From: Felix Fietkau nbd@nbd.name
commit e66b7920aa5ac5b1a1997a454004ba9246a3c005 upstream.
There are some codepaths that do not initialize rx->link_sta properly. This causes a crash in places which assume that rx->link_sta is valid if rx->sta is valid. One known instance is triggered by __ieee80211_rx_h_amsdu being called from fast-rx. It results in a crash like this one:
BUG: kernel NULL pointer dereference, address: 00000000000000a8 #PF: supervisor write access in kernel mode #PF: error_code(0x0002) - not-present page PGD 0 P4D 0 Oops: 0002 [#1] PREEMPT SMP PTI CPU: 1 PID: 506 Comm: mt76-usb-rx phy Tainted: G E 6.1.0-debian64x+1.7 #3 Hardware name: ZOTAC ZBOX-ID92/ZBOX-IQ01/ZBOX-ID92/ZBOX-IQ01, BIOS B220P007 05/21/2014 RIP: 0010:ieee80211_deliver_skb+0x62/0x1f0 [mac80211] Code: 00 48 89 04 24 e8 9e a7 c3 df 89 c0 48 03 1c c5 a0 ea 39 a1 4c 01 6b 08 48 ff 03 48 83 7d 28 00 74 11 48 8b 45 30 48 63 55 44 <48> 83 84 d0 a8 00 00 00 01 41 8b 86 c0 11 00 00 8d 50 fd 83 fa 01 RSP: 0018:ffff999040803b10 EFLAGS: 00010286 RAX: 0000000000000000 RBX: ffffb9903f496480 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffff999040803ce0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff8d21828ac900 R13: 000000000000004a R14: ffff8d2198ed89c0 R15: ffff8d2198ed8000 FS: 0000000000000000(0000) GS:ffff8d24afe80000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000000000a8 CR3: 0000000429810002 CR4: 00000000001706e0 Call Trace: <TASK> __ieee80211_rx_h_amsdu+0x1b5/0x240 [mac80211] ? ieee80211_prepare_and_rx_handle+0xcdd/0x1320 [mac80211] ? __local_bh_enable_ip+0x3b/0xa0 ieee80211_prepare_and_rx_handle+0xcdd/0x1320 [mac80211] ? prepare_transfer+0x109/0x1a0 [xhci_hcd] ieee80211_rx_list+0xa80/0xda0 [mac80211] mt76_rx_complete+0x207/0x2e0 [mt76] mt76_rx_poll_complete+0x357/0x5a0 [mt76] mt76u_rx_worker+0x4f5/0x600 [mt76_usb] ? mt76_get_min_avg_rssi+0x140/0x140 [mt76] __mt76_worker_fn+0x50/0x80 [mt76] kthread+0xed/0x120 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x22/0x30
Since the initialization of rx->link and rx->link_sta is rather convoluted and duplicated in many places, clean it up by using a helper function to set it.
Fixes: ccdde7c74ffd ("wifi: mac80211: properly implement MLO key handling") Fixes: b320d6c456ff ("wifi: mac80211: use correct rx link_sta instead of default") Signed-off-by: Felix Fietkau nbd@nbd.name Link: https://lore.kernel.org/r/20221230200747.19040-1-nbd@nbd.name [remove unnecessary rx->sta->sta.mlo check] Cc: stable@vger.kernel.org Signed-off-by: Johannes Berg johannes.berg@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- net/mac80211/rx.c | 222 ++++++++++++++++++++++++------------------------------ 1 file changed, 99 insertions(+), 123 deletions(-)
--- a/net/mac80211/rx.c +++ b/net/mac80211/rx.c @@ -4070,6 +4070,58 @@ static void ieee80211_invoke_rx_handlers #undef CALL_RXH }
+static bool +ieee80211_rx_is_valid_sta_link_id(struct ieee80211_sta *sta, u8 link_id) +{ + if (!sta->mlo) + return false; + + return !!(sta->valid_links & BIT(link_id)); +} + +static bool ieee80211_rx_data_set_link(struct ieee80211_rx_data *rx, + u8 link_id) +{ + rx->link_id = link_id; + rx->link = rcu_dereference(rx->sdata->link[link_id]); + + if (!rx->sta) + return rx->link; + + if (!ieee80211_rx_is_valid_sta_link_id(&rx->sta->sta, link_id)) + return false; + + rx->link_sta = rcu_dereference(rx->sta->link[link_id]); + + return rx->link && rx->link_sta; +} + +static bool ieee80211_rx_data_set_sta(struct ieee80211_rx_data *rx, + struct ieee80211_sta *pubsta, + int link_id) +{ + struct sta_info *sta; + + sta = container_of(pubsta, struct sta_info, sta); + + rx->link_id = link_id; + rx->sta = sta; + + if (sta) { + rx->local = sta->sdata->local; + if (!rx->sdata) + rx->sdata = sta->sdata; + rx->link_sta = &sta->deflink; + } + + if (link_id < 0) + rx->link = &rx->sdata->deflink; + else if (!ieee80211_rx_data_set_link(rx, link_id)) + return false; + + return true; +} + /* * This function makes calls into the RX path, therefore * it has to be invoked under RCU read lock. @@ -4078,16 +4130,19 @@ void ieee80211_release_reorder_timeout(s { struct sk_buff_head frames; struct ieee80211_rx_data rx = { - .sta = sta, - .sdata = sta->sdata, - .local = sta->local, /* This is OK -- must be QoS data frame */ .security_idx = tid, .seqno_idx = tid, - .link_id = -1, }; struct tid_ampdu_rx *tid_agg_rx; - u8 link_id; + int link_id = -1; + + /* FIXME: statistics won't be right with this */ + if (sta->sta.valid_links) + link_id = ffs(sta->sta.valid_links) - 1; + + if (!ieee80211_rx_data_set_sta(&rx, &sta->sta, link_id)) + return;
tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]); if (!tid_agg_rx) @@ -4107,10 +4162,6 @@ void ieee80211_release_reorder_timeout(s }; drv_event_callback(rx.local, rx.sdata, &event); } - /* FIXME: statistics won't be right with this */ - link_id = sta->sta.valid_links ? ffs(sta->sta.valid_links) - 1 : 0; - rx.link = rcu_dereference(sta->sdata->link[link_id]); - rx.link_sta = rcu_dereference(sta->link[link_id]);
ieee80211_rx_handlers(&rx, &frames); } @@ -4126,7 +4177,6 @@ void ieee80211_mark_rx_ba_filtered_frame /* This is OK -- must be QoS data frame */ .security_idx = tid, .seqno_idx = tid, - .link_id = -1, }; int i, diff;
@@ -4137,10 +4187,8 @@ void ieee80211_mark_rx_ba_filtered_frame
sta = container_of(pubsta, struct sta_info, sta);
- rx.sta = sta; - rx.sdata = sta->sdata; - rx.link = &rx.sdata->deflink; - rx.local = sta->local; + if (!ieee80211_rx_data_set_sta(&rx, pubsta, -1)) + return;
rcu_read_lock(); tid_agg_rx = rcu_dereference(sta->ampdu_mlme.tid_rx[tid]); @@ -4527,15 +4575,6 @@ void ieee80211_check_fast_rx_iface(struc mutex_unlock(&local->sta_mtx); }
-static bool -ieee80211_rx_is_valid_sta_link_id(struct ieee80211_sta *sta, u8 link_id) -{ - if (!sta->mlo) - return false; - - return !!(sta->valid_links & BIT(link_id)); -} - static void ieee80211_rx_8023(struct ieee80211_rx_data *rx, struct ieee80211_fast_rx *fast_rx, int orig_len) @@ -4646,7 +4685,6 @@ static bool ieee80211_invoke_fast_rx(str struct sk_buff *skb = rx->skb; struct ieee80211_hdr *hdr = (void *)skb->data; struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); - struct sta_info *sta = rx->sta; int orig_len = skb->len; int hdrlen = ieee80211_hdrlen(hdr->frame_control); int snap_offs = hdrlen; @@ -4658,7 +4696,6 @@ static bool ieee80211_invoke_fast_rx(str u8 da[ETH_ALEN]; u8 sa[ETH_ALEN]; } addrs __aligned(2); - struct link_sta_info *link_sta; struct ieee80211_sta_rx_stats *stats;
/* for parallel-rx, we need to have DUP_VALIDATED, otherwise we write @@ -4761,18 +4798,10 @@ static bool ieee80211_invoke_fast_rx(str drop: dev_kfree_skb(skb);
- if (rx->link_id >= 0) { - link_sta = rcu_dereference(sta->link[rx->link_id]); - if (!link_sta) - return true; - } else { - link_sta = &sta->deflink; - } - if (fast_rx->uses_rss) - stats = this_cpu_ptr(link_sta->pcpu_rx_stats); + stats = this_cpu_ptr(rx->link_sta->pcpu_rx_stats); else - stats = &link_sta->rx_stats; + stats = &rx->link_sta->rx_stats;
stats->dropped++; return true; @@ -4790,8 +4819,8 @@ static bool ieee80211_prepare_and_rx_han struct ieee80211_local *local = rx->local; struct ieee80211_sub_if_data *sdata = rx->sdata; struct ieee80211_hdr *hdr = (void *)skb->data; - struct link_sta_info *link_sta = NULL; - struct ieee80211_link_data *link; + struct link_sta_info *link_sta = rx->link_sta; + struct ieee80211_link_data *link = rx->link;
rx->skb = skb;
@@ -4813,35 +4842,6 @@ static bool ieee80211_prepare_and_rx_han if (!ieee80211_accept_frame(rx)) return false;
- if (rx->link_id >= 0) { - link = rcu_dereference(rx->sdata->link[rx->link_id]); - - /* we might race link removal */ - if (!link) - return true; - rx->link = link; - - if (rx->sta) { - rx->link_sta = - rcu_dereference(rx->sta->link[rx->link_id]); - if (!rx->link_sta) - return true; - } - } else { - if (rx->sta) - rx->link_sta = &rx->sta->deflink; - - rx->link = &sdata->deflink; - } - - if (unlikely(!is_multicast_ether_addr(hdr->addr1) && - rx->link_id >= 0 && rx->sta && rx->sta->sta.mlo)) { - link_sta = rcu_dereference(rx->sta->link[rx->link_id]); - - if (WARN_ON_ONCE(!link_sta)) - return true; - } - if (!consume) { struct skb_shared_hwtstamps *shwt;
@@ -4861,7 +4861,7 @@ static bool ieee80211_prepare_and_rx_han shwt->hwtstamp = skb_hwtstamps(skb)->hwtstamp; }
- if (unlikely(link_sta)) { + if (unlikely(rx->sta && rx->sta->sta.mlo)) { /* translate to MLD addresses */ if (ether_addr_equal(link->conf->addr, hdr->addr1)) ether_addr_copy(hdr->addr1, rx->sdata->vif.addr); @@ -4891,6 +4891,7 @@ static void __ieee80211_rx_handle_8023(s struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb); struct ieee80211_fast_rx *fast_rx; struct ieee80211_rx_data rx; + int link_id = -1;
memset(&rx, 0, sizeof(rx)); rx.skb = skb; @@ -4907,12 +4908,8 @@ static void __ieee80211_rx_handle_8023(s if (!pubsta) goto drop;
- rx.sta = container_of(pubsta, struct sta_info, sta); - rx.sdata = rx.sta->sdata; - - if (status->link_valid && - !ieee80211_rx_is_valid_sta_link_id(pubsta, status->link_id)) - goto drop; + if (status->link_valid) + link_id = status->link_id;
/* * TODO: Should the frame be dropped if the right link_id is not @@ -4921,19 +4918,8 @@ static void __ieee80211_rx_handle_8023(s * link_id is used only for stats purpose and updating the stats on * the deflink is fine? */ - if (status->link_valid) - rx.link_id = status->link_id; - - if (rx.link_id >= 0) { - struct ieee80211_link_data *link; - - link = rcu_dereference(rx.sdata->link[rx.link_id]); - if (!link) - goto drop; - rx.link = link; - } else { - rx.link = &rx.sdata->deflink; - } + if (!ieee80211_rx_data_set_sta(&rx, pubsta, link_id)) + goto drop;
fast_rx = rcu_dereference(rx.sta->fast_rx); if (!fast_rx) @@ -4951,6 +4937,8 @@ static bool ieee80211_rx_for_interface(s { struct link_sta_info *link_sta; struct ieee80211_hdr *hdr = (void *)skb->data; + struct sta_info *sta; + int link_id = -1;
/* * Look up link station first, in case there's a @@ -4960,24 +4948,19 @@ static bool ieee80211_rx_for_interface(s */ link_sta = link_sta_info_get_bss(rx->sdata, hdr->addr2); if (link_sta) { - rx->sta = link_sta->sta; - rx->link_id = link_sta->link_id; + sta = link_sta->sta; + link_id = link_sta->link_id; } else { struct ieee80211_rx_status *status = IEEE80211_SKB_RXCB(skb);
- rx->sta = sta_info_get_bss(rx->sdata, hdr->addr2); - if (rx->sta) { - if (status->link_valid && - !ieee80211_rx_is_valid_sta_link_id(&rx->sta->sta, - status->link_id)) - return false; - - rx->link_id = status->link_valid ? status->link_id : -1; - } else { - rx->link_id = -1; - } + sta = sta_info_get_bss(rx->sdata, hdr->addr2); + if (status->link_valid) + link_id = status->link_id; }
+ if (!ieee80211_rx_data_set_sta(rx, &sta->sta, link_id)) + return false; + return ieee80211_prepare_and_rx_handle(rx, skb, consume); }
@@ -5036,19 +5019,15 @@ static void __ieee80211_rx_handle_packet
if (ieee80211_is_data(fc)) { struct sta_info *sta, *prev_sta; - u8 link_id = status->link_id; + int link_id = -1;
- if (pubsta) { - rx.sta = container_of(pubsta, struct sta_info, sta); - rx.sdata = rx.sta->sdata; + if (status->link_valid) + link_id = status->link_id;
- if (status->link_valid && - !ieee80211_rx_is_valid_sta_link_id(pubsta, link_id)) + if (pubsta) { + if (!ieee80211_rx_data_set_sta(&rx, pubsta, link_id)) goto out;
- if (status->link_valid) - rx.link_id = status->link_id; - /* * In MLO connection, fetch the link_id using addr2 * when the driver does not pass link_id in status. @@ -5066,7 +5045,7 @@ static void __ieee80211_rx_handle_packet if (!link_sta) goto out;
- rx.link_id = link_sta->link_id; + ieee80211_rx_data_set_link(&rx, link_sta->link_id); }
if (ieee80211_prepare_and_rx_handle(&rx, skb, true)) @@ -5082,30 +5061,27 @@ static void __ieee80211_rx_handle_packet continue; }
- if ((status->link_valid && - !ieee80211_rx_is_valid_sta_link_id(&prev_sta->sta, - link_id)) || - (!status->link_valid && prev_sta->sta.mlo)) + rx.sdata = prev_sta->sdata; + if (!ieee80211_rx_data_set_sta(&rx, &prev_sta->sta, + link_id)) + goto out; + + if (!status->link_valid && prev_sta->sta.mlo) continue;
- rx.link_id = status->link_valid ? link_id : -1; - rx.sta = prev_sta; - rx.sdata = prev_sta->sdata; ieee80211_prepare_and_rx_handle(&rx, skb, false);
prev_sta = sta; }
if (prev_sta) { - if ((status->link_valid && - !ieee80211_rx_is_valid_sta_link_id(&prev_sta->sta, - link_id)) || - (!status->link_valid && prev_sta->sta.mlo)) + rx.sdata = prev_sta->sdata; + if (!ieee80211_rx_data_set_sta(&rx, &prev_sta->sta, + link_id)) goto out;
- rx.link_id = status->link_valid ? link_id : -1; - rx.sta = prev_sta; - rx.sdata = prev_sta->sdata; + if (!status->link_valid && prev_sta->sta.mlo) + goto out;
if (ieee80211_prepare_and_rx_handle(&rx, skb, true)) return;