/32 host LOCAL
           +-- 172.20.20.16/30 2 0 1
    ®xhV'
netlink: 4 bytes leftover after parsing attributes in process `syz-executor3'.
==================================================================
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 ffff8800b8bb87b0 by task syz-executor0/6695

CPU: 1 PID: 6695 Comm: syz-executor0 Not tainted 4.4.163+ #122
 0000000000000000 2573b18a4d66b184 ffff8801d9677870 ffffffff81aa556d
 ffffea0002e2ee00 ffff8800b8bb87b0 0000000000000000 ffff8800b8bb87b0
 dffffc0000000000 ffff8801d96778a8 ffffffff8148a8db ffff8800b8bb87b0
Call Trace:
 [<ffffffff81aa556d>] __dump_stack lib/dump_stack.c:15 [inline]
 [<ffffffff81aa556d>] dump_stack+0xc1/0x124 lib/dump_stack.c:51
 [<ffffffff8148a8db>] print_address_description+0x6c/0x217 mm/kasan/report.c:252
 [<ffffffff8148abfb>] kasan_report_error mm/kasan/report.c:351 [inline]
 [<ffffffff8148abfb>] kasan_report.cold.6+0x175/0x2f7 mm/kasan/report.c:408
 [<ffffffff8147f8e4>] __asan_report_load2_noabort+0x14/0x20 mm/kasan/report.c:427
 [<ffffffff82430342>] tcp_skb_pcount include/net/tcp.h:798 [inline]
 [<ffffffff82430342>] tcp_init_tso_segs net/ipv4/tcp_output.c:1631 [inline]
 [<ffffffff82430342>] tcp_write_xmit+0x3b22/0x4680 net/ipv4/tcp_output.c:2068
 [<ffffffff82431734>] __tcp_push_pending_frames+0xa4/0x2a0 net/ipv4/tcp_output.c:2319
 [<ffffffff823e72b2>] tcp_push+0x3e2/0x5a0 net/ipv4/tcp.c:692
 [<ffffffff823f5d44>] tcp_sendmsg+0x16b4/0x2b30 net/ipv4/tcp.c:1293
 [<ffffffff824a27c3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821cf9eb>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821cf9eb>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821d3c10>] SYSC_sendto net/socket.c:1678 [inline]
 [<ffffffff821d3c10>] SyS_sendto+0x220/0x370 net/socket.c:1646
 [<ffffffff827123e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

Allocated by task 6695:
 [<ffffffff8102e4d6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff8147e962>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff8147e962>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff8147e962>] kasan_kmalloc.part.1+0x62/0xf0 mm/kasan/kasan.c:616
 [<ffffffff8147ebdf>] kasan_kmalloc+0xaf/0xc0 mm/kasan/kasan.c:601
 [<ffffffff8147f1a2>] kasan_slab_alloc+0x12/0x20 mm/kasan/kasan.c:554
 [<ffffffff8147a89c>] slab_post_alloc_hook mm/slub.c:1349 [inline]
 [<ffffffff8147a89c>] slab_alloc_node mm/slub.c:2615 [inline]
 [<ffffffff8147a89c>] slab_alloc mm/slub.c:2623 [inline]
 [<ffffffff8147a89c>] kmem_cache_alloc+0xdc/0x2c0 mm/slub.c:2628
 [<ffffffff821eef56>] kmem_cache_alloc_node include/linux/slab.h:350 [inline]
 [<ffffffff821eef56>] __alloc_skb+0xe6/0x5b0 net/core/skbuff.c:218
 [<ffffffff823f2983>] alloc_skb_fclone include/linux/skbuff.h:856 [inline]
 [<ffffffff823f2983>] sk_stream_alloc_skb+0xa3/0x5d0 net/ipv4/tcp.c:833
 [<ffffffff823f5611>] tcp_sendmsg+0xf81/0x2b30 net/ipv4/tcp.c:1178
 [<ffffffff824a27c3>] inet_sendmsg+0x203/0x4d0 net/ipv4/af_inet.c:755
 [<ffffffff821cf9eb>] sock_sendmsg_nosec net/socket.c:638 [inline]
 [<ffffffff821cf9eb>] sock_sendmsg+0xbb/0x110 net/socket.c:648
 [<ffffffff821d3c10>] SYSC_sendto net/socket.c:1678 [inline]
 [<ffffffff821d3c10>] SyS_sendto+0x220/0x370 net/socket.c:1646
 [<ffffffff827123e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

Freed by task 6704:
 [<ffffffff8102e4d6>] save_stack_trace+0x26/0x50 arch/x86/kernel/stacktrace.c:63
 [<ffffffff8147f25c>] save_stack mm/kasan/kasan.c:512 [inline]
 [<ffffffff8147f25c>] set_track mm/kasan/kasan.c:524 [inline]
 [<ffffffff8147f25c>] kasan_slab_free+0xac/0x190 mm/kasan/kasan.c:589
 [<ffffffff8147bf5e>] slab_free_hook mm/slub.c:1383 [inline]
 [<ffffffff8147bf5e>] slab_free_freelist_hook mm/slub.c:1405 [inline]
 [<ffffffff8147bf5e>] slab_free mm/slub.c:2859 [inline]
 [<ffffffff8147bf5e>] kmem_cache_free+0xbe/0x350 mm/slub.c:2881
 [<ffffffff821e741f>] kfree_skbmem+0xcf/0x100 net/core/skbuff.c:635
 [<ffffffff821f47bd>] __kfree_skb+0x1d/0x20 net/core/skbuff.c:676
 [<ffffffff824324f9>] sk_wmem_free_skb include/net/sock.h:1447 [inline]
 [<ffffffff824324f9>] tcp_write_queue_purge include/net/tcp.h:1460 [inline]
 [<ffffffff824324f9>] tcp_connect_init net/ipv4/tcp_output.c:3134 [inline]
 [<ffffffff824324f9>] tcp_connect+0xae9/0x3110 net/ipv4/tcp_output.c:3273
 [<ffffffff82440401>] tcp_v4_connect+0xf31/0x1890 net/ipv4/tcp_ipv4.c:246
 [<ffffffff824a16d9>] __inet_stream_connect+0x2a9/0xc30 net/ipv4/af_inet.c:615
 [<ffffffff824a20b5>] inet_stream_connect+0x55/0xa0 net/ipv4/af_inet.c:676
 [<ffffffff821d3378>] SYSC_connect net/socket.c:1570 [inline]
 [<ffffffff821d3378>] SyS_connect+0x1b8/0x310 net/socket.c:1551
 [<ffffffff827123e1>] entry_SYSCALL_64_fastpath+0x1e/0x9a

The buggy address belongs to the object at ffff8800b8bb8780
 which belongs to the cache skbuff_fclone_cache of size 456
The buggy address is located 48 bytes inside of
 456-byte region [ffff8800b8bb8780, ffff8800b8bb8948)
The buggy address belongs to the page:
BUG: unable to handle kernel paging request at fffff4fff00001fe
IP: [<ffffffff810a90c8>] vmalloc_fault+0x458/0x930 arch/x86/mm/fault.c:413
PGD 0 
Oops: 0000 [#1] PREEMPT SMP KASAN
Modules linked in:
CPU: 0 PID: 0 Comm: swapper/0 Not tainted 4.4.163+ #122
task: ffffffff82e151c0 task.stack: ffffffff82e00000
RIP: 0010:[<ffffffff810a90c8>]  [<ffffffff810a90c8>] vmalloc_fault+0x458/0x930 arch/x86/mm/fault.c:413
RSP: 0018:ffff8801db607d30  EFLAGS: 00010802
RAX: dffffc0000000000 RBX: ffffc7ff80000ff0 RCX: ffffffff82713000
RDX: 1ffff8fff00001fe RSI: ffffffff810a90b1 RDI: 0000000000000080
RBP: ffff8801db607d60 R08: ffffffff82e15aa8 R09: 0000000000000024
R10: ffffffff82e151c0 R11: 0000000000000001 R12: ffffc7ff80000ff0
R13: ffffe8ffffc0228c R14: ffff880000000ff0 R15: 00003fffc0000000
FS:  0000000000000000(0000) GS:ffff8801db600000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: fffff4fff00001fe CR3: 00000000baa27000 CR4: 00000000001606b0
DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
Stack:
 0000000000040000 0000000000000000 ffffe8ffffc0228c ffffffff82e151c0
 ffffffff82e00000 ffff8801db607df8 ffff8801db607dc8 ffffffff810ab6f1
 0000000000000046 0000000000000001 ffff8800ba1f0a74 00000000000000a0
Call Trace:
 <IRQ> 
 [<ffffffff810ab6f1>] __do_page_fault+0x3e1/0x7e0 arch/x86/mm/fault.c:1101
 [<ffffffff810abb47>] do_page_fault+0x27/0x30 arch/x86/mm/fault.c:1306
 [<ffffffff82713635>] page_fault+0x25/0x30 arch/x86/entry/entry_64.S:1037
 [<ffffffff81012ab6>] generic_handle_irq_desc include/linux/irqdesc.h:140 [inline]
 [<ffffffff81012ab6>] handle_irq+0x256/0x390 arch/x86/kernel/irq_64.c:78
 [<ffffffff82714889>] do_IRQ+0x89/0x1c0 arch/x86/kernel/irq.c:239
 [<ffffffff82712f1d>] common_interrupt+0x9d/0x9d arch/x86/entry/entry_64.S:596
 <EOI> 
 [<ffffffff81020cd5>] arch_safe_halt arch/x86/include/asm/paravirt.h:117 [inline]
 [<ffffffff81020cd5>] default_idle+0x55/0x3c0 arch/x86/kernel/process.c:432
 [<ffffffff81022f00>] arch_cpu_idle+0x10/0x20 arch/x86/kernel/process.c:423
 [<ffffffff811e7be7>] default_idle_call+0x57/0x70 kernel/sched/idle.c:93
 [<ffffffff811e7ffa>] cpuidle_idle_call kernel/sched/idle.c:157 [inline]
 [<ffffffff811e7ffa>] cpu_idle_loop kernel/sched/idle.c:253 [inline]
 [<ffffffff811e7ffa>] cpu_startup_entry+0x31a/0x7a0 kernel/sched/idle.c:301
 [<ffffffff827003e1>] rest_init+0x188/0x18e init/main.c:410
 [<ffffffff831d2875>] start_kernel+0x62c/0x660 init/main.c:682
 [<ffffffff831d130f>] x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:196
 [<ffffffff831d144b>] x86_64_start_kernel+0x13a/0x15d arch/x86/kernel/head64.c:185
Code: c3 48 b8 00 f0 ff ff ff 3f 00 00 4c 0f 44 f8 e8 cf e1 25 00 48 b8 00 00 00 00 00 fc ff df 4c 21 fb 4c 01 f3 48 89 da 48 c1 ea 03 <80> 3c 02 00 0f 85 69 04 00 00 48 83 3b 00 0f 84 80 03 00 00 e8 
RIP  [<ffffffff810a90c8>] vmalloc_fault+0x458/0x930 arch/x86/mm/fault.c:413
 RSP <ffff8801db607d30>
CR2: fffff4fff00001fe
---[ end trace 3e02b6094ee24833 ]---