From 63f63d3ce535ca59a9da05ba3004187033495b7d Mon Sep 17 00:00:00 2001 From: Ryan Sullivan Date: Mon, 23 Jan 2023 11:41:37 -0500 Subject: [KPATCH CVE-2022-3564] kpatch fixes for CVE-2022-3564 Kernels: 3.10.0-1160.71.1.el7 3.10.0-1160.76.1.el7 3.10.0-1160.80.1.el7 3.10.0-1160.81.1.el7 Kpatch-MR: https://gitlab.com/redhat/prdsc/rhel/src/kpatch/rhel-7/-/merge_requests/49 Approved-by: Yannick Cote (@ycote1) Approved-by: Joe Lawrence (@joe.lawrence) Changes since last build: [x86_64]: l2cap_core.o: changed function: l2cap_data_channel l2cap_core.o: changed function: l2cap_rx_state_recv nf_tables_api.o: changed function: __nf_tables_abort nf_tables_api.o: changed function: nf_tables_delsetelem nf_tables_api.o: changed function: nf_tables_newset nf_tables_api.o: changed function: nft_delrule nf_tables_api.o: changed function: nft_set_destroy nf_tables_api.o: changed function: nft_validate_register_store nf_tables_api.o: new function: nf_tables_activate_set nf_tables_api.o: new function: nf_tables_deactivate_set nf_tables_api.o: new function: nft_rule_expr_deactivate nft_dynset.o: new function: klp_is_nft_dynset nft_dynset.o: new function: nft_dynset_activate nft_dynset.o: new function: nft_dynset_deactivate nft_lookup.o: new function: klp_is_nft_lookup nft_lookup.o: new function: nft_lookup_activate nft_lookup.o: new function: nft_lookup_deactivate [ppc64le]: l2cap_core.o: changed function: l2cap_data_channel l2cap_core.o: changed function: l2cap_rx_state_recv nf_tables_api.o: changed function: __nf_tables_abort nf_tables_api.o: changed function: nf_tables_bind_check_setelem nf_tables_api.o: changed function: nf_tables_bind_set nf_tables_api.o: changed function: nf_tables_commit nf_tables_api.o: changed function: nf_tables_delrule nf_tables_api.o: changed function: nf_tables_delsetelem nf_tables_api.o: changed function: nf_tables_newset nf_tables_api.o: changed function: nf_tables_unbind_set nf_tables_api.o: changed function: nft_add_set_elem nf_tables_api.o: changed function: nft_delrule_by_chain nf_tables_api.o: changed function: nft_unregister_afinfo nf_tables_api.o: changed function: nft_validate_register_store nf_tables_api.o: new function: nf_tables_activate_set nf_tables_api.o: new function: nf_tables_deactivate_set nft_dynset.o: new function: klp_is_nft_dynset nft_dynset.o: new function: nft_dynset_activate nft_dynset.o: new function: nft_dynset_deactivate nft_lookup.o: new function: klp_is_nft_lookup nft_lookup.o: new function: nft_lookup_activate nft_lookup.o: new function: nft_lookup_deactivate --------------------------- Modifications: none commit ce15ab7416bca0378f144b0aa9183abb532bfb7d Author: Wander Lairson Costa Date: Mon Jan 9 14:37:35 2023 -0300 Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu Bugzilla: https://bugzilla.redhat.com/2152941 CVE: CVE-2022-3564 commit 3aff8aaca4e36dc8b17eaa011684881a80238966 Author: Maxim Mikityanskiy Date: Wed Oct 5 00:27:18 2022 +0300 Bluetooth: L2CAP: Fix use-after-free caused by l2cap_reassemble_sdu Fix the race condition between the following two flows that run in parallel: 1. l2cap_reassemble_sdu -> chan->ops->recv (l2cap_sock_recv_cb) -> __sock_queue_rcv_skb. 2. bt_sock_recvmsg -> skb_recv_datagram, skb_free_datagram. An SKB can be queued by the first flow and immediately dequeued and freed by the second flow, therefore the callers of l2cap_reassemble_sdu can't use the SKB after that function returns. However, some places continue accessing struct l2cap_ctrl that resides in the SKB's CB for a short time after l2cap_reassemble_sdu returns, leading to a use-after-free condition (the stack trace is below, line numbers for kernel 5.19.8). Fix it by keeping a local copy of struct l2cap_ctrl. BUG: KASAN: use-after-free in l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth Read of size 1 at addr ffff88812025f2f0 by task kworker/u17:3/43169 Workqueue: hci0 hci_rx_work [bluetooth] Call Trace: dump_stack_lvl (lib/dump_stack.c:107 (discriminator 4)) print_report.cold (mm/kasan/report.c:314 mm/kasan/report.c:429) ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493) ? l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth l2cap_rx_state_recv (net/bluetooth/l2cap_core.c:6906) bluetooth l2cap_rx (net/bluetooth/l2cap_core.c:7236 net/bluetooth/l2cap_core.c:7271) bluetooth ret_from_fork (arch/x86/entry/entry_64.S:306) Allocated by task 43169: kasan_save_stack (mm/kasan/common.c:39) __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469) kmem_cache_alloc_node (mm/slab.h:750 mm/slub.c:3243 mm/slub.c:3293) __alloc_skb (net/core/skbuff.c:414) l2cap_recv_frag (./include/net/bluetooth/bluetooth.h:425 net/bluetooth/l2cap_core.c:8329) bluetooth l2cap_recv_acldata (net/bluetooth/l2cap_core.c:8442) bluetooth hci_rx_work (net/bluetooth/hci_core.c:3642 net/bluetooth/hci_core.c:3832) bluetooth process_one_work (kernel/workqueue.c:2289) worker_thread (./include/linux/list.h:292 kernel/workqueue.c:2437) kthread (kernel/kthread.c:376) ret_from_fork (arch/x86/entry/entry_64.S:306) Freed by task 27920: kasan_save_stack (mm/kasan/common.c:39) kasan_set_track (mm/kasan/common.c:45) kasan_set_free_info (mm/kasan/generic.c:372) ____kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328) slab_free_freelist_hook (mm/slub.c:1780) kmem_cache_free (mm/slub.c:3536 mm/slub.c:3553) skb_free_datagram (./include/net/sock.h:1578 ./include/net/sock.h:1639 net/core/datagram.c:323) bt_sock_recvmsg (net/bluetooth/af_bluetooth.c:295) bluetooth l2cap_sock_recvmsg (net/bluetooth/l2cap_sock.c:1212) bluetooth sock_read_iter (net/socket.c:1087) new_sync_read (./include/linux/fs.h:2052 fs/read_write.c:401) vfs_read (fs/read_write.c:482) ksys_read (fs/read_write.c:620) do_syscall_64 (arch/x86/entry/common.c:50 arch/x86/entry/common.c:80) entry_SYSCALL_64_after_hwframe (arch/x86/entry/entry_64.S:120) Link: https://lore.kernel.org/linux-bluetooth/CAKErNvoqga1WcmoR3-0875esY6TVWFQDandbVZncSiuGPBQXLA@mail.gmail.com/T/#u Fixes: d2a7ac5d5d3a ("Bluetooth: Add the ERTM receive state machine") Fixes: 4b51dae96731 ("Bluetooth: Add streaming mode receive and incoming packet classifier") Signed-off-by: Maxim Mikityanskiy Signed-off-by: Luiz Augusto von Dentz Signed-off-by: Wander Lairson Costa Signed-off-by: Ryan Sullivan --- net/bluetooth/l2cap_core.c | 48 ++++++++++++++++++++++++++++++++------ 1 file changed, 41 insertions(+), 7 deletions(-) diff --git a/net/bluetooth/l2cap_core.c b/net/bluetooth/l2cap_core.c index 6e94fd907d89..4338810b0d58 100644 --- a/net/bluetooth/l2cap_core.c +++ b/net/bluetooth/l2cap_core.c @@ -6197,6 +6197,7 @@ static int l2cap_rx_state_recv(struct l2cap_chan *chan, struct l2cap_ctrl *control, struct sk_buff *skb, u8 event) { + struct l2cap_ctrl local_control; int err = 0; bool skb_in_use = false; @@ -6221,15 +6222,32 @@ static int l2cap_rx_state_recv(struct l2cap_chan *chan, chan->buffer_seq = chan->expected_tx_seq; skb_in_use = true; + /* l2cap_reassemble_sdu may free skb, hence invalidate + * control, so make a copy in advance to use it after + * l2cap_reassemble_sdu returns and to avoid the race + * condition, for example: + * + * The current thread calls: + * l2cap_reassemble_sdu + * chan->ops->recv == l2cap_sock_recv_cb + * __sock_queue_rcv_skb + * Another thread calls: + * bt_sock_recvmsg + * skb_recv_datagram + * skb_free_datagram + * Then the current thread tries to access control, but + * it was freed by skb_free_datagram. + */ + local_control = *control; err = l2cap_reassemble_sdu(chan, skb, control); if (err) break; - if (control->final) { + if (local_control.final) { if (!test_and_clear_bit(CONN_REJ_ACT, &chan->conn_state)) { - control->final = 0; - l2cap_retransmit_all(chan, control); + local_control.final = 0; + l2cap_retransmit_all(chan, &local_control); l2cap_ertm_send(chan); } } @@ -6609,11 +6627,27 @@ static int l2cap_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, struct sk_buff *skb) { + /* l2cap_reassemble_sdu may free skb, hence invalidate control, so store + * the txseq field in advance to use it after l2cap_reassemble_sdu + * returns and to avoid the race condition, for example: + * + * The current thread calls: + * l2cap_reassemble_sdu + * chan->ops->recv == l2cap_sock_recv_cb + * __sock_queue_rcv_skb + * Another thread calls: + * bt_sock_recvmsg + * skb_recv_datagram + * skb_free_datagram + * Then the current thread tries to access control, but it was freed by + * skb_free_datagram. + */ + u16 txseq = control->txseq; + BT_DBG("chan %p, control %p, skb %p, state %d", chan, control, skb, chan->rx_state); - if (l2cap_classify_txseq(chan, control->txseq) == - L2CAP_TXSEQ_EXPECTED) { + if (l2cap_classify_txseq(chan, txseq) == L2CAP_TXSEQ_EXPECTED) { l2cap_pass_to_tx(chan, control); BT_DBG("buffer_seq %d->%d", chan->buffer_seq, @@ -6636,8 +6670,8 @@ static int l2cap_stream_rx(struct l2cap_chan *chan, struct l2cap_ctrl *control, } } - chan->last_acked_seq = control->txseq; - chan->expected_tx_seq = __next_seq(chan, control->txseq); + chan->last_acked_seq = txseq; + chan->expected_tx_seq = __next_seq(chan, txseq); return 0; } -- 2.40.1