==================================================================
BUG: KASAN: use-after-free in tcp_skb_pcount include/net/tcp.h:798 [inline]
BUG: KASAN: use-after-free in tcp_init_tso_segs net/ipv4/tcp_output.c:1631 [inline]
BUG: KASAN: use-after-free in tcp_write_xmit+0x3b22/0x4680 net/ipv4/tcp_output.c:2068
Read of size 2 at addr ffff8800b65a11b0 by task syz-executor0/2579

CPU: 1 PID: 2579 Comm: syz-executor0 Not tainted 4.4.162+ #7
 0000000000000000 792b7806a596f9ac ffff8801ceac7838 ffffffff81a994bd
 ffffea0002d96800 ffff8800b65a11b0 0000000000000000 ffff8800b65a11b0
 dffffc0000000000 ffff8801ceac7870 ffffffff8148a669 ffff8800b65a11b0
Call Trace:
 [<ffffffff81a994bd>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81a994bd>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8148a669>] print_address_description+0x6c/0x217 mm/kasan/report.c:252
 [<ffffffff8148a989>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8148a989>] kasan_report.cold.6+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff8147f5c4>] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427
 [<ffffffff82424012>] tcp_skb_pcount include/net/tcp.h:798 [inline]
 [<ffffffff82424012>] tcp_init_tso_segs net/ipv4/tcp_output.c:1631 [inline]
 [<ffffffff82424012>] tcp_write_xmit+0x3b22/0x4680 net/ipv4/tcp_output.c:2068
 [<ffffffff82425404>] __tcp_push_pending_frames+0xa4/0x2a0 net/ipv4/tcp_output.c:2319
 [<ffffffff8242c3a6>] tcp_send_fin+0x176/0xab0 net/ipv4/tcp_output.c:2895
 [<ffffffff823ec027>] tcp_close+0xc97/0xf60 net/ipv4/tcp.c:2112
 [<ffffffff8249440f>] inet_release+0xff/0x1d0 net/ipv4/af_inet.c:435
 [<ffffffff821beba9>] __sock_release+0xd9/0x260 net/socket.c:592
 [<ffffffff821bed49>] sock_close+0x19/0x20 net/socket.c:1050
 [<ffffffff81496bc5>] __fput+0x235/0x6f0 fs/file_table.c:208
 [<ffffffff81497105>] ____fput+0x15/0x20 fs/file_table.c:244
 [<ffffffff8112ef7f>] task_work_run+0x10f/0x190 kernel/task_work.c:115
 [<ffffffff811018b2>] get_signal+0x1182/0x14a0 kernel/signal.c:2151
 [<ffffffff8100bf65>] do_signal+0x95/0x1840 arch/x86/kernel/signal.c:712
 [<ffffffff81003eba>] exit_to_usermode_loop+0x11a/0x160 arch/x86/entry/common.c:250
 [<ffffffff81006712>] prepare_exit_to_usermode arch/x86/entry/common.c:287 [inline]
 [<ffffffff81006712>] syscall_return_slowpath arch/x86/entry/common.c:352 [inline]
 [<ffffffff81006712>] do_syscall_32_irqs_on arch/x86/entry/common.c:402 [inline]
 [<ffffffff81006712>] do_fast_syscall_32+0x792/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707a50>] sysenter_flags_fixed+0xd/0x1a

Allocated by task 2577:
 [<ffffffff8102e496>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff8147e642>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff8147e642>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff8147e642>] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:616
 [<ffffffff8147e8bf>] kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:601
 [<ffffffff8147ee82>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff8147a58c>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff8147a58c>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff8147a58c>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff8147a58c>] kmem_cache_alloc+0xdc/0x2c0 mm/slub.c:2628
 [<ffffffff821e2cd6>] kmem_cache_alloc_node include/linux/slab.h:350 [inline]
 [<ffffffff821e2cd6>] __alloc_skb+0xe6/0x5b0 net/core/skbuff.c:218
 [<ffffffff823e6653>] alloc_skb_fclone include/linux/skbuff.h:856 [inline]
 [<ffffffff823e6653>] sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:833
 [<ffffffff823e92e1>] tcp_sendmsg+0xf81/0x2b30 net/ipv4/tcp.c:1178
 [<ffffffff82496493>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c376b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c376b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c7990>] SYSC_sendto net/socket.c:1678 [inline]
 [<ffffffff821c7990>] SyS_sendto+0x220/0x370 net/socket.c:1646
 [<ffffffff8100629e>] do_syscall_32_irqs_on arch/x86/entry/common.c:396 [inline]
 [<ffffffff8100629e>] do_fast_syscall_32+0x31e/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707a50>] sysenter_flags_fixed+0xd/0x1a

Freed by task 2578:
 [<ffffffff8102e496>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff8147ef3c>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff8147ef3c>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff8147ef3c>] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:589
 [<ffffffff8147bc4e>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff8147bc4e>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff8147bc4e>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff8147bc4e>] kmem_cache_free+0xbe/0x340 mm/slub.c:2881
 [<ffffffff821db19f>] kfree_skbmem+0xcf/0x100 net/core/skbuff.c:635
 [<ffffffff821e853d>] __kfree_skb+0x1d/0x20 net/core/skbuff.c:676
 [<ffffffff824261c9>] sk_wmem_free_skb include/net/sock.h:1447 [inline]
 [<ffffffff824261c9>] tcp_write_queue_purge include/net/tcp.h:1460 [inline]
 [<ffffffff824261c9>] tcp_connect_init net/ipv4/tcp_output.c:3134 [inline]
 [<ffffffff824261c9>] tcp_connect+0xae9/0x3110 net/ipv4/tcp_output.c:3273
 [<ffffffff824340d1>] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246
 [<ffffffff824953a9>] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615
 [<ffffffff823e9d67>] tcp_sendmsg_fastopen net/ipv4/tcp.c:1092 [inline]
 [<ffffffff823e9d67>] tcp_sendmsg+0x1a07/0x2b30 net/ipv4/tcp.c:1112
 [<ffffffff82496493>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821c376b>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821c376b>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821c7990>] SYSC_sendto net/socket.c:1678 [inline]
 [<ffffffff821c7990>] SyS_sendto+0x220/0x370 net/socket.c:1646
 [<ffffffff8100629e>] do_syscall_32_irqs_on arch/x86/entry/common.c:396 [inline]
 [<ffffffff8100629e>] do_fast_syscall_32+0x31e/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707a50>] sysenter_flags_fixed+0xd/0x1a

The buggy address belongs to the object at ffff8800b65a1180
 which belongs to the cache skbuff_fclone_cache of size 456
The buggy address is located 48 bytes inside of
 456-byte region [ffff8800b65a1180, ffff8800b65a1348)
The buggy address belongs to the page:
BUG: spinlock bad magic on CPU#0, syz-executor0/2135
 lock: 0xffff8801ce9d6808, .magic: ffffea00, .owner: �o��
���O_B�����/-1235610808, .owner_cpu: 0
BUG: unable to handle kernel paging request at fffffffd35eab940
IP: [<ffffffff811f0a35>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
PGD 2e0d067 PUD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 2135 Comm: syz-executor0 Not tainted 4.4.162+ #7
task: ffff8800b5b0af80 task.stack: ffff8801d2fd8000
RIP: 0010:[<ffffffff811f0a35>]  [<ffffffff811f0a35>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
RSP: 0018:ffff8801db607968  EFLAGS: 00010046
RAX: 1ffffffff05d2a0b RBX: 00000000000181a8 RCX: ffffffff831a1f00
RDX: fffffbffa6bd5728 RSI: fffffffd35eab940 RDI: ffffffff82e95058
RBP: ffff8801db6079a8 R08: 0000000000000000 R09: 0000000000000000
R10: ffffed0043fffa01 R11: 0000001f66ce7156 R12: ffffffff82e94f80
R13: dffffc0000000000 R14: 000000001d62ed92 R15: ffffffffb65a1348
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 002b ES: 002b CR0: 0000000080050033
CR2: fffffffd35eab940 CR3: 0000000002e0a000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 ffffffff811f0940 0000000082e15aa9 ffffffff82e15ab0 ffff8800b3a88060
 ffff8800b3a88000 000000001d62ed92 ffff8800b3a880b0 0000000000000000
 ffff8801db6079f0 ffffffff8117c219 0000000000000008 0000000000000000
Call Trace:
 <IRQ> 
 [<ffffffff8117c219>] update_curr+0x2c9/0x6d0 kernel/sched/fair.c:882
 [<ffffffff8119be6a>] enqueue_entity kernel/sched/fair.c:3512 [inline]
 [<ffffffff8119be6a>] enqueue_task_fair+0x12a/0xab90 kernel/sched/fair.c:4695
 [<ffffffff8116384d>] enqueue_task kernel/sched/core.c:858 [inline]
 [<ffffffff8116384d>] activate_task+0x1dd/0x280 kernel/sched/core.c:874
 [<ffffffff81164a2f>] ttwu_activate kernel/sched/core.c:1736 [inline]
 [<ffffffff81164a2f>] ttwu_do_activate.constprop.29+0xbf/0x1e0 kernel/sched/core.c:1789
 [<ffffffff81167ecd>] ttwu_queue kernel/sched/core.c:1934 [inline]
 [<ffffffff81167ecd>] try_to_wake_up+0x6dd/0x1120 kernel/sched/core.c:2068
 [<ffffffff81168a95>] default_wake_function+0x35/0x50 kernel/sched/core.c:3494
 [<ffffffff811e7151>] autoremove_wake_function+0x11/0x40 kernel/sched/wait.c:293
 [<ffffffff811e4fa6>] __wake_up_common+0xb6/0x150 kernel/sched/wait.c:73
 [<ffffffff811e5074>] __wake_up+0x34/0x50 kernel/sched/wait.c:95
 [<ffffffff8121eb30>] wake_up_klogd_work_func+0x80/0x90 kernel/printk/printk.c:2736
 [<ffffffff8136ae07>] irq_work_run_list+0xd7/0x140 kernel/irq_work.c:156
 [<ffffffff8136b486>] irq_work_tick+0x116/0x170 kernel/irq_work.c:182
 [<ffffffff8125ac19>] update_process_times+0x69/0x70 kernel/time/timer.c:1430
 [<ffffffff81288baa>] tick_sched_handle.isra.6+0x4a/0xf0 kernel/time/tick-sched.c:151
 [<ffffffff81288cc6>] tick_sched_timer+0x76/0x130 kernel/time/tick-sched.c:1097
 [<ffffffff8125cc60>] __run_hrtimer kernel/time/hrtimer.c:1261 [inline]
 [<ffffffff8125cc60>] __hrtimer_run_queues+0x390/0xfc0 kernel/time/hrtimer.c:1325
 [<ffffffff8125f8e1>] hrtimer_interrupt+0x1b1/0x430 kernel/time/hrtimer.c:1359
 [<ffffffff8108b4c4>] local_apic_timer_interrupt+0x74/0xa0 arch/x86/kernel/apic/apic.c:901
 [<ffffffff8270893c>] smp_apic_timer_interrupt+0x7c/0xa0 arch/x86/kernel/apic/apic.c:925
 [<ffffffff82707c9d>] apic_timer_interrupt+0x9d/0xb0 arch/x86/entry/entry_64.S:741
 <EOI> 
 [<ffffffff8121d645>] vprintk_emit+0x3f5/0x830 kernel/printk/printk.c:1832
 [<ffffffff8121daa8>] vprintk+0x28/0x30 kernel/printk/printk.c:1843
 [<ffffffff8121dacd>] vprintk_default+0x1d/0x30 kernel/printk/printk.c:1844
 [<ffffffff813ac946>] printk+0xaf/0xd7 kernel/printk/printk.c:1922
 [<ffffffff813aad1a>] spin_dump+0x15b/0x169 kernel/locking/spinlock_debug.c:61
 [<ffffffff813aae18>] spin_bug kernel/locking/spinlock_debug.c:75 [inline]
 [<ffffffff813aae18>] debug_spin_lock_before kernel/locking/spinlock_debug.c:83 [inline]
 [<ffffffff813aae18>] do_raw_spin_lock.cold.1+0x75/0x7a kernel/locking/spinlock_debug.c:135
 [<ffffffff8270542e>] __raw_spin_lock include/linux/spinlock_api_smp.h:145 [inline]
 [<ffffffff8270542e>] _raw_spin_lock+0x3e/0x50 kernel/locking/spinlock.c:151
 [<ffffffff815350aa>] spin_lock include/linux/spinlock.h:302 [inline]
 [<ffffffff815350aa>] exit_fs+0x6a/0x120 fs/fs_struct.c:102
 [<ffffffff810d921f>] do_exit+0x99f/0x28d0 kernel/exit.c:751
 [<ffffffff810df3b1>] do_group_exit+0x111/0x300 kernel/exit.c:885
 [<ffffffff810df5bd>] SYSC_exit_group kernel/exit.c:896 [inline]
 [<ffffffff810df5bd>] SyS_exit_group+0x1d/0x20 kernel/exit.c:894
 [<ffffffff8100629e>] do_syscall_32_irqs_on arch/x86/entry/common.c:396 [inline]
 [<ffffffff8100629e>] do_fast_syscall_32+0x31e/0xa80 arch/x86/entry/common.c:463
 [<ffffffff82707a50>] sysenter_flags_fixed+0xd/0x1a
Code: 49 8d bc 24 d8 00 00 00 48 89 f8 48 c1 e8 03 42 80 3c 28 00 0f 85 c4 01 00 00 49 8b 9c 24 d8 00 00 00 80 3a 00 0f 85 8f 01 00 00 <4a> 03 1c f9 48 89 d8 48 c1 e8 03 42 80 3c 28 00 0f 85 be 01 00 
RIP  [<ffffffff811f0a35>] cpuacct_charge+0x155/0x380 kernel/sched/cpuacct.c:247
 RSP <ffff8801db607968>
CR2: fffffffd35eab940
---[ end trace 79f5e977a538cf3a ]---