==================================================================
BUG: KCSAN: data-race in __splice_from_pipe / pipe_poll

write to 0xffff888103a52b78 of 4 bytes by task 7637 on cpu 1:
 splice_from_pipe_feed fs/splice.c:515 [inline]
 __splice_from_pipe+0x3ce/0x480 fs/splice.c:624
 vmsplice_to_user fs/splice.c:1272 [inline]
 do_vmsplice.part.0+0x1c5/0x210 fs/splice.c:1350
 do_vmsplice fs/splice.c:1344 [inline]
 __do_sys_vmsplice+0x15f/0x1c0 fs/splice.c:1371
 __se_sys_vmsplice fs/splice.c:1353 [inline]
 __x64_sys_vmsplice+0x5e/0x80 fs/splice.c:1353
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff888103a52b78 of 4 bytes by task 7634 on cpu 0:
 pipe_poll+0x84/0x1d0 fs/pipe.c:549
 vfs_poll include/linux/poll.h:90 [inline]
 do_select+0x7d0/0x1020 fs/select.c:534
 core_sys_select+0x38b/0x520 fs/select.c:677
 do_pselect fs/select.c:759 [inline]
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6 fs/select.c:769 [inline]
 __x64_sys_pselect6+0x22a/0x280 fs/select.c:769
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 0 PID: 7634 Comm: syz-executor.5 Not tainted 5.3.0+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 7634 Comm: syz-executor.5 Not tainted 5.3.0+ #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+0xf5/0x159 lib/dump_stack.c:113
 panic+0x209/0x639 kernel/panic.c:219
 end_report kernel/kcsan/report.c:135 [inline]
 kcsan_report.cold+0x57/0xeb kernel/kcsan/report.c:283
 __kcsan_setup_watchpoint+0x342/0x500 kernel/kcsan/core.c:456
 __tsan_read4 kernel/kcsan/kcsan.c:30 [inline]
 __tsan_read4+0x2c/0x30 kernel/kcsan/kcsan.c:30
 pipe_poll+0x84/0x1d0 fs/pipe.c:549
 vfs_poll include/linux/poll.h:90 [inline]
 do_select+0x7d0/0x1020 fs/select.c:534
 core_sys_select+0x38b/0x520 fs/select.c:677
 do_pselect fs/select.c:759 [inline]
 __do_sys_pselect6 fs/select.c:784 [inline]
 __se_sys_pselect6 fs/select.c:769 [inline]
 __x64_sys_pselect6+0x22a/0x280 fs/select.c:769
 do_syscall_64+0xcf/0x2f0 arch/x86/entry/common.c:296
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x459a59
Code: fd b7 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 cb b7 fb ff c3 66 2e 0f 1f 84 00 00 00 00
RSP: 002b:00007f5d52021c78 EFLAGS: 00000246 ORIG_RAX: 000000000000010e
RAX: ffffffffffffffda RBX: 0000000000000006 RCX: 0000000000459a59
RDX: 0000000000000000 RSI: 00000000200000c0 RDI: 0000000000000040
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000020000140 R11: 0000000000000246 R12: 00007f5d520226d4
R13: 00000000004c6fd9 R14: 00000000004dc720 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..