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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 ffff888093faed28 by task syz-executor002/9741

CPU: 0 PID: 9741 Comm: syz-executor002 Not tainted 5.4.0-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:638
 __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: 0033:0x4466c9
Code: e8 5c b3 02 00 48 83 c4 18 c3 0f 1f 80 00 00 00 00 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 0b 08 fc ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f46cd364db8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 00000000006dbc28 RCX: 00000000004466c9
RDX: 00000000fffffef3 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 00000000006dbc20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00000000006dbc2c
R13: 00007fffda5c440f R14: 00007f46cd3659c0 R15: 20c49ba5e353f7cf

Allocated by task 9743:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 __kasan_kmalloc mm/kasan/common.c:512 [inline]
 __kasan_kmalloc.constprop.0+0xcf/0xe0 mm/kasan/common.c:485
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:526
 __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 3987:
 save_stack+0x23/0x90 mm/kasan/common.c:71
 set_track mm/kasan/common.c:79 [inline]
 kasan_set_free_info mm/kasan/common.c:334 [inline]
 __kasan_slab_free+0x102/0x150 mm/kasan/common.c:473
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:482
 __cache_free mm/slab.c:3426 [inline]
 kfree+0x10a/0x2c0 mm/slab.c:3757
 __vunmap+0x6a5/0x9b0 mm/vmalloc.c:2315
 __vfree+0x41/0xd0 mm/vmalloc.c:2356
 vfree+0x5f/0x90 mm/vmalloc.c:2386
 n_tty_close+0xc3/0x130 drivers/tty/n_tty.c:1895
 tty_ldisc_close.isra.0+0x119/0x1a0 drivers/tty/tty_ldisc.c:494
 tty_ldisc_kill+0x9c/0x160 drivers/tty/tty_ldisc.c:642
 tty_ldisc_release+0xe9/0x2b0 drivers/tty/tty_ldisc.c:814
 tty_release_struct+0x1b/0x50 drivers/tty/tty_io.c:1613
 tty_release+0xbcb/0xe90 drivers/tty/tty_io.c:1786
 __fput+0x2ff/0x890 fs/file_table.c:280
 ____fput+0x16/0x20 fs/file_table.c:313
 task_work_run+0x145/0x1c0 kernel/task_work.c:113
 tracehook_notify_resume include/linux/tracehook.h:188 [inline]
 exit_to_usermode_loop+0x316/0x380 arch/x86/entry/common.c:164
 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 ffff888093faed00
 which belongs to the cache kmalloc-64 of size 64
The buggy address is located 40 bytes inside of
 64-byte region [ffff888093faed00, ffff888093faed40)
The buggy address belongs to the page:
page:ffffea00024feb80 refcount:1 mapcount:0 mapping:ffff8880aa400380 index:0x0
raw: 00fffe0000000200 ffffea000234ce88 ffffea00028219c8 ffff8880aa400380
raw: 0000000000000000 ffff888093fae000 0000000100000020 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888093faec00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888093faec80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
>ffff888093faed00: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff888093faed80: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
 ffff888093faee00: 00 00 00 00 00 00 00 00 fc fc fc fc fc fc fc fc
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