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BUG: KASAN: slab-out-of-bounds in pipe_write+0xe30/0x1000 fs/pipe.c:488
Write of size 8 at addr ffff88809ee0b2a8 by task syz-executor.0/14582

CPU: 0 PID: 14582 Comm: syz-executor.0 Not tainted 5.4.0-next-20191206-syzkaller #0
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+0x197/0x210 lib/dump_stack.c:118
 print_address_description.constprop.0.cold+0xd4/0x30b mm/kasan/report.c:374
 __kasan_report.cold+0x1b/0x41 mm/kasan/report.c:506
 kasan_report+0x12/0x20 mm/kasan/common.c:639
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:140
 pipe_write+0xe30/0x1000 fs/pipe.c:488
 call_write_iter include/linux/fs.h:1902 [inline]
 new_sync_write+0x4d3/0x770 fs/read_write.c:483
 __vfs_write+0xe1/0x110 fs/read_write.c:496
 vfs_write+0x268/0x5d0 fs/read_write.c:558
 ksys_write+0x220/0x290 fs/read_write.c:611
 __do_sys_write fs/read_write.c:623 [inline]
 __se_sys_write fs/read_write.c:620 [inline]
 __x64_sys_write+0x73/0xb0 fs/read_write.c:620
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a6f9
Code: ad b6 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 b6 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007fc7fb35bc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a6f9
RDX: 0000000041395527 RSI: 0000000020000340 RDI: 0000000000000005
RBP: 000000000075c1c0 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fc7fb35c6d4
R13: 00000000004c79e9 R14: 00000000004e49f0 R15: 00000000ffffffff

Allocated by task 14559:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 __kasan_kmalloc mm/kasan/common.c:513 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:486
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:527
 __do_kmalloc mm/slab.c:3656 [inline]
 __kmalloc+0x163/0x770 mm/slab.c:3665
 kmalloc_array include/linux/slab.h:598 [inline]
 kcalloc include/linux/slab.h:609 [inline]
 pipe_set_size fs/pipe.c:1143 [inline]
 pipe_fcntl+0x3f7/0x8e0 fs/pipe.c:1209
 do_fcntl+0x255/0x1030 fs/fcntl.c:417
 __do_sys_fcntl fs/fcntl.c:463 [inline]
 __se_sys_fcntl fs/fcntl.c:448 [inline]
 __x64_sys_fcntl+0x16d/0x1e0 fs/fcntl.c:448
 do_syscall_64+0xfa/0x790 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 14075:
 save_stack+0x23/0x90 mm/kasan/common.c:72
 set_track mm/kasan/common.c:80 [inline]
 kasan_set_free_info mm/kasan/common.c:335 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:474
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:483
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 __free_fdtable+0x62/0x80 fs/file.c:33
 put_files_struct fs/file.c:420 [inline]
 put_files_struct+0x253/0x2f0 fs/file.c:413
 exit_files+0x83/0xb0 fs/file.c:445
 do_exit+0x8b5/0x2ef0 kernel/exit.c:792
 do_group_exit+0x135/0x360 kernel/exit.c:895
 get_signal+0x47c/0x24f0 kernel/signal.c:2734
 do_signal+0x87/0x1700 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop+0x286/0x380 arch/x86/entry/common.c:160
 prepare_exit_to_usermode arch/x86/entry/common.c:195 [inline]
 syscall_return_slowpath arch/x86/entry/common.c:278 [inline]
 do_syscall_64+0x676/0x790 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff88809ee0b280
 which belongs to the cache kmalloc-64(17:syz0) of size 64
The buggy address is located 40 bytes inside of
 64-byte region [ffff88809ee0b280, ffff88809ee0b2c0)
The buggy address belongs to the page:
page:ffffea00027b82c0 refcount:1 mapcount:0 mapping:ffff8880627b2540 index:0x0
raw: 00fffe0000000200 ffffea0002a4bd48 ffffea0002816f88 ffff8880627b2540
raw: 0000000000000000 ffff88809ee0b000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff88809ee0b180: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809ee0b200: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff88809ee0b280: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff88809ee0b300: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff88809ee0b380: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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