1. 27 Feb, 2019 36 commits
  2. 23 Feb, 2019 4 commits
    • Greg Kroah-Hartman's avatar
      Linux 4.19.25 · eb1e5b1a
      Greg Kroah-Hartman authored
      eb1e5b1a
    • Eric Dumazet's avatar
      ax25: fix possible use-after-free · eed11c69
      Eric Dumazet authored
      commit 63530aba upstream.
      
      syzbot found that ax25 routes where not properly protected
      against concurrent use [1].
      
      In this particular report the bug happened while
      copying ax25->digipeat.
      
      Fix this problem by making sure we call ax25_get_route()
      while ax25_route_lock is held, so that no modification
      could happen while using the route.
      
      The current two ax25_get_route() callers do not sleep,
      so this change should be fine.
      
      Once we do that, ax25_get_route() no longer needs to
      grab a reference on the found route.
      
      [1]
      ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
      BUG: KASAN: use-after-free in memcpy include/linux/string.h:352 [inline]
      BUG: KASAN: use-after-free in kmemdup+0x42/0x60 mm/util.c:113
      Read of size 66 at addr ffff888066641a80 by task syz-executor2/531
      
      ax25_connect(): syz-executor0 uses autobind, please contact jreuter@yaina.de
      CPU: 1 PID: 531 Comm: syz-executor2 Not tainted 5.0.0-rc2+ #10
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x1db/0x2d0 lib/dump_stack.c:113
       print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
       kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
       check_memory_region_inline mm/kasan/generic.c:185 [inline]
       check_memory_region+0x123/0x190 mm/kasan/generic.c:191
       memcpy+0x24/0x50 mm/kasan/common.c:130
       memcpy include/linux/string.h:352 [inline]
       kmemdup+0x42/0x60 mm/util.c:113
       kmemdup include/linux/string.h:425 [inline]
       ax25_rt_autobind+0x25d/0x750 net/ax25/ax25_route.c:424
       ax25_connect.cold+0x30/0xa4 net/ax25/af_ax25.c:1224
       __sys_connect+0x357/0x490 net/socket.c:1664
       __do_sys_connect net/socket.c:1675 [inline]
       __se_sys_connect net/socket.c:1672 [inline]
       __x64_sys_connect+0x73/0xb0 net/socket.c:1672
       do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x458099
      Code: 6d b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 3b b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
      RSP: 002b:00007f870ee22c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
      RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000458099
      RDX: 0000000000000048 RSI: 0000000020000080 RDI: 0000000000000005
      RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
      ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
      R10: 0000000000000000 R11: 0000000000000246 R12: 00007f870ee236d4
      R13: 00000000004be48e R14: 00000000004ce9a8 R15: 00000000ffffffff
      
      Allocated by task 526:
       save_stack+0x45/0xd0 mm/kasan/common.c:73
       set_track mm/kasan/common.c:85 [inline]
       __kasan_kmalloc mm/kasan/common.c:496 [inline]
       __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
       kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
      ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
       kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
       kmalloc include/linux/slab.h:545 [inline]
       ax25_rt_add net/ax25/ax25_route.c:95 [inline]
       ax25_rt_ioctl+0x3b9/0x1270 net/ax25/ax25_route.c:233
       ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
       sock_do_ioctl+0xe2/0x400 net/socket.c:950
       sock_ioctl+0x32f/0x6c0 net/socket.c:1074
       vfs_ioctl fs/ioctl.c:46 [inline]
       file_ioctl fs/ioctl.c:509 [inline]
       do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
       ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
       __do_sys_ioctl fs/ioctl.c:720 [inline]
       __se_sys_ioctl fs/ioctl.c:718 [inline]
       __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
       do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      
      ax25_connect(): syz-executor5 uses autobind, please contact jreuter@yaina.de
      Freed by task 550:
       save_stack+0x45/0xd0 mm/kasan/common.c:73
       set_track mm/kasan/common.c:85 [inline]
       __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
       kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
       __cache_free mm/slab.c:3487 [inline]
       kfree+0xcf/0x230 mm/slab.c:3806
       ax25_rt_add net/ax25/ax25_route.c:92 [inline]
       ax25_rt_ioctl+0x304/0x1270 net/ax25/ax25_route.c:233
       ax25_ioctl+0x322/0x10b0 net/ax25/af_ax25.c:1763
       sock_do_ioctl+0xe2/0x400 net/socket.c:950
       sock_ioctl+0x32f/0x6c0 net/socket.c:1074
       vfs_ioctl fs/ioctl.c:46 [inline]
       file_ioctl fs/ioctl.c:509 [inline]
       do_vfs_ioctl+0x107b/0x17d0 fs/ioctl.c:696
       ksys_ioctl+0xab/0xd0 fs/ioctl.c:713
       __do_sys_ioctl fs/ioctl.c:720 [inline]
       __se_sys_ioctl fs/ioctl.c:718 [inline]
       __x64_sys_ioctl+0x73/0xb0 fs/ioctl.c:718
       do_syscall_64+0x1a3/0x800 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      
      The buggy address belongs to the object at ffff888066641a80
       which belongs to the cache kmalloc-96 of size 96
      The buggy address is located 0 bytes inside of
       96-byte region [ffff888066641a80, ffff888066641ae0)
      The buggy address belongs to the page:
      page:ffffea0001999040 count:1 mapcount:0 mapping:ffff88812c3f04c0 index:0x0
      flags: 0x1fffc0000000200(slab)
      ax25_connect(): syz-executor4 uses autobind, please contact jreuter@yaina.de
      raw: 01fffc0000000200 ffffea0001817948 ffffea0002341dc8 ffff88812c3f04c0
      raw: 0000000000000000 ffff888066641000 0000000100000020 0000000000000000
      page dumped because: kasan: bad access detected
      
      Memory state around the buggy address:
       ffff888066641980: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
       ffff888066641a00: 00 00 00 00 00 00 00 00 02 fc fc fc fc fc fc fc
      >ffff888066641a80: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
                         ^
       ffff888066641b00: fb fb fb fb fb fb fb fb fb fb fb fb fc fc fc fc
       ffff888066641b80: 00 00 00 00 00 00 00 00 00 00 00 00 fc fc fc fc
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Ralf Baechle <ralf@linux-mips.org>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      eed11c69
    • Eric Dumazet's avatar
      mISDN: fix a race in dev_expire_timer() · 0137890a
      Eric Dumazet authored
      commit bdcc5bc2 upstream.
      
      Since mISDN_close() uses dev->pending to iterate over active
      timers, there is a chance that one timer got removed from the
      ->pending list in dev_expire_timer() but that the thread
      has not called yet wake_up_interruptible()
      
      So mISDN_close() could miss this and free dev before
      completion of at least one dev_expire_timer()
      
      syzbot was able to catch this race :
      
      BUG: KASAN: use-after-free in register_lock_class+0x140c/0x1bf0 kernel/locking/lockdep.c:827
      Write of size 8 at addr ffff88809fc18948 by task syz-executor1/24769
      
      CPU: 1 PID: 24769 Comm: syz-executor1 Not tainted 5.0.0-rc5 #60
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       <IRQ>
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x172/0x1f0 lib/dump_stack.c:113
       print_address_description.cold+0x7c/0x20d mm/kasan/report.c:187
       kasan_report.cold+0x1b/0x40 mm/kasan/report.c:317
       __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:140
       register_lock_class+0x140c/0x1bf0 kernel/locking/lockdep.c:827
       __lock_acquire+0x11f/0x4700 kernel/locking/lockdep.c:3224
       lock_acquire+0x16f/0x3f0 kernel/locking/lockdep.c:3841
       __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline]
       _raw_spin_lock_irqsave+0x95/0xcd kernel/locking/spinlock.c:152
       __wake_up_common_lock+0xc7/0x190 kernel/sched/wait.c:120
       __wake_up+0xe/0x10 kernel/sched/wait.c:145
       dev_expire_timer+0xe4/0x3b0 drivers/isdn/mISDN/timerdev.c:174
       call_timer_fn+0x190/0x720 kernel/time/timer.c:1325
      protocol 88fb is buggy, dev hsr_slave_0
      protocol 88fb is buggy, dev hsr_slave_1
       expire_timers kernel/time/timer.c:1362 [inline]
       __run_timers kernel/time/timer.c:1681 [inline]
       __run_timers kernel/time/timer.c:1649 [inline]
       run_timer_softirq+0x652/0x1700 kernel/time/timer.c:1694
       __do_softirq+0x266/0x95a kernel/softirq.c:292
       invoke_softirq kernel/softirq.c:373 [inline]
       irq_exit+0x180/0x1d0 kernel/softirq.c:413
       exiting_irq arch/x86/include/asm/apic.h:536 [inline]
       smp_apic_timer_interrupt+0x14a/0x570 arch/x86/kernel/apic/apic.c:1062
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
       </IRQ>
      RIP: 0010:__sanitizer_cov_trace_pc+0x26/0x50 kernel/kcov.c:101
      Code: 90 90 90 90 55 48 89 e5 48 8b 75 08 65 48 8b 04 25 40 ee 01 00 65 8b 15 98 12 92 7e 81 e2 00 01 1f 00 75 2b 8b 90 d8 12 00 00 <83> fa 02 75 20 48 8b 88 e0 12 00 00 8b 80 dc 12 00 00 48 8b 11 48
      RSP: 0018:ffff8880589b7a60 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
      RAX: ffff888087ce25c0 RBX: 0000000000000001 RCX: ffffffff818f8ca3
      RDX: 0000000000000000 RSI: ffffffff818f8b48 RDI: 0000000000000001
      RBP: ffff8880589b7a60 R08: ffff888087ce25c0 R09: ffffed1015d25bd0
      R10: ffffed1015d25bcf R11: ffff8880ae92de7b R12: ffffea0001ae4680
      R13: ffffea0001ae4688 R14: 0000000000000000 R15: ffffea0001b41648
       PageIdle include/linux/page-flags.h:398 [inline]
       page_is_idle include/linux/page_idle.h:29 [inline]
       mark_page_accessed+0x618/0x1140 mm/swap.c:398
       touch_buffer fs/buffer.c:59 [inline]
       __find_get_block+0x312/0xcc0 fs/buffer.c:1298
       sb_find_get_block include/linux/buffer_head.h:338 [inline]
       recently_deleted fs/ext4/ialloc.c:682 [inline]
       find_inode_bit.isra.0+0x202/0x510 fs/ext4/ialloc.c:722
       __ext4_new_inode+0x14ad/0x52c0 fs/ext4/ialloc.c:914
       ext4_symlink+0x3f8/0xbe0 fs/ext4/namei.c:3096
       vfs_symlink fs/namei.c:4126 [inline]
       vfs_symlink+0x378/0x5d0 fs/namei.c:4112
       do_symlinkat+0x22b/0x290 fs/namei.c:4153
       __do_sys_symlink fs/namei.c:4172 [inline]
       __se_sys_symlink fs/namei.c:4170 [inline]
       __x64_sys_symlink+0x59/0x80 fs/namei.c:4170
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x457b67
      Code: 0f 1f 00 b8 5c 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 6d bb fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 b8 58 00 00 00 0f 05 <48> 3d 01 f0 ff ff 0f 83 4d bb fb ff c3 66 2e 0f 1f 84 00 00 00 00
      RSP: 002b:00007fff045ce0f8 EFLAGS: 00000202 ORIG_RAX: 0000000000000058
      RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 0000000000457b67
      RDX: 00007fff045ce173 RSI: 00000000004bd63f RDI: 00007fff045ce160
      RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000013
      R10: 0000000000000075 R11: 0000000000000202 R12: 0000000000000000
      R13: 0000000000000001 R14: 000000000000029b R15: 0000000000000001
      
      Allocated by task 24763:
       save_stack+0x45/0xd0 mm/kasan/common.c:73
       set_track mm/kasan/common.c:85 [inline]
       __kasan_kmalloc mm/kasan/common.c:496 [inline]
       __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:469
       kasan_kmalloc+0x9/0x10 mm/kasan/common.c:504
       kmem_cache_alloc_trace+0x151/0x760 mm/slab.c:3609
       kmalloc include/linux/slab.h:545 [inline]
       mISDN_open+0x9a/0x270 drivers/isdn/mISDN/timerdev.c:59
       misc_open+0x398/0x4c0 drivers/char/misc.c:141
       chrdev_open+0x247/0x6b0 fs/char_dev.c:417
       do_dentry_open+0x47d/0x1130 fs/open.c:771
       vfs_open+0xa0/0xd0 fs/open.c:880
       do_last fs/namei.c:3418 [inline]
       path_openat+0x10d7/0x4690 fs/namei.c:3534
       do_filp_open+0x1a1/0x280 fs/namei.c:3564
       do_sys_open+0x3fe/0x5d0 fs/open.c:1063
       __do_sys_openat fs/open.c:1090 [inline]
       __se_sys_openat fs/open.c:1084 [inline]
       __x64_sys_openat+0x9d/0x100 fs/open.c:1084
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      
      Freed by task 24762:
       save_stack+0x45/0xd0 mm/kasan/common.c:73
       set_track mm/kasan/common.c:85 [inline]
       __kasan_slab_free+0x102/0x150 mm/kasan/common.c:458
       kasan_slab_free+0xe/0x10 mm/kasan/common.c:466
       __cache_free mm/slab.c:3487 [inline]
       kfree+0xcf/0x230 mm/slab.c:3806
       mISDN_close+0x2a1/0x390 drivers/isdn/mISDN/timerdev.c:97
       __fput+0x2df/0x8d0 fs/file_table.c:278
       ____fput+0x16/0x20 fs/file_table.c:309
       task_work_run+0x14a/0x1c0 kernel/task_work.c:113
       tracehook_notify_resume include/linux/tracehook.h:188 [inline]
       exit_to_usermode_loop+0x273/0x2c0 arch/x86/entry/common.c:166
       prepare_exit_to_usermode arch/x86/entry/common.c:197 [inline]
       syscall_return_slowpath arch/x86/entry/common.c:268 [inline]
       do_syscall_64+0x52d/0x610 arch/x86/entry/common.c:293
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      
      The buggy address belongs to the object at ffff88809fc18900
       which belongs to the cache kmalloc-192 of size 192
      The buggy address is located 72 bytes inside of
       192-byte region [ffff88809fc18900, ffff88809fc189c0)
      The buggy address belongs to the page:
      page:ffffea00027f0600 count:1 mapcount:0 mapping:ffff88812c3f0040 index:0xffff88809fc18000
      flags: 0x1fffc0000000200(slab)
      raw: 01fffc0000000200 ffffea000269f648 ffffea00029f7408 ffff88812c3f0040
      raw: ffff88809fc18000 ffff88809fc18000 000000010000000b 0000000000000000
      page dumped because: kasan: bad access detected
      
      Memory state around the buggy address:
       ffff88809fc18800: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
       ffff88809fc18880: 00 fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc
      >ffff88809fc18900: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb
                                                    ^
       ffff88809fc18980: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
       ffff88809fc18a00: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Cc: Karsten Keil <isdn@linux-pingi.de>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      0137890a
    • Eric Dumazet's avatar
      net/x25: do not hold the cpu too long in x25_new_lci() · 74e1493e
      Eric Dumazet authored
      commit cf657d22 upstream.
      
      Due to quadratic behavior of x25_new_lci(), syzbot was able
      to trigger an rcu stall.
      
      Fix this by not blocking BH for the whole duration of
      the function, and inserting a reschedule point when possible.
      
      If we care enough, using a bitmap could get rid of the quadratic
      behavior.
      
      syzbot report :
      
      rcu: INFO: rcu_preempt self-detected stall on CPU
      rcu:    0-...!: (10500 ticks this GP) idle=4fa/1/0x4000000000000002 softirq=283376/283376 fqs=0
      rcu:     (t=10501 jiffies g=383105 q=136)
      rcu: rcu_preempt kthread starved for 10502 jiffies! g383105 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
      rcu: RCU grace-period kthread stack dump:
      rcu_preempt     I28928    10      2 0x80000000
      Call Trace:
       context_switch kernel/sched/core.c:2844 [inline]
       __schedule+0x817/0x1cc0 kernel/sched/core.c:3485
       schedule+0x92/0x180 kernel/sched/core.c:3529
       schedule_timeout+0x4db/0xfd0 kernel/time/timer.c:1803
       rcu_gp_fqs_loop kernel/rcu/tree.c:1948 [inline]
       rcu_gp_kthread+0x956/0x17a0 kernel/rcu/tree.c:2105
       kthread+0x357/0x430 kernel/kthread.c:246
       ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
      NMI backtrace for cpu 0
      CPU: 0 PID: 8759 Comm: syz-executor2 Not tainted 5.0.0-rc4+ #51
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      Call Trace:
       <IRQ>
       __dump_stack lib/dump_stack.c:77 [inline]
       dump_stack+0x172/0x1f0 lib/dump_stack.c:113
       nmi_cpu_backtrace.cold+0x63/0xa4 lib/nmi_backtrace.c:101
       nmi_trigger_cpumask_backtrace+0x1be/0x236 lib/nmi_backtrace.c:62
       arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
       trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
       rcu_dump_cpu_stacks+0x183/0x1cf kernel/rcu/tree.c:1211
       print_cpu_stall kernel/rcu/tree.c:1348 [inline]
       check_cpu_stall kernel/rcu/tree.c:1422 [inline]
       rcu_pending kernel/rcu/tree.c:3018 [inline]
       rcu_check_callbacks.cold+0x500/0xa4a kernel/rcu/tree.c:2521
       update_process_times+0x32/0x80 kernel/time/timer.c:1635
       tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:161
       tick_sched_timer+0x47/0x130 kernel/time/tick-sched.c:1271
       __run_hrtimer kernel/time/hrtimer.c:1389 [inline]
       __hrtimer_run_queues+0x33e/0xde0 kernel/time/hrtimer.c:1451
       hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1509
       local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1035 [inline]
       smp_apic_timer_interrupt+0x120/0x570 arch/x86/kernel/apic/apic.c:1060
       apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:807
       </IRQ>
      RIP: 0010:__read_once_size include/linux/compiler.h:193 [inline]
      RIP: 0010:queued_write_lock_slowpath+0x13e/0x290 kernel/locking/qrwlock.c:86
      Code: 00 00 fc ff df 4c 8d 2c 01 41 83 c7 03 41 0f b6 45 00 41 38 c7 7c 08 84 c0 0f 85 0c 01 00 00 8b 03 3d 00 01 00 00 74 1a f3 90 <41> 0f b6 55 00 41 38 d7 7c eb 84 d2 74 e7 48 89 df e8 6c 0f 4f 00
      RSP: 0018:ffff88805f117bd8 EFLAGS: 00000206 ORIG_RAX: ffffffffffffff13
      RAX: 0000000000000300 RBX: ffffffff89413ba0 RCX: 1ffffffff1282774
      RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffffffff89413ba0
      RBP: ffff88805f117c70 R08: 1ffffffff1282774 R09: fffffbfff1282775
      R10: fffffbfff1282774 R11: ffffffff89413ba3 R12: 00000000000000ff
      R13: fffffbfff1282774 R14: 1ffff1100be22f7d R15: 0000000000000003
       queued_write_lock include/asm-generic/qrwlock.h:104 [inline]
       do_raw_write_lock+0x1d6/0x290 kernel/locking/spinlock_debug.c:203
       __raw_write_lock_bh include/linux/rwlock_api_smp.h:204 [inline]
       _raw_write_lock_bh+0x3b/0x50 kernel/locking/spinlock.c:312
       x25_insert_socket+0x21/0xe0 net/x25/af_x25.c:267
       x25_bind+0x273/0x340 net/x25/af_x25.c:705
       __sys_bind+0x23f/0x290 net/socket.c:1505
       __do_sys_bind net/socket.c:1516 [inline]
       __se_sys_bind net/socket.c:1514 [inline]
       __x64_sys_bind+0x73/0xb0 net/socket.c:1514
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x457e39
      Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
      RSP: 002b:00007fafccd0dc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000031
      RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39
      RDX: 0000000000000012 RSI: 0000000020000240 RDI: 0000000000000004
      RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000246 R12: 00007fafccd0e6d4
      R13: 00000000004bdf8b R14: 00000000004ce4b8 R15: 00000000ffffffff
      Sending NMI from CPU 0 to CPUs 1:
      NMI backtrace for cpu 1
      CPU: 1 PID: 8752 Comm: syz-executor4 Not tainted 5.0.0-rc4+ #51
      Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
      RIP: 0010:__x25_find_socket+0x78/0x120 net/x25/af_x25.c:328
      Code: 89 f8 48 c1 e8 03 80 3c 18 00 0f 85 a6 00 00 00 4d 8b 64 24 68 4d 85 e4 74 7f e8 03 97 3d fb 49 83 ec 68 74 74 e8 f8 96 3d fb <49> 8d bc 24 88 04 00 00 48 89 f8 48 c1 e8 03 0f b6 04 18 84 c0 74
      RSP: 0018:ffff8880639efc58 EFLAGS: 00000246
      RAX: 0000000000040000 RBX: dffffc0000000000 RCX: ffffc9000e677000
      RDX: 0000000000040000 RSI: ffffffff863244b8 RDI: ffff88806a764628
      RBP: ffff8880639efc80 R08: ffff8880a80d05c0 R09: fffffbfff1282775
      R10: fffffbfff1282774 R11: ffffffff89413ba3 R12: ffff88806a7645c0
      R13: 0000000000000001 R14: ffff88809f29ac00 R15: 0000000000000000
      FS:  00007fe8d0c58700(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000
      CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
      CR2: 0000001b32823000 CR3: 00000000672eb000 CR4: 00000000001406e0
      DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
      DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
      Call Trace:
       x25_new_lci net/x25/af_x25.c:357 [inline]
       x25_connect+0x374/0xdf0 net/x25/af_x25.c:786
       __sys_connect+0x266/0x330 net/socket.c:1686
       __do_sys_connect net/socket.c:1697 [inline]
       __se_sys_connect net/socket.c:1694 [inline]
       __x64_sys_connect+0x73/0xb0 net/socket.c:1694
       do_syscall_64+0x103/0x610 arch/x86/entry/common.c:290
       entry_SYSCALL_64_after_hwframe+0x49/0xbe
      RIP: 0033:0x457e39
      Code: ad b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 7b b8 fb ff c3 66 2e 0f 1f 84 00 00 00 00
      RSP: 002b:00007fe8d0c57c78 EFLAGS: 00000246 ORIG_RAX: 000000000000002a
      RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 0000000000457e39
      RDX: 0000000000000012 RSI: 0000000020000200 RDI: 0000000000000004
      RBP: 000000000073bf00 R08: 0000000000000000 R09: 0000000000000000
      R10: 0000000000000000 R11: 0000000000000246 R12: 00007fe8d0c586d4
      R13: 00000000004be378 R14: 00000000004ceb00 R15: 00000000ffffffff
      Signed-off-by: default avatarEric Dumazet <edumazet@google.com>
      Reported-by: default avatarsyzbot <syzkaller@googlegroups.com>
      Cc: Andrew Hendry <andrew.hendry@gmail.com>
      Cc: linux-x25@vger.kernel.org
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
      74e1493e