2021-12-22 07:04:48

by Wen Gong

[permalink] [raw]
Subject: [PATCH v3] ath11k: free peer for station when disconnect from AP for QCA6390/WCN6855

Commit b4a0f54156ac ("ath11k: move peer delete after vdev stop of station
for QCA6390 and WCN6855") is to fix firmware crash by changing the WMI
command sequence, but actually skip all the peer delete operation, then
it lead commit 58595c9874c6 ("ath11k: Fixing dangling pointer issue upon
peer delete failure") not take effect, and then happened a use-after-free
warning from KASAN. because the peer->sta is not set to NULL and then used
later.

Change to only skip the WMI_PEER_DELETE_CMDID for QCA6390/WCN6855.

log of user-after-free:

[ 534.888665] BUG: KASAN: use-after-free in ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888696] Read of size 8 at addr ffff8881396bb1b8 by task rtcwake/2860

[ 534.888705] CPU: 4 PID: 2860 Comm: rtcwake Kdump: loaded Tainted: G W 5.15.0-wt-ath+ #523
[ 534.888712] Hardware name: Intel(R) Client Systems NUC8i7HVK/NUC8i7HVB, BIOS HNKBLi70.86A.0067.2021.0528.1339 05/28/2021
[ 534.888716] Call Trace:
[ 534.888720] <IRQ>
[ 534.888726] dump_stack_lvl+0x57/0x7d
[ 534.888736] print_address_description.constprop.0+0x1f/0x170
[ 534.888745] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888771] kasan_report.cold+0x83/0xdf
[ 534.888783] ? ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888810] ath11k_dp_rx_update_peer_stats+0x912/0xc10 [ath11k]
[ 534.888840] ath11k_dp_rx_process_mon_status+0x529/0xa70 [ath11k]
[ 534.888874] ? ath11k_dp_rx_mon_status_bufs_replenish+0x3f0/0x3f0 [ath11k]
[ 534.888897] ? check_prev_add+0x20f0/0x20f0
[ 534.888922] ? __lock_acquire+0xb72/0x1870
[ 534.888937] ? find_held_lock+0x33/0x110
[ 534.888954] ath11k_dp_rx_process_mon_rings+0x297/0x520 [ath11k]
[ 534.888981] ? rcu_read_unlock+0x40/0x40
[ 534.888990] ? ath11k_dp_rx_pdev_alloc+0xd90/0xd90 [ath11k]
[ 534.889026] ath11k_dp_service_mon_ring+0x67/0xe0 [ath11k]
[ 534.889053] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k]
[ 534.889075] call_timer_fn+0x167/0x4a0
[ 534.889084] ? add_timer_on+0x3b0/0x3b0
[ 534.889103] ? lockdep_hardirqs_on_prepare.part.0+0x18c/0x370
[ 534.889117] __run_timers.part.0+0x539/0x8b0
[ 534.889123] ? ath11k_dp_rx_process_mon_rings+0x520/0x520 [ath11k]
[ 534.889157] ? call_timer_fn+0x4a0/0x4a0
[ 534.889164] ? mark_lock_irq+0x1c30/0x1c30
[ 534.889173] ? clockevents_program_event+0xdd/0x280
[ 534.889189] ? mark_held_locks+0xa5/0xe0
[ 534.889203] run_timer_softirq+0x97/0x180
[ 534.889213] __do_softirq+0x276/0x86a
[ 534.889230] __irq_exit_rcu+0x11c/0x180
[ 534.889238] irq_exit_rcu+0x5/0x20
[ 534.889244] sysvec_apic_timer_interrupt+0x8e/0xc0
[ 534.889251] </IRQ>
[ 534.889254] <TASK>
[ 534.889259] asm_sysvec_apic_timer_interrupt+0x12/0x20
[ 534.889265] RIP: 0010:_raw_spin_unlock_irqrestore+0x38/0x70
[ 534.889271] Code: 74 24 10 e8 ea c2 bf fd 48 89 ef e8 12 53 c0 fd 81 e3 00 02 00 00 75 25 9c 58 f6 c4 02 75 2d 48 85 db 74 01 fb bf 01 00 00 00 <e8> 13 a7 b5 fd 65 8b 05 cc d9 9c 5e 85 c0 74 0a 5b 5d c3 e8 a0 ee
[ 534.889276] RSP: 0018:ffffc90002e5f880 EFLAGS: 00000206
[ 534.889284] RAX: 0000000000000006 RBX: 0000000000000200 RCX: ffffffff9f256f10
[ 534.889289] RDX: 0000000000000000 RSI: ffffffffa1c6e420 RDI: 0000000000000001
[ 534.889293] RBP: ffff8881095e6200 R08: 0000000000000001 R09: ffffffffa40d2b8f
[ 534.889298] R10: fffffbfff481a571 R11: 0000000000000001 R12: ffff8881095e6e68
[ 534.889302] R13: ffffc90002e5f908 R14: 0000000000000246 R15: 0000000000000000
[ 534.889316] ? mark_lock+0xd0/0x14a0
[ 534.889332] klist_next+0x1d4/0x450
[ 534.889340] ? dpm_wait_for_subordinate+0x2d0/0x2d0
[ 534.889350] device_for_each_child+0xa8/0x140
[ 534.889360] ? device_remove_class_symlinks+0x1b0/0x1b0
[ 534.889370] ? __lock_release+0x4bd/0x9f0
[ 534.889378] ? dpm_suspend+0x26b/0x3f0
[ 534.889390] dpm_wait_for_subordinate+0x82/0x2d0
[ 534.889400] ? dpm_for_each_dev+0xa0/0xa0
[ 534.889410] ? dpm_suspend+0x233/0x3f0
[ 534.889427] __device_suspend+0xd4/0x10c0
[ 534.889440] ? wait_for_completion_io+0x270/0x270
[ 534.889456] ? async_suspend_late+0xe0/0xe0
[ 534.889463] ? async_schedule_node_domain+0x468/0x640
[ 534.889482] dpm_suspend+0x25a/0x3f0
[ 534.889491] ? dpm_suspend_end+0x1a0/0x1a0
[ 534.889497] ? ktime_get+0x214/0x2f0
[ 534.889502] ? lockdep_hardirqs_on+0x79/0x100
[ 534.889509] ? recalibrate_cpu_khz+0x10/0x10
[ 534.889516] ? ktime_get+0x119/0x2f0
[ 534.889528] dpm_suspend_start+0xab/0xc0
[ 534.889538] suspend_devices_and_enter+0x1ca/0x350
[ 534.889546] ? suspend_enter+0x850/0x850
[ 534.889566] enter_state+0x27c/0x3d7
[ 534.889575] pm_suspend.cold+0x42/0x189
[ 534.889583] state_store+0xab/0x160
[ 534.889595] ? sysfs_file_ops+0x160/0x160
[ 534.889601] kernfs_fop_write_iter+0x2b5/0x450
[ 534.889615] new_sync_write+0x36a/0x600
[ 534.889625] ? new_sync_read+0x600/0x600
[ 534.889639] ? rcu_read_unlock+0x40/0x40
[ 534.889668] vfs_write+0x619/0x910
[ 534.889681] ksys_write+0xf4/0x1d0
[ 534.889689] ? __ia32_sys_read+0xa0/0xa0
[ 534.889699] ? lockdep_hardirqs_on_prepare.part.0+0x18c/0x370
[ 534.889707] ? syscall_enter_from_user_mode+0x1d/0x50
[ 534.889719] do_syscall_64+0x3b/0x90
[ 534.889725] entry_SYSCALL_64_after_hwframe+0x44/0xae
[ 534.889731] RIP: 0033:0x7f0b9bc931e7
[ 534.889736] Code: 64 89 02 48 c7 c0 ff ff ff ff eb bb 0f 1f 80 00 00 00 00 f3 0f 1e fa 64 8b 04 25 18 00 00 00 85 c0 75 10 b8 01 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 51 c3 48 83 ec 28 48 89 54 24 18 48 89 74 24
[ 534.889741] RSP: 002b:00007ffd9d34cc88 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
[ 534.889749] RAX: ffffffffffffffda RBX: 0000000000000004 RCX: 00007f0b9bc931e7
[ 534.889753] RDX: 0000000000000004 RSI: 0000561cd023c5f0 RDI: 0000000000000004
[ 534.889757] RBP: 0000561cd023c5f0 R08: 0000000000000000 R09: 0000000000000004
[ 534.889761] R10: 0000561ccef842a6 R11: 0000000000000246 R12: 0000000000000004
[ 534.889765] R13: 0000561cd0239590 R14: 00007f0b9bd6f4a0 R15: 00007f0b9bd6e8a0
[ 534.889789] </TASK>

[ 534.889796] Allocated by task 2711:
[ 534.889800] kasan_save_stack+0x1b/0x40
[ 534.889805] __kasan_kmalloc+0x7c/0x90
[ 534.889810] sta_info_alloc+0x98/0x1ef0 [mac80211]
[ 534.889874] ieee80211_prep_connection+0x30b/0x11e0 [mac80211]
[ 534.889950] ieee80211_mgd_auth+0x529/0xe00 [mac80211]
[ 534.890024] cfg80211_mlme_auth+0x332/0x6f0 [cfg80211]
[ 534.890090] nl80211_authenticate+0x839/0xcf0 [cfg80211]
[ 534.890147] genl_family_rcv_msg_doit+0x1f4/0x2f0
[ 534.890154] genl_rcv_msg+0x280/0x500
[ 534.890160] netlink_rcv_skb+0x11c/0x340
[ 534.890165] genl_rcv+0x1f/0x30
[ 534.890170] netlink_unicast+0x42b/0x700
[ 534.890176] netlink_sendmsg+0x71b/0xc60
[ 534.890181] sock_sendmsg+0xdf/0x110
[ 534.890187] ____sys_sendmsg+0x5c0/0x850
[ 534.890192] ___sys_sendmsg+0xe4/0x160
[ 534.890197] __sys_sendmsg+0xb2/0x140
[ 534.890202] do_syscall_64+0x3b/0x90
[ 534.890207] entry_SYSCALL_64_after_hwframe+0x44/0xae

[ 534.890215] Freed by task 2825:
[ 534.890218] kasan_save_stack+0x1b/0x40
[ 534.890223] kasan_set_track+0x1c/0x30
[ 534.890227] kasan_set_free_info+0x20/0x30
[ 534.890232] __kasan_slab_free+0xce/0x100
[ 534.890237] slab_free_freelist_hook+0xf0/0x1a0
[ 534.890242] kfree+0xe5/0x370
[ 534.890248] __sta_info_flush+0x333/0x4b0 [mac80211]
[ 534.890308] ieee80211_set_disassoc+0x324/0xd20 [mac80211]
[ 534.890382] ieee80211_mgd_deauth+0x537/0xee0 [mac80211]
[ 534.890472] cfg80211_mlme_deauth+0x349/0x810 [cfg80211]
[ 534.890526] cfg80211_mlme_down+0x1ce/0x270 [cfg80211]
[ 534.890578] cfg80211_disconnect+0x4f5/0x7b0 [cfg80211]
[ 534.890631] cfg80211_leave+0x24/0x40 [cfg80211]
[ 534.890677] wiphy_suspend+0x23d/0x2f0 [cfg80211]
[ 534.890723] dpm_run_callback+0xf4/0x1b0
[ 534.890728] __device_suspend+0x648/0x10c0
[ 534.890733] async_suspend+0x16/0xe0
[ 534.890737] async_run_entry_fn+0x90/0x4f0
[ 534.890741] process_one_work+0x866/0x1490
[ 534.890747] worker_thread+0x596/0x1010
[ 534.890751] kthread+0x35d/0x420
[ 534.890756] ret_from_fork+0x22/0x30

[ 534.890763] The buggy address belongs to the object at ffff8881396ba000
which belongs to the cache kmalloc-8k of size 8192
[ 534.890767] The buggy address is located 4536 bytes inside of
8192-byte region [ffff8881396ba000, ffff8881396bc000)
[ 534.890772] The buggy address belongs to the page:
[ 534.890775] page:ffffea0004e5ae00 refcount:1 mapcount:0 mapping:0000000000000000 index:0x0 pfn:0x1396b8
[ 534.890780] head:ffffea0004e5ae00 order:3 compound_mapcount:0 compound_pincount:0
[ 534.890784] flags: 0x200000000010200(slab|head|node=0|zone=2)
[ 534.890791] raw: 0200000000010200 ffffea000562be08 ffffea0004b04c08 ffff88810004e340
[ 534.890795] raw: 0000000000000000 0000000000010001 00000001ffffffff 0000000000000000
[ 534.890798] page dumped because: kasan: bad access detected

[ 534.890804] Memory state around the buggy address:
[ 534.890807] ffff8881396bb080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 534.890811] ffff8881396bb100: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 534.890814] >ffff8881396bb180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 534.890817] ^
[ 534.890821] ffff8881396bb200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 534.890824] ffff8881396bb280: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
[ 534.890827] ==================================================================
[ 534.890830] Disabling lock debugging due to kernel taint

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1

Fixes: b4a0f54156ac ("ath11k: move peer delete after vdev stop of station for QCA6390 and WCN6855")
Signed-off-by: Wen Gong <[email protected]>
---
v3:
1. rebased to ath.git ath-202112220603
2. change back warning "Found peer entry %pM n vdev %i after it was supposedly removed" to ath11k_warn()
3. fix warning "peer-unmap-event: unknown peer id"
4. only set peer->sta = NULL in patch, not remove peer in ab->peers list. ath11k_peer_unmap_event() will remove the peer.

v2:
1. rebased to ath.git ath-202112141538
2. remove label 'free' defined but not used
3. change warning "Found peer entry %pM n vdev %i after it was supposedly removed" to ath11k_dbg()

drivers/net/wireless/ath/ath11k/mac.c | 31 ++++++++++++++++-----------
1 file changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 07f499d5ec92..ac6a192185c1 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -4504,24 +4504,30 @@ static int ath11k_mac_op_sta_state(struct ieee80211_hw *hw,
sta->addr, arvif->vdev_id);
} else if ((old_state == IEEE80211_STA_NONE &&
new_state == IEEE80211_STA_NOTEXIST)) {
- ath11k_dp_peer_cleanup(ar, arvif->vdev_id, sta->addr);
+ bool skip_peer_delete = ar->ab->hw_params.vdev_start_delay &&
+ vif->type == NL80211_IFTYPE_STATION;

- if (ar->ab->hw_params.vdev_start_delay &&
- vif->type == NL80211_IFTYPE_STATION)
- goto free;
+ ath11k_dp_peer_cleanup(ar, arvif->vdev_id, sta->addr);

- ret = ath11k_peer_delete(ar, arvif->vdev_id, sta->addr);
- if (ret)
- ath11k_warn(ar->ab, "Failed to delete peer: %pM for VDEV: %d\n",
- sta->addr, arvif->vdev_id);
- else
- ath11k_dbg(ar->ab, ATH11K_DBG_MAC, "Removed peer: %pM for VDEV: %d\n",
- sta->addr, arvif->vdev_id);
+ if (!skip_peer_delete) {
+ ret = ath11k_peer_delete(ar, arvif->vdev_id, sta->addr);
+ if (ret)
+ ath11k_warn(ar->ab,
+ "Failed to delete peer: %pM for VDEV: %d\n",
+ sta->addr, arvif->vdev_id);
+ else
+ ath11k_dbg(ar->ab,
+ ATH11K_DBG_MAC,
+ "Removed peer: %pM for VDEV: %d\n",
+ sta->addr, arvif->vdev_id);
+ }

ath11k_mac_dec_num_stations(arvif, sta);
spin_lock_bh(&ar->ab->base_lock);
peer = ath11k_peer_find(ar->ab, arvif->vdev_id, sta->addr);
- if (peer && peer->sta == sta) {
+ if (skip_peer_delete && peer) {
+ peer->sta = NULL;
+ } else if (peer && peer->sta == sta) {
ath11k_warn(ar->ab, "Found peer entry %pM n vdev %i after it was supposedly removed\n",
vif->addr, arvif->vdev_id);
peer->sta = NULL;
@@ -4531,7 +4537,6 @@ static int ath11k_mac_op_sta_state(struct ieee80211_hw *hw,
}
spin_unlock_bh(&ar->ab->base_lock);

-free:
kfree(arsta->tx_stats);
arsta->tx_stats = NULL;


base-commit: e5da5e8c54e27d8fa86765cd733c1a05aee53ae9
--
2.31.1