syzbot

==================================================================
BUG: KCSAN: data-race in do_fcntl / uinput_read

write to 0xffff88809d453440 of 4 bytes by task 23127 on cpu 0:
 setfl fs/fcntl.c:80 [inline]
 do_fcntl+0x7ec/0xa80 fs/fcntl.c:347
 __do_sys_fcntl fs/fcntl.c:463 [inline]
 __se_sys_fcntl fs/fcntl.c:448 [inline]
 __x64_sys_fcntl+0x118/0x160 fs/fcntl.c:448
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

read to 0xffff88809d453440 of 4 bytes by task 23132 on cpu 1:
 uinput_read+0x18f/0x780 drivers/input/misc/uinput.c:670
 do_loop_readv_writev fs/read_write.c:714 [inline]
 do_loop_readv_writev fs/read_write.c:701 [inline]
 do_iter_read+0x357/0x3d0 fs/read_write.c:935
 vfs_readv+0x9c/0xf0 fs/read_write.c:997
 do_readv+0x20f/0x250 fs/read_write.c:1034
 __do_sys_readv fs/read_write.c:1125 [inline]
 __se_sys_readv fs/read_write.c:1122 [inline]
 __x64_sys_readv+0x4e/0x60 fs/read_write.c:1122
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9

Reported by Kernel Concurrency Sanitizer on:
CPU: 1 PID: 23132 Comm: syz-executor.3 Not tainted 5.5.0-rc1-syzkaller #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
==================================================================
Kernel panic - not syncing: panic_on_warn set ...
CPU: 1 PID: 23132 Comm: syz-executor.3 Not tainted 5.5.0-rc1-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+0x11d/0x181 lib/dump_stack.c:118
 panic+0x210/0x640 kernel/panic.c:221
 kcsan_report.cold+0xc/0xd kernel/kcsan/report.c:313
 kcsan_setup_watchpoint+0x3fe/0x460 kernel/kcsan/core.c:416
 check_access kernel/kcsan/core.c:459 [inline]
 __tsan_read4+0xc6/0x100 kernel/kcsan/core.c:588
 uinput_read+0x18f/0x780 drivers/input/misc/uinput.c:670
 do_loop_readv_writev fs/read_write.c:714 [inline]
 do_loop_readv_writev fs/read_write.c:701 [inline]
 do_iter_read+0x357/0x3d0 fs/read_write.c:935
 vfs_readv+0x9c/0xf0 fs/read_write.c:997
 do_readv+0x20f/0x250 fs/read_write.c:1034
 __do_sys_readv fs/read_write.c:1125 [inline]
 __se_sys_readv fs/read_write.c:1122 [inline]
 __x64_sys_readv+0x4e/0x60 fs/read_write.c:1122
 do_syscall_64+0xcc/0x3a0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x44/0xa9
RIP: 0033:0x45af49
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:00007fca6efefc78 EFLAGS: 00000246 ORIG_RAX: 0000000000000013
RAX: ffffffffffffffda RBX: 0000000000000003 RCX: 000000000045af49
RDX: 00000000000003d3 RSI: 00000000200004c0 RDI: 0000000000000004
RBP: 000000000075bfc8 R08: 0000000000000000 R09: 0000000000000000
R10: 0000000000000000 R11: 0000000000000246 R12: 00007fca6eff06d4
R13: 00000000004c9548 R14: 00000000004e2370 R15: 00000000ffffffff
Kernel Offset: disabled
Rebooting in 86400 seconds..