On Fri, Mar 3, 2017 at 3:11 PM, Dmitry Vyukov <dvyukov@xxxxxxxxxx> wrote: > On Mon, Feb 13, 2017 at 11:29 PM, Cong Wang <xiyou.wangcong@xxxxxxxxx> wrote: >> On Mon, Feb 13, 2017 at 11:19 AM, Andrey Konovalov >> <andreyknvl@xxxxxxxxxx> wrote: >>> Hi, >>> >>> I've got the following error report while fuzzing the kernel with syzkaller. >>> >>> On commit 926af6273fc683cd98cd0ce7bf0d04a02eed6742. >>> >>> A reproducer and .config are attached. >>> Note, that it takes quite some time to trigger the bug (up to 10 minutes). >>> >>> BUG: KASAN: use-after-free in dccp_feat_activate_values+0x967/0xab0 >>> net/dccp/feat.c:1541 at addr ffff88003713be68 >>> Read of size 8 by task syz-executor2/8457 >>> CPU: 2 PID: 8457 Comm: syz-executor2 Not tainted 4.10.0-rc7+ #127 >>> Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 >>> Call Trace: >>> <IRQ> >>> __dump_stack lib/dump_stack.c:15 [inline] >>> dump_stack+0x292/0x398 lib/dump_stack.c:51 >>> kasan_object_err+0x1c/0x70 mm/kasan/report.c:162 >>> print_address_description mm/kasan/report.c:200 [inline] >>> kasan_report_error mm/kasan/report.c:289 [inline] >>> kasan_report.part.1+0x20e/0x4e0 mm/kasan/report.c:311 >>> kasan_report mm/kasan/report.c:332 [inline] >>> __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:332 >>> dccp_feat_activate_values+0x967/0xab0 net/dccp/feat.c:1541 >>> dccp_create_openreq_child+0x464/0x610 net/dccp/minisocks.c:121 >>> dccp_v6_request_recv_sock+0x1f6/0x1960 net/dccp/ipv6.c:457 >>> dccp_check_req+0x335/0x5a0 net/dccp/minisocks.c:186 >>> dccp_v6_rcv+0x69e/0x1d00 net/dccp/ipv6.c:711 >>> ip6_input_finish+0x46d/0x17a0 net/ipv6/ip6_input.c:279 >>> NF_HOOK include/linux/netfilter.h:257 [inline] >>> ip6_input+0xdb/0x590 net/ipv6/ip6_input.c:322 >>> dst_input include/net/dst.h:507 [inline] >>> ip6_rcv_finish+0x289/0x890 net/ipv6/ip6_input.c:69 >>> NF_HOOK include/linux/netfilter.h:257 [inline] >>> ipv6_rcv+0x12ec/0x23d0 net/ipv6/ip6_input.c:203 >>> __netif_receive_skb_core+0x1ae5/0x3400 net/core/dev.c:4190 >>> __netif_receive_skb+0x2a/0x170 net/core/dev.c:4228 >>> process_backlog+0xe5/0x6c0 net/core/dev.c:4839 >>> napi_poll net/core/dev.c:5202 [inline] >>> net_rx_action+0xe70/0x1900 net/core/dev.c:5267 >>> __do_softirq+0x2fb/0xb7d kernel/softirq.c:284 >>> do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:902 >> >> >> Seems there is a race condition between iterating dccp_feat_entry >> and freeing it, bh_lock_sock() seems not held in this path. > > > > Cong, where exactly do we need to add bh_lock_sock()? > > I am still seeing this on 4977ab6e92e267afe9d8f78438c3db330ca8434c > > ================================================================== > BUG: KASAN: use-after-free in dccp_feat_activate_values+0x94c/0xa90 > net/dccp/feat.c:1541 at addr ffff880059f18998 > Read of size 8 by task syz-executor/3952 > CPU: 2 PID: 3952 Comm: syz-executor Not tainted 4.10.0+ #269 > Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 > Call Trace: > <IRQ> > __dump_stack lib/dump_stack.c:15 [inline] > dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 > kasan_object_err+0x1c/0x70 mm/kasan/report.c:166 > print_address_description mm/kasan/report.c:204 [inline] > kasan_report_error mm/kasan/report.c:288 [inline] > kasan_report.part.2+0x198/0x440 mm/kasan/report.c:310 > kasan_report mm/kasan/report.c:331 [inline] > __asan_report_load8_noabort+0x29/0x30 mm/kasan/report.c:331 > dccp_feat_activate_values+0x94c/0xa90 net/dccp/feat.c:1541 > dccp_create_openreq_child+0x464/0x610 net/dccp/minisocks.c:121 > dccp_v6_request_recv_sock+0x1f1/0x17e0 net/dccp/ipv6.c:457 > dccp_check_req+0x335/0x5a0 net/dccp/minisocks.c:186 > dccp_v6_rcv+0x653/0x1d10 net/dccp/ipv6.c:711 > ip6_input_finish+0x45b/0x1700 net/ipv6/ip6_input.c:279 > NF_HOOK include/linux/netfilter.h:257 [inline] > ip6_input+0xdb/0x580 net/ipv6/ip6_input.c:322 > dst_input include/net/dst.h:492 [inline] > ip6_rcv_finish+0x194/0x720 net/ipv6/ip6_input.c:69 > NF_HOOK include/linux/netfilter.h:257 [inline] > ipv6_rcv+0x12df/0x2380 net/ipv6/ip6_input.c:203 > __netif_receive_skb_core+0x1ac8/0x33f0 net/core/dev.c:4179 > __netif_receive_skb+0x2a/0x170 net/core/dev.c:4217 > process_backlog+0x11e/0x730 net/core/dev.c:4837 > napi_poll net/core/dev.c:5171 [inline] > net_rx_action+0xf0a/0x1980 net/core/dev.c:5236 > __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 > do_softirq_own_stack+0x1c/0x30 arch/x86/entry/entry_64.S:902 > </IRQ> > do_softirq.part.21+0x2c0/0x300 kernel/softirq.c:328 > do_softirq kernel/softirq.c:176 [inline] > __local_bh_enable_ip+0x24c/0x290 kernel/softirq.c:181 > local_bh_enable include/linux/bottom_half.h:31 [inline] > rcu_read_unlock_bh include/linux/rcupdate.h:971 [inline] > ip6_finish_output2+0xb85/0x2380 net/ipv6/ip6_output.c:124 > ip6_finish_output+0x2f9/0x950 net/ipv6/ip6_output.c:149 > NF_HOOK_COND include/linux/netfilter.h:246 [inline] > ip6_output+0x1cb/0x8c0 net/ipv6/ip6_output.c:163 > ip6_xmit+0xc36/0x1e80 include/net/dst.h:486 > inet6_csk_xmit+0x320/0x5d0 net/ipv6/inet6_connection_sock.c:139 > dccp_transmit_skb+0xac5/0x10e0 net/dccp/output.c:141 > dccp_xmit_packet+0x20f/0x750 net/dccp/output.c:280 > dccp_write_xmit+0x168/0x1d0 net/dccp/output.c:362 > dccp_sendmsg+0x793/0xb00 net/dccp/proto.c:796 > inet_sendmsg+0x164/0x5b0 net/ipv4/af_inet.c:761 > sock_sendmsg_nosec net/socket.c:633 [inline] > sock_sendmsg+0xca/0x110 net/socket.c:643 > SYSC_sendto+0x660/0x810 net/socket.c:1685 > SyS_sendto+0x40/0x50 net/socket.c:1653 > entry_SYSCALL_64_fastpath+0x1f/0xc2 > RIP: 0033:0x4458d9 > RSP: 002b:00007f59f536bb58 EFLAGS: 00000282 ORIG_RAX: 000000000000002c > RAX: ffffffffffffffda RBX: 000000000000001a RCX: 00000000004458d9 > RDX: 0000000000000037 RSI: 0000000020e62000 RDI: 000000000000001a > RBP: 00000000006e1b90 R08: 0000000020e62fe0 R09: 0000000000000020 > R10: 0000000000008000 R11: 0000000000000282 R12: 0000000000708150 > R13: 0000000020d0aff8 R14: 0000000000000004 R15: 0000000000000000 > Object at ffff880059f18980, in cache kmalloc-64 size: 64 > Allocated: > PID = 3932 > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 > save_stack+0x43/0xd0 mm/kasan/kasan.c:502 > set_track mm/kasan/kasan.c:514 [inline] > kasan_kmalloc+0xaa/0xd0 mm/kasan/kasan.c:605 > kmem_cache_alloc_trace+0x10b/0x6e0 mm/slab.c:3637 > kmalloc include/linux/slab.h:490 [inline] > dccp_feat_entry_new+0x20b/0x400 net/dccp/feat.c:467 > dccp_feat_push_change+0x38/0x220 net/dccp/feat.c:487 > __feat_register_sp+0x223/0x2f0 net/dccp/feat.c:741 > dccp_feat_propagate_ccid+0x22b/0x2b0 net/dccp/feat.c:949 > dccp_feat_server_ccid_dependencies+0x1b3/0x250 net/dccp/feat.c:1012 > dccp_make_response+0x1f1/0xc50 net/dccp/output.c:423 > dccp_v6_send_response+0x4ec/0xc20 net/dccp/ipv6.c:217 > dccp_v6_conn_request+0xab2/0x1100 net/dccp/ipv6.c:377 > dccp_rcv_state_process+0x50c/0x1650 net/dccp/input.c:606 > dccp_v6_do_rcv+0x20d/0x350 net/dccp/ipv6.c:632 > sk_backlog_rcv include/net/sock.h:896 [inline] > __sk_receive_skb+0x350/0xca0 net/core/sock.c:479 > dccp_v6_rcv+0xb17/0x1d10 net/dccp/ipv6.c:742 > ip6_input_finish+0x45b/0x1700 net/ipv6/ip6_input.c:279 > NF_HOOK include/linux/netfilter.h:257 [inline] > ip6_input+0xdb/0x580 net/ipv6/ip6_input.c:322 > dst_input include/net/dst.h:492 [inline] > ip6_rcv_finish+0x194/0x720 net/ipv6/ip6_input.c:69 > NF_HOOK include/linux/netfilter.h:257 [inline] > ipv6_rcv+0x12df/0x2380 net/ipv6/ip6_input.c:203 > __netif_receive_skb_core+0x1ac8/0x33f0 net/core/dev.c:4179 > __netif_receive_skb+0x2a/0x170 net/core/dev.c:4217 > process_backlog+0x11e/0x730 net/core/dev.c:4837 > napi_poll net/core/dev.c:5171 [inline] > net_rx_action+0xf0a/0x1980 net/core/dev.c:5236 > __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 > Freed: > PID = 24 > save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:57 > save_stack+0x43/0xd0 mm/kasan/kasan.c:502 > set_track mm/kasan/kasan.c:514 [inline] > kasan_slab_free+0x6f/0xb0 mm/kasan/kasan.c:578 > __cache_free mm/slab.c:3513 [inline] > kfree+0xd3/0x250 mm/slab.c:3830 > dccp_feat_entry_destructor.part.4+0x48/0x60 net/dccp/feat.c:418 > dccp_feat_entry_destructor net/dccp/feat.c:416 [inline] > dccp_feat_list_pop net/dccp/feat.c:541 [inline] > dccp_feat_activate_values+0x57f/0xa90 net/dccp/feat.c:1543 > dccp_create_openreq_child+0x464/0x610 net/dccp/minisocks.c:121 > dccp_v6_request_recv_sock+0x1f1/0x17e0 net/dccp/ipv6.c:457 > dccp_check_req+0x335/0x5a0 net/dccp/minisocks.c:186 > dccp_v6_rcv+0x653/0x1d10 net/dccp/ipv6.c:711 > ip6_input_finish+0x45b/0x1700 net/ipv6/ip6_input.c:279 > NF_HOOK include/linux/netfilter.h:257 [inline] > ip6_input+0xdb/0x580 net/ipv6/ip6_input.c:322 > dst_input include/net/dst.h:492 [inline] > ip6_rcv_finish+0x194/0x720 net/ipv6/ip6_input.c:69 > NF_HOOK include/linux/netfilter.h:257 [inline] > ipv6_rcv+0x12df/0x2380 net/ipv6/ip6_input.c:203 > __netif_receive_skb_core+0x1ac8/0x33f0 net/core/dev.c:4179 > __netif_receive_skb+0x2a/0x170 net/core/dev.c:4217 > process_backlog+0x11e/0x730 net/core/dev.c:4837 > napi_poll net/core/dev.c:5171 [inline] > net_rx_action+0xf0a/0x1980 net/core/dev.c:5236 > __do_softirq+0x31f/0xbe7 kernel/softirq.c:284 > Memory state around the buggy address: > ffff880059f18880: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > ffff880059f18900: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc >>ffff880059f18980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ^ > ffff880059f18a00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc > ffff880059f18a80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc > ================================================================== Hit this while trying to reproduce another WARNING in networking stack, so now I suspect that it may be an induced WARNING and not sure if it worth pursuing spending more time on it... WARNING: CPU: 1 PID: 29691 at net/core/stream.c:198 sk_stream_kill_queues+0x401/0x570 net/core/stream.c:198 Call Trace: __dump_stack lib/dump_stack.c:15 [inline] dump_stack+0x2ee/0x3ef lib/dump_stack.c:51 panic+0x1fb/0x412 kernel/panic.c:179 __warn+0x1c4/0x1e0 kernel/panic.c:539 warn_slowpath_null+0x2c/0x40 kernel/panic.c:582 sk_stream_kill_queues+0x401/0x570 net/core/stream.c:198 inet_csk_destroy_sock+0x175/0x450 net/ipv4/inet_connection_sock.c:708 dccp_close+0x951/0xc60 net/dccp/proto.c:1067 inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425 inet6_release+0x50/0x70 net/ipv6/af_inet6.c:431 sock_release+0x8d/0x1e0 net/socket.c:599 sock_close+0x16/0x20 net/socket.c:1063 __fput+0x332/0x7f0 fs/file_table.c:208 ____fput+0x15/0x20 fs/file_table.c:244 task_work_run+0x18a/0x260 kernel/task_work.c:116 exit_task_work include/linux/task_work.h:21 [inline] do_exit+0x18ef/0x28b0 kernel/exit.c:841 do_group_exit+0x149/0x420 kernel/exit.c:945 get_signal+0x7e0/0x1820 kernel/signal.c:2313 do_signal+0xd2/0x2190 arch/x86/kernel/signal.c:807 exit_to_usermode_loop+0x200/0x2a0 arch/x86/entry/common.c:156 prepare_exit_to_usermode arch/x86/entry/common.c:190 [inline] syscall_return_slowpath+0x4d3/0x570 arch/x86/entry/common.c:259 entry_SYSCALL_64_fastpath+0xc0/0xc2 -- To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
