1. 30 Aug, 2017 3 commits
    • Eric Dumazet's avatar
      dccp: defer ccid_hc_tx_delete() at dismantle time · c207ec46
      Eric Dumazet authored
      
      [ Upstream commit 120e9dab ]
      
      syszkaller team reported another problem in DCCP [1]
      
      Problem here is that the structure holding RTO timer
      (ccid2_hc_tx_rto_expire() handler) is freed too soon.
      
      We can not use del_timer_sync() to cancel the timer
      since this timer wants to grab socket lock (that would risk a dead lock)
      
      Solution is to defer the freeing of memory when all references to
      the socket were released. Socket timers do own a reference, so this
      should fix the issue.
      
      [1]
      
      ==================================================================
      BUG: KASAN: use-after-free in ccid2_hc_tx_rto_expire+0x51c/0x5c0 net/dccp/ccids/ccid2.c:144
      Read of size 4 at addr ffff8801d2660540 by task kworker/u4:7/3365
      
      CPU: 1 PID: 3365 Comm: kworker/u4:7 Not tainted 4.13.0-rc4+ #3
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Workqueue: events_unbound call_usermodehelper_exec_work
      Call Trace:
       <IRQ>
       __dump_stack lib/dump_stack.c:16 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:52
       print_address_description+0x73/0x250 mm/kasan/report.c:252
       kasan_report_error mm/kasan/report.c:351 [inline]
       kasan_report+0x24e/0x340 mm/kasan/report.c:409
       __asan_report_load4_noabort+0x14/0x20 mm/kasan/report.c:429
       ccid2_hc_tx_rto_expire+0x51c/0x5c0 net/dccp/ccids/ccid2.c:144
       call_timer_fn+0x233/0x830 kernel/time/timer.c:1268
       expire_timers kernel/time/timer.c:1307 [inline]
       __run_timers+0x7fd/0xb90 kernel/time/timer.c:1601
       run_timer_softirq+0x21/0x80 kernel/time/timer.c:1614
       __do_softirq+0x2f5/0xba3 kernel/softirq.c:284
       invoke_softirq kernel/softirq.c:364 [inline]
       irq_exit+0x1cc/0x200 kernel/softirq.c:405
       exiting_irq arch/x86/include/asm/apic.h:638 [inline]
       smp_apic_timer_interrupt+0x76/0xa0 arch/x86/kernel/apic/apic.c:1044
       apic_timer_interrupt+0x93/0xa0 arch/x86/entry/entry_64.S:702
      RIP: 0010:arch_local_irq_enable arch/x86/include/asm/paravirt.h:824 [inline]
      RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:267 [inline]
      RIP: 0010:_raw_write_unlock_irq+0x56/0x70 kernel/locking/spinlock.c:343
      RSP: 0018:ffff8801cd50eaa8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff10
      RAX: dffffc0000000000 RBX: ffffffff85a090c0 RCX: 0000000000000006
      RDX: 1ffffffff0b595f3 RSI: 1ffff1003962f989 RDI: ffffffff85acaf98
      RBP: ffff8801cd50eab0 R08: 0000000000000001 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801cc96ea60
      R13: dffffc0000000000 R14: ffff8801cc96e4c0 R15: ffff8801cc96e4c0
       </IRQ>
       release_task+0xe9e/0x1a40 kernel/exit.c:220
       wait_task_zombie kernel/exit.c:1162 [inline]
       wait_consider_task+0x29b8/0x33c0 kernel/exit.c:1389
       do_wait_thread kernel/exit.c:1452 [inline]
       do_wait+0x441/0xa90 kernel/exit.c:1523
       kernel_wait4+0x1f5/0x370 kernel/exit.c:1665
       SYSC_wait4+0x134/0x140 kernel/exit.c:1677
       SyS_wait4+0x2c/0x40 kernel/exit.c:1673
       call_usermodehelper_exec_sync kernel/kmod.c:286 [inline]
       call_usermodehelper_exec_work+0x1a0/0x2c0 kernel/kmod.c:323
       process_one_work+0xbf3/0x1bc0 kernel/workqueue.c:2097
       worker_thread+0x223/0x1860 kernel/workqueue.c:2231
       kthread+0x35e/0x430 kernel/kthread.c:231
       ret_from_fork+0x2a/0x40 arch/x86/entry/entry_64.S:425
      
      Allocated by task 21267:
       save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
       save_stack+0x43/0xd0 mm/kasan/kasan.c:447
       set_track mm/kasan/kasan.c:459 [inline]
       kasan_kmalloc+0xad/0xe0 mm/kasan/kasan.c:551
       kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:489
       kmem_cache_alloc+0x127/0x750 mm/slab.c:3561
       ccid_new+0x20e/0x390 net/dccp/ccid.c:151
       dccp_hdlr_ccid+0x27/0x140 net/dccp/feat.c:44
       __dccp_feat_activate+0x142/0x2a0 net/dccp/feat.c:344
       dccp_feat_activate_values+0x34e/0xa90 net/dccp/feat.c:1538
       dccp_rcv_request_sent_state_process net/dccp/input.c:472 [inline]
       dccp_rcv_state_process+0xed1/0x1620 net/dccp/input.c:677
       dccp_v4_do_rcv+0xeb/0x160 net/dccp/ipv4.c:679
       sk_backlog_rcv include/net/sock.h:911 [inline]
       __release_sock+0x124/0x360 net/core/sock.c:2269
       release_sock+0xa4/0x2a0 net/core/sock.c:2784
       inet_wait_for_connect net/ipv4/af_inet.c:557 [inline]
       __inet_stream_connect+0x671/0xf00 net/ipv4/af_inet.c:643
       inet_stream_connect+0x58/0xa0 net/ipv4/af_inet.c:682
       SYSC_connect+0x204/0x470 net/socket.c:1642
       SyS_connect+0x24/0x30 net/socket.c:1623
       entry_SYSCALL_64_fastpath+0x1f/0xbe
      
      Freed by task 3049:
       save_stack_trace+0x16/0x20 arch/x86/kernel/stacktrace.c:59
       save_stack+0x43/0xd0 mm/kasan/kasan.c:447
       set_track mm/kasan/kasan.c:459 [inline]
       kasan_slab_free+0x71/0xc0 mm/kasan/kasan.c:524
       __cache_free mm/slab.c:3503 [inline]
       kmem_cache_free+0x77/0x280 mm/slab.c:3763
       ccid_hc_tx_delete+0xc5/0x100 net/dccp/ccid.c:190
       dccp_destroy_sock+0x1d1/0x2b0 net/dccp/proto.c:225
       inet_csk_destroy_sock+0x166/0x3f0 net/ipv4/inet_connection_sock.c:833
       dccp_done+0xb7/0xd0 net/dccp/proto.c:145
       dccp_time_wait+0x13d/0x300 net/dccp/minisocks.c:72
       dccp_rcv_reset+0x1d1/0x5b0 net/dccp/input.c:160
       dccp_rcv_state_process+0x8fc/0x1620 net/dccp/input.c:663
       dccp_v4_do_rcv+0xeb/0x160 net/dccp/ipv4.c:679
       sk_backlog_rcv include/net/sock.h:911 [inline]
       __sk_receive_skb+0x33e/0xc00 net/core/sock.c:521
       dccp_v4_rcv+0xef1/0x1c00 net/dccp/ipv4.c:871
       ip_local_deliver_finish+0x2e2/0xba0 net/ipv4/ip_input.c:216
       NF_HOOK include/linux/netfilter.h:248 [inline]
       ip_local_deliver+0x1ce/0x6d0 net/ipv4/ip_input.c:257
       dst_input include/net/dst.h:477 [inline]
       ip_rcv_finish+0x8db/0x19c0 net/ipv4/ip_input.c:397
       NF_HOOK include/linux/netfilter.h:248 [inline]
       ip_rcv+0xc3f/0x17d0 net/ipv4/ip_input.c:488
       __netif_receive_skb_core+0x19af/0x33d0 net/core/dev.c:4417
       __netif_receive_skb+0x2c/0x1b0 net/core/dev.c:4455
       process_backlog+0x203/0x740 net/core/dev.c:5130
       napi_poll net/core/dev.c:5527 [inline]
       net_rx_action+0x792/0x1910 net/core/dev.c:5593
       __do_softirq+0x2f5/0xba3 kernel/softirq.c:284
      
      The buggy address belongs to the object at ffff8801d2660100
       which belongs to the cache ccid2_hc_tx_sock of size 1240
      The buggy address is located 1088 bytes inside of
       1240-byte region [ffff8801d2660100, ffff8801d26605d8)
      The buggy address belongs to the page:
      page:ffffea0007499800 count:1 mapcount:0 mapping:ffff8801d2660100 index:0x0 compound_mapcount: 0
      flags: 0x200000000008100(slab|head)
      raw: 0200000000008100 ffff8801d2660100 0000000000000000 0000000100000005
      raw: ffffea00075271a0 ffffea0007538820 ffff8801d3aef9c0 0000000000000000
      page dumped because: kasan: bad access detected
      
      Memory state around the buggy address:
       ffff8801d2660400: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
       ffff8801d2660480: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
      >ffff8801d2660500: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                 ^
       ffff8801d2660580: fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc fc
       ffff8801d2660600: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      ==================================================================
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: Gerrit Renker <gerrit@erg.abdn.ac.uk>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c207ec46
    • Eric Dumazet's avatar
      dccp: purge write queue in dccp_destroy_sock() · c65eca7d
      Eric Dumazet authored
      
      [ Upstream commit 7749d4ff ]
      
      syzkaller reported that DCCP could have a non empty
      write queue at dismantle time.
      
      WARNING: CPU: 1 PID: 2953 at net/core/stream.c:199 sk_stream_kill_queues+0x3ce/0x520 net/core/stream.c:199
      Kernel panic - not syncing: panic_on_warn set ...
      
      CPU: 1 PID: 2953 Comm: syz-executor0 Not tainted 4.13.0-rc4+ #2
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:16 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:52
       panic+0x1e4/0x417 kernel/panic.c:180
       __warn+0x1c4/0x1d9 kernel/panic.c:541
       report_bug+0x211/0x2d0 lib/bug.c:183
       fixup_bug+0x40/0x90 arch/x86/kernel/traps.c:190
       do_trap_no_signal arch/x86/kernel/traps.c:224 [inline]
       do_trap+0x260/0x390 arch/x86/kernel/traps.c:273
       do_error_trap+0x120/0x390 arch/x86/kernel/traps.c:310
       do_invalid_op+0x1b/0x20 arch/x86/kernel/traps.c:323
       invalid_op+0x1e/0x30 arch/x86/entry/entry_64.S:846
      RIP: 0010:sk_stream_kill_queues+0x3ce/0x520 net/core/stream.c:199
      RSP: 0018:ffff8801d182f108 EFLAGS: 00010297
      RAX: ffff8801d1144140 RBX: ffff8801d13cb280 RCX: 0000000000000000
      RDX: 0000000000000000 RSI: ffffffff85137b00 RDI: ffff8801d13cb280
      RBP: ffff8801d182f148 R08: 0000000000000001 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000000 R12: ffff8801d13cb4d0
      R13: ffff8801d13cb3b8 R14: ffff8801d13cb300 R15: ffff8801d13cb3b8
       inet_csk_destroy_sock+0x175/0x3f0 net/ipv4/inet_connection_sock.c:835
       dccp_close+0x84d/0xc10 net/dccp/proto.c:1067
       inet_release+0xed/0x1c0 net/ipv4/af_inet.c:425
       sock_release+0x8d/0x1e0 net/socket.c:597
       sock_close+0x16/0x20 net/socket.c:1126
       __fput+0x327/0x7e0 fs/file_table.c:210
       ____fput+0x15/0x20 fs/file_table.c:246
       task_work_run+0x18a/0x260 kernel/task_work.c:116
       exit_task_work include/linux/task_work.h:21 [inline]
       do_exit+0xa32/0x1b10 kernel/exit.c:865
       do_group_exit+0x149/0x400 kernel/exit.c:969
       get_signal+0x7e8/0x17e0 kernel/signal.c:2330
       do_signal+0x94/0x1ee0 arch/x86/kernel/signal.c:808
       exit_to_usermode_loop+0x21c/0x2d0 arch/x86/entry/common.c:157
       prepare_exit_to_usermode arch/x86/entry/common.c:194 [inline]
       syscall_return_slowpath+0x3a7/0x450 arch/x86/entry/common.c:263
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      c65eca7d
    • Eric Dumazet's avatar
      af_key: do not use GFP_KERNEL in atomic contexts · f0cd9201
      Eric Dumazet authored
      
      [ Upstream commit 36f41f8f ]
      
      pfkey_broadcast() might be called from non process contexts,
      we can not use GFP_KERNEL in these cases [1].
      
      This patch partially reverts commit ba51b6be ("net: Fix RCU splat in
      af_key"), only keeping the GFP_ATOMIC forcing under rcu_read_lock()
      section.
      
      [1] : syzkaller reported :
      
      in_atomic(): 1, irqs_disabled(): 0, pid: 2932, name: syzkaller183439
      3 locks held by syzkaller183439/2932:
       #0:  (&net->xfrm.xfrm_cfg_mutex){+.+.+.}, at: [<ffffffff83b43888>] pfkey_sendmsg+0x4c8/0x9f0 net/key/af_key.c:3649
       #1:  (&pfk->dump_lock){+.+.+.}, at: [<ffffffff83b467f6>] pfkey_do_dump+0x76/0x3f0 net/key/af_key.c:293
       #2:  (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] spin_lock_bh include/linux/spinlock.h:304 [inline]
       #2:  (&(&net->xfrm.xfrm_policy_lock)->rlock){+...+.}, at: [<ffffffff83957632>] xfrm_policy_walk+0x192/0xa30 net/xfrm/xfrm_policy.c:1028
      CPU: 0 PID: 2932 Comm: syzkaller183439 Not tainted 4.13.0-rc4+ #24
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:16 [inline]
       dump_stack+0x194/0x257 lib/dump_stack.c:52
       ___might_sleep+0x2b2/0x470 kernel/sched/core.c:5994
       __might_sleep+0x95/0x190 kernel/sched/core.c:5947
       slab_pre_alloc_hook mm/slab.h:416 [inline]
       slab_alloc mm/slab.c:3383 [inline]
       kmem_cache_alloc+0x24b/0x6e0 mm/slab.c:3559
       skb_clone+0x1a0/0x400 net/core/skbuff.c:1037
       pfkey_broadcast_one+0x4b2/0x6f0 net/key/af_key.c:207
       pfkey_broadcast+0x4ba/0x770 net/key/af_key.c:281
       dump_sp+0x3d6/0x500 net/key/af_key.c:2685
       xfrm_policy_walk+0x2f1/0xa30 net/xfrm/xfrm_policy.c:1042
       pfkey_dump_sp+0x42/0x50 net/key/af_key.c:2695
       pfkey_do_dump+0xaa/0x3f0 net/key/af_key.c:299
       pfkey_spddump+0x1a0/0x210 net/key/af_key.c:2722
       pfkey_process+0x606/0x710 net/key/af_key.c:2814
       pfkey_sendmsg+0x4d6/0x9f0 net/key/af_key.c:3650
      sock_sendmsg_nosec net/socket.c:633 [inline]
       sock_sendmsg+0xca/0x110 net/socket.c:643
       ___sys_sendmsg+0x755/0x890 net/socket.c:2035
       __sys_sendmsg+0xe5/0x210 net/socket.c:2069
       SYSC_sendmsg net/socket.c:2080 [inline]
       SyS_sendmsg+0x2d/0x50 net/socket.c:2076
       entry_SYSCALL_64_fastpath+0x1f/0xbe
      RIP: 0033:0x445d79
      RSP: 002b:00007f32447c1dc8 EFLAGS: 00000202 ORIG_RAX: 000000000000002e
      RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 0000000000445d79
      RDX: 0000000000000000 RSI: 000000002023dfc8 RDI: 0000000000000008
      RBP: 0000000000000086 R08: 00007f32447c2700 R09: 00007f32447c2700
      R10: 00007f32447c2700 R11: 0000000000000202 R12: 0000000000000000
      R13: 00007ffe33edec4f R14: 00007f32447c29c0 R15: 0000000000000000
      
      Fixes: ba51b6be ("net: Fix RCU splat in af_key")
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarDmitry Vyukov <dvyukov@google.com>
      Cc: David Ahern <dsa@cumulusnetworks.com>
      Acked-by: default avatarDavid Ahern <dsahern@gmail.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      f0cd9201
  2. 25 Aug, 2017 21 commits
  3. 16 Aug, 2017 16 commits