From: Joe Lawrence Subject: [RHEL8.4 KPATCH v2] bluetooth: kpatch fixes for CVE-2021-33034 Date: Thu, 10 Jun 2021 09:06:37 -0400 Changes since last build: [x86_64]: hci_event.o: changed function: hci_event_packet [ppc64le]: hci_event.o: changed function: hci_event_packet hci_event.o: new function: hci_resolve_name --------------------------- Kernels: 4.18.0-305.el8 4.18.0-305.3.1.el8_4 Modifications: - Remove modification of struct hci_chan and add hchan_amp shadow variable as flag instead commit 418fac0a2503c7e5b310052431cecab67a0efb8f Author: Gopal Tiwari Date: Thu May 20 11:27:10 2021 +0530 Bluetooth: verify AMP hci_chan before amp_destroy Bugzilla: https://bugzilla.redhat.com/1962544 CVE: CVE-2021-33034 Y-Commit: 162078c99ca2f976692d81b532a9eea80332cf82 O-Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=1962546 O-CVE: CVE-2021-33034 Testing: Verified by me with the help of reproducer. https://bugzilla.redhat.com/show_bug.cgi?id=1962546#c1 Upstream: Merged. commit 5c4c8c9544099bb9043a10a5318130a943e32fc3 Author: Archie Pusaka Date: Mon Mar 22 14:03:11 2021 +0800 Bluetooth: verify AMP hci_chan before amp_destroy hci_chan can be created in 2 places: hci_loglink_complete_evt() if it is an AMP hci_chan, or l2cap_conn_add() otherwise. In theory, Only AMP hci_chan should be removed by a call to hci_disconn_loglink_complete_evt(). However, the controller might mess up, call that function, and destroy an hci_chan which is not initiated by hci_loglink_complete_evt(). This patch adds a verification that the destroyed hci_chan must have been init'd by hci_loglink_complete_evt(). Example crash call trace: Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0xe3/0x144 lib/dump_stack.c:118 print_address_description+0x67/0x22a mm/kasan/report.c:256 kasan_report_error mm/kasan/report.c:354 [inline] kasan_report mm/kasan/report.c:412 [inline] kasan_report+0x251/0x28f mm/kasan/report.c:396 hci_send_acl+0x3b/0x56e net/bluetooth/hci_core.c:4072 l2cap_send_cmd+0x5af/0x5c2 net/bluetooth/l2cap_core.c:877 l2cap_send_move_chan_cfm_icid+0x8e/0xb1 net/bluetooth/l2cap_core.c:4661 l2cap_move_fail net/bluetooth/l2cap_core.c:5146 [inline] l2cap_move_channel_rsp net/bluetooth/l2cap_core.c:5185 [inline] l2cap_bredr_sig_cmd net/bluetooth/l2cap_core.c:5464 [inline] l2cap_sig_channel net/bluetooth/l2cap_core.c:5799 [inline] l2cap_recv_frame+0x1d12/0x51aa net/bluetooth/l2cap_core.c:7023 l2cap_recv_acldata+0x2ea/0x693 net/bluetooth/l2cap_core.c:7596 hci_acldata_packet net/bluetooth/hci_core.c:4606 [inline] hci_rx_work+0x2bd/0x45e net/bluetooth/hci_core.c:4796 process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175 worker_thread+0x4fc/0x670 kernel/workqueue.c:2321 kthread+0x2f0/0x304 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Allocated by task 38: set_track mm/kasan/kasan.c:460 [inline] kasan_kmalloc+0x8d/0x9a mm/kasan/kasan.c:553 kmem_cache_alloc_trace+0x102/0x129 mm/slub.c:2787 kmalloc include/linux/slab.h:515 [inline] kzalloc include/linux/slab.h:709 [inline] hci_chan_create+0x86/0x26d net/bluetooth/hci_conn.c:1674 l2cap_conn_add.part.0+0x1c/0x814 net/bluetooth/l2cap_core.c:7062 l2cap_conn_add net/bluetooth/l2cap_core.c:7059 [inline] l2cap_connect_cfm+0x134/0x852 net/bluetooth/l2cap_core.c:7381 hci_connect_cfm+0x9d/0x122 include/net/bluetooth/hci_core.h:1404 hci_remote_ext_features_evt net/bluetooth/hci_event.c:4161 [inline] hci_event_packet+0x463f/0x72fa net/bluetooth/hci_event.c:5981 hci_rx_work+0x197/0x45e net/bluetooth/hci_core.c:4791 process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175 worker_thread+0x4fc/0x670 kernel/workqueue.c:2321 kthread+0x2f0/0x304 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 Freed by task 1732: set_track mm/kasan/kasan.c:460 [inline] __kasan_slab_free mm/kasan/kasan.c:521 [inline] __kasan_slab_free+0x106/0x128 mm/kasan/kasan.c:493 slab_free_hook mm/slub.c:1409 [inline] slab_free_freelist_hook+0xaa/0xf6 mm/slub.c:1436 slab_free mm/slub.c:3009 [inline] kfree+0x182/0x21e mm/slub.c:3972 hci_disconn_loglink_complete_evt net/bluetooth/hci_event.c:4891 [inline] hci_event_packet+0x6a1c/0x72fa net/bluetooth/hci_event.c:6050 hci_rx_work+0x197/0x45e net/bluetooth/hci_core.c:4791 process_one_work+0x6f8/0xb50 kernel/workqueue.c:2175 worker_thread+0x4fc/0x670 kernel/workqueue.c:2321 kthread+0x2f0/0x304 kernel/kthread.c:253 ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:415 The buggy address belongs to the object at ffff8881d7af9180 which belongs to the cache kmalloc-128 of size 128 The buggy address is located 24 bytes inside of 128-byte region [ffff8881d7af9180, ffff8881d7af9200) The buggy address belongs to the page: page:ffffea00075ebe40 count:1 mapcount:0 mapping:ffff8881da403200 index:0x0 flags: 0x8000000000000200(slab) raw: 8000000000000200 dead000000000100 dead000000000200 ffff8881da403200 raw: 0000000000000000 0000000080150015 00000001ffffffff 0000000000000000 page dumped because: kasan: bad access detected Memory state around the buggy address: ffff8881d7af9080: fc fc fc fc fc fc fc fc fb fb fb fb fb fb fb fb ffff8881d7af9100: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc >ffff8881d7af9180: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ^ ffff8881d7af9200: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff8881d7af9280: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc Signed-off-by: Archie Pusaka Reported-by: syzbot+98228e7407314d2d4ba2@syzkaller.appspotmail.com Reviewed-by: Alain Michaud Reviewed-by: Abhishek Pandit-Subedi Signed-off-by: Marcel Holtmann (cherry picked from commit 5c4c8c9544099bb9043a10a5318130a943e32fc3) Signed-off-by: Gopal Tiwari Signed-off-by: Jan Stancek Signed-off-by: Joel Savitz for v1 Signed-off-by: Joe Lawrence Acked-by: Artem Savkov Acked-by: Yannick Cote --- v2: - minor code cleanup from v1, removed intermediate variables - I tried forcing hci_resolve_name() as always_inline on ppc64le, but this cascaded into a series of neverending inline / half inline / etc. compiler decisions that I could never completely eliminate. Z-MR: https://gitlab.com/redhat/rhel/src/kernel/rhel-8/-/merge_requests/692 KT0 test PASS: https://beaker.engineering.redhat.com/jobs/5457381 for kpatch-patch-4_18_0-193_1_2-1-12.el8_2 scratch build: https://brewweb.engineering.redhat.com/brew/taskinfo?taskID=37373415 net/bluetooth/hci_event.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/net/bluetooth/hci_event.c b/net/bluetooth/hci_event.c index 8a7af33b0a3e..e66687f5b701 100644 --- a/net/bluetooth/hci_event.c +++ b/net/bluetooth/hci_event.c @@ -29,6 +29,9 @@ #include #include #include +#include + +#define KLP_CVE_2021_33034_HCHAN_AMP 0x2021330340000000 #include "hci_request.h" #include "hci_debugfs.h" @@ -4929,6 +4932,11 @@ static void hci_loglink_complete_evt(struct hci_dev *hdev, struct sk_buff *skb) return; hchan->handle = le16_to_cpu(ev->handle); + if (!klp_shadow_get_or_alloc(hchan, KLP_CVE_2021_33034_HCHAN_AMP, + 0, GFP_KERNEL, NULL, NULL)) { + hci_chan_del(hchan); + return; + } BT_DBG("hcon %p mgr %p hchan %p", hcon, hcon->amp_mgr, hchan); @@ -4961,9 +4969,10 @@ static void hci_disconn_loglink_complete_evt(struct hci_dev *hdev, hci_dev_lock(hdev); hchan = hci_chan_lookup_handle(hdev, le16_to_cpu(ev->handle)); - if (!hchan) + if (!hchan || !klp_shadow_get(hchan, KLP_CVE_2021_33034_HCHAN_AMP)) goto unlock; + klp_shadow_free(hchan, KLP_CVE_2021_33034_HCHAN_AMP, NULL); amp_destroy_logical_link(hchan, ev->reason); unlock: -- 2.26.3