mac80211] [18853.877635] ieee80211_auth+0x20/0x2c [mac80211] [18853.877733] rdev_auth+0x7c/0x438 [cfg80211] [18853.877826] cfg80211_mlme_auth+0x26c/0x390 [cfg80211] [18853.877919] nl80211_authenticate+0x6d4/0x904 [cfg80211] [18853.877938] genl_rcv_msg+0x748/0x93c [18853.877954] netlink_rcv_skb+0x160/0x2a8 [18853.877969] genl_rcv+0x3c/0x54 [18853.877985] netlink_unicast_kernel+0x104/0x1ec [18853.877999] netlink_unicast+0x178/0x268 [18853.878015] netlink_sendmsg+0x3cc/0x5f0 [18853.878030] sock_sendmsg+0xb4/0xd8 [18853.878043] ____sys_sendmsg+0x2f8/0x53c [18853.878058] ___sys_sendmsg+0xe8/0x150 [18853.878071] __sys_sendmsg+0xc4/0x1f4 [18853.878087] __arm64_compat_sys_sendmsg+0x88/0x9c [18853.878101] el0_svc_common+0x1b4/0x390 [18853.878115] do_el0_svc_compat+0x8c/0xdc [18853.878131] el0_svc_compat+0x10/0x1c [18853.878146] el0_sync_compat_handler+0xa8/0xcc [18853.878161] el0_sync_compat+0x188/0x1c0 [18853.878171] [18853.878183] Freed by task 10927: [18853.878200] kasan_save_stack+0x38/0x68 [18853.878215] kasan_set_track+0x28/0x3c [18853.878228] kasan_set_free_info+0x24/0x48 [18853.878244] __kasan_slab_free+0x11c/0x154 [18853.878259] kasan_slab_free+0x14/0x24 [18853.878273] slab_free_freelist_hook+0xac/0x1b0 [18853.878287] kfree+0x104/0x390 [18853.878402] sta_info_free+0x198/0x210 [mac80211] [18853.878515] __sta_info_destroy_part2+0x230/0x2d4 [mac80211] [18853.878628] __sta_info_flush+0x300/0x37c [mac80211] [18853.878740] ieee80211_set_disassoc+0x2cc/0xa7c [mac80211] [18853.878851] ieee80211_mgd_deauth+0x4a4/0x10a0 [mac80211] [18853.878962] ieee80211_deauth+0x20/0x2c [mac80211] [18853.879057] rdev_deauth+0x7c/0x438 [cfg80211] [18853.879150] cfg80211_mlme_deauth+0x274/0x414 [cfg80211] [18853.879243] cfg80211_mlme_down+0xe4/0x118 [cfg80211] [18853.879335] cfg80211_disconnect+0x218/0x2d8 [cfg80211] [18853.879427] __cfg80211_leave+0x17c/0x240 [cfg80211] [18853.879519] cfg80211_leave+0x3c/0x58 [cfg80211] [18853.879611] wiphy_suspend+0xdc/0x200 [cfg80211] [18853.879628] dpm_run_callback+0x58/0x408 [18853.879642] __device_suspend+0x4cc/0x864 [18853.879658] async_suspend+0x34/0xf4 [18 ---truncated---

An update for kernel is now available for Red Hat Enterprise Linux 8.6 Advanced Mission Critical Update Support, Red Hat Enterprise Linux 8.6 Update Services for SAP Solutions, and Red Hat Enterprise Linux 8.6 Telecommunications Update Service. Issues addressed include a use-after-free vulnerability.