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BUG: KASAN: slab-out-of-bounds in pipe_write+0x579/0x1130 fs/pipe.c:488
Write of size 8 at addr ffff888095f48ba8 by task syz-executor.0/15855

CPU: 1 PID: 15855 Comm: syz-executor.0 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+0x1fb/0x318 lib/dump_stack.c:118
 print_address_description+0x75/0x5c0 mm/kasan/report.c:374
 __kasan_report+0x14b/0x1c0 mm/kasan/report.c:506
 kasan_report+0x26/0x50 mm/kasan/common.c:634
 __asan_report_store8_noabort+0x17/0x20 mm/kasan/generic_report.c:137
 pipe_write+0x579/0x1130 fs/pipe.c:488
 call_write_iter include/linux/fs.h:1895 [inline]
 new_sync_write fs/read_write.c:483 [inline]
 __vfs_write+0x5a1/0x740 fs/read_write.c:496
 vfs_write+0x275/0x590 fs/read_write.c:558
 ksys_write+0x117/0x220 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+0x7b/0x90 fs/read_write.c:620
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x45a679
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:00007f92dd4a0c78 EFLAGS: 00000246 ORIG_RAX: 0000000000000001
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045a679
RDX: 00000000fffffef3 RSI: 00000000200001c0 RDI: 0000000000000004
RBP: 000000000075bf20 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007f92dd4a16d4
R13: 00000000004c7830 R14: 00000000004e44b0 R15: 00000000ffffffff

Allocated by task 15863:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 __kasan_kmalloc+0x11c/0x1b0 mm/kasan/common.c:510
 kasan_kmalloc+0x9/0x10 mm/kasan/common.c:524
 __do_kmalloc mm/slab.c:3655 [inline]
 __kmalloc+0x254/0x340 mm/slab.c:3664
 kmalloc_array include/linux/slab.h:618 [inline]
 kcalloc+0x36/0x60 include/linux/slab.h:629
 pipe_set_size fs/pipe.c:1143 [inline]
 pipe_fcntl+0x413/0x810 fs/pipe.c:1209
 do_fcntl+0x56d/0x1180 fs/fcntl.c:417
 __do_sys_fcntl fs/fcntl.c:463 [inline]
 __se_sys_fcntl+0xde/0x1b0 fs/fcntl.c:448
 __x64_sys_fcntl+0x7b/0x90 fs/fcntl.c:448
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

Freed by task 13280:
 save_stack mm/kasan/common.c:69 [inline]
 set_track mm/kasan/common.c:77 [inline]
 kasan_set_free_info mm/kasan/common.c:332 [inline]
 __kasan_slab_free+0x12a/0x1e0 mm/kasan/common.c:471
 kasan_slab_free+0xe/0x10 mm/kasan/common.c:480
 __cache_free mm/slab.c:3425 [inline]
 kfree+0x115/0x200 mm/slab.c:3756
 __free_fdtable fs/file.c:33 [inline]
 put_files_struct+0x2c9/0x340 fs/file.c:420
 exit_files+0x80/0xa0 fs/file.c:445
 do_exit+0x572/0x2020 kernel/exit.c:792
 do_group_exit+0x15c/0x2b0 kernel/exit.c:895
 get_signal+0x4ac/0x1d60 kernel/signal.c:2734
 do_signal+0x37/0x640 arch/x86/kernel/signal.c:815
 exit_to_usermode_loop arch/x86/entry/common.c:160 [inline]
 prepare_exit_to_usermode+0x32d/0x5b0 arch/x86/entry/common.c:195
 syscall_return_slowpath+0x113/0x4a0 arch/x86/entry/common.c:278
 do_syscall_64+0x11f/0x1c0 arch/x86/entry/common.c:304
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

The buggy address belongs to the object at ffff888095f48b80
 which belongs to the cache kmalloc-64(17:syz0) of size 64
The buggy address is located 40 bytes inside of
 64-byte region [ffff888095f48b80, ffff888095f48bc0)
The buggy address belongs to the page:
page:ffffea000257d200 refcount:1 mapcount:0 mapping:ffff88809f99b380 index:0xffff888095f48100
raw: 00fffe0000000200 ffff8880a2481638 ffffea0002190a88 ffff88809f99b380
raw: ffff888095f48100 ffff888095f48000 0000000100000008 0000000000000000
page dumped because: kasan: bad access detected

Memory state around the buggy address:
 ffff888095f48a80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888095f48b00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
>ffff888095f48b80: 00 00 00 00 00 fc fc fc fc fc fc fc fc fc fc fc
                                  ^
 ffff888095f48c00: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
 ffff888095f48c80: fb fb fb fb fb fb fb fb fc fc fc fc fc fc fc fc
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